Method of formation of semiconductor gate dielectric

Claim 1

A method for forming a semiconductor gate dielectric comprising the steps of: providing a base layer having a surface; exposing the base layer to an elevated temperature wherein the elevated temperature is at least 50° C. above room temperature; simultaneously exposing the base layer to an environment containing oxygen while at the elevated temperature; growing a thermal oxide from the base layer in response to the elevated temperature and exposure to the environment; exposing the thermal oxide to a nitrogen containing environment to form an oxynitride from the thermal oxide, wherein the step of exposing the thermal oxide to a nitrogen containing environment occurs during a same time that the base layer is exposed to the environment containing oxygen so that nitrogen is incorporated into the thermal oxide to form the oxynitride layer while the thermal oxide is being grown whereby an oxynitride layer is formed on and in contact with the base layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the base layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the nitrogen concentration of the nitrogen interface region being greater than a concentration of nitrogen at a top surface of the oxynitride layer; and forming a deposited dielectric layer overlying the first dielectric region, the deposited dielectric being a deposited oxide layer.

Claim 2

A method for forming a semiconductor gate dielectric comprising the steps of: providing a base layer having a surface; exposing the base layer to an elevated temperature wherein the elevated temperature is at least 50° C. above room temperature; simultaneously exposing the base layer to an environment containing oxygen while at the elevated temperature; growing a thermal oxide from the base layer in response to the elevated temperature and exposure to the environment; exposing the thermal oxide to a nitrogen containing environment to form an oxynitride from the thermal oxide, wherein the step of exposing the thermal oxide to a nitrogen containing environment occurs during a same time that the base layer is exposed to the environment containing oxygen so that nitrogen is incorporated into the thermal oxide to form the oxynitride layer while the thermal oxide is being grown whereby an oxynitride layer is formed on and in contact with the base layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the base layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the nitrogen concentration of the nitrogen interface region being greater than a concentration of nitrogen at a top surface of the oxynitride layer; and forming a deposited dielectric layer overlying the first dielectric region, the deposited dielectric being a deposited oxide layer.

Claim 7

A method for forming a semiconductor gate dielectric comprising the steps of: providing a silicon-containing layer having a surface; exposing the silicon-containing layer to an elevated temperature wherein the elevated temperature is at least 50° C. above room temperature; simultaneously exposing the silicon-containing layer to an environment containing oxygen while at the elevated temperature; growing a thermal oxide from the silicon-containing layer in response to the elevated temperature and exposure to the environment; exposing the thermal oxide to a nitrogen containing environment to form an oxynitride from the thermal oxide wherein the step of exposing the thermal oxide to a nitrogen containing environment occurs during a same time that the silicon-containing layer is exposed to the environment containing oxygen so that nitrogen is incorporated into the thermal oxide to form the oxynitride layer while the thermal oxide is being grown whereby an oxynitride layer is formed on and in contact with the silicon-containing layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the silicon-containing layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the dielectric region of the oxynitride layer being a thermally grown layer, the oxynitride layer having micropores; and forming a deposited dielectric layer overlying the first dielectric region the deposited dielectric layer having micropores that are misaligned to the micropores of the oxynitride layer.

Claim 8

A method for forming a semiconductor gate dielectric comprising the steps of: providing a silicon-containing layer having a surface; exposing the silicon-containing layer to an elevated temperature wherein the elevated temperature is at least 50° C. above room temperature; simultaneously exposing the silicon-containing layer to an environment containing oxygen while at the elevated temperature; growing a thermal oxide from the silicon-containing layer in response to the elevated temperature and exposure to the environment; exposing the thermal oxide to a nitrogen containing environment to form an oxynitride from the thermal oxide wherein the step of exposing the thermal oxide to a nitrogen containing environment occurs during a same time that the silicon-containing layer is exposed to the environment containing oxygen so that nitrogen is incorporated into the thermal oxide to form the oxynitride layer while the thermal oxide is being grown whereby an oxynitride layer is formed on and in contact with the silicon-containing layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the silicon-containing layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the dielectric region of the oxynitride layer being a thermally grown layer, the oxynitride layer having micropores; and forming a deposited dielectric layer overlying the first dielectric region the deposited dielectric layer having micropores that are misaligned to the micropores of the oxynitride layer.

Claim 11

A method for forming a semiconductor gate dielectric comprising the steps of: providing a silicon-containing layer having a surface; forming an oxynitride layer on and in contact with the silicon-containing layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the silicon-containing layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the dielectric region of the oxynitride layer being a thermally grown layer; forming a deposited dielectric layer overlying the oxynitride layer wherein the deposited dielectric layer is formed by a tetraethlyorthosilicate (TEOS) chemical vapor deposition (CVD) process, the deposited dielectric layer and the oxynitride layer having a common interface wherein a nitrogen concentration at this common interface is less than the nitrogen concentration of the nitrogen interface region; and forming a polysilicon gate electrode overlying a top portion of the deposited dielectric layer, wherein the nitrogen interface region is formed so that the nitrogen interface region is not directly in contact with a portion of the polysilicon gate electrode.

Claim 12

A method for forming a semiconductor gate dielectric comprising the steps of: providing a silicon-containing layer having a surface; forming an oxynitride layer on and in contact with the silicon-containing layer, the oxynitride layer comprising both a nitrogen interface region at the surface of the silicon-containing layer which has a nitrogen concentration and a dielectric region which overlies the nitrogen interface region and has a nitrogen concentration which is less than the nitrogen concentration of the nitrogen interface region, the dielectric region of the oxynitride layer being a thermally grown layer; forming a deposited dielectric layer overlying the oxynitride layer wherein the deposited dielectric layer is formed by a tetraethlyorthosilicate (TEOS) chemical vapor deposition (CVD) process, the deposited dielectric layer and the oxynitride layer having a common interface wherein a nitrogen concentration at this common interface is less than the nitrogen concentration of the nitrogen interface region; and forming a polysilicon gate electrode overlying a top portion of the deposited dielectric layer, wherein the nitrogen interface region is formed so that the nitrogen interface region is not directly in contact with a portion of the polysilicon gate electrode.