Method for forming a grown bipolar electrode contact using a sidewall seed

Claim 1

A method for forming an electrical contact to a bipolar transistor electrode comprising the steps of: providing a substrate; forming a layer of material having a top surface and overlying the substrate; forming a contact opening in the layer of material wherein the contact opening exposes a portion of the substrate and has a sidewall, said contact opening having a first radius; forming a conductive region within the substrate, the conductive region functioning as a portion of said bipolar transistor electrode; forming a sidewall selective source material adjacent the sidewall of the contact opening, the sidewall selective source material reducing the contact opening from the first radius to a second radius wherein the second radius is smaller than the first radius; and forming a conductive contact region within the contact opening by growing the conductive contact region using the sidewall selective source material as a growth source, the conductive contact region forming said electrical contact to the bipolar transistor electrode in a reduced growth time due to reduction in radius of the contact opening.

Claim 2

A method for forming an electrical contact to a bipolar transistor electrode comprising the steps of: providing a substrate; forming a layer of material having a top surface and overlying the substrate; forming a contact opening in the layer of material wherein the contact opening exposes a portion of the substrate and has a sidewall, said contact opening having a first radius; forming a conductive region within the substrate, the conductive region functioning as a portion of said bipolar transistor electrode; forming a sidewall selective source material adjacent the sidewall of the contact opening, the sidewall selective source material reducing the contact opening from the first radius to a second radius wherein the second radius is smaller than the first radius; and forming a conductive contact region within the contact opening by growing the conductive contact region using the sidewall selective source material as a growth source, the conductive contact region forming said electrical contact to the bipolar transistor electrode in a reduced growth time due to reduction in radius of the contact opening.

Claim 10

A method for forming an electrical contact to a bipolar transistor electrode comprising the steps of: providing a silicon substrate; forming a layer of material having a top surface and overlying the silicon substrate; etching an opening in the layer of material wherein the opening has a volume, exposes a portion of the silicon substrate to form an exposed silicon substrate portion, defines placement of the electrical contact, and has a sidewall; forming a conductive region within the exposed silicon substrate portion, the conductive region functioning as said bipolar transistor electrode; forming an etch stop layer within the opening; depositing a layer of conductive material which comprises silicon; etching the layer of conductive material selective to the etch stop layer to form a conductive sidewall spacer which is adjacent the sidewall of the opening and which reduces said volume of the opening, the conductive sidewall spacer comprising silicon; and growing a conductive contact region, which comprises silicon, within the opening by using the conductive sidewall spacer as a source for growth, the conductive contact region forming said electrical contact to the bipolar transistor electrode.

Claim 11

A method for forming an electrical contact to a bipolar transistor electrode comprising the steps of: providing a silicon substrate; forming a layer of material having a top surface and overlying the silicon substrate; etching an opening in the layer of material wherein the opening has a volume, exposes a portion of the silicon substrate to form an exposed silicon substrate portion, defines placement of the electrical contact, and has a sidewall; forming a conductive region within the exposed silicon substrate portion, the conductive region functioning as said bipolar transistor electrode; forming an etch stop layer within the opening; depositing a layer of conductive material which comprises silicon; etching the layer of conductive material selective to the etch stop layer to form a conductive sidewall spacer which is adjacent the sidewall of the opening and which reduces said volume of the opening, the conductive sidewall spacer comprising silicon; and growing a conductive contact region, which comprises silicon, within the opening by using the conductive sidewall spacer as a source for growth, the conductive contact region forming said electrical contact to the bipolar transistor electrode.

Claim 16

A method for forming a self-aligned electrical contact region to a bipolar transistor electrode comprising the steps of: providing a silicon substrate; forming a dielectric layer of material overlying the silicon substrate, the dielectric layer of material having a top surface; forming a contact opening in the dielectric layer of material wherein the contact opening exposes a portion of the silicon substrate to form an exposed portion of the silicon substrate and has a sidewall; forming a conductive doped region within the silicon substrate, the conductive doped region functioning as at least a portion of said bipolar transistor electrode; forming a sidewall spacer adjacent the sidewall of the contact opening, for the purpose of reducing the contact opening from a first radius to a smaller second radius to reduce contact opening volume; growing a conductive epitaxial region to fill a portion of the contact opening by using the sidewall spacer and a portion of the exposed portion of the silicon substrate as a source for growth, the conductive epitaxial region forming said electrical contact to at least a portion of said bipolar transistor electrode; and overgrowing the conductive epitaxial region laterally over the top surface of the dielectric layer of material to form said self-aligned electrical contact region for the bipolar transistor electrode, the self-aligned electrical contact region at least partially overlying the conductive doped region.

Claim 17

A method for forming a self-aligned electrical contact region to a bipolar transistor electrode comprising the steps of: providing a silicon substrate; forming a dielectric layer of material overlying the silicon substrate, the dielectric layer of material having a top surface; forming a contact opening in the dielectric layer of material wherein the contact opening exposes a portion of the silicon substrate to form an exposed portion of the silicon substrate and has a sidewall; forming a conductive doped region within the silicon substrate, the conductive doped region functioning as at least a portion of said bipolar transistor electrode; forming a sidewall spacer adjacent the sidewall of the contact opening, for the purpose of reducing the contact opening from a first radius to a smaller second radius to reduce contact opening volume; growing a conductive epitaxial region to fill a portion of the contact opening by using the sidewall spacer and a portion of the exposed portion of the silicon substrate as a source for growth, the conductive epitaxial region forming said electrical contact to at least a portion of said bipolar transistor electrode; and overgrowing the conductive epitaxial region laterally over the top surface of the dielectric layer of material to form said self-aligned electrical contact region for the bipolar transistor electrode, the self-aligned electrical contact region at least partially overlying the conductive doped region.