Enhanced Two States Current in MOS-Gated MIS Separate Write/Read Storage Device by Oxide Soft Breakdown in Remote Gate

MOS-gated metal-insulator-semiconductor (MIS) separate write/read storage device is a new storage structure design. The device utilizes an MIS tunnel diode as a sensor to sense the fluctuation of the neighboring minority carriers controlled by a remote gate structure. Two current states can be read by the tunnel diode when the gate is in SET or RESET states. In this paper, the effect of gate oxide soft breakdown to the proposed device is studied. It is found that after gate oxide soft breakdown, the device exhibits improved two states current window and retention performance because of the stress-generated traps, e.g., a seven times larger two states current window. Also, the write voltage for the device reduces considerably after gate oxide soft breakdown, e.g., reduction of about 91% for SET and 36% for RESET process. The power consumption of the device is therefore reduced. Therefore, the gate oxide soft breakdown process can be regarded as a method to enhance the performance of MOS-gated MIS separate write/read storage device.