METHOD OF ISOLATION OF A SEMICONDUCTOR DEVICE

摘要

(A) removing a LPCVD oxide film(5), a nitrided film(4) and an oxide film(3) on a region(6); (B) forming a trench by etching a substrate on the region(6) selectively, and forming a first oxide film(8) on the trench; (C) forming a mask oxide film(10) by etching the LPCVD oxide film(5); (D) forming a second oxide film(11); (E) removing the second oxide film(11) on the bottom(12) of the trench and the exposed nitrided film(4) of a region(14); (F) grounding the substrate by forming p+ region(16) after filling the trench with Boron-doped polysilicone(15); (G) obtaining a wafer surface(17) of flattening polysilicone by etching the oxide film(13) on the nitrided film(4); (H) defining an active region by using a photoresist film(18); (I) forming an thermal oxide film(20) by etching the exposed nitrided film(4).