Comparative study of AZPF514 and UVIII chemically amplified resists for electron beam nanolithography

Two commercial positive tone chemically amplified resists, AZPF514 and UVIII, were investigated and compared for their performance in e-beam direct write of wafers at sub-150nm resolutions. The resist sensitivity, process latitude and post exposure delay effect were studied. Both resists are of high sensitivity. They are insensitive to variation of post exposure bake conditions. The post exposure vacuum delay effect is much more pronounced in AZPF514. AZPF514 also suffers severely the ''T-topping'' effect. Feature dimension below 150nm cannot be achieved with AZPF514, while sub-50nm lines have been obtained with UVIII.