A new optical lithographic technique using phase shifting mask with concurrent development and planarization for the formation of 0.15 mu m T shaped gate

Abstract

We propose a simple optical lithographic technique to form 0.15 mu m length T-shaped gate. The Lithography technique is composed of i-line (numerical aperture 0.40) edge typed phase shifting mask, low temperature PECVD of silicon nitride, concurrent development and planarization of photo-resist, and the silicon nitride etching. The margins of +/-0.8 mu m defocus and +/-5% exposure of 0.15 mu m gate pattern were obtained. Also, this result was consistent with simulation obtained by a homemade simulator. The process margin of planarization and silicon nitride etching process were 230% and 59.5%, respectively. The process margins were found to be enough for the application of device fabrication.