US4481046A — Method for making diffusions into a substrate and…

Claim 1

Independent Claim 98 words

A method for diffusing a conductivity determining impurity in a semiconductor substrate and making electrical contact thereto comprising: depositing a conductive layer of a rare earth hexaboride material containing a predetermined amount of silicon in it over a predetermined surface portion of said substrate; heating said substrate for a predetermined period of time at a predetermined temperature sufficient to cause boron from said hexaboride material to diffuse into said portion of said substrate so as to modify the conduction characteristics of said portion and to establish an electrical ohmic contact between said conductive layer and said substrate portion.

Claim 2

Independent Claim 98 words

A method for diffusing a conductivity determining impurity in a semiconductor substrate and making electrical contact thereto comprising: depositing a conductive layer of a rare earth hexaboride material containing a predetermined amount of silicon in it over a predetermined surface portion of said substrate; heating said substrate for a predetermined period of time at a predetermined temperature sufficient to cause boron from said hexaboride material to diffuse into said portion of said substrate so as to modify the conduction characteristics of said portion and to establish an electrical ohmic contact between said conductive layer and said substrate portion.

Claim 3

Dependent Claim 34 words

A method as set forth in claim 1, wherein silicon from said conductive layer is oxidized during said heating step to form a silicon dioxide layer over the exposed surfaces of said conductive layer.

Claim 4

Dependent Claim 24 words

A method as set forth in claim 1 whereing said rare earth hexaboride material is deposited over said substrate portion in a predetermined pattern.

Claim 5

Dependent Claim 52 words

A method as set forth in claim 3 wherein said predetermined pattern is formed by forming a layer of an electrically insulating material on a surface of said substrate and then etching away portions of said insulating material to expose portions of said substrate with said exposed portions forming said predetermined pattern.

Claim 6

Dependent Claim 30 words

A method as set forth in claim 1 wherein said rare earth hexaboride containing silicon is one selected from the group consisting of: YB 6 Si, and LaB 6 Si.

Claim 7

Dependent Claim 27 words

A method as set forth in claim 1 wherein said rare earth hexaboride material contains silicon having an atomic percentage in the range between 2 to 25%.

Claim 8

Independent Claim 84 words

A method for making semiconductor devices wherein a conductive layer makes electrical contact with a predetermined region in a semiconductor substrate characterized in that said conductive layer is made of a rare earth hexaboride material containing a predetermined quantity of silicon and in that boron from said conductive material outdiffuses during a heating cycle into said predetermined region so as to modify the conduction characteristics of said region and to establish a low resistance ohmic contact between said conductor layer and said substrate region.

Claim 9

Independent Claim 84 words

A method for making semiconductor devices wherein a conductive layer makes electrical contact with a predetermined region in a semiconductor substrate characterized in that said conductive layer is made of a rare earth hexaboride material containing a predetermined quantity of silicon and in that boron from said conductive material outdiffuses during a heating cycle into said predetermined region so as to modify the conduction characteristics of said region and to establish a low resistance ohmic contact between said conductor layer and said substrate region.

Claim 10

Dependent Claim 41 words

A method as set forth in claim 7 which is further characterized in that silicon from certain portions of said conductive layer oxidize during said heating cycle to form a silicon dioxide layer over the exposed surfaces of said conductive layer.

Claim 11

Dependent Claim 30 words

A method as set forth in claim 8 wherein said rare earth boride is a rare earth hexaboride selected from the group consisting of LaB 6 and YB 6 .

Claim 12

Independent Claim 132 words

A method for forming an interconnect conductor structure on a semiconductor substrate and forming doped regions in said substrate and electrical contacts between said conductor structure and said doped regions characterized in that said conductor structure comprises a layer of a rare earth earth hexaboride material containing a predetermined amount of silicon in it disposed over portions of said substrate and in direct contact with said substrate over predetermined substrate regions and in that boron from said rare earth hexaboride material outdiffuses during a heating cycle of predetermined time and temperature, from said conductor structure and into said predetermined substrate regions to thereby modify the conductive characteristics of said substrate regions through the addition of this P-type impurity and to establish ohmic electric contacts between said conductor structure and said substrate regions.

Claim 13

Independent Claim 132 words

A method for forming an interconnect conductor structure on a semiconductor substrate and forming doped regions in said substrate and electrical contacts between said conductor structure and said doped regions characterized in that said conductor structure comprises a layer of a rare earth earth hexaboride material containing a predetermined amount of silicon in it disposed over portions of said substrate and in direct contact with said substrate over predetermined substrate regions and in that boron from said rare earth hexaboride material outdiffuses during a heating cycle of predetermined time and temperature, from said conductor structure and into said predetermined substrate regions to thereby modify the conductive characteristics of said substrate regions through the addition of this P-type impurity and to establish ohmic electric contacts between said conductor structure and said substrate regions.

Claim 14

Independent Claim 38 words

A method for making semiconductor devices wherein a conductive layer is patterned to make electrical contact with predetermined regions of said devices characterized in that said conductive layer is made of a silicon containing rare earth hexaboride material.

Claim 15

Independent Claim 38 words

A method for making semiconductor devices wherein a conductive layer is patterned to make electrical contact with predetermined regions of said devices characterized in that said conductive layer is made of a silicon containing rare earth hexaboride material.

Claim 16

Dependent Claim 23 words

A method as set forth in claim 11, which is further characterized by forming an oxidation preventing capping layer over said conductive layer.

Claim 17

Dependent Claim 17 words

A method as set forth in claim 12, wherein said oxidation preventing layer is made of silicon.

Claim 18

Dependent Claim 24 words

A method as set forth in claim 13, wherein said oxidation preventing layer comprises a layer of silicon covered by a phospho-silicate glass material.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-11-06	1988-05-07	1988-11-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-11-06	1992-05-07	1992-11-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-11-06	1996-05-07	1996-11-06	$7700.00	Window Closed / Lapsed

Method for making diffusions into a substrate and electrical connections thereto using silicon containing rare earth hexaboride materials

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