Dielectric Isolated Wafer (DIW)

An active wafer is oxidized after V-shaped grooves are formed on the surface for isolation. A polycrystalline silicon layer is then deposited on the surface by CVD (chemical vapor deposition) process. The active wafer is subsequently bonded with an oxidized handle wafer, and the following heat treatment makes the two wafers join together. The bonded wafer is then ground and polished on the active wafer side up to a certain thickness.

Process flow