Minimization of Residual Stress in SOI Films by Using AlN Interlaid Insulator

It was found that residual stress in SOI film recrystallized by laser annealing depends on both substrates and interlaid insulator materials. For a stress free Si film, a thermal expansion coefficient of the underlaid material, comprising of a substrate and an interlaid insulator should be slightly larger than that of Si. AlN found to be a very effective interlaid insulator. In the structure of resolidified-Si/3 µm thick insulator/Si substrate, the residual stress in SOI film on AlN (5×109 dyn/cm2) was lower than that on SiO2 (7×109 dyn/cm2).