| 摘要 |
Polysilicon diodes fabricated in standard CMOS logic processes can be used as program selectors for One-Time Programmable (OTP) devices, such as electrical fuse, contact/via fuse, contact/via anti-fuse, or gate-oxide breakdown anti-fuse, etc. The OTP device has an OTP element coupled to a diode in a memory cell. The diode can be constructed by P+/N+ implants on a polysilicon as a program selector. By applying a high voltage to an OTP element coupled to the P-terminal of a diode and switching the N-terminal of a diode to a low voltage for suitable duration of time, a current flows through the OTP element may change the resistance state. On the polysilicon diode, the spacing and doping level of a gap between the P- and N-implants can be controlled for different breakdown voltages and leakage currents. The Silicide Block Layer (SBL) can be used to block silicide formation on the top of polysilicon to prevent shorting. If the OTP element is a polysilicon electrical fuse, the fuse element can be merged with the polysilicon diode in one piece to save area. |
