The effect of thickness variation of an intermediate insulator layer on the grain size of a recrystallized large Si grain in an a-Si/SiO2/metal stack with an array of bumps in the oxide has been investigated. Increased thickness of the intermediate oxide portion and bump height resulted in grain size enlargement of the Si grain. Si crystal grains as large as 5.1 mu m were obtained located exactly at the desired position on the oxide. The explanation of the growth-enhanced mechanism by the solidification rate behavior, based on numerical simulation in terms of temperature gradient arguments is given.