Flash cell and forming process thereof
A flash cell forming process includes the following steps. A first gate is formed on a substrate. A first spacer is formed at a side of the first gate, where the first spacer includes a bottom part and a top part. The bottom part is removed, thereby an undercut being formed. A first selective gate is formed beside the first spacer and fills into the undercut. The present invention also provides a flash cell formed by said flash cell forming process. The flash cell includes a first gate, a first spacer and a first selective gate. The first gate is disposed on a substrate. The first spacer is disposed at a side of the first gate, where the first spacer has an undercut at a bottom part, and therefore exposes the substrate. The first selective gate is disposed beside the first spacer and extends into the undercut.
UNITED MICROELECTRONICS CORP.
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Yi-Shan Wang Zhen Weichang Shen-De Wei
Chiu Xiang Chen Liu Wang Ta