发明授权
- 专利标题： Electrically programmable read-only memory cell
- 专利标题（中）： 电可编程只读存储单元
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申请号： US531357申请日： 1995-09-20
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公开(公告)号： US5616941A公开(公告)日： 1997-04-01
- 发明人: Scott S. Roth , Howard C. Kirsch
- 申请人： Scott S. Roth , Howard C. Kirsch
- 申请人地址： IL Schaumburg
- 专利权人： Motorola Inc.
- 当前专利权人： Motorola Inc.
- 当前专利权人地址： IL Schaumburg
- 主分类号： H01L21/8247
- IPC分类号： H01L21/8247 ; H01L29/423 ; H01C29/788 ; H01C27/148
摘要：
A floating gate (51)is formed to have a cavity (52) that increases the capacitive coupling between the floating gate (51) and a control gate for the memory cell. The memory cell may be used in EPROM, EEPROM, and flash EEPROM arrays and may be programmed and erased by hot carrier injection, Fowler-Nordheim tunneling or the like. The process sequence for forming the cavity (52) of the floating gate (51) has good process margin allowing some lithographic misalignment. In one embodiment, a multi-tiered floating gate may be formed. The multi-tier structure allows the capacitive coupling to further increase without occupying more area.