Nonselective germanium deposition by UHV/CVD

Claim 1

A method of nonselectively depositing Ge onto a substrate in an ultra high vacuum chemical vapor deposition (UHV/CVD) system, the UHV/CVD system comprising a reaction chamber and a load lock chamber, said method comprising the steps of: a) placing said substrate in said load lock chamber and pre-evacuating said load lock chamber to a pressure of approximately 10 to 50 mTorr and then subsequently evacuating said load lock chamber quickly to a pressure of approximately 10 -7 Torr; b) evacuating said reaction chamber to a pressure below 10 -7 Torr; c) bleeding hydrogen (H 2 ) into said reaction chamber at a rate of approximately 650 sccm; d) opening said load lock chamber to said reaction chamber and transferring the substrate from said load lock chamber to said reaction chamber, whereby the bleeding of the H 2 of the previous step reduces cross contamination between said load lock chamber and said reaction chamber during the transferring of said substrate from said load lock chamber to said reaction chamber; e) heating said substrate to a temperature on the order of 300° to 600° C.; and, f) stopping the bleeding of H 2 and providing a mixture of GeH 4 , He, and B 2 H 6 gas in said reaction chamber, wherein a flow of GeH 4 and He is at a rate of approximately 10 to 25 sccm to produce a GeH 4 partial pressure of approximately 2-50 mTorr and a flow of B 2 H 6 is at a rate sufficient to produce a B 2 H 6 partial pressure of approximately 0.08 to 2 mTorr, the mixture thereby having a partial pressure ratio of GeH 4 to B 2 H 6 on the order of 25:1.

Claim 2

A method of nonselectively depositing Ge onto a substrate in an ultra high vacuum chemical vapor deposition (UHV/CVD) system, the UHV/CVD system comprising a reaction chamber and a load lock chamber, said method comprising the steps of: a) placing said substrate in said load lock chamber and pre-evacuating said load lock chamber to a pressure of approximately 10 to 50 mTorr and then subsequently evacuating said load lock chamber quickly to a pressure of approximately 10 -7 Torr; b) evacuating said reaction chamber to a pressure below 10 -7 Torr; c) bleeding hydrogen (H 2 ) into said reaction chamber at a rate of approximately 650 sccm; d) opening said load lock chamber to said reaction chamber and transferring the substrate from said load lock chamber to said reaction chamber, whereby the bleeding of the H 2 of the previous step reduces cross contamination between said load lock chamber and said reaction chamber during the transferring of said substrate from said load lock chamber to said reaction chamber; e) heating said substrate to a temperature on the order of 300° to 600° C.; and, f) stopping the bleeding of H 2 and providing a mixture of GeH 4 , He, and B 2 H 6 gas in said reaction chamber, wherein a flow of GeH 4 and He is at a rate of approximately 10 to 25 sccm to produce a GeH 4 partial pressure of approximately 2-50 mTorr and a flow of B 2 H 6 is at a rate sufficient to produce a B 2 H 6 partial pressure of approximately 0.08 to 2 mTorr, the mixture thereby having a partial pressure ratio of GeH 4 to B 2 H 6 on the order of 25:1.

Claim 7

A method of nonselectively depositing Ge onto a substrate in an ultra high vacuum chemical vapor deposition (UHV/CVD) system, the UHV/CVD system comprising a reaction chamber and a load lock chamber, said method comprising the steps of: a) immersing said substrate in about a 5:1:1 solution of H 2 O:H 2 O 2 :NH 4 OH at about 65° C. for about 1 minute; b) rinsing said substrate with deionized H 2 O; c) immersing said substrate in about a 5:1:1 solution of H 2 O:H 2 O 2 :HCl at about 65° C. for about 1 minute; d) rinsing said substrate with deionized H 2 O; e) immersing said substrate in about a 10:1 solution of H 2 O:HF at room temperature for about 10 to 15 seconds; f) placing said substrate into said load lock chamber and pre-evacuating said load lock chamber to a pressure of approximately 10 to 50 mTorr and then subsequently evacuating said load lock chamber quickly to a pressure of approximately 10 -7 Torr; g) evacuating said reaction chamber to a pressure below 10 -7 Torr; h) bleeding hydrogen (H 2 ) into said reaction chamber at a rate of approximately 650 sccm; i) opening said load lock chamber to said reaction chamber and transferring the substrate from said load lock chamber to said reaction chamber, whereby the bleeding of the H 2 of the previous step reduces cross contamination between said load lock chamber and said reaction chamber during the transferring of said substrate from said load lock chamber to said reaction chamber; j) heating said reaction chamber and said substrate to a temperature on the order of 300° to 600° C.; and, k) stopping the bleeding of H 2 and providing a mixture of GeH 4 , He, and B 2 H 6 gas in said reaction chamber, wherein a flow of GeH 4 and He is at a rate of approximately 10 to 25 sccm to produce a partial pressure of GeH 4 on the order of 2 to 50 mTorr and a flow of B 2 H 6 is at a rate sufficient to produce a partial pressure of B 2 H 6 on the order of 0.08 to 2 mTorr, the mixture thereby having a partial pressure ratio of GeH 4 to B 2 H 6 on the order of 25:1.

Claim 8

A method of nonselectively depositing Ge onto a substrate in an ultra high vacuum chemical vapor deposition (UHV/CVD) system, the UHV/CVD system comprising a reaction chamber and a load lock chamber, said method comprising the steps of: a) immersing said substrate in about a 5:1:1 solution of H 2 O:H 2 O 2 :NH 4 OH at about 65° C. for about 1 minute; b) rinsing said substrate with deionized H 2 O; c) immersing said substrate in about a 5:1:1 solution of H 2 O:H 2 O 2 :HCl at about 65° C. for about 1 minute; d) rinsing said substrate with deionized H 2 O; e) immersing said substrate in about a 10:1 solution of H 2 O:HF at room temperature for about 10 to 15 seconds; f) placing said substrate into said load lock chamber and pre-evacuating said load lock chamber to a pressure of approximately 10 to 50 mTorr and then subsequently evacuating said load lock chamber quickly to a pressure of approximately 10 -7 Torr; g) evacuating said reaction chamber to a pressure below 10 -7 Torr; h) bleeding hydrogen (H 2 ) into said reaction chamber at a rate of approximately 650 sccm; i) opening said load lock chamber to said reaction chamber and transferring the substrate from said load lock chamber to said reaction chamber, whereby the bleeding of the H 2 of the previous step reduces cross contamination between said load lock chamber and said reaction chamber during the transferring of said substrate from said load lock chamber to said reaction chamber; j) heating said reaction chamber and said substrate to a temperature on the order of 300° to 600° C.; and, k) stopping the bleeding of H 2 and providing a mixture of GeH 4 , He, and B 2 H 6 gas in said reaction chamber, wherein a flow of GeH 4 and He is at a rate of approximately 10 to 25 sccm to produce a partial pressure of GeH 4 on the order of 2 to 50 mTorr and a flow of B 2 H 6 is at a rate sufficient to produce a partial pressure of B 2 H 6 on the order of 0.08 to 2 mTorr, the mixture thereby having a partial pressure ratio of GeH 4 to B 2 H 6 on the order of 25:1.