Sputtering target for forming ZrO2-In2O3 based protective film for optical storage medium

SiO 2 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 2; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 2, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 1 to 9 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 2 were thereby produced.

The percentage of Zr, as an oxidative product in which Zr and In are combined, that is included in the targets 1 to 9 of the invention and that is dispersed in a base material, is measured by use of EPMA (JXA-8500F, JEOL Ltd.) in a below-described manner.

Firstly, by use of the EPMA and by capture of a Backscattered Electron Image, a composition of a polished cross-sectional face of the target in an area of 5000 μm 2 or more was captured with a magnification ratio of 3000 or more.

Furthermore, by use of a WDS (Wavelength-Dispersive Spectrometer) technique, a phase including Zr and a phase simultaneously including Zr and In are determined. An area of the phase including only Zr and an area of the phase made of the oxidative product in which Zr and In are combined are calculated based on the captured image. The percentage of Zr that is included in the target and is in the oxidative product in which Zr and In are combined is determined, and the result thereof is indicated in Table 2.

Conventional Example 1

ZrO 2 powders, In 2 O 3 powders, and SiO 2 powders which have been prepared as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 2; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 2, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 1 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 2 were thereby produced.

The percentage of Zr, as an oxidative product in which Zr and In are combined, that is included in the conventional target 1, and that is dispersed in a base material, is measured by use of EPMA (JXA-8500F, JEOL Ltd.) in a below-described manner.

Firstly, by use of the EPMA and by capture of a Backscattered Electron Image, a composition of a polished cross-sectional face of the target in an area of 5000 μm 2 or more was captured with a magnification ratio of 3000 or more.

Furthermore, by use of a WDS (Wavelength-Dispersive Spectrometer) technique, a phase including Zr and a phase simultaneously including Zr and In are determined. An area of the phase including only Zr and an area of the phase made of the oxidative product in which Zr and In are combined are calculated based on the captured image. The percentage of Zr that is included in the target and is in the oxidative product in which Zr and In are combined is determined, and the result thereof is indicated in Table 2.

In a state where each of the targets 1 to 9 of the invention and conventional target 1 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 1 to 9 of the invention and the conventional target 1 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 2.

Based on the result indicated in Table 2, in the targets 1 to 9 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 1, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 1 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 1 to 9 of the invention.

Al 2 O 3 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 3; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 3, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 10 to 18 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 3 were thereby produced.

The percentage of Zr that is included in the targets 10 to 18 of the invention as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Example 1, and the result thereof is indicated in Table 3.

Conventional Example 2

ZrO 2 powders, In 2 O 3 powders, and Al 2 O 3 powders which have been prepared as as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 3; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 3, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 2 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 3 were thereby produced.

The percentage of Zr that is included in the conventional target 2 as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Conventional Example 1, and the result thereof is indicated in Table 3.

In a state where each of the targets 10 to 18 of the invention and conventional target 2 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 10 to 18 of the invention and the conventional target 2 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 3.

Based on the result indicated in Table 3, in the targets 10 to 18 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 2, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 2 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 10 to 18 of the invention.

TiO 2 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 4; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 4, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 19 to 27 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 4 were thereby produced.

The percentage of Zr that is included in the targets 19 to 27 of the invention as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Example 1, and the result thereof is indicated in Table 4.

Conventional Example 3

ZrO 2 powders, In 2 O 3 powders, and TiO 2 powders which have been prepared as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 4; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 4, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 3 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 4 were thereby produced.

The percentage of Zr that is included in the conventional target 3 as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Conventional Example 1, and the result thereof is indicated in Table 4.

In a state where each of the targets 19 to 27 of the invention and conventional target 3 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 19 to 27 of the invention and the conventional target 3 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 4.

Based on the result indicated in Table 4, in the targets 19 to 27 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 3, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 3 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 19 to 27 of the invention.

CeO 2 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 5; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 5, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 28 to 36 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 5 were thereby produced.

The percentage of Zr that is included in the targets 28 to 36 of the invention as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Example 1, and the result thereof is indicated in Table 5.

Conventional Example 4

ZrO 2 powders, In 2 O 3 powders, and CeO 2 powders which have been prepared as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 5; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 5, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 4 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 5 were thereby produced.

The percentage of Zr that is included in the conventional target 4 as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Conventional Example 1, and the result thereof is indicated in Table 5.

In a state where each of the targets 28 to 36 of the invention and conventional target 4 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 28 to 36 of the invention and the conventional target 4 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 5.

Based on the result indicated in Table 5, in the targets 28 to 36 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 4, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 4 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 28 to 36 of the invention.

SnO 2 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 6; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 6, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 37 to 45 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 6 were thereby produced.

The percentage of Zr that is included in the targets 37 to 45 of the invention as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Example 1, and the result thereof is indicated in Table 6.

Conventional Example 5

ZrO 2 powders, In 2 O 3 powders, and SnO 2 powders which have been prepared as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 6; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 6, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 5 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 6 were thereby produced.

The percentage of Zr that is included in the conventional target 5 as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Conventional Example 1, and the result thereof is indicated in Table 6.

In a state where each of the targets 37 to 45 of the invention and conventional target 5 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 37 to 45 of the invention and the conventional target 5 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 6.

Based on the result indicated in Table 6, in the targets 37 to 45 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 5, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 5 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 37 to 45 of the invention.

Cr 2 O 3 powders and In 2 O 3 powders which had been prepared in advance were added to the powders A to F which were made of oxidative products in which Zr and In are combined, and which had been prepared in advance as indicated in Table 1, so as to obtain the percentage indicated in Table 7; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 7, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and targets 46 to 54 of the invention having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 7 were thereby produced.

The percentage of Zr that is included in the targets 46 to 54 of the invention as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Example 1, and the result thereof is indicated in Table 7.

Conventional Example 6

ZrO 2 powders, In 2 O 3 powders, and Cr 2 O 3 powders which have been prepared as raw material powders in advance were mixed together so as to obtain the percentage indicated in Table 7; furthermore, zirconia balls having a diameter of 1 mm and the dispersion liquid which serves as deionized water were added thereto and were mixed for 10 minutes in a bead mill of a wet grinding apparatus; and mixed powders were produced.

The obtained mixed powders were dried using a hot plate that was heated at 150° C., and moisture was thereby removed.

By use of a cold isostatic pressing method (CIP method), a molded body having a diameter of 200 mm and a thickness of 10 mm was produced from the mixed powders from which moisture had been removed by drying in the above-described manner.

Consequently, under the conditions indicated in Table 7, a baked body was produced by baking the molded body; furthermore, a surface of the baked body was machined by mechanical working, and a conventional target 6 having a diameter of 125 mm and a thickness of 6 mm and having component compositions as indicated in Table 7 were thereby produced.

The percentage of Zr that is included in the conventional target 6 as the oxidative product phase in which Zr and In are combined and that is dispersed in a base material is determined in a manner similar to the Conventional Example 1, and the result thereof is indicated in Table 7.

In a state where each of the targets 46 to 54 of the invention and conventional target 6 which are obtained in the above-described manner is solder-mounted to a water-cooling backing plate made of oxygen-free copper, the target is attached to a sputtering apparatus, the inside of the apparatus is evacuated by use of a vacuum evacuation device so as to be less than or equal to 1×10 −6 Torr; thereafter, the inside of the apparatus is set to a gas partial pressure of 10 mTorr of Ar in an atmosphere by supplying Ar gas into the apparatus.

By use of the targets 46 to 54 of the invention and the conventional target 6 in the above-described conditions, a sputtering is performed for 3 minutes by applying 2 kW greater than normal of sputtering power by use of an RF power source; thereafter, the sputtering is stopped for 1 minute.

The foregoing operation in which the sputtering is stopped for 1 minute after the sputtering for 3 minutes was repeated at 10 times.

Subsequently, the target is removed from the sputtering apparatus, the target is observed and it is determined whether or not a crack has been generated in the target, and the results of which are indicated in Table 7.

Based on the result indicated in Table 7, in the targets 46 to 54 of the invention, 90% or more of Zr as the oxidative product phase in which Zr and In are combined is dispersed in a base material. In the conventional target 6, an amount of Zr that is less than 90%, which serves as the oxidative product phase in which Zr and In are combined, is dispersed in the base material.

Compared with the conventional target 6 having compositions in which a ZrO 2 phase exists in large numbers, it is seen that a crack is not generated in a high output sputtering in the targets 46 to 54 of the invention.