FABRICATION METHOD OF THICK BOTTOM OXIDE IN DEEP TRENCH OF METAL OXIDE SEMICONDUCTOR FIELD EFFECT TRANSISTORS

摘要

A method of fabrication of an oxide layer at the bottom of a trench in a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is provided. The method includes deposition of a pad oxide layer on a semiconductor substrate of the MOSFET; etching the pad oxide layer and the semiconductor substrate to form a trench in the semiconductor substrate, depositing a silicone oxide layer to fill the trench in the semiconductor substrate; etching the silicone oxide layer to remove the silicone oxide layer from a plurality of sidewalls of the trench; coating the silicone substrate and silicone oxide layer with a photoresist to protect them of etching; etching the photoresist and the silicone oxide layer until surface of the silicone substrate is reached; and removing the photoresist from inside the trench to obtain a thick bottom oxide (TBO) layer in the trench.