Semiconductor device and method of manufacturing the same

This U.S. nonprovisional application claims priority under 35 U.S.C § 119 to Korean Patent Application No. 10-2018-0056825 filed on May 18, 2018 in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.

Inventive concepts relate to a semiconductor device and a method of manufacturing the same, and more particularly, to a method of manufacturing a semiconductor device, in which method a line patterning is used to form pillars, and a semiconductor device manufactured by the same.

Semiconductor devices are widely used in the electronic industry because of their small size, multi-functionality, and/or low fabrication cost. Semiconductor devices may encompass a memory device for storing data, a logic device for processing data, and a hybrid device for operating various functions contemporaneously or simultaneously.

Semiconductor devices have been increasingly required for high integration with the advanced development of the electronic industry. It therefore is increasingly difficult to manufacture semiconductor devices because there is a problem of process margin reduction in an exposure process defining fine patterns. Semiconductor devices also have been increasingly requested for high speed with the advanced development of the electronic industry. Various studies have been conducted to meet the requirements of high integration and/or high speed in semiconductor devices.

Some embodiments of inventive concepts provide a semiconductor device having a constant minimum distance between any neighboring pillars and a method of manufacturing the same.

According to some example embodiments of inventive concepts, a method of manufacturing a semiconductor device may comprise: forming an active structure including a plurality of active patterns, a device isolation layer defining the active patterns, and a gate structure across the active patterns and extending in a first direction; forming a first mask pattern on the active structure; and forming a trench by using the first mask pattern as an etching mask to pattern the active structure. The step of forming the first mask pattern may comprise: forming in a first mask layer a plurality of first openings extending in a second direction intersecting the first direction; and forming in the first mask layer a plurality of second openings extending in a third direction that intersects the first and second directions.

According to some example embodiments of inventive concepts, a method of manufacturing a semiconductor device may comprise: forming an active structure including a plurality of active patterns, a device isolation layer between the active patterns, and a gate structure across the active patterns and extending in a first direction; forming a first mask pattern on the active structure; and forming a trench by using the first mask pattern as an etching mask to pattern the active structure. The step of forming the first mask pattern may comprise: forming in a first mask layer a plurality of first openings extending in a second direction intersecting the first direction; and forming in the first mask layer a plurality of second openings extending in the first direction.

According to some example embodiments of inventive concepts, a semiconductor device may comprise: an active structure comprising an active pattern and a gate structure, wherein the active pattern comprises a first impurity region and a second impurity region, and wherein the gate structure between the first and second impurity regions and extends in a first direction; a trench defining a pillar body in an upper portion of the active structure; and a conductive pattern extending in a second direction on the active structure and electrically connected to the first impurity region exposed to the trench, the second direction intersecting the first direction. The pillar body may comprise a first pillar, a second pillar, and a third pillar. The first to third pillars may be spaced apart from each other in a third direction intersecting the first and second directions. A minimum distance between the first and second pillars may be substantially the same as a minimum distance between the second and third pillars.

FIGS. 1A to 14A illustrate plan views showing a method of manufacturing a semiconductor device according to example embodiments of inventive concepts.

FIGS. 1B to 14B illustrate cross-sectional views taken along line A-A′ of FIGS. 1A to 14A , respectively.

FIGS. 1C to 14C illustrate cross-sectional views taken along line B-B′ of FIGS. 1A to 14A , respectively.

FIGS. 15A and 15B illustrate plan views showing a semiconductor device according to example embodiments of inventive concepts.

FIGS. 16A to 21A illustrate plan views showing a method of manufacturing a semiconductor device according to example embodiments of inventive concepts.

FIGS. 16B to 21B illustrate cross-sectional views taken along line A-A′ of FIGS. 16A to 21A , respectively.

FIGS. 16C to 21C illustrate cross-sectional views taken along line B-B′ of FIGS. 16A to 21A , respectively.

FIGS. 1A to 14A illustrate plan views showing a method of manufacturing a semiconductor device according to example embodiments of inventive concepts. FIGS. 1B to 14B illustrate cross-sectional views taken along line A-A′ of FIGS. 1A to 14A , respectively. FIGS. 1C to 14C illustrate cross-sectional views taken along line B-B′ of FIGS. 1A to 14A , respectively.

Referring to FIGS. 1A, 1B, and 1C , a device isolation layer ST may be formed on a substrate 100 including a cell region CR and a dummy region DR adjacent to the cell region CR. For example, a portion of the substrate 100 may be etched, and then the etched portion may be filled with an insulating material to form the device isolation layer ST. The formation of the device isolation layer ST may define active patterns ACT surrounded by the device isolation layer ST. The device isolation layer ST may include silicon oxide. The substrate 100 may be or include a semiconductor substrate including silicon, germanium, or silicon-germanium. Each of the active patterns ACT may extend in a third direction D 3 parallel to a top surface of the substrate 100 . The active patterns ACT may be spaced apart from each other in the third direction D 3 .

Referring to FIGS. 2A, 2B, and 2C , gate structures GS may be formed to run across the device isolation layer ST and the active patterns ACT. Each of the gate structures GS may include a gate dielectric layer GI, a gate electrode GE, and/or a gate capping layer GP.

For example, the device isolation layer ST and the active patterns ACT may be patterned to form first trenches TR 1 . The first trenches TR 1 may extend in a second direction D 2 that is parallel to the top surface of the substrate 100 and intersects the third direction D 3 . The first trenches TR 1 may be spaced apart from each other in a first direction D 1 that is parallel to the top surface of the substrate 100 and intersects the second and third directions D 2 and D 3 . The first trenches TR 1 may run across the active patterns ACT.

The formation of the first trenches TR 1 may include forming a hardmask pattern having openings and then using the hardmask pattern as an etching mask to etch the active patterns ACT and the device isolation layer ST exposed to the openings.

The gate dielectric layer GI may be conformally formed in each of the first trenches TR 1 . The gate dielectric layer GI may include one or more of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and a high-k dielectric material. For example, the high-k dielectric material may include hafnium oxide, hafnium silicon oxide, lanthanum oxide, zirconium oxide, zirconium silicon oxide, tantalum oxide, titanium oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, lithium oxide, aluminum oxide, lead scandium tantalum oxide, lead zinc niobate, or a combination thereof.

A conductive layer filling the first trenches TR 1 may be formed on the gate dielectric layer GI, which may result in the formation of the gate electrodes GE. The conductive layer may include one or more of conductive metal nitride (e.g., titanium nitride or tantalum nitride) and metal (e.g., titanium, tantalum, tungsten, copper, or aluminum).

The gate dielectric layer GI and the gate electrode GE may be recessed, and then the gate capping layer GP may be formed on the recessed gate electrode GE. The gate capping layer GP may have a top surface coplanar with that of the active pattern ACT. The gate capping layer GP may include one or more of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer.

The active patterns ACT may be implanted with impurities to form a first impurity region SD 1 and a pair of second impurity regions SD 2 in an upper portion of each of the active patterns ACT. The pair of second impurity regions SD 2 may be spaced apart from each other in the third direction D 3 across the first impurity region SD 1 . The first and second impurity regions SD 1 and SD 2 may be doped to have the same conductive type (e.g., N-type).

The active patterns ACT, the gate structures GS, and/or the device isolation layer ST may constitute or form an active structure AS. A planarization process may be performed to cause the active structure AS to have a substantially flat top surface.

The active structure AS may be provided thereon with a target layer TL, a first mask layer ML 1 , a hardmask layer HM, a first insulating layer IL 1 , a second mask layer ML 2 , a third mask layer ML 3 , and/or a second insulating layer IL 2 that are sequentially formed.

The target layer TL may include a plurality of insulating layers. The insulating layers may be or include a silicon oxide layer, a silicon nitride layer, or a combination thereof. The first mask layer ML 1 may include a doped polysilicon layer. The hardmask layer HM may include a spin-on-hardmask (SOH) layer. The hardmask layer HM may further include a silicon oxide layer below the SOH layer. The first insulating layer IL 1 may include one or more of a silicon nitride layer and a silicon oxynitride layer. The second mask layer ML 2 may include a silicon oxide layer. The third mask layer ML 3 may include a spin-on-hardmask (SOH) layer. The second insulating layer IL 2 may include one or more of a silicon nitride layer and a silicon oxynitride layer.

Referring to FIGS. 3A, 3B, and 3C , the third mask layer ML 3 and the second insulating layer IL 2 may be patterned to form first openings OP 1 . The first openings OP 1 may extend in a fourth direction D 4 that is parallel to the top surface of the substrate 100 and intersects the second direction D 2 . For example, the first openings OP 1 may extend in a direction intersecting the gate electrodes GE.

The formation of the first openings OP 1 may include forming a first photoresist layer on the second insulating layer IL 2 , using a first photomask to pattern the first photoresist layer, and using the patterned first photoresist layer as an etching mask to pattern the third mask layer ML 3 and the second insulating layer IL 2 . A remaining first photoresist layer may be removed.

A first dielectric film IF 1 may be conformally formed on an entire surface of the substrate 100 . The first dielectric film IF 1 may include a silicon oxide layer. The first dielectric film IF 1 may be formed by atomic layer deposition (ALD).

Referring to FIGS. 4A, 4B, and 4C , a first filling layer FL 1 may be formed on the first dielectric film IF 1 . The first filling layer FL 1 may fill the first openings OP 1 . The first filling layer FL 1 may include a spin-on-hardmask (SOH) layer.

After the first filling layer FL 1 is formed, a first etch-back process may be performed. The first etch-back process may be performed such that the second insulating layer IL 2 is removed, the first dielectric film IF 1 is removed on its portion on the second insulating layer IL 2 , and the first filling layer FL 1 is removed on its portion on the second insulating layer IL 2 . Both remaining first dielectric film IF 1 and first filling layer FL 1 may selectively fill each of the first openings OP 1 . The both remaining first dielectric film IF 1 and first filling layer FL 1 may be provided in the third mask layer ML 3 . When viewed in plan, the third mask layer ML 3 , the first dielectric film IF 1 , and the first filling layer FL 1 may be exposed on the entire surface of the substrate 100 .

Referring to FIGS. 5A, 5B, and 5C , a first etching process may be performed to pattern the second mask layer ML 2 . The first etching process may include removing the first dielectric film IF 1 between the third mask layer ML 3 and the first filling layer FL 1 , and using the third mask layer ML 3 and the first filling layer FL 1 as an etching mask to pattern the second mask layer ML 2 . A removal process may be performed to remove the third mask layer ML 3 and the first filling layer FL 1 that remain after the first etching process.

The first etching process may form second openings OP 2 in the second mask layer ML 2 . The second openings OP 2 may extend in the fourth direction D 4 . The first etching process may cause that the second mask layer ML 2 is patterned to have a linear shape extending in the fourth direction D 4 .

Referring to FIGS. 6A, 6B, and 6C , a second filling layer FL 2 may be formed on the entire surface of the substrate 100 . The second filling layer FL 2 may fill the second openings OP 2 . The second filling layer FL 2 may include a spin-on-hardmask (SOH) layer.

A third insulating layer IL 3 , a fourth mask layer ML 4 , and/or a fourth insulating layer IL 4 may be sequentially formed on the second filling layer FL 2 . The third insulating layer IL 3 may include a silicon oxide layer. The fourth mask layer ML 4 may include a spin-on-hardmask (SOH) layer. The fourth insulating layer IL 4 may include one or more of a silicon nitride layer and a silicon oxynitride layer.

The fourth mask layer ML 4 and the fourth insulating layer IL 4 may be patterned to form third openings OP 3 . The third openings OP 3 may extend in a fifth direction D 5 that is parallel to the top surface of the substrate 100 and intersects the second direction D 2 . For example, the third openings OP 3 may extend in a direction intersecting the gate electrodes GE and the second openings OP 2 .

The formation of the third openings OP 3 may include forming a second photoresist layer on the fourth insulating layer IL 4 , using a second photomask to pattern the second photoresist layer, and using the patterned second photoresist layer as an etching mask to pattern the fourth mask layer ML 4 and the fourth insulating layer IL 4 . A remaining second photoresist layer may be removed.

A second dielectric film IF 2 may be conformally formed on the entire surface of the substrate 100 . The second dielectric film IF 2 may include a silicon oxide layer. The second dielectric film IF 2 may be formed by atomic layer deposition (ALD).

Referring to FIGS. 7A, 7B, and 7C , a third filling layer FL 3 may be formed on the second dielectric film IF 2 . The third filling layer FL 3 may fill the third openings OP 3 . The third filling layer FL 3 may include a spin-on-hardmask (SOH) layer.

After the third filling layer FL 3 is formed, a second etch-back process may be performed. The second etch-back process may be performed such that the fourth insulating layer IL 4 is removed, the second dielectric film IF 2 is removed on its portion on the fourth insulating layer IL 4 , and the third filling layer FL 3 is removed on its portion on the fourth insulating layer IL 4 . Both remaining second dielectric film IF 2 and third filling layer FL 3 may selectively fill each of the third openings OP 3 . The both remaining second dielectric film IF 2 and third filling layer FL 3 may be provided in the fourth mask layer ML 4 . When viewed in plan, the fourth mask layer ML 4 , the second dielectric film IF 2 , and the third filling layer FL 3 may be exposed on the entire surface of the substrate 100 .

Referring to FIGS. 8A, 8B, and 8C , a second etching process may be performed to pattern the second mask layer ML 2 . The second etching process may include removing the second dielectric film IF 2 between the fourth mask layer ML 4 and the third filling layer FL 3 , and using the fourth mask layer ML 4 and the third filling layer FL 3 as an etching mask to pattern the third insulating layer IL 3 , the second filling layer FL 2 , and the second mask layer ML 2 . A removal process may be performed to remove the fourth mask layer ML 4 , the third filling layer FL 3 , the second dielectric film IF 2 , the third insulating layer IL 3 , and/or the second filing layer FL 2 that remain after the second etching process.

The second etching process may form fourth openings OP 4 in the second mask layer ML 2 . The fourth openings OP 4 may extend in the fifth direction D 5 . The fourth opening OP 4 may partially overlap the second openings OP 2 .

The second etching process may cause that the second mask layer ML 2 is patterned to form first mask patterns MP 1 . When viewed in plan, each of the first mask patterns MP 1 may have a rhombic shape. Each of the first mask patterns MP 1 may be defined by the second openings OP 2 and the fourth openings OP 4 .

Referring to FIGS. 9A, 9B, and 9C , a photoresist pattern PR may be formed on the dummy region DR of the substrate 100 . For example, the formation of the photoresist pattern PR may include forming a third photoresist layer on the entire surface of the substrate 100 , and using a third photomask to pattern the third photoresist layer. The photoresist pattern PR may fill portions OP 2 P of the second openings OP 2 on the dummy region DR of the substrate 100 . The photoresist pattern PR may also fill portions OP 4 P of the fourth openings OP 4 on the dummy region DR of the substrate 100 . The photoresist pattern PR may mutually connect the first mask patterns MP 1 on the dummy region DR.

Referring to FIGS. 10A, 10B, and 10C , a third etching process may be performed to form a second trench TR 2 . The third etching process may include using the first mask patterns MP 1 as an etching mask to pattern the first insulating layer IL 1 , using the patterned first insulating layer IL 1 as an etching mask to pattern the hardmask layer HM, using the patterned hardmask layer HM as an etching mask to pattern the first mask layer ML 1 and the target layer TL, and using the patterned first mask layer ML 1 and patterned target layer TL as an etching mask to pattern the active structure AS. A removal process may be performed to remove the photoresist pattern PR, the first mask patterns MP 1 , the first dielectric film IF 1 , the first insulating layer IL 1 , and the hardmask layer HM that remain after the third etching process. The pattering of the first insulating layer IL 1 using the first mask patterns MP 1 as an etching mask may include that the second and fourth openings OP 2 and OP 4 are used to pattern the first insulating layer ILL

The patterning of the first mask layer ML 1 may form second mask patterns MP 2 on the cell region CR of the substrate 100 . When viewed in plan, each of the second mask patterns MP 2 may have an elliptical shape. Although each of the first mask patterns MP 1 has a rhombic shape, pattern shapes of a plurality of layers may be changed while being sequentially etched during the third etching process. Finally, each of the second mask patterns MP 2 may be formed to have an elliptical shape. The second mask patterns MP 2 may be spaced apart from each other in the fourth direction D 4 . The second mask patterns MP 2 may also be spaced apart from each other in the fifth direction D 5 . A single second mask pattern MP 2 may vertically overlap two second impurity regions SD 2 adjacent to each other in the second direction D 2 .

The patterning of the target layer TL may form target patterns TP on the cell region CR of the substrate 100 . The target patterns TP may vertically overlap the second mask patterns MP 2 . For example, the target patterns TP and the second mask patterns MP 2 may have the same planar shape and arrangement.

The patterning of the active structure AS may form pillars PL on the cell region CR of the substrate 100 and also form the second trench TR 2 between the pillars PL. For example, the second trench TR 2 may define the pillars PL of the active structure AS. The active structure AS may have a portion at a level higher than that of a floor surface of the second trench TR 2 , and the portion of the active structure AS may be defined as the pillar PL. The second trench TR 2 may expose the first impurity regions SD 1 . Each of the pillars PL may include an upper device isolation layer UST, upper second impurity regions USD 2 , and/or upper gate capping layers UGP. The upper device isolation layer UST may be a portion of the device isolation layer ST, which portion is placed at a level higher than that of the floor surface of the second trench TR 2 . The upper second impurity region USD 2 may be a portion of the second impurity region SD 2 , which portion is placed at a level higher than that of the floor surface of the second trench TR 2 . The upper gate capping layer UGP may be a portion of the gate capping layer GP, which portion is placed at a level higher than that of the floor surface of the second trench TR 2 .

When viewed in plan, each of the pillars PL may have an elliptical shape. The pillars PL may be spaced apart from each other in the fourth direction D 4 . The pillars PL may also be spaced apart from each other in the fifth direction D 5 .

The patterning of the first mask layer ML 1 may form a first dummy pattern DP 1 on the dummy region DR of the substrate 100 . The first dummy pattern DP 1 may include a segment extending in the first direction D 1 and other segment extending in the second direction D 2 .

The patterning of the target layer TL may form a second dummy pattern DP 2 on the dummy region DR of the substrate 100 . The second dummy pattern DP 2 may vertically overlap the first dummy pattern DP 1 . For example, the first and second dummy patterns DP 1 and DP 2 may have the same planar shape.

Referring to FIGS. 11A, 11B, and 11C , a first conductive layer CL 1 , a second conductive layer CL 2 , and/or a fifth mask layer ML 5 may be sequentially formed on the entire surface of the substrate 100 . The first conductive layer CL 1 may fill the second trench TR 2 . The first conductive layer CL 1 may contact the first impurity regions SD 1 . The first conductive layer CL 1 may include one of a doped semiconductor material (e.g., doped silicon or doped germanium), a metallic material (e.g., titanium, tantalum, tungsten, copper, or aluminum), and a metal-semiconductor compound (e.g., tungsten silicide, cobalt silicide, or titanium silicide). The first conductive layer CL 1 may have an electrical conductivity greater than that of the second mask pattern MP 2 . The second conductive layer CL 2 may include a metallic material (e.g., titanium, tantalum, tungsten, copper, or aluminum). The fifth mask layer ML 5 may include a silicon nitride layer or a silicon oxynitride layer.

Referring to FIGS. 12A, 12B, and 12C , line structures LST may be formed to extend in the first direction D 1 . The line structures LST may be spaced apart from each other in the second direction D 2 .

For example, the fifth mask layer ML 5 may be patterned to form third mask patterns MP 3 . A photolithography process may be used to pattern the third mask patterns MP 3 .

The third mask patterns MP 3 may be used as an etching mask to sequentially etch the second conductive layer CL 2 and the first conductive layer CL 1 to respectively form bit lines BL and conductive patterns CP. The third mask pattern MP 3 , the bit line BL, and the conductive pattern CP may vertically overlap each other. The third mask pattern MP 3 , the bit line BL, and/or the conductive pattern CP may constitute or form the line structure LST. When viewed in plan, the bit lines BL may extend while intersecting the gate electrodes GE.

The conductive pattern CP may be connected to the first impurity region SD 1 . For example, the bit line BL may be electrically connected through the conductive pattern CP to the first impurity region SD 1 . The second mask patterns MP 2 and the target patterns TP covering the second impurity regions SD 2 may separate the conductive pattern CP from the second impurity regions SD 2 .

Referring to FIGS. 13A, 13B, and 13C , spacers SP may be formed to cover opposite sidewalls of each of the line structures LST. The second trench TR 2 may be filled with portions of the spacers SP. The formation of the spacers SP may include conformally forming a spacer layer on the entire surface of the substrate 100 and anisotropically etching the spacer layer. The spacer layer may include one or more of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer.

Referring to FIGS. 14A, 14B, and 14C , a third dielectric film IF 3 may be formed on the entire surface of the substrate 100 . The third dielectric film IF 3 may include a silicon oxide layer. A planarization process may be performed to remove an upper portion of the third dielectric film IF 3 and upper portions of the third mask patterns MP 3 .

A patterning process may be performed on the third dielectric film IF 3 , the second mask patterns MP 2 , and the target patterns TP, and thus contact holes CTH may be formed. Alternatively, the contact holes CTH may be formed by a patterning process performed on the third dielectric film IF 3 , the first dummy pattern DP 1 , and the second dummy pattern DP 2 . Since the third mask patterns MP 3 and the spacers SP are used as an etching mask during the patterning process, the contact holes CTH may be formed in a self-alignment manner.

The contact holes CTH may be filled with a conductive material to form contacts CNT. The conductive material may include one or more of conductive metal nitride (e.g., titanium nitride or tantalum nitride) and metal (e.g., titanium, tantalum, tungsten, copper, or aluminum). The contacts CNT may penetrate the second mask pattern MP 2 and the target pattern TP and may be electrically connected to the second impurity regions SD 2 . The spacers SP may separate the contacts CNT from the bit lines BL.

A data storage element DS may be formed on each of the contacts CNT. The data storage element DS may be a memory element that uses one of a capacitor, a magnetic tunnel junction pattern, and a variable resistance body including a phase change material. For example, the data storage element DS may be a capacitor.

The following describes a semiconductor device according to example embodiments of inventive concepts with reference back to FIGS. 14A, 14B, and 14C .

A substrate 100 may be provided thereon with a device isolation layer ST defining active patterns ACT. Each of the active patterns ACT may extend in a third direction D 3 . The active patterns ACT may be spaced apart from each other in the third direction D 3 . The active patterns ACT may be two-dimensionally arranged.

The device isolation layer ST may fill between the active patterns ACT.

Each of the active patterns ACT may include a first impurity region SD 1 and a pair of second impurity regions SD 2 . The first impurity region SD 1 may be placed between the pair of second impurity regions SD 2 . The first and second impurity regions SD 1 and SD 2 may have the same conductive type (e.g., N-type).

First trenches TR 1 may be defined on the active patterns ACT and the device isolation layer ST. Each of the first trenches TR 1 may be defined between the first impurity region SD 1 and the second impurity region SD 2 . The first trench TR 1 may downwardly extend from a top surface of the active pattern ACT toward a bottom surface of the substrate 100 .

Gate electrodes GE may be provided to run across the active patterns ACT and the device isolation layer ST. The gate electrodes GE may be provided in the first trenches TR 1 . The gate electrodes GE may extend in parallel to each other in a second direction D 2 . The gate electrode GE may have a top surface lower than that of the active pattern ACT (e.g., a top surface of the first impurity region SD 1 or the second impurity region SD 2 ).

A gate dielectric layer GI may be interposed between the gate electrode GE and the active pattern ACT. A gate capping layer GP may be provided on the gate electrode GE. The gate capping layer GP may cover the top surface of the gate electrode GE. The gate capping layer GP may have a top surface coplanar with that of the active pattern ACT. The gate electrode GE, the gate dielectric layer GI, and the gate capping layer GP may constitute or form a gate structure GS.

The active patterns ACT, the gate structures GS, and the device isolation layer ST may constitute or form an active structure AS. A second trench TR 2 may be defined on the active structure AS. The second trench TR 2 may downwardly extend from a top surface of the active structure AS toward the bottom surface of the substrate 100 . The second trench TR 2 may define pillars PL in an upper portion of the active structure AS. Each of the pillars PL may have an island shape that vertically protrudes from a floor surface of the second trench TR 2 . Each of the pillars PL may include an upper portion of the second impurity region SD 2 . Each of the pillars PL may be provided on a cell region CR of the substrate 100 .

When viewed in plan, any two neighboring ones of the pillars PL may be spaced apart at a constant minimum distance. For example, a minimum distance L 1 between a first pillar PL 1 and a second pillar PL 2 adjacent to each other in a fifth direction D 5 may be substantially the same as a minimum distance L 2 between the second pillar PL 2 and a third pillar PL 3 adjacent to each other in the fifth direction D 5 .

Target patterns TP and second mask patterns MP 2 may be sequentially provided on the cell region CR of the substrate 100 . The target patterns TP may vertically overlap the second mask patterns MP 2 .

A second dummy pattern DP 2 and a first dummy pattern DP 1 may be sequentially provided on a dummy region DR of the substrate 100 . The first dummy pattern DP 1 may vertically overlap the second dummy pattern DP 2 .

The active structure AS may be provided thereon with line structures LST extending in a first direction D 1 . The line structures LST may be spaced apart from each other in the second direction D 2 . When viewed in plan, the line structures LST may intersect the gate electrodes GE. Spacers SP may be provided on opposite sidewalls of each of the line structures LST. The second trench TR 2 may be filled with portions of the spacers SP.

Each of the line structures LST may include a conductive pattern CP, a bit line BL, and a third mask pattern MP 3 that are sequentially stacked. The bit line BL may be electrically connected through the conductive pattern CP to the first impurity region SD 1 .

Third dielectric films IF 3 may be provided on the active structure AS. Each of the third dielectric films IF 3 may be provided between the spacers SP. Contacts CNT may be provided to come into connection with the second impurity region SD 2 . Each of the contacts CNT may be provided between the third dielectric films IF 3 . The spacers SP may separate the contacts CNT from the bit lines BL. A data storage element DS may be provided on each of the contacts CNT. For example, the data storage element DS may be a capacitor.

FIGS. 15A and 15B illustrate plan views showing a semiconductor device according to example embodiments of inventive concepts.

For brevity of description, components substantially the same as those discussed with reference to FIGS. 1A to 14C are allocated the same reference numerals thereto, and a repetitive explanation thereof will be omitted.

Referring to FIG. 15A , when viewed in plan, each of pillars PL 1 , PL 2 , and PL 3 may have a rhombic shape. The pillars PL 1 , PL 2 , and PL 3 may include a first pillar PL 1 , a second pillar PL 2 , and a third pillar PL 3 . The first, second, and third pillars PL 1 , PL 2 , and PL 3 may have the same maximum width in the second direction D 2 . The first pillar PL 1 may have a first width W 1 indicating a maximum width in the first direction D 1 . The second pillar PL 2 may have a second width W 2 indicating a maximum width in the first direction D 1 . The third pillar PL 3 may have a third width W 3 indicating a maximum width in the first direction D 1 . The second width W 2 may be greater than the first width W 1 . The third width W 3 may be greater than the second width W 2 .

Referring to FIG. 15B , when viewed in plan, each of pillars PL 1 , PL 2 , and PL 3 may have an elliptical shape. The pillars PL 1 , PL 2 , and PL 3 may include a first pillar PL 1 , a second pillar PL 2 , and a third pillar PL 3 . The first, second, and third pillars PL 1 , PL 2 , and PL 3 may have the same maximum width in the second direction D 2 . The first pillar PL 1 may have a first width W 1 indicating a maximum width in the first direction D 1 . The second pillar PL 2 may have a second width W 2 indicating a maximum width in the first direction D 1 . The third pillar PL 3 may have a third width W 3 indicating a maximum width in the first direction D 1 . The second width W 2 may be greater than the first width W 1 . The third width W 3 may be greater than the second width W 2 .

FIGS. 16A to 21A illustrate plan views showing a method of manufacturing a semiconductor device according to example embodiments of inventive concepts. FIGS. 16B to 21B illustrate cross-sectional views taken along line A-A′ of FIGS. 16A to 21A , respectively. FIGS. 16C to 21C illustrate cross-sectional views taken along line B-B′ of FIGS. 16A to 21A , respectively.

For brevity of description, components substantially the same as those discussed with reference to FIGS. 1A to 14C are allocated the same reference numerals thereto, and a repetitive explanation thereof will be omitted.

Referring to FIGS. 16A, 16B, and 16C , identically to those discussed with reference to FIGS. 1A to 5C , there may be formed an active structure AS, a target layer TL, a first mask layer ML 1 , a hardmask layer HM, a first insulating layer IL 1 , a second mask layer ML 2 , a first dielectric film IF 1 , and second openings OP 2 .

A second filling layer FL 2 may be formed on an entire surface of the substrate 100 . The second filling layer FL 2 may fill the second openings OP 2 . The second filling layer FL 2 may include a spin-on-hardmask (SOH) layer.

A third insulating layer IL 3 , a fourth mask layer ML 4 , and a fourth insulating layer IL 4 may be sequentially formed on the second filling layer FL 2 . The third insulating layer IL 3 may include a silicon oxide layer. The fourth mask layer ML 4 may include a spin-on-hardmask (SOH) layer. The fourth insulating layer IL 4 may include one or more of a silicon nitride layer and a silicon oxynitride layer.

The fourth mask layer ML 4 and the fourth insulating layer IL 4 may be patterned to form third openings OP 3 . The third openings OP 3 may extend in a second direction D 2 . For example, the third openings OP 3 may extend in a direction parallel to gate electrodes GE.

The formation of the third openings OP 3 may include forming a second photoresist layer on the fourth insulating layer IL 4 , using a second photomask to pattern the second photoresist layer, and using the patterned second photoresist layer as an etching mask to pattern the fourth mask layer ML 4 and the fourth insulating layer IL 4 .

A second dielectric film IF 2 may be conformally formed on the entire surface of the substrate 100 . The second dielectric film IF 2 may include a silicon oxide layer. The second dielectric film IF 2 may be formed by atomic layer deposition (ALD).

Referring to FIGS. 17A, 17B, and 17C , a third filling layer FL 3 may be formed on the second dielectric film IF 2 . The third filling layer FL 3 may fill the third openings OP 3 . The third filling layer FL 3 may include a spin-on-hardmask (SOH) layer.

After the third filling layer FL 3 is formed, a second etch-back process may be performed. The second etch-back process may be performed such that the fourth insulating layer IL 4 is removed, the second dielectric film IF 2 is removed on its portion on the fourth insulating layer IL 4 , and the third filling layer FL 3 is removed on its portion on the fourth insulating layer IL 4 . Both remaining second dielectric film IF 2 and third filling layer FL 3 may selectively fill each of the third openings OP 3 . The both remaining second dielectric film IF 2 and third filling layer FL 3 may be provided in the fourth mask layer ML 4 . When viewed in plan, the fourth mask layer ML 4 , the second dielectric film IF 2 , and the third filling layer FL 3 may be exposed on the entire surface of the substrate 100 .

Referring to FIGS. 18A, 18B, and 18C , a second etching process may be performed to pattern the second mask layer ML 2 . The second etching process may include removing the second dielectric film IF 2 between the fourth mask layer ML 4 and the third filling layer FL 3 , and using the fourth mask layer ML 4 and the third filling layer FL 3 as an etching mask to pattern the third insulating layer IL 3 , the second filling layer FL 2 , and the second mask layer ML 2 . A removal process may be performed to remove the fourth mask layer ML 4 , the third filling layer FL 3 , the second dielectric film IF 2 , the third insulating layer IL 3 , and the second filing layer FL 2 that remain after the second etching process.

The second etching process may form fourth openings OP 4 in the second mask layer ML 2 . The fourth openings OP 4 may extend in the second direction D 2 . The fourth opening OP 4 may partially overlap the second openings OP 2 .

The second etching process may cause that the second mask layer ML 2 is patterned to form first mask patterns MP 1 . When viewed in plan, each of the first mask patterns MP 1 may have a parallelogram shape. Each of the first mask patterns MP 1 may be defined by the second openings OP 2 and the fourth openings OP 4 .

Referring to FIGS. 19A, 19B, and 19C , a photoresist pattern PR may be formed on a dummy region DR of the substrate 100 . For example, the formation of the photoresist pattern PR may include forming a third photoresist layer on the entire surface of the substrate 100 , and using a third photomask to pattern the third photoresist layer. The photoresist pattern PR may fill portions OP 2 P of the second openings OP 2 on the dummy region DR of the substrate 100 . The photoresist pattern PR may also fill portions OP 4 P of the fourth openings OP 4 on the dummy region DR of the substrate 100 . The photoresist pattern PR may mutually connect the first mask patterns MP 1 on the dummy region DR.

Referring to FIGS. 20A, 20B, and 20C , a third etching process may be performed to form a second trench TR 2 . The third etching process may include using the first mask patterns MP 1 as an etching mask to pattern the first insulating layer IL 1 , using the patterned first insulating layer IL 1 as an etching mask to pattern the hardmask layer HM, using the patterned hardmask layer HM as an etching mask to pattern the first mask layer ML 1 and the target layer TL, and using the patterned first mask layer ML 1 and patterned target layer TL as an etching mask to pattern the active structure AS. A removal process may be performed to remove the photoresist pattern PR, the first mask patterns MP 1 , the first dielectric film IF 1 , the first insulating layer IL 1 , and the hardmask layer HM that remain after the third etching process. The pattering of the first insulating layer IL 1 using the first mask patterns MP 1 as an etching mask may include that the second and fourth openings OP 2 and OP 4 are used to pattern the first insulating layer ILL

The patterning of the first mask layer ML 1 may form second mask patterns MP 2 on a cell region CR of the substrate 100 . Each of the second mask patterns MP 2 may include first sidewalls MP 21 extending in the second direction D 2 and second sidewalls MP 22 connecting the first sidewalls MP 21 to each other. When viewed in plan, the second sidewalls MP 22 may be curved. Although each of the first mask patterns MP 1 has a parallelogram shape, pattern shapes of a plurality of layers may be changed while being sequentially etched during the third etching process. Finally, each of the second mask patterns MP 2 may include the curved second sidewalls MP 22 . The second mask patterns MP 2 may be spaced apart from each other in a fourth direction D 4 . The second mask patterns MP 2 may be spaced apart from each other in the second direction D 2 . A single second mask pattern MP 2 may vertically overlap two second impurity regions SD 2 adjacent to each other in the second direction D 2 .

The patterning of the target layer TL may form target patterns TP on the cell region CR of the substrate 100 . The target patterns TP may vertically overlap the second mask patterns MP 2 . For example, the target patterns TP and the second mask patterns MP 2 may have the same planar shape and arrangement.

The patterning of the active structure AS may form pillars PL on the cell region CR of the substrate 100 and also form the second trench TR 2 between the pillars PL. For example, the second trench TR 2 may define the pillars PL of the active structure AS. The active structure AS may have a portion at a level higher than that of a floor surface of the second trench TR 2 , and the portion of the active structure AS may be defined as the pillar PL. The second trench TR 2 may expose first impurity regions SD 1 . Each of the pillars PL may include an upper device isolation layer UST, upper second impurity regions USD 2 , and upper gate capping layers UGP. The upper device isolation layer UST may be a portion of the device isolation layer ST, which portion is placed at a level higher than that of the floor surface of the second trench TR 2 . The upper second impurity region USD 2 may be a portion of the second impurity region SD 2 , which portion is placed at a level higher than that of the floor surface of the second trench TR 2 . The upper gate capping layer UGP may be a portion of the gate capping layer GP, which portion is placed at a level higher than that of the floor surface of the second trench TR 2 .

When viewed in plan, each of the pillars PL may include first sidewalls PLW 1 extending in the second direction D 2 and second sidewalls PLW 2 connecting the first sidewalls PLW 1 to each other. The second sidewalls PLW 2 may be curved. The pillars PL may be spaced apart from each other in the fourth direction D 4 . The pillars PL may also be spaced apart from each other in the second direction D 2 .

The patterning of the first mask layer ML 1 may form a first dummy pattern DP 1 on the dummy region DR of the substrate 100 . The first dummy pattern DP 1 may include a segment extending in a first direction D 1 and other segment extending in the second direction D 2 .

The patterning of the target layer TL may form a second dummy pattern DP 2 on the dummy region DR of the substrate 100 . The second dummy pattern DP 2 may vertically overlap the first dummy pattern DP 1 . For example, the first and second dummy patterns DP 1 and DP 2 may have the same planar shape.

Referring to FIGS. 21A, 21B, and 21C , processes similar to those discussed in FIGS. 11A to 12C may be performed to form line structures LST extending in the first direction D 1 . The line structures LST may be spaced apart from each other in the second direction D 2 . Each of the line structures LST may include a third mask pattern MP 3 , a bit line BL, and a conductive pattern CP. The conductive pattern CP may have an electrical conductivity greater than that of the second mask pattern MP 2 . When viewed in plan, the bit lines BL may extend while intersecting the gate electrodes GE. The conductive pattern CP may be connected to the first impurity region SD 1 . For example, the bit line BL may be electrically connected through the conductive pattern CP to the first impurity region SD 1 . The second mask patterns MP 2 and the target patterns TP covering the second impurity regions SD 2 may separate the conductive pattern CP from the second impurity regions SD 2 .

Processes similar to those discussed in FIGS. 13A, 13B, and 13C may be performed to form spacers SP covering opposite sidewalls of each of the line structures LST. The second trench TR 2 may be filled with portions of the spacers SP.

Processes similar to those discussed in FIGS. 14A, 14B, and 14C may be performed to form a third dielectric film IF 3 , contact holes CTH, contacts CNT, and a data storage element DS. The contacts CNT may penetrate the second mask pattern MP 2 and the target pattern TP and may be electrically connected to the second impurity regions SD 2 . The spacers SP may separate the contacts CNT from the bit lines BL. The data storage element DS may be formed on each of the contacts CNT.

According to inventive concepts, a line patterning may be used to form pillars such that a constant minimum distance may be provided between any two neighboring pillars.

Although the present invention has been described in connection with the embodiments of inventive concepts illustrated in the accompanying drawings, it will be understood to those skilled in the art that various changes and modifications may be made without departing from the technical spirit and essential feature of inventive concepts. It will be apparent to those skilled in the art that various substitution, modifications, and changes may be thereto without departing from the scope and spirit of the inventive concepts.