发明授权
- 专利标题: High density flash EPROM
- 专利标题(中): 高密度闪存EPROM
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申请号: US847876申请日: 1997-04-28
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公开(公告)号: US5721442A公开(公告)日: 1998-02-24
- 发明人: Gary Hong
- 申请人: Gary Hong
- 申请人地址: TWX Hsin-Chu
- 专利权人: United Microelectronics Corporation
- 当前专利权人: United Microelectronics Corporation
- 当前专利权人地址: TWX Hsin-Chu
- 主分类号: H01L21/336
- IPC分类号: H01L21/336 ; H01L21/8247 ; H01L29/788
摘要:
A method and structure for manufacturing a high-density EPROM or flash memory cell is described. A structure having silicon islands is formed from a device-well that has been implanted with a first conductivity-imparting dopant, over a silicon substrate. A first dielectric layer surrounds the vertical surfaces of the silicon islands, whereby the first dielectric layer is a gate oxide. A first conductive layer is formed over vertical surfaces of the first dielectric layer, and acts as the floating surrounding-gate for the memory cell. A source region is formed in the device-well by implanting with a second and opposite conductivity-imparting dopant to the first conductivity-imparting dopant, and surrounds the base of the silicon islands. A drain region is in the top of the silicon islands, formed by implanting with a second and opposite conductivity-imparting dopant to the first conductivity-imparting dopant. A thin dielectric layer surrounds the silicon islands, over the source region and under the first conductive layer, and acts as a tunnel oxide for the memory cell. A second dielectric layer is formed over vertical surfaces of the first conductive layer, and horizontally over the source region, and is an interpoly dielectric. A second conductive layer is formed over vertical surfaces of the second dielectric layer, and is the control gate for the memory cell.
公开/授权文献
- US5338694A Method of fabricating BiCMOS device 公开/授权日:1994-08-16