PRIME process for deep UV and E-beam lithography

Abstract

Abstract A new positive working system for deep UV and E-beam lithography, called PRIME ( p ositive r esist im age by dry e tching) using silylation and dry development is proposed. This paper will first compare PRIME to other dry developed processes such as DESIRE and SUPER. This part will include results obtained with different caracterization tools such as Rutherford Back Scattering, Infrared Spectroscopy and glass transition measurements. Moreover a comparison between PRIME in deep UV, PRIME in E-beam and DESIRE will be made in terms of swelling. In second part, results obtained with PRIME in deep UV and E-beam lithography will be discussed. At 249 nm with a mask aligner, 0.2 μm L/S patterns were resolved in 0.7 μm thick resist. Moreover these patterns were transfered in 0.6 μm thick silicon dioxide and 0.3 μm thick polysilicon. With E-beam exposure at 50 keV, 75 nm L/S in 0.35 μm thick resist was achieved and a wide process latitude was shown: isolated lines from 0.2 μm to 5 μm can be made with a ± 10 percent accuracy at the same dose. Very steep profiles can be obtained : 0.3 μm L/S in 1.2 μm thick resist at 50 keV, 0.2 μm hole in 1.2 μm thick resist at 20 keV.