Bonding of integrated circuit chip to carrier using gold/tin eutectic alloy and refractory metal barrier layer to block migration of tin through via holes
US5156998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1991 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Sep 30, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/913
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A gallium arsenide monolithic microwave integrated circuit (MMIC) chip (12) has microelectronic devices (16,18) formed on a frontside surface (12a), and via holes (12c,12d) formed through the chip (12) from the frontside surface (12a) to the backside surface (12b). The backside surface (12b) of the chip (12) is bonded to a molybdenum carrier (14) by an eutectic gold/tin alloy (20). A barrier layer (22) including a refractory metal nitride material (22a) is sputtered onto the backside surface (12b) and into the via holes (12c,12d) of the chip (12) prior to bonding. The barrier layer (22) blocks migration of tin from the eutectic gold/tin alloy (20) through the via holes 12c,-12d) to the frontside surface (12a) of the chip (12) during the bonding operation, thereby preventing migrated tin from adversely affecting the microelectronic devices (16,18 ).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.