Scanning thermal lithography: Maskless, submicron thermochemical patterning of photoresist by ultracompliant probes
Abstract
This article introduces a scanning probe lithography technique in which ultracompliant thermal probes are used in the selective thermochemical patterning of commercially available photoresist. The micromachined single-probe and multiprobe arrays include a thin-film metal resistive heater and sensor sandwiched between two layers of polyimide. The low spring constant (<0.1N∕m) and high thermal isolation provided by the polyimide shank is suitable for contact mode scanning across soft resists without force feedback control. The probes provide what is effectively a spatially localized postexposure bake that crosslinks the photoresist in the desired pattern, rendering it insoluble in developer. For 450-nm-1400-nm-thick AZ5214E (Clariant Corp.), line and dot features with sizes of 450-1800nm can be printed using probe powers of 13.5-18mW, and durations of 1-60s per pixel. Variation of feature sizes with process parameters is described.
- Publication:
-
Journal of Vacuum Science Technology B: Microelectronics and Nanometer Structures
- Pub Date:
- November 2004
- DOI:
- 10.1116/1.1808732
- Bibcode:
- 2004JVSTB..22.3217B