Development of nanocomposite resists with high plasma etch resistance

摘要

We report about the development of novel nanocomposite resists that incorporate colloidal silica nanoparticles into conventional resist materials to yield thick coatings with both excellent lithographic properties and significantly increased plasma etch resistance. 10-50 wt% silica nanoparticles of 10-15 nm in size were dispersed homogeneously in a variety of standard resist resins by a simple process. The nanocomposite resists have similar lithographic performances to conventional resists without silica nanoparticles. The nanocomposite resists also show excellent process window capability and stability. Oxygen plasma etch and deep reactive ion etching (DRIE) processes were used to evaluate the etch resistance of the nanocomposite resists. Compared with standard photoresists, the oxygen plasma etch rate is reduced by 38 - 80 % when the silica content increases from 20 to 50 wt%. The etch selectivity of nanocomposite resists with 40 wt% silica is increased by 70% in DRIE test.