The Bond Meister MWB-12-ST, from Mitsubishi Heavy Industries Ltd (MHI), is the world’s first fully automated 12-inch (300 millimeters) wafer bonding machine that can produce 3-dimensionally integrated LSI (large-scale integration) circuits at room temperature. The wafer bonding machine is able to undertake continuous bonding of up to five 12-inch wafers and can perform wafer transfer and alignment for automatic bonding. The HI system is also capable of preliminarily setting the bonding conditions for each wafer individually, to accommodate production of various types in small lots.
The Bond Meister MWB-12-ST wafer bonding machine. does not use a conventional ion beam gun. Instead, it uses a fast atom beam (FAB) gun to irradiate atoms for activating a material surface to bond. While an ion gun radiates an argon ion beam, a FAB gun radiates a neutral atom beam of argon. The FAB gun, which 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. Up to 20-ton weight loading is applicable for bonding.
The Mitsubishi system bonds various materials, such as silicon and metals, at room temperature by radiating an ion or atom beam on the surface of the bonding material. This process has conventionally been performed by heating. By eliminating the heating process, room-temperature bonding not only frees devices from heat stress and strain, thereby enabling rigid and highly reliable bonding, but also reduces processing time by eliminating the need for a heating/cooling cycle. These advantages, coupled with automated wafer alignment, enable room-temperature bonding to achieve significantly shorter production time and a higher yield ratio. As a result, the Bond Meister MWB-12-ST reduces device production costs.
Today, ongoing size reduction and further functionality enhancement of electronic hardware are supported by large-capacity, high-performance LSIs. As further enhancement of LSI integration through miniaturization on two-dimensional (plane) surfaces is reaching a limit, 3-D integration is seen as a promising breakthrough technology to solve this matter. With 3-D LSI circuits, the key lies in achieving technologies for creating electrodes through multiple layers, in order to send signals between layered wafers, and for bonding electrodes with high reliability. MHI’s room-temperature bonding technology enables secure alignment with higher accuracy than heated bonding and realizes repeated wafer-layer bonding without heat stress.
More info: Mitsubishi Heavy Industries