OPTIMIZATION OF DEEP UV POSITIVE TONE TOP SURFACE IMAGING PROCESS

Top surface imaging (TSI) process as a dry development process has bee n developed for many years to be contributed to device application, Bu t, because conventional wet development process has already been devel oped so well, there was no room for TSI process to be utilized in devi ces. TSI process, even though having swelling problem, still has stron g potential to be utilized in such layers which have severe topography and which contain small features exceeding the resolution limit of a stepper used. In this paper, swelling effect and its control by means of WEBS (WEt development Before Silylation) treatment for SS-201 resis t is discussed. Also soft bake temperature is discussed in view of pro cess optimization. How to form small contact holes beyond resolution l imit is another topic for discussion. Finally, application result with TSI process will be shown.