Silicon Direct Bonding on Vacuum and Force

In this paper, the novel and low cost method for silicon-silicon bonding is introduced in detail. This direct silicon bonding process on the vacuum and force was developed which any commercial polished silicon wafers can be bonded, include P+ diffusion wafers, without CMP (chemical mechanical polishing) technology at room temperature by using IC technology standard clean. A simple low vacuum micro cleanroom in which uniform force is applied on the bonding wafers is designed for room temperature bonding. Bonding process can be monitored by an infrared (IR) camera system. The criteria for bonding quality evaluation are also presented. All of the process developed is good for MEMS practical application purpose. In this paper, it reports the investigation of low temperature silicon wafer fusion bonding for MEMS application. A bonding process utilizing annealing temperature between 400degC~1100degC was characterized. It was given the process of pressure sensor of Si-Si bonding use vacuum and force equipment and analysis the results using vacuum and force equipment in detail. The silicon-silicon bonded interface was analysed by infrared camera (IR) and scan electron microscope (SEM). The quality of silicon-silicon bonded was tested by etch in TMAH and KOH solution