Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Polystyrene negative resist for high-resolution electron beam lithography | Ma et al. Nanoscale Research Letters 2011 6 446 http content 6 1 446 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Polystyrene negative resist for high-resolution electron beam lithography Siqi Ma Celal Con Mustafa Yavuz and Bo Cui Abstract We studied the exposure behavior of low molecular weight polystyrene as a negative tone electron beam lithography EBL resist with the goal of finding the ultimate achievable resolution. It demonstrated fairly well-defined patterning of a 20-nm period line array and a 15-nm period dot array which are the densest patterns ever achieved using organic EBL resists. Such dense patterns can be achieved both at 20 and 5 keV beam energies using different developers. In addition to its ultra-high resolution capability polystyrene is a simple and low-cost resist with easy process control and practically unlimited shelf life. It is also considerably more resistant to dry etching than PMMA. With a low sensitivity it would find applications where negative resist is desired and throughput is not a major concern. 1. Introduction Electron beam lithography EBL 1 focused ion beam FIB lithography 2 and nanoimprint lithography NIL 3 are currently the three most widely employed nanolithography techniques. Among them EBL is undoubtedly the most popular for R D. Unlike NIL EBL can generate arbitrary patterns without the need of fabricating a mold first. Though not as versatile as FIB which can do both lithography using a resist and milling EBL is capable of exposing thick 100 nm resist without ion contamination to the resist. In addition it is faster than FIB exposure since the electron beam can remain well-focused below 10-nm beam size even with nA beam current as is needed for fast writing. In recent years one main trend in EBL development is the effort being made toward ultra-high resolution and pattern density with the record pattern density of 9-nm period line arrays 4 . Desirable properties
