P‐6.15: Novel Patterning Photoresist for Making TFT Array with Very High Resolution and Controllable Taper Angle by Adjusting Process

For making a‐Si TFT array, fast photo‐speed positive photoresist with moderate taper angle profile is preferred. On the other hand, for making poly‐Si TFT, fast i‐line photo‐speed positive photoresist that shows a very vertical profile and has fine resolution is required. Because of the required performance is slightly different in a‐Si and poly‐Si TFT, different types of photoresist are usually used. This paper introduces a novel positive patterning photoresist that might be useful for both a‐Si and poly‐Si TFT manufacturing. This new type of positive photoresist shows fast photo‐speed and its pattern profile is vertical with very fine resolution. Under suitable process conditions, resolution down to 1um line and space is achieved even with contact aligner exposure. At the same time taper angle is controllable by choosing proper process conditions such as prebake temperature, inserting post exposure bake (PEB) process or not.