Newly developed resolution enhancement lithography assisted by chemical shrink process and materials for next-generation devices

We have newly developed a resolution enhancement lithography assisted by chemical shrink (RELACS) material for ArF lithography. Several process performances were evaluated for 65 nm nodes and next-generation devices. The principle and procedure of the RELACS process is similar to those developed previously for KrF lithography. The extent of cross-linking reaction and the mobility balance of chemical components at the boundary between the resist and RELACS film is adjusted to ArF resist chemistry. The novel RELACS material causes variation in shrinkage from 10 to 50nm by controlling process conditions. The shrinkage amount is independent of pattern pitch and lithography conditions, i.e., dose and focus. We confirmed that the pattern profile, lithography margin, critical dimension (CD) uniformity, etching resistance, and pattern defects were not deteriorated by the RELACS process with distilled water. We believe that the novel RELACS process and materials are extremely useful for 65 nm nodes and next-generation devices.