Method for providing silicide bridge contact between silicon regions separated by a thin dielectric

Claim 1

A process for forming a bridge contact between first silicon regions separated by a narrow insulator gap without forming a contact between second silicon regions separated by insulator gaps that are wider than the narrow insulator gap, comprising the steps of: providing a substrate having a plurality of first and second exposed silicon regions on an exposed surface thereof separated by a plurality of insulator regions, said first regions being separated by narrow insulator gaps and said second regions being separated by other insulator gaps appreciably wider than said narrow insulator gaps, at least some of said first and second regions comprising shallow diffusion regions; growing undoped silicon regions over said plurality of first and second regions by exposure to a deposition gas comprised of a silicon component and an etchant component, said silicon component and said etchant component being present at a ratio sufficient to allow said silicon to grow over said narrow insulator gaps without allowing said silicon to grow over said other insulator gaps, said undoped silicon regions being grown under conditions that do not appreciably vary dopant profiles of said shallow diffusion regions; depositing a refractory metal on said substrate, said refractory meal being of a thickness commensurate with that of said grown silicon regions; sintering said substrate to form silicide regions over said first and second regions as well as over said narrow insulator gaps without forming a silicide over said other insulator gaps; and removing unreacted portions of said refractory metal without appreciably etching said silicide regions.

Claim 14

A method for forming a bridge contact between silicon regions separated by a thin insulator gap, without coupling other silicon regions separated by insulator gaps appreciably greater than the thin insulator gap, comprising the steps of: forming a plurality of shallow diffusion regions and polycrystalline silicon regions on a monocrystalline silicon substrate, at least some of said shallow diffusion regions and polycrystalline silicon regions being separated by a thin insulator gap while others of said shallow diffusion regions and polycrystalline silicon regions being separated by other insulator gaps of a width substantially greater than said thin insulator gap; growing undoped silicon regions on said plurality of shallow diffusion regions and polycrystalline silicon regions and over said thin insulator gap without growing silicon over said thick insulator gap and without appreciably varying dopant profiles of said plurality of shallow diffusion regions, by exposure to a deposition gas comprising a silane-based gas and a halogen-based gas, said gases being present at a ratio between approximately 0.7:1 and 1.15:1; depositing a blanket layer of titanium of a thickness commensurate to that of said silicon regions on said substrate, said refractory metal layer being deposited under conditions that promote step coverage; heating the substrate in the presence of a nitrogen-based gas to form silicide regions over said silicon regions and over said thin insulator gap without forming a silicide region over said other insulator gaps; and removing unreacted portions of said refractory metal by exposure to an etchant that does not appreciably attack said silicide regions.

Claim 15

A method for forming a bridge contact between silicon regions separated by a thin insulator gap, without coupling other silicon regions separated by insulator gaps appreciably greater than the thin insulator gap, comprising the steps of: forming a plurality of shallow diffusion regions and polycrystalline silicon regions on a monocrystalline silicon substrate, at least some of said shallow diffusion regions and polycrystalline silicon regions being separated by a thin insulator gap while others of said shallow diffusion regions and polycrystalline silicon regions being separated by other insulator gaps of a width substantially greater than said thin insulator gap; growing undoped silicon regions on said plurality of shallow diffusion regions and polycrystalline silicon regions and over said thin insulator gap without growing silicon over said thick insulator gap and without appreciably varying dopant profiles of said plurality of shallow diffusion regions, by exposure to a deposition gas comprising a silane-based gas and a halogen-based gas, said gases being present at a ratio between approximately 0.7:1 and 1.15:1; depositing a blanket layer of titanium of a thickness commensurate to that of said silicon regions on said substrate, said refractory metal layer being deposited under conditions that promote step coverage; heating the substrate in the presence of a nitrogen-based gas to form silicide regions over said silicon regions and over said thin insulator gap without forming a silicide region over said other insulator gaps; and removing unreacted portions of said refractory metal by exposure to an etchant that does not appreciably attack said silicide regions.