Low voltage/Sub-ns Operation Bulk Thyristor-SRAM (BT-RAM) Cell with Double Selective Epitaxy Emitters (DEE)

We have successfully developed an alternative SRAM cell for the first time using a Bulk Thyristor-RAM (BT-RAM) with a Double selective Epitaxy technique for two Emitter regions (DEE). The DEE BT-RAM can read/write at Ins at a low-voltage of 0.6 V or read/write at 1.5 V at a high speed of 100 ps. It also has good retention characteristics even at 125degC, suggesting good scalability for gate length of 65 nm and beyond, and its ideal cell size is expected to be 30 F², one-fourth that of a conventional 6T-SRAM cell. The DEE BT-RAM is therefore a promising alternative SRAM for the 65-nm generation and beyond.