Patent ID: 9443740
Filing Date: 2016-09-13
CPC Classification: H01L

Claim Text:
1. A process for forming a gate of a thin film transistor device with enhanced mechanical strength comprises the steps of: forming a first photoresist layer having a first photoresist layer thickness and a first photoresist type on a semiconductor substrate and performing a first soft baking of said first photoresist layer; exposing said first photoresist layer to a first light source through a first mask having first mask patterns with a selected first defocus value; performing a first post exposure baking of said first photoresist layer, developing and rinsing to form a first stem portion cavity having rounded top edges and a first stem portion cavity length in said first photoresist layer; performing a first hard baking of said developed first photoresist layer; forming a second photoresist layer having a second photoresist layer thickness, a second photoresist type and a second photoresist developing sensitivity on said first photoresist layer and performing a second soft baking of said second photoresist layer; exposing said second photoresist layer to a second light source through a second mask having second mask patterns with a selected second defocus value; performing a second post exposure baking of said second photoresist layer, developing and rinsing to form a head portion cavity in said second photoresist layer; performing a second hard baking of said developed second photoresist layer; depositing gate metal layers by a vacuum deposition method; performing lift-off of said gate metal layers on said second photoresist layer; removing said first photoresist layer and second photoresist layer; and rinsing and baking to complete fabrication of said gate.