Systematic Low Temperature Silicon Bonding using Pressure and Temperature

Abstract

We have developed a systematic three-step process to low temperature direct bond silicon and/or SiO₂ surfaces. The process activates the surface with ammonia, argon and oxygen plasma. While these activation processes allow a very strong low temperature bond to be created, they require techniques distinctly different from those found in previous work for reproducible results. The plasma processes do not result in a bond that propagates as a wave resulting from a point source initiation. A substantial pressure is required to initiate the bond. We have found that a three-step process using pressure and temperature results in very strong, reproducible bonds.