Recently, a new technology called double exposure lithography is emerging as new technology that extends lithography factor under 0.25. The need of this technology comes from the delay in maturity of EUV technology such as light source, reflective mask and optics, and resist. However, double exposure technology requires additional processes including two hard mask deposition steps, one more lithography patterning step and two hard mask etching steps. In addition, there would be several issues such as patterning on topology problems for the case of second patterning and complexity in etching process. In brief, the complex process of double exposure technology should be simplified for real device production.
In this paper, we will introduce novel double exposure technology that minimizes the number of process steps by using silicon containing BARC. Silicon BARC acts as BARC and hard mask at the same time in our double exposure process so the process step and cost can be reduced. During first exposure step, silicon containing BARC take a role of BARC for first resist patterning and then remaining pattern of silicon containing BARC acts as hard mask pattern for second patterning and etching. Using this simple and novel process, more economic way of double exposure technology can be available. In this paper, the issues and countermeasures for silicon containing BARC based double exposure technology will be reported.