Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
298 words
In a process for preparing an infrared sensitive photodiode comprising the steps of (1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consisting of PbS, PbSe, PbTe, PbS x Se 1-x , PbS x Te 1-x , PbSe x Te 1-x , Pb y Sn 1-y S, Pb y Sn 1-y Se, Pb y Sn 1-y Te, Pb y Sn 1-y S x Se 1-x , Pb y Sn 1-y S x Te 1-x , Pb y Sn 1-y Se x Te 1-x , Pb z Cd 1-z S, Pb z Cd 1-z Se, Pb z Cd 1-z Te, Pb z Cd 1-z S x Se 1-x , Pb z Cd 1-z S x Te 1-x , and Pb z Cd 1-z Se x Te 1-x , wherein 0<x<1, 0<y<1, and 0<z<1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material selected from the group consisting of (a) alkali halides and (b) alkaline earth halides; (2) vacuum depositing Pb metal onto a portion of the epitaxial layer of semiconductor alloy material to form a non-Ohmic Pb metal contact; and (3) forming an Ohmic contact on another portion of the epitaxial layer of semiconductor material; the improvement comprising: after step (1) but prior to step (2), forming a layer of a lead halide selected from the group consisting of PbCl 2 , PbBr 2 , PbF 2 , and mixtures thereof on the epitaxial layer of semiconductor material by exposing the epitaxial layer to vapor of the lead halide in air for at least 6 hours wherein the lead halide vapor is produced by heating the lead halide at a temperature of from about 175° C. to about 225° C.
Claim 2
Dependent Claim
298 words
In a process for preparing an infrared sensitive photodiode comprising the steps of (1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consisting of PbS, PbSe, PbTe, PbS x Se 1-x , PbS x Te 1-x , PbSe x Te 1-x , Pb y Sn 1-y S, Pb y Sn 1-y Se, Pb y Sn 1-y Te, Pb y Sn 1-y S x Se 1-x , Pb y Sn 1-y S x Te 1-x , Pb y Sn 1-y Se x Te 1-x , Pb z Cd 1-z S, Pb z Cd 1-z Se, Pb z Cd 1-z Te, Pb z Cd 1-z S x Se 1-x , Pb z Cd 1-z S x Te 1-x , and Pb z Cd 1-z Se x Te 1-x , wherein 0<x<1, 0<y<1, and 0<z<1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material selected from the group consisting of (a) alkali halides and (b) alkaline earth halides; (2) vacuum depositing Pb metal onto a portion of the epitaxial layer of semiconductor alloy material to form a non-Ohmic Pb metal contact; and (3) forming an Ohmic contact on another portion of the epitaxial layer of semiconductor material; the improvement comprising: after step (1) but prior to step (2), forming a layer of a lead halide selected from the group consisting of PbCl 2 , PbBr 2 , PbF 2 , and mixtures thereof on the epitaxial layer of semiconductor material by exposing the epitaxial layer to vapor of the lead halide in air for at least 6 hours wherein the lead halide vapor is produced by heating the lead halide at a temperature of from about 175° C. to about 225° C.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the epitaxial semiconductor alloy material is selected from the group consisting of PbS, PbSe, PbTe, PbS x Se 1-x , and PbSe x Te 1-x wherein 0<x<1.
Claim 4
Dependent Claim
9 words
The process of claim 1 wherein 0.9<y<1 and 0.80<z<1.0.
Claim 5
Dependent Claim
16 words
The process of claim 1, 2, or 3 wherein the lead halide is PbCl 2 .
Claim 6
Dependent Claim
24 words
The process of claim 1, 2, and 3 wherein the lead halide is heated at a temperature of from 190° C. to 210° C.
Claim 7
Dependent Claim
20 words
The process of claim 4 wherein the lead halide is heated at a temperature of from 190° to 210° C.