Compressively stresses titanium metallurgy for contacting passivated semiconductor devices

• US 4,514,751 A
• Filed: 12/23/1982
• Issued: 04/30/1985
• Est. Priority Date: 12/23/1982
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bhattacharya, Somnath
• Primary Examiner(s): Edlow, Martin H.
• Assistant Examiner(s): JACKSON JR, JEROME
• Application Number:
  US06/452,542
• Time in Patent Office: 859 Days
• Field of Search: 357/71, 357/67, 252/62.3 BT, 252/507, 252/520
• US Class Current: 257/737
• CPC Class Codes: B23K 35/001 Interlayers, transition pieces for metallurgical bonding of workpieces
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05024 the internal layer being disposed on a redistribution layer on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 23/532 characterised by the materials
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01018 Argon [Ar]
• CPC Class Codes: H01L 2924/01022 Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01042 Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01044 Ruthenium [Ru]
• CPC Class Codes: H01L 2924/01061 Promethium [Pm]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits

Abstract

Contact metallurgy is disclosed for passivated semiconductor devices. The metallurgy comprises a compressively stressed, oxygen-containing titanium underlayer covered by a solder-bondable layer extending through via holes in dielectric material on the semiconductor device. The solder bondable layer is either nickel or ruthenium, where lower current densities are encountered or a composite of layers of copper, titanium, copper and gold for higher current densities.

Claims

1. Contact metallurgy for an integrated semiconductor substrate having circuit elements therein, comprising:

a dielectric coating on said substrate having an aperture therethrough for electrical connection to a said element in said substrate;

a contact pad comprising

a first layer of compressively stressed titanium covering said aperture and having peripheral portions extending on and bonded to said coating externally of said aperture, with said titanium having oxygen dispersed therein, and

a second layer of solder bondable contact metallurgy concentrically formed on said first layer.

2. The structure of claim 1 wherein the thickness of said titanium is in the range of 2 to 20K angstroms.

3. The structure of claim 1 including a solder mound on said pad.

4. The structure of claim 1 wherein said coating is selected from the group of glass, quartz, silicon dioxide and polymide compositions.

5. The structure of claim 1 wherein said second layer comprises sequential films of copper, titanium, copper and gold.

6. The structure of claim 5 including a solder mound on said pad.

7. The structure of claim 5 wherein the thicknesses of said films are in the ranges of 10K-30K, 2K-5K, 1K-3K and 1K angstroms, respectively.

8. The structure of claim 1 wherein said second layer comprises a layer of nickel or ruthenium.

9. The structure of claim 8 including a solder mound on said pad.

10. The structure of claim 8 wherein the thickness of said second layer is in the range of 2-5K angstroms of ruthenium.

11. The structure of claim 1 wherein the oxygen is dispersed in said compressively stressed titanium by evaporation in an oxygen-containing ambient at a partial pressure between 5×

10^-5 and 5×

10^-6 Torr at a temperature in the range of 100°

C. to 300°

C.