Patent ID: 7632725

Claim:
A method for forming an ESD protection device in an ESD protection circuit, comprising: providing a substrate having a device area and an ESD protection circuit area; forming a first polysilicon film of a first thickness on said substrate to cover said device area and said ESD protection circuit area; forming a patterned photoresist layer on said first polysilicon film to expose a portion of said first polysilicon film corresponding to said device area; etching said first polysilicon film to expose said substrate by using said patterned photoresist layer as a mask; removing said patterned photoresist layer; and depositing a second polysilicon film of a second thickness on said substrate so as to form a polysilicon film on said device area having the second thickness and a polysilicon film on said ESD protection circuit area having a third thickness, wherein said third thickness equals said first thickness plus said second thickness.