METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A fabrication method of a semiconductor device is provided to constantly maintain a step-difference of an align key by using different etching selectivity. CONSTITUTION: An STI(Shallow Trench Isolation) is formed by selectively etching a semiconductor substrate(11). A polysilicon layer and an oxide layer having different etching selectivity are sequentially filled into the STI region. After selectively etching the oxide layer, the step-difference has about 1200Å. That is, the step-difference of a key region(100) maintains constantly about 1200Å. Then, an oxide layer(21) and a silane(23) are sequentially formed on the resultant structure.