Wafer bonding machine yields 3D integrated LSI ICs

Mitsubishi Heavy Industries Ltd (MHI) has announced what it touts as the world's first fully automated 12in (300mm) wafer bonding machine that can produce 3D integrated large-scale integration (LSI) circuits at room temperature. The Bond Meister MWB-12-ST offers the ability to eliminate heat stress and strain in the bonding process and help achieve high productivity, stated the company.

Instead of a conventional ion beam gun, the Bond Meister MWB-12-ST adopts a fast atom beam (FAB) gun to irradiate atoms for activating a material surface to bond. Whereas an ion gun radiates an argon ion beam, an FAB gun radiates a neutral atom beam of argon. The FAB gun that features about 20 times greater energy per particle than an ion gun is capable of effectively removing oxide film on the surface of the bonding metal material that normally impedes bonding, MHI described.

The system can bond continuously up to five 12in wafers and can perform wafer transfer and alignment for automatic bonding. The machine is also capable of preliminarily setting the bonding conditions for each wafer individually to accommodate production of various types in small lots.

The room-temperature bonding technology enables secure alignment with higher accuracy than heated bonding and realizes repeated wafer-layer bonding without heat stress. MHI also looks to contribute to efforts to further enhance the capacity and performance of LSIs, which currently face limitations in miniaturization, added the company.