Toshinobu Furusho

Resist dispense system for further defect reduction

As pattern size becomes smaller, requirement for defect reduction is getting higher and higher. It is known that defects occur in various steps of lithography process. In this study, we focus on defects related to the resist dispense system. Of those defects, the most typical is bridge type defect which caused by foreign substances contained in resist film. The source of those is considered to be insoluble substances, such as resist gels, in resist liquid. So far, the conventional countermeasure has been the development of resist line filters (optimization of materials, shrinking of pore size, and so on). But, according to the recent reports and our experimental result, we can say that not only filter type but also filtration condition has certain influence on bridge type defect generation. In this study, we examine the influences of resist dispense system and its parameters on bridge type defect generation. This paper provides some experimental data and introduces our approaches to the optimization of resist dispense system and its effects.