Thin film metallization process for improved metal to substrate adhesion

• US 5,631,498 A
• Filed: 05/19/1995
• Issued: 05/20/1997
• Est. Priority Date: 06/04/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hayunga, Carl P., Ormond, Douglas W., Anschel, Morris
• Primary Examiner(s): Saadat, Mahshid D.
• Assistant Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US08/444,667
• Time in Patent Office: 732 Days
• Field of Search: 257/690, 257/697, 257/758, 257/750, 257/730, 257/754, 257/753, 257/759, 257/792, 257/762, 257/766, 257/700
• US Class Current: 257/690
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/4847 the connecting portion on the bonding area of the semiconductor or solid-state body being a wedge bond
• CPC Class Codes: H01L 23/49866 characterised by the materials materials of the substrates H01L23/14, of the lead-frames H01L23/49579
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/2075 larger or equal to 1 micron less than 10 microns
• CPC Class Codes: H01L 2924/20754 larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/20755 larger or equal to 50 microns less than 60 microns
• CPC Class Codes: H05K 2201/2063 mixed adhesion layer containing metallic/inorganic and polymeric materials
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer

Abstract

A metallization layer is formed on a substrate with improved adhesion thereto by performing the deposition at an elevated temperature which favors the formation of chemical bonds of the metal to the substrate as well as clusters of metal embedded within the substrate and contiguous with the metallization layer. In polymer substrates the chemical bond is made to carbonyl functional groups such as ketones or aldehydes. The adhesion is enhanced by the removal of moisture from the surface of the substrate at the elevated temperatures employed. A high degree of adhesion is also obtained through the deposition of a mixture of metals including chromium and copper which initially has a high chromium to copper ratio which is decreased during the deposition process. Completion of the process is determined by the reaching of a final desired chromium to copper ratio as observed by optical emission spectroscopy. The process can be carried out on a continuous basis by the use of a multi-chamber vacuum sputtering system.

Claims

1. An electronic circuit module including a metallization layer formed on an exterior surface of said electronic circuit module, said metallization layer of metal containing a mixture of chromium and copper in a ratio in a range of 0.3:

1 to 3.0;

1 including clusters of said metal embedded within said electronic circuit module adjacent said exterior surface.

2. An electronic circuit module as recited in claim 1, wherein said metallization layer forms a pad.

3. An electronic circuit module as recited in claim 1, wherein said metallization layer forms a mounting surface for a connection pin.