Lowe, Price, LeBlanc & Becker
Fabricating method of micro lens
 A testing sample is formed in a three-story structure consisting of a photo-resist 13, a silicon dioxide film 12, and a GaAs substrate 11. The pattern of the photo-resist 13 is transferred onto the silicon dioxide film 12 by effecting the photo-resist 13 as a mask. Thus obtained silicon dioxide film mask 14 and the GaAs substrate 11 are processed in compliance with a reactive ion beam etching method; that is, the silicon dioxide film mask 14 and the GaAs substrate 11 are irradiated by the chlorine ion beam 15. The silicon dioxide film and the GaAs substrate are gradually etched by the irradiation of the chlorine ion beam 15. In this case, the etching is differently developed in two regions. In one region which is not covered by the mask, the etching advances uniformly in a normal direction with respect to the GaAs substrate at a certain etching rate. On the other hand, in the other region which is covered by the mask, the silicon dioxide film is gradually etched first of all, and the tapered portion of the silicon dioxide film is completely etched earlier than other portion of the silicon dioxide film. Then, the GaAs surface is exposed to the chlorine ion beam at the portion the silicon dioxide film is removed and, in turn, the GaAs substrate is gradually etched by being directly irradiated by the chlorine beam. And, when the silicon dioxide film mask is completely removed, the micro lens is finally formed on the GaAs substrate. 
Matsushita Electric Industrial Co., Ltd.
G
G02B
inventional
Shinichi Yoshimasa Hitomaro Yukio
Wakabayashi Ohki Tougou Toyoda