Challenges On Oxide Etch With 193nm Photoresist

With the continuous development of VLSI technology, 193 nm photoresist (PR) has been adopted to meet the scaling down requirement of feature sizes. However, it is difficult to maintain the completeness of PR structures during oxide etch due to the characteristics of 193nm PR. Obvious PR striation, PR roughness and the pattern of PR difficult to maintain was commonly observed. This paper analyses the baseline of the 193nm and 248nm PR films and the 193PR roughening mechanism, find out the ion impact plus radicals activates PR striation. Bese on these factors this papaer addresses which process factors (total power, frequence ratio, gas ratio, total flow, process pressure, chamber temperature and addional hydrogen) affecting the PR striation and presents our recent work on the study of 193nm photoresist roughness(Profile impact,sidewall roughness ,weaving / line tilting and pinhole) and the study of striation control during oxide etch.。The issues and the solutions developed during this research are also helpful to improve other VLSI manufacturing processes.