Method of fabricating thin-film transistors in which contact with connecting electrodes becomes reliable. When contact holes are formed, the bottom insulating layer is subjected to a wet etching process, thus producing undercuttings inside the contact holes. In order to remove the undercuttings, a light etching process is carried out to widen the contact holes. Thus, tapering section are obtained, and the covering of connection wiring is improved.

Claims

13 · 1 independent · depth 2

13 granted claims

›1.independentA semiconductor device comprising:na semiconductor substrate including at least a source region and a drain region;a gate electrode over the semicondu…+12

›2.↳ 1The semiconductor device according to claim 1, wherein said semiconductor substrate is a single-crystal silicon wafer.d2

›3.↳ 1The semiconductor device according to claim 1, wherein said source region and said drain region contain phosphorus or boron.d2

›4.↳ 1The semiconductor device according to claim 1, wherein said first insulating film and said second insulating film are formed from a same material.d2

›5.↳ 1The semiconductor device according to claim 1, wherein at least any one of said first insulating film and said second insulating film are formed from …d2

›6.↳ 1The semiconductor device according to claim 1, wherein a composition ratio of the first insulating film is different from a composition ratio of the s…d2

›7.↳ 1The semiconductor device according to claim 1, wherein an etching rate of the first insulating film is different from an etching rate of the second in…d2

›8.↳ 1The semiconductor device according to claim 1, wherein an etching rate of the second insulating film is higher than an etching rate of the first insul…d2

›9.↳ 1The semiconductor device according to claim 1, wherein a film property of the first insulating film is different from a film property of the second in…d2

›10.↳ 1The semiconductor device according to claim 1, wherein a film thickness of the second insulating film is greater than a film thickness of the first in…d2

›11.↳ 1The semiconductor device according to claim 1, wherein the gate insulating film and the first insulating film are formed from different materials.d2

›12.↳ 1The semiconductor device according to claim 1, wherein the contact hole is formed in the gate insulating film.d2

›13.↳ 1The semiconductor device according to claim 1, wherein said electrode is formed over the second insulating film.d2

Classifications

5 codes

IPC · International Patent Classification

Section H — Electricity

H01L23/48

USPC · US Patent Classification

257/774257/347257/775257/E21.577

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Pendency

1.6 y

572 days filing → grant

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after a restriction

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1 RCE

Examiner

Wai Sing Louie

art unit 2814 · TC 2800

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1 priority documents

›Priority documents — 1

Type	Document	Date
related publication	US 20110001192 A1	6 Jan 2011

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