Patent ID: 7659167
Filing Date: 2010-02-09
Classification: H01L

Abstract:
1. A method for forming a flash memory using a microcrystalline polysilicon layer as a floating gate, said method comprising: providing a substrate having source, channel and drain regions therein; forming a gate dielectric layer on said substrate; forming a microcrystalline polysilicon layer using a low pressure chemical vapor deposition method, as a floating gate on said gate dielectric layer; said microcrystalline polysilicon layer having a grain size within a range of about 500 angstroms to 1000 angstroms, said low pressure chemical vapor deposition method utilizes a gas stream containing hydrogen gas having a gas ratio not less than 5% under a reaction pressure of 200 torr to 400 torr; forming a dielectric layer on said microcrystalline polysilicon layer; and forming a polysilicon layer as a control gate on said dielectric layer.