An investigation into the characteristics of deep reactive ion etching of quartz using SU-8 as a mask

In this paper, we present our recent investigations into the characteristics of the deep reactive ion etching (DRIE) of quartz. Three different etching gas mixtures, namely SF6/Ar, CF4/Ar and CHF3/Ar, with process parameters such as the Ar flow ratio, bias power, ICP power, chamber gas pressure and gas total flow rate were systematically studied. Furthermore, SU-8 was applied as the mask layer instead of metal in all experiments presented in this paper. We have found that SU-8 is a valid alternative mask material when the CF4/Ar and CHF3/Ar gas mixtures are selected as the DRIE etching media. A microchannel with a depth of 55 µm is fabricated, and a nearly vertical side-wall profile (86°) is achieved. The processed data gathered in this paper may offer basic reference material for future research endeavours regarding the DRIE of quartz