METHOD FOR FORMING TRENCH ISOLATION LAYER OF SEMICONDUCTOR DEVICE TO PREVENT MOAT USING PAD POLYSILICON INSTEAD OF PAD NITRIDE

摘要

PURPOSE: A method for forming a trench isolation layer of a semiconductor device is provided to prevent moat by using a pad polysilicon layer instead of a pad nitride layer. CONSTITUTION: A pad oxide layer(21), a pad polysilicon layer(22) and a photoresist pattern are sequentially stacked on a substrate(20). A trench is formed in the substrate. An isolation layer(27) is formed in the trench by filling an isolating layer in the trench and polishing. By blanket etching of the isolation layer and the pad oxide layer, the topology between an active region and the isolation layer is improved. Then, the pad polysilicon layer is removed.