Integration of SBT thin film into MFMOS structure for one transistor memory applications

摘要

The SBT thin film has been successfully integrated into a MFMOS structure for one-transistor memory applications. A new high temperature stable electrode, IrMO, that consists of Ir, metal, and O was used as the bottom electrode. This new electrode can maintain good conductivity and integrity even after very high temperature (800-1000/spl deg/C) oxygen ambient annealing. Therefore the SBT film can be deposited on the bottom electrode using MOD methods and annealed at high temperature (700-800/spl deg/C) without any hillock and peeling problems. Excellent ferroelectric properties were achieved. The thermal stability of the bottom electrode on thin gate oxide (35 /spl Aring/) was also very stable. Good C-V characteristics maintained even after the SBT capacitor formation. The etching damage to the SBT capacitor stack can be minimized by optimizing the etching conditions. No polarization loss and just slightly Ec increase was observed after etching of the SBT capacitor stack. The aluminum oxide based passivation layer was successfully integrated into this device with excellent passivation properties. Finally, the memory window of the MFMOS device will be presented.