3D Micro-Fabrication using Combination Technique of Nano-scale Processing and Chemical Etching (5th Report, Dependence of Mask on Processing Conditions)

Abstract

This study is intended to fabricate 3D microstructures on single crystal silicon by tribo-nanolithography (TNL) and wet chemical etching. In previous report, it could be known that height of microstructure fabricated by the TNL and subsequent wet chemical etching can be controlled by adjusting the TNL conditions such as normal load, pitch of processing line and number of processing. This paper reports an etch result by HF solution in order to evaluate the mechanism of height change with the TNL conditions. As a result, it is found that amorphous layer formed by the TNL can be selectively etched in HF solution though non-processed area withstands etching. The mechanism of change of masking effect is evaluated by utilizing this phenomenon. As a result, it can be known that change of masking effect by normal load is resulted from change of thickness of the amorphous layer. On the other hand, those by pitch of processing line and number of processing are resulted from conversion ratio of single crystal to amorphous structure.