Dual metal-insulator-semiconductor contact structure and formulation method

Patent metadata

Field	Value
Publication number	US-9735111-B2
Application number	US-201514862894-A
Country	US
Kind code	B2
Filing date	Sep 23, 2015
Priority date	Sep 23, 2015
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A method of making a semiconductor device includes forming a first source/drain trench and a second source/drain trench over a first and second source/drain region, respectively; forming a first silicon dioxide layer in the first source/drain trench and a second silicon dioxide layer in the second source/drain trench; forming a first source/drain contact over the first source/drain region, the first source/drain contact including a first tri-layer contact disposed between the first silicon dioxide layer and a first conductive material; and forming a second source/drain contact over the second source/drain region, the second source/drain contact including a second tri-layer contact disposed between the second silicon dioxide layer and a second conductive material; wherein the first tri-layer contact includes a first metal oxide layer in contact with the first silicon dioxide layer, and the second tri-layer contact includes a second metal oxide layer in contact with the second silicon dioxide layer.

First claim

What is claimed is:

1. A method of making a semiconductor device, the method comprising:
forming a first source/drain trench over a first source/drain region in a first transistor and a second source/drain trench over a second source/drain region in a second transistor;
forming a first silicon dioxide layer in the first source/drain trench and a second silicon dioxide layer in the second source/drain trench;
forming a first source/drain contact over the first source/drain region, the first source/drain contact comprising a first tri-layer contact disposed between the first silicon dioxide layer and a first conductive material; and
forming a second source/drain contact over the second source/drain region, the second source/drain contact comprising a second tri-layer contact disposed between the second silicon dioxide layer and a second conductive material;
wherein the first tri-layer contact comprises a first metal oxide layer in contact with the first silicon dioxide layer, and the second tri-layer contact comprises a second metal oxide layer in contact with the second silicon dioxide layer.

2. The method of claim 1 , wherein the first metal oxide layer is different than the second metal oxide layer.

3. The method of claim 1 , wherein the first metal oxide layer is aluminum oxide, and the second metal oxide layer is lanthanum oxide.

4. The method of claim 1 , further comprising disposing a conductive liner layer between the first silicon dioxide layer and the first tri-layer contact or the second silicon dioxide layer and the second tri-layer contact.

5. The method of claim 1 , wherein the conductive liner layer comprises titanium nitride.

6. The method of claim 1 , wherein the first tri-layer contact further comprises a layer of titanium disposed over the first metal oxide layer.

7. The method of claim 6 , wherein the first tri-layer contact further comprises a layer of titanium nitride disposed between the layer of titanium and the first conductive material.

8. The method of claim 1 , wherein the second tri-layer contact further comprises a layer of titanium disposed over the second metal oxide layer.

9. The method of claim 1 , wherein the second tri-layer contact further comprises a layer of titanium disposed over the second metal oxide layer and a layer of titanium nitride disposed between the layer of titanium and the second conductive material.

10. A method of making a semiconductor device, the method comprising:
forming a first source/drain trench over a first source/drain region in a first transistor and a second source/drain trench over a second source/drain region in a second transistor;
forming a first silicon dioxide layer in the first source/drain trench and a second silicon dioxide layer in the second source/drain trench;
disposing a first metal oxide layer onto the first silicon dioxide layer and along a first sidewall of the first source/drain trench and over the second silicon dioxide layer and along a sidewall of the second source/drain trench;
removing the first metal oxide layer from the second source/drain trench;
disposing a second metal oxide layer followed by a conductive liner layer over the first metal oxide layer within the first source/drain trench and directly onto the second silicon dioxide layer and along the sidewall of the second source/drain trench;
removing by a selective process, the second metal oxide layer and the conductive liner layer from the first source/drain trench; and
filling the first source/drain trench and the second source/drain trench with a conductive material.

11. The method of claim 10 , further comprising disposing a conductive layer over the first silicon dioxide layer within the first source/drain trench and removing the conductive layer from the first source/drain trench before disposing the first metal oxide layer.

12. The method of claim 10 , further comprising disposing a conductive layer over the second silicon dioxide layer within the second source/drain trench before disposing the first metal oxide layer, and then removing the conductive layer along with the first metal oxide layer.

13. The method of claim 10 , further comprising disposing a titanium layer and a titanium nitride layer between the conductive material and the first metal oxide layer within the first source/drain trench and between the conductive material and the second metal oxide layer within the second source/drain trench.

14. The method of claim 10 , further comprising removing the conductive liner layer before filling the first source/drain trench and the second source/drain trench with the conductive material.

15. The method of claim 10 , wherein the first metal oxide layer comprises aluminum oxide, and the second metal oxide layer comprises lanthanum oxide.

16. A method of making a semiconductor device, the method comprising:
forming a first source/drain trench over a first source/drain in a first transistor and a second source/drain trench over a second source/drain in a second transistor;
forming a first silicon dioxide layer in the first source/drain trench and a second silicon dioxide layer in the second source/drain trench, the first silicon dioxide layer directly contacting a top portion of the first source/drain, and the second silicon dioxide layer directly contacting a top portion of the second source/drain;
forming a first source/drain contact over the first source/drain, the first source/drain contact comprising a first tri-layer liner disposed between the first silicon dioxide layer and a first conductive material, the first tri-layer liner comprising a first metal oxide layer in contact with the first silicon dioxide layer; and
forming a second source/drain contact over the second source/drain, the second source/drain contact comprising a second tri-layer liner disposed between the second silicon dioxide layer and a second conductive material, the second tri-layer contact comprising a second metal oxide layer in contact with the second silicon dioxide layer;
wherein the first metal oxide layer is different than the second metal oxide layer.

Assignees

• IBM
• Globalfoundries Inc
• Globalfoundries Inc

Inventors

• Ando Takashi
• Niimi Hiroaki
• Yamashita Tenko

Classifications

• H10P14/69396

  the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium · CPC title

• H10P14/69391

  the material containing aluminium, e.g. Al2O3 · CPC title

• H10P14/69215

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

• H10P14/42

  using a gas or vapour · CPC title

• H10W20/081

  by forming openings in the dielectric parts · CPC title