Method of fabricating moat-free MOS transistor

摘要

PURPOSE: A moat free MOS transistor and a method for manufacturing the same are provided to remove moat by forming an oxide layer on a field oxide layer. CONSTITUTION: An STI(Shallow Trench Isolation) region is formed by selectively etching a silicon substrate using a pad nitride layer as a mask. A field oxide layer(108) is filled in the STI region. An oxide layer(110) is formed on the field oxide layer to compensate the loss of silicon due to cleaning after the pad nitride layer is removed. The oxide layer is selectively etched to expose an active region(102) of the substrate. A gate oxide layer(112) and a polysilicon gate(116) are formed on the exposed active region. The oxide layer is removed. Then, a source and drain region are formed.