公开(公告)号：US11081553B2

公开(公告)日：2021-08-03

申请号：US16868143

申请日：2020-05-06

Applicant: Silicon Storage Technology, Inc.

Inventor： Leo Xing ,  Chunming Wang ,  Guo Yong Liu ,  Melvin Diao ,  Xian Liu ,  Nhan Do

IPC: H01L21/00 ,  H01L21/28 ,  H01L27/11521 ,  H01L27/11531 ,  H01L29/423 ,  H01L21/265 ,  H01L29/66 ,  H01L21/02 ,  H01L21/3213 ,  H01L29/788

Abstract: A method of forming a memory device includes forming a second insulation layer on a first conductive layer formed on a first insulation layer formed on semiconductor substrate. A trench is formed into the second insulation layer extending down and exposing a portion of the first conductive layer, which is etched or oxidized to have a concave upper surface. Two insulation spacers are formed along sidewalls of the trench, having inner surfaces facing each other and outer surfaces facing away from each other. A source region is formed in the substrate between the insulation spacers. The second insulation layer and portions of the first conductive layer are removed to form floating gates under the insulation spacers. A third insulation layer is formed on side surfaces of the floating gates. Two conductive spacers are formed along the outer surfaces. Drain regions are formed in the substrate adjacent the conductive spacers.

公开(公告)号：US20210005724A1

公开(公告)日：2021-01-07

申请号：US16796412

申请日：2020-02-20

Applicant: Silicon Storage Technology, Inc.

Inventor： Chunming Wang ,  Xian Liu ,  Nhan Do ,  Leo Xing ,  Guo Yong Liu ,  Melvin Diao

IPC: H01L21/28 ,  H01L27/11521

Abstract: A method of forming a memory device that includes forming a first polysilicon layer using a first polysilicon deposition over a semiconductor substrate, forming an insulation spacer on the first polysilicon layer, and removing some of the first polysilicon layer to leave a first polysilicon block under the insulation spacer. A source region is formed in the substrate adjacent a first side surface of the first polysilicon block. A second polysilicon layer is formed using a second polysilicon deposition. The second polysilicon layer is partially removed to leave a second polysilicon block over the substrate and adjacent to a second side surface of the first polysilicon block. A third polysilicon layer is formed using a third polysilicon deposition. The third polysilicon layer is partially removed to leave a third polysilicon block over the source region. A drain region is formed in the substrate adjacent to the second polysilicon block.