E-beam and RIE examination of chemically amplified positive-tone resist CAMP6

We report on e-beam lithographic (EEL) and reactive ion etching (RIE) experiments with the positive chemically amplified resist (CAR) CAMP6 used for the fabrication of silicon structures ranging in size from the nanometer scale up to the micron scale in relatively thick resist film. Direct-write EEL at 30 keV was used to study the pre- and post-exposure processing on the resulting resist-relief structures. We measured the basic resist characteristics and also the influence of proximity effects. The resolved single-layer resist-relief structures at optimised process conditions have shown high aspect ratios with nearly vertical side-walls and T-top profiles in 0.6-1.7 mu m thick films up to nanometer lateral dimensions. The paper will discuss the deep pattern transfer results into the underlying 2.6 mu m thick SiO2 and/or directly into the Si-substrate by using RIE. We achieved excellent vertical side-walls free of passivation. The building of facets was observed to be on an acceptable scale.