Dopant Precursors and Processes
AssigneeASM America, Inc.
InventorMichael A. Todd
Life of this patent
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Abstract
Abstract of Disclosure Silicon alloys and doped silicon films are prepared by chemical vapor deposition and ion implantation processes using Si-containing chemical precursors as sources for Group III and Group V atoms. Preferred dopant precursors include (H3Si)3-xMRx, (H3Si)3N, and (H3Si)4N2, wherein R is H or D, x = 0, 1 or 2, and M is selected from the group consisting of B, P, As, and Sb. Preferred deposition methods produce non-hydrogenated silicon alloy and doped Si-containing films, including crystalline films.
Claims50
A deposition process for making a non-hydrogenated Si-containing film, comprising:
- providing a vapor deposition chamber having a substrate disposed therein;
- introducing a dopant precursor to the chamber, wherein the dopant precursor comprises at least one silicon atom and at least one Group III or Group V atom;
- and
- depositing a non-hydrogenated Si-containing film onto the substrate.
The process of Claim 1, wherein the dopant precursor has the form (H3Si)3-xMRx, and wherein R is H or D, x = 0, 1 or 2, and M is selected from the group consisting of B, P, As, and Sb.
The process of Claim 2, further comprising introducing a silicon source to the chamber.
The process of Claim 3, wherein the silicon source is selected from the group consisting of silane, disilane and trisilane.
The process of Claim 2, wherein the dopant precursor is selected from the group consisting of trisilylarsine and trisilylphosphine.
The process of Claim 5, wherein the Si-containing film is an alloy comprising an amount of silicon in the range of about 50 atomic % to about 99.9 atomic %.
The process of Claim 5, wherein the Si-containing film comprises an amount of arsenic or phosphorous in the range of about 1 part per billion to about 1,000 parts per million.
The process of Claim 2, wherein the Si-containing film is a crystalline film.
The process of Claim 8, wherein the Si-containing film is an epitaxial film.
The process of Claim 2, wherein the Si-containing film is a solid diffusion source.
The process of Claim 1, wherein the Si-containing film is deposited by thermal chemical vapor deposition.
The process of Claim 11, wherein the dopant precursor is selected from the group consisting of (H3Si)3N and (H3Si)2N2.
The process of Claim 12, further comprising introducing a carbon source and a silicon source to the chamber to thereby deposit a nitrogen-doped SiC film as the non-hydrogenated Si-containing film.
The process of Claim 1, wherein the Si-containing film is deposited by plasma-enhanced chemical vapor deposition.
The process of Claim 1, wherein the Si-containing film is deposited at a temperature of about 400°C or greater.
The process of Claim 1, wherein the Si-containing film is deposited at a temperature in the range of about 450°C to about 700°C.
The process of Claim 1, wherein the Si-containing film contains about 5 atomic % hydrogen or less.
The process of Claim 1, wherein the Si-containing film contains about 2 atomic % hydrogen or less.
The process of Claim 1, further comprising introducing an oxygen-containing pulse to the chamber, wherein the dopant precursor is selected from the group consisting of trisilylamine and tetrasilylhydrazine, and wherein the non-hydrogenated Si-containing film is deposited by atomic layer deposition.
The process of Claim 19, wherein the dopant precursor is trisilylamine.
The process of Claim 1, further comprising introducing a germanium source to the chamber.
The process of Claim 1, wherein the Si-containing film comprises a material selected from the group consisting of doped amorphous silicon, doped polysilicon, doped epitaxial silicon, doped SiC, doped SiGe, and doped SiGeC.
A chemical vapor deposition process for making an at least partially crystalline Si-containing film, comprising
- providing a chemical vapor deposition chamber having a substrate disposed therein,
- introducing a silicon source and a dopant precursor to the chamber, wherein the dopant precursor is comprised of at least one silicon atom and at least one Group III or Group V atom, and
- depositing a doped Si-containing film onto the substrate.
The process of Claim 23, wherein the substrate is maintained at a temperature between about 550°C and about 700°C and the film is at least partially crystalline as deposited.
The process of Claim 23, wherein the silicon source is selected from the group consisting of silane, disilane and trisilane.
The process of Claim 25, wherein the dopant precursor is selected from the group consisting of trisilylarsine and trisilylphosphine.
The process of Claim 26, wherein the doped Si-containing film comprises an amount of arsenic or phosphorous in the range of about 1 part per billion to about 1,000 parts per million.
The process of Claim 23, further comprising introducing a carbon source to the chamber to thereby deposit a nitrogen-doped SiC film as the doped Si-containing film.
The process of Claim 28, wherein the dopant precursor is selected from the group consisting of (H3Si)3N and (H3Si)4N2.
The process of Claim 29, wherein the dopant precursor is (H3Si)3N.
The process of Claim 23, wherein the doped Si-containing film is a single crystal.
The process of Claim 23, further comprising introducing a germanium source to the chamber.
The process of Claim 23, wherein the doped Si-containing film is amorphous as deposited, further comprising:
- heating the doped amorphous Si-containing film to a temperature in the range of about 550°C to about 700°C for a period of time effective to at least partially crystallize the doped amorphous Si-containing film.
The process of Claim 33, wherein the doped amorphous Si-containing film is deposited by plasma-enhanced chemical vapor deposition.
The process of Claim 33, wherein the doped amorphous Si-containing film is non-hydrogenated.
The process of Claim 33, wherein the dopant precursor is selected from the group consisting of trisilylarsine and trisilylphosphine.
The process of Claim 36, wherein the silicon source is selected from the group consisting of silane, disilane and trisilane.
The process of Claim 36, wherein the doped Si-containing film comprises an amount of arsenic or phosphorous in the range of about 1 part per billion to about 1,000 parts per million.
The process of Claim 33, wherein the period of time for the heating of the doped Si-containing film is in the range of about 2 minutes to about 1 hour.
An ion implantation process for making a doped Si-containing film, comprising
- providing a Si-containing film on a substrate,
- providing an ionization chamber upstream of the substrate,
- introducing a dopant precursor to the ionization chamber, wherein the dopant precursor comprises at least one silicon atom and at least one Group III or Group V atom,
- ionizing at least a portion of the dopant precursor to form dopant excited species by applying electromagnetic energy to the dopant precursor,
- applying a magnetic field to the dopant excited species to create a sub-population of mass-selected dopant excited species, and
- directing at least a portion of the sub-population of mass-selected dopant excited species onto the Si-containing film to produce a doped Si-containing film.
The process of Claim 40, wherein the Si-containing film is a crystalline film.
The process of Claim 41, wherein the crystalline film is a silicon carbide film and the dopant precursor is selected from the group consisting of (H3Si)3N and (H3Si)4N2.
The process of Claim 40, wherein the dopant precursor is selected from the group consisting of (H3Si)3-xMRx, (H3Si)3N, and (H3Si)4N2, wherein R is H or D, x = 0, 1 or 2, and M is selected from the group consisting of B, P, As, and Sb.
The process of Claim 43, wherein the dopant precursor is selected from the group consisting of trisilylarsine and trisilylphosphine.
The process of Claim 43, wherein the dopant precursor is (H3Si)3N.
The process of Claim 40, further comprising heating the doped Si-containing film to a temperature in the range of about 100°C to about 700°C.
A method for making a doped Si-containing film, comprising:
- providing a Si-containing film,
- forming a plasma from a gas comprising a dopant precursor selected from the group consisting of (H3Si)3-xMRx, (H3Si)3N, and (H3Si)4N2, wherein R is H or D, x = 0, 1 or 2, and M is selected from the group consisting of B, P, As, and Sb;
- and
- implanting active species of the dopant precursor from the plasma into the Si-containing film by ion implantation.
The process of Claim 47, wherein the dopant precursor is selected from the group consisting of trisilylarsine and trisilylphosphine.
The process of Claim 47, wherein implanting comprises a mass selection process.
The process of Claim 47, wherein implanting comprises plasma immersion.