Fabrication of flash memory device includes depositing first oxide layer, polysilicon layers, and dielectric layer, forming second oxide layer, performing heat treatment, and removing parts of dielectric layer and second polysilicon layer

摘要

Flash memory device is fabricated by depositing first oxide layer (22) on substrate (21); depositing first polysilicon layer (23) on first oxide layer; forming second oxide layer on entire surface of first polysilicon layer; removing second oxide layer; performing heat treatment; depositing dielectric layer; depositing second polysilicon layer; and removing some parts of the dielectric layer and the second polysilicon layer. Fabrication of flash memory device comprises depositing first oxide layer on a substrate; depositing first polysilicon layer on the first oxide layer; forming a second oxide layer on the entire surface of the first polysilicon layer; removing the second oxide layer; performing a heat treatment to make the first polysilicon layer have an embossed shape; depositing a dielectric layer on the top of the first polysilicon layer; depositing a second polysilicon layer on the entire surface of the dielectric layer; and removing some parts of the dielectric layer and the second polysilicon layer through a patterning process and an etching process.