Method of fabrication of a semiconductor apparatus comprising substrates including Al/Ge and Cu contact layers to form a metallic alloy

• US 8,741,738 B2
• Filed: 06/08/2011
• Issued: 06/03/2014
• Est. Priority Date: 06/08/2011
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Su, Ching-Hou, Ni, Chyi-Tsong, Chiu, Yi Hsun, Chien, Ting-Ying
• Primary Examiner(s): Weiss, Howard
• Assistant Examiner(s): LOPEZ, CESAR OSWALDO
• Application Number:
  US13/156,052
• Publication Number:
  US 20120313246A1
• Time in Patent Office: 1,091 Days
• Field of Search: 257/616
• US Class Current: 438/455
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 2203/035 Soldering

Abstract

The disclosure relates to integrated circuit fabrication, and more particularly to a semiconductor apparatus with a metallic alloy. An exemplary structure for an apparatus comprises a first silicon substrate; a second silicon substrate; and a contact connecting each of the first and second substrates, wherein the contact comprises a Ge layer adjacent to the first silicon substrate, a Cu layer adjacent to the second silicon substrate, and a metallic alloy between the Ge layer and Cu layer.

Claims

1. A method of fabricating a semiconductor apparatus comprising:

providing a first silicon substrate having a first contact, wherein the first contact comprises a Ge layer interposed between the substrate and an Al layer;

providing a second silicon substrate having a second contact, wherein the second contact comprises a Cu layer as an outmost layer;

placing the first contact in contact with the second contact; and

heating the first and second contacts to form a metallic alloy, wherein the heating is performed at a temperature of about 420°

to 500°

C. and under a compressive force of about 45 to 55 kN.

2. The method of claim 1, wherein the metallic alloy comprises an alloy of Ge, Al, and Cu.

3. The method of claim 1, wherein a thickness ratio of the metallic alloy to the Cu layer is from about 0.2 to 2.

4. The method of claim 1, wherein one of the first or second silicon substrates comprises a micro-electro-mechanical system (MEMS) and the other substrate comprises a complementary metal-oxide-semiconductor (CMOS) circuit.

5. The method of claim 1, wherein the first silicon substrate comprises a micro-electro-mechanical system (MEMS) and the second silicon substrate comprises a complementary metal-oxide-semiconductor (CMOS) circuit.

6. The method of claim 1, wherein the Ge layer is formed using a low-pressure chemical vapor deposition (LPCVD) process.

7. The method of claim 6, wherein the LPCVD process is performed using GeH₄ as the Ge source gas.

8. The method of claim 1, wherein the Ge layer is formed using a sputtering process.

9. The method of claim 8, wherein the sputtering process is performed using Ge as a target and Ar as a sputtering gas.

10. A method of fabricating a semiconductor apparatus comprising:

forming a first contact over a first substrate, the first contact comprising Al and Ge that entirely cover a raised portion of the first substrate, wherein the forming the first contact comprises;

forming a Ge layer over the first substrate; and

forming an Al-containing layer over the Ge layer;

forming a second contact over a second substrate, the second contact comprising a Cu-containing layer;

placing the first contact in contact with the second contact; and

heating the first and second contacts to form a metallic alloy structure, wherein the heating is performed in a chamber at a temperature within a range from about 420°

C. to 500°

C.

11. The method of claim 10, wherein the heating is performed in the chamber under a compressive force ranging from about 45 kN to 55 kN.

12. The method of claim 10, wherein the formation of the metallic alloy structure is controlled to cause a thickness ratio of the metallic alloy structure to the Ge layer ranging from about 0.4 to 10.

13. The method of claim 10, wherein the formation of the metallic alloy structure is controlled to cause a thickness ratio of the metallic alloy structure to the Cu-containing layer ranging from about 0.2 to 2.

14. The method of claim 10, wherein the Ge layer is formed using a low-pressure chemical vapor deposition (LPCVD) process.

15. The method of claim 14, wherein the LPCVD process is performed using GeH₄ as the Ge source gas.

16. The method of claim 10, wherein the Ge layer is formed using a sputtering process.

17. The method of claim 16, wherein the sputtering process is performed using Ge as a target and Ar as a sputtering gas.

18. A method of fabricating a semiconductor apparatus comprising:

forming a first contact over a first substrate, the first contact comprising an Al-containing layer and a Ge layer between the Al-containing layer and the first substrate;

forming a second contact over a second substrate, the second contact comprising a Cu-containing layer;

placing the first contact in contact with the second contact; and

heating the first and second contacts to form a metallic alloy structure, wherein the heating is performed at a temperature that is greater than a eutectic temperature of Ge and Al and less than a eutectic temperature of Cu and Al.

19. The method of claim 18, wherein the heating is performed under a compressive force, applied to the first contact and the second contact, ranging from about 45 kN to 55 kN.