Patent ID: 6200841
Filing Date: 2001-03-13
Classification: H01L

Abstract:
A method for making a MOS transistor, comprising the acts of:forming a trench on a channel surface of a semiconductor substrate;forming an oxide layer in the trench;removing the oxide layer such that an isolator is formed on an inner side of the trench;forming a polysilicon layer on the substrate, wherein the polysilicon layer fills the trench;forming a photoresist pattern on a portion of the polysilicon layer filling the trench;removing the polysilicon layer using the photoresist pattern as a mask, whereby a portion of the polysilicon layer protrudes above a surface of the semiconductor substrate;removing the protruding portion of the polysilicon layer using a chemical mechanical polishing process;forming a gate conductor on the channel surface of the semiconductor substrate; andforming a source/drain region by doping impurities in the semiconductor substrate using the gate conductor as a mask.