A Study On 193nm PR Plasma Cure Process

Together with the continuous growing of IC industry and the scaling down of feature sizes, lithography technology is also developing。193nm photo resist(PR) is as the successor of 248nm PR, developed to meet the constant demand for shorter wavelengths for higher packing densities and faster device speed.193nm PR based on acrylate chemistry has raised issues regarding dry etch resistance. These resists undergo severe degradations during typical dry etch processes involved in gate patterning, resulting in strong film loss, resist chemical modifications, critical surface roughening and also line width roughness(LWR). The studies have shown that applying plasma treatments to 193nm PR patterns prior to the other plasma etching processes is a way to minimize PR degradation. HBr plasma cure is known to reinforce the 193nm PR etch resistance and to reduce the resist LWR.This paper shows that a high ion density environment is needed to obtain high PR etch resistance. Increasing the plasma density by decreasing pressure and increasing TCP RF power was established to be an effective way to improve PR etches resistance.