August 30, 2006 – Dongbu Electronics, Seoul, Korea, says it is now using an optical proximity correction (OPC) tool developed in collaboration with Mentor Graphics for 90nm wafer processing, extending earlier work that resulted in a 0.13-micron system.
OPC techniques help compensate for diffraction and process effects, which emerge when wavelengths of light used to expose masks are longer than a chips’ feature sizes. The process selectively distorts shapes on a photomask to ensure more faithful transfer of circuit patterns onto the wafer, particularly where linewidths vary on the same chip (e.g., center vs. edge of an array, or nested vs. isolated lines). OPC is also used where there is line end shortening, such as caused by gate overlap on field oxide.
The new OPC tool can potentially improve yields while reducing time to reach volume production by up to six months, according to Jae Song, EVP of Dongbu Electronics, which has invested more than $5 million in OPC development. He added that OPC resolution enhancement enables use of a lower-grade mask set, thus reducing manufacturing costs.