Nitridation on HDP oxide before high-k deposition to prevent oxygen ingress

Patent metadata

Field	Value
Publication number	US-9412596-B1
Application number	US-201514609782-A
Country	US
Kind code	B1
Filing date	Jan 30, 2015
Priority date	Jan 30, 2015
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A method of reducing a migration of oxygen into a high-k dielectric layer of a semiconducting device is disclosed. An oxide layer of the semiconducting device is deposited on a substrate. A chemical composition of a top portion of the oxide layer is altered. The high-k dielectric layer is deposited on the top portion of the oxide layer to form the semiconducting device. The altered chemical composition of the top portion of the oxide layer reduces migration of oxygen into the high-k dielectric layer.

First claim

What is claimed is:

1. A method of reducing a migration of oxygen into a high-k dielectric layer of a semiconducting device, comprising:
forming a first dummy gate and a second dummy gate to define a first gap;
depositing an oxide layer of the semiconducting device on a substrate in the first gap;
altering a chemical composition of a top portion of the oxide layer;
removing the first dummy gate and the second dummy gate to define a second gap;
depositing the high-k dielectric layer on the top portion of the oxide layer and in the second gap, wherein the altered chemical composition of the top portion of the oxide layer reduces migration of oxygen into the high-k dielectric layer;
annealing the semiconducting device, wherein the top portion of the oxide layer prevents migration of oxygen from the oxide layer into the high-k dielectric layer during the annealing; and
removing a first segment of the high-k dielectric layer from the top portion of the oxide layer after the annealing of the semi-conducting device to dissociate the high-k dielectric layer from the oxide layer, wherein a second segment of the high-k dielectric layer lines the second gap to define a gate lining.

2. The method of claim 1 , wherein altering the chemical composition of the top portion of the oxide layer further comprises diffusing nitrogen into the top portion of the oxide layer.

3. The method of claim 2 , further comprising diffusing the nitrogen into the top portion by performing at least one of: nitrogen implantation; annealing under an ammonia (NH 3 ) ambient; a plasma treatment with nitrogen in the plasma; and a plasma treatment with ammonia in the plasma.

4. A method of reducing oxygen migration into a high-k dielectric layer of a transistor during manufacture of the transistor, comprising:
forming a first dummy gate and a second dummy gate on a substrate to define a first gap;
depositing an oxide layer of the transistor on the substrate in the first gap;
altering a chemical composition of a top portion of the oxide layer;
removing the first dummy gate and the second dummy gate to define a second gap;
depositing the high-k dielectric layer on the top portion of the oxide layer and in the second gap, wherein the altered chemical composition top portion of the oxide layer reduces migration of oxygen from the oxide layer into the high-k dielectric layer, and wherein the high-k dielectric layer is deposited onto surfaces of the substrate within the second gap;
annealing the transistor, wherein the top portion of the oxide layer prevents migration of oxygen from the oxide layer into the high-k dielectric layer during the annealing;
removing a first segment of the high-k dielectric layer from the top portion of the oxide layer after the annealing of the transistor to dissociate the high-k dielectric layer from the oxide layer, wherein a second segment of the high-k dielectric layer lines the second gap to define a gate lining;
depositing a titanium nitride layer over the high-k dielectric layer; and
depositing a low resistivity metal in the second gap to form the transistor.

5. The method of claim 4 , wherein the substrate includes at least one of a source of the transistor and the drain of the transistor formed therein.

6. The method of claim 4 , wherein altering the chemical composition of the top portion of the oxide layer further comprises diffusing nitrogen into the top portion of the oxide layer.

7. The method of claim 6 , further comprising diffusing the nitrogen into the top portion of the oxide layer by performing at least one of: nitrogen implantation; annealing under an ammonia (NH 3 ) ambient; a plasma treatment with nitrogen in the plasma; and a plasma treatment with ammonia in the plasma.

8. A method of manufacturing a high-k metal gate (HKMG) transistor, comprising:
forming a first dummy gate and a second dummy gate on a substrate to define a first gap;
depositing an oxide layer in the first gap;
altering a chemical composition of a top portion of the oxide layer;
removing the first dummy gate and the second dummy gate to define a second gap;
depositing a high-k dielectric layer on the top portion of the oxide material and in the second gap, wherein the altered chemical composition of the top portion of the oxide layer reduces migration of oxygen into the high-k dielectric layer;
annealing the HKMG transistor, wherein the top portion of the oxide layer prevents migration of oxygen from the oxide layer into the high-k dielectric layer during the annealing; and
removing a first segment of the high-k dielectric layer from the top portion of the oxide layer after the annealing of the semi-conducting device to dissociate the high-k dielectric layer from the oxide layer, wherein a second segment of the high-k dielectric layer lines the second gap and a portion of the substrate in the second gap to define a gate lining;
depositing a titanium nitride layer over the high-k dielectric layer; and
depositing a low resistivity metal in the second gap to form the transistor.

9. The method of claim 8 , wherein altering the chemical composition of the top portion of the oxide layer further comprises diffusing nitrogen into the top portion of the oxide layer.

10. The method of claim 9 , further comprising diffusing the nitrogen into the top portion of the oxide layer by performing at least one of: nitrogen implantation; annealing under an ammonia (NH 3 ) ambient; a plasma treatment with nitrogen in the plasma; and a plasma treatment with ammonia in the plasma.

Assignees

• IBM

Inventors

• Ando Takashi
• Basker Veeraraghavan S
• Faltermeier Johnathan E
• Jagannathan Hemanth
• Yamashita Tenko

Classifications

• H10P14/69394

  the material containing titanium, e.g. TiO2 · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6526 Primary

  introduced into an oxide material, e.g. changing SiO to SiON · CPC title

• H10P14/6502

  of treatments performed before formation of the materials · CPC title

• H10P14/6302

  Non-deposition formation processes · CPC title