公开(公告)号：US20220101920A1

公开(公告)日：2022-03-31

申请号：US17152696

申请日：2021-01-19

Applicant: Silicon Storage Technology, Inc.

Inventor： CHUNMING WANG ,  XIAN LIU ,  GUO XIANG SONG ,  LEO XING ,  NHAN DO

IPC: G11C16/04 ,  G11C16/16 ,  H01L29/423 ,  H01L27/11521 ,  H01L27/11556

Abstract: A memory device includes a semiconductor substrate, first and second regions in the substrate having a conductivity type different than that of the substrate, with a channel region in the substrate extending between the first and second regions. The channel region is continuous between the first and second regions. A first floating gate is disposed over and insulated from a first portion of the channel region. A second floating gate is disposed over and insulated from a second portion of the channel region. A first coupling gate is disposed over and insulated from the first floating gate. A second coupling gate is disposed over and insulated from the second floating gate. A word line gate is disposed over and insulated from a third portion of the channel region between the first and second channel region portions. An erase gate is disposed over and insulated from the word line gate.

公开(公告)号：US20220293756A1

公开(公告)日：2022-09-15

申请号：US17346524

申请日：2021-06-14

Applicant: Silicon Storage Technology, Inc.

Inventor： Leo Xing ,  CHUNMING WANG ,  XIAN LIU ,  NHAN DO ,  GUO XIANG SONG

IPC: H01L29/423 ,  H01L29/788 ,  H01L21/28 ,  H01L29/66

Abstract: A method of forming a memory device that includes forming a first insulation layer, a first conductive layer, and a second insulation layer on a semiconductor substrate, forming a trench in the second insulation layer to expose the upper surface of the first conductive layer, performing an oxidation process and a sloped etch process to reshape the upper surface to a concave shape, forming a third insulation layer on the reshaped upper surface, forming a conductive spacer on the third insulation layer, removing portions of the first conductive layer leaving a floating gate under the conductive spacer with the reshaped upper surface terminating at a side surface at a sharp edge, and forming a word line gate laterally adjacent to and insulated from the floating gate. The conductive spacer includes a lower surface that faces and matches the shape of the reshaped upper surface.