Improved Plasma Etch Process Control of TiWN Gate Length
Jason Fender, Susan Chorrushi-Patino, Janet Hill-Tinkler
Compound Semiconductor-1 Motorola, Inc.
2100 E. Elliot Rd. MD
Phone: 480-413-3521, email: firstname.lastname@example.org
Keywords: plasma etch, gate length
In this fab, a plasma etch process is used to define the TiWN gate length. An isotropic etch process is used to undercut the photoresist mask to etch the TiWN metal. To improve the control of the TiWN gate etch process, a system was developed to change the etch time based on the photoresist critical dimension. By measuring the photo cd, and then feeding that data through an equipment interface to the etch tool, the etch time is adjusted to target a desired final cd. Consequently, the lot-to-lot photo cd variation has a reduced effect on the final cd.