The Study Of Halftone PSM Side Lobe Effect

In the recent twenty years, IC technology made a huge progress. The integration keeps on increasing following Moore’s law:the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years (or18months). With the critical dimension turns smaller and smaller, and the integration turns higher and higher, lithography meets more and more challenge. The development and application of resolution enhance technology increased lithography process capability and drive IC industry moving.This paper also introduces the technology such as the OAI which can improve resolution, PSM which can enhance the contrast, OPC that can improve IC reliability, BARC resist which is used to reduce the reflection.The half tone phase shift mask(PSM) use the semi transparent material to block exposure light. The unwanted light induce side lobe effect while PSM improving the image quality. With the development of IC industry, the exposure light source do relative evolution from1-Line to KrF.Meanwhile,KrF’s lower illumination intensity drives photoresist to higher sensitivity and contrast. As DUV resist light reaction need energy low. The side lobe is easy to form image on the wafer then induc yield loss.This paper takes a production which suffer yield loss for side lobe as example, doing detailed analysis for wafer image by SEM, studying the influence of mask CD and NA on exposure energy deeply, get a efficient solution which can solve side lobe in wafer.