High resolution 100 kV electron beam lithography in SU-8

• Published in: Microelectronic engineering 2006-04, Vol.83 (4), p.1609-1612
• Main Authors: Bilenberg, B., Jacobsen, S., Schmidt, M.S., Skjolding, L.H.D., Shi, P., Bøggild, P., Tegenfeldt, J.O., Kristensen, A.
• Format: Article
• Language: English
• Subjects: 100 kV electron beam lithography; Applied sciences; Biological and medical sciences; Biotechnology; DNA stretching; Electronics; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Microelectronic fabrication (materials and surfaces technology); Miscellaneous; Nanochannels; Others; Reactive ion etch; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SU-8; Various methods and equipments
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2006.01.142

High resolution 100 kV electron beam lithography in thin layers of the negative resist SU-8 is demonstrated. Sub-30 nm lines with a pitch down to 300 nm are written in 100 nm thick SU-8. Two reactive ion etch processes are developed in order to transfer the SU-8 structures into a silicon substrate, a soft O 2-plasma process to remove SU-8 residues on the silicon surface after development and a highly anisotropic SF 6/O 2/CHF 3 based process to transfer the pattern into a silicon substrate, with selectivity between silicon and SU-8 of approximately 2. 30 nm lines patterned in SU-8 are successfully transferred into a silicon substrate, which is used as a stamp in a nanoimprint lithography process to fabricate a nanochannel device for DNA stretching experiments.