High performance chemically amplified positive electron-beam resist

The effect of an alkali decomposable additive on a chemically amplified.(CA) positive electron-beam (EB) resist was studied. HalogenoMethylEster (HME) 1,4-bis (bromoacetoxy) benzene was synthesized and used as an alkali decomposable additive. The hydrophobic HME decomposed with an alkali solution and changed into a hydrophilic, which in turn increased the alkali dissolution rate (ADR) of the exposed region of the resist and enhanced the resist contrast. In addition, the bromomethyl groups and ester groups are hydrolyzed with a high degree of polarity change. HME having the large dissolution acceleration effect at an exposed region is suitable for application as a positive resist. HME was added to 2-component CA positive EB resists consisting of a base polymer and a photo acid generator. As a result of a high degree of polarity change, HME enhanced the resist contrast with no loss in sensitivity. The delineation of a fine 0.13 mu m hole-pattern was possible with the addition of HME. The addition of HME rendered the sidewalls smooth and vertical.