Taku Hirayama

Molecular resists based on cholate derivatives for electron-beam lithography

We have reported the characteristics and LER properties of molecular resists based on low molecular weight polyphenols as a chemically amplified (CA) positive-tone EB resist (Hirayama et al., 2004; Hirayama et al., 2005). In this paper, new molecular resist based on cholate derivatives for EB lithography was reported.

A new 193nm resist

A new ArF matrix based on poly(vinylsulfonamide) has been developed. Sulfonamides, whose pKa values are comparable to those of phenols, can be used as acidic functional groups in the design of chemically amplified resist (CAR) and aqueous base developable resist. Various poly(N-alkyl vinylsulfonamide)s were prepared (R=H, CH2CF3, Pr, 1-adanmantyl), and showed high transparency at round 193 nm region. Depending on the substituents, the dissolution rates of films in a 2.38 wt% aqueous tetraethylammonium hydroxide solution were varied from 500 to 0.0035 nm/s. The tetrahydropyranyl (THP) protected poly(vinylsulfonamide) was prepared and the deprotection of THP was easily occurred when the photoresist containing a photoacid generator was exposed to UV light, followed by post-exposure baking.