Silicon on SiO/sub 2/ by two step thermal bonding (TSTB) process

Abstract

The bonding process and mechanism and the electrical and material properties of the Si on SiO/sub 2/ substrate produced by two-step thermal bonding technology are described. Experimental results on the relation between fracture strength and treatment temperature are reported. They show that the bonding process consists of two main steps. The first step is a low-temperature initial bonding process in which polymerization of silanol bonds occurs. The second step is a high-temperature process (900-1250 degrees C) in which the mutual-diffusion process acts as the primary means of grain boundary rearrangement and void elimination. The mating surface contact area grows to a large fraction of bonding area, which increases the fracture strength greatly. The experiments show that the process can be applied to other semiconductors and insulators, such as GaAs, quartz, and silicon nitride.<>