| US 7,393,791 B2 | ||
| Etching method, method of fabricating metal film structure, and etching structure | ||
| Katsuaki Kaifu, Tokyo (Japan); and Juro Mita, Tokyo (Japan) | ||
| Assigned to Oki Electric Industry Co., Ltd., Tokyo (Japan) | ||
| Filed on Aug. 30, 2006, as Appl. No. 11/512,341. | ||
| Claims priority of application No. 2005-248804 (JP), filed on Aug. 30, 2005. | ||
| Prior Publication US 2007/0049031 A1, Mar. 01, 2007 | ||
| Int. Cl. H01L 21/302 (2006.01) | ||
| U.S. Cl. 438—700 [438/701; 438/713; 438/724; 438/725; 438/744] | 18 Claims |
| 1. An etching method, comprising the steps of:
preparing a substrate structure comprising a substrate, a to be etched film formed on the principal surface of said substrate,
and an etching protection film formed on said to be etched film and having a hole formed therethrough;
said hole being formed by an opening in the surface of said etching protection film and a hollow linked to said opening and
reaching said to be etched film through said etching protection film;
the planar shape of said opening being congruent to the planar shape of an etching-destined region of said to be etched film
and a hole width of said hole widening toward said to be etched film in the depth direction from the surface of said etching
protection film; and
forming an exposure region in said principal surface of said substrate by removing, through inductively coupled plasma reactive
ion etching under the following conditions, a to be etched film part existing in said etching-destined region of said to be
etched film
(1) ICP power has a value in the range of 20 to 100 W,
(2) RIE power has a value in the range of 5 to 50 W, and
(3) the pressure in an etching chamber has a value in the range of 1 to 100 mTorr.
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