Bonding of integrated circuit chip to carrier using gold/tin eutectic alloy and refractory metal nitride barrier layer to block migration of tin through via holes
US5378926A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1994 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Jan 10, 2014 |
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 a 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.