公开(公告)号：US20020052121A1

公开(公告)日：2002-05-02

申请号：US09997928

申请日：2001-11-30

Applicant: Micron Technology, Inc.

Inventor： Whonchee Lee ,  Pai Pan ,  Terry Gilton

IPC: H01L021/302 ,  H01L021/461

CPC classification number: H01L21/30604 ,  H01L21/76224

Abstract: A silicon etching method includes providing a substrate assembly including an exposed silicon region and an exposed oxide region. An etch composition including an ammonium fluoride component, an inorganic acid component, and an oxidizing agent is also provided. The etch composition has a pH in the range of about 7.0 to about 8.0. The substrate assembly is exposed to the etch composition. Exposing the substrate assembly to the etch composition may result in etching the exposed silicon region at an etching rate that is greater than about 3 times the etching rate of the exposed oxide region and/or etching the silicon region at an etch rate greater than about 9 null/minute. The etching method may be used in forming isolation structures. Further, etch compositions for performing the desired etch are provided.