Research/Vapor HF Sacrificial Oxide Release with Lab Utensils

2008-05-09 (金) 01:10:59 (4479d)

Labware Setup for Vapor HF Release


Thermal oxide (or similar pure SiO2) can be removed in vapor HF from 49% concentrated HF acid. Sample wafer(s) can be warmed by a light bulb to remove moisture on the surface to keep the process dry.

Etch Rate


Etchrate seems to be almost equivalent to that of BHF (buffered HF) for thermal oxide. Careful trial & error is needed for your best results.

Release Results


Maximum 1 millimeter long cantilever has been successfully released (with stress-controlled smartcut SOI, 1.5 microns SOI / 1.0 micron BOX).


  1. Yamato Fukuta, Hiroyuki Fujita, and Hiroshi Toshiyoshi, "Vapor Hydrofluoric Acid Sacrificial Release Technique for Micro Electro Mechanical Systems Using Labware," Jpn. J. Appl. Phys. Vol. 42, Part 1, No. 6A (2003), pp. 3690 - 3694.
  2. Y. Fukuta, H. Fujita and H. Toshiyoshi, presented at IEE Japan (in Japanese):