[15a-B410-1~9] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

[15a-B410-5] Study on taper angle control in Silicon via hole etching

〇Hiroyuki Tanaka¹, Hiroshi Tokunaga², Yoshiyuki Nozawa³, Toshihiro Hayami³, Khumpuang Sommawan^1,4, Shiro Hara^1,4,5 (1.AIST, 2.MTC, 3.SPPT, 4.MINIMAL, 5.Hundred)

Keywords:Bosch, minimal, MEMS

In order to improve mounting technology, deep etching of through-silicon vias by Bosch Process using minimal equipment does not interfere with the formation of an insulating layer or seed sputtering until the Si substrate is etched to the desired depth. It is desirable to have a slightly forward tapered shape. However, in the case of a via hole with a high aspect ratio, it is difficult to form a tapered shape. To solve this problem, we were able to form a silicon via hole that maintains a slight taper by adding a small amount of C4F8 gas to SF6 in the etching step, even though it is the Bosch Process method.