BISMUTH-BASED LAYERED PEROVSKITE THIN-FILMS AS A CHARGE STORAGE MATERIAL FOR LOW-POWER NONVOLATILE GAAS MEMORY APPLICATIONS

This work details initial process development and integration of ferro electric SrBi2Ta2O9 and SrBi2Ta2(1-x)Nb2xO9 for use in low power nonvo latile GaAs memory technology. A spin on process is used to deposit th e ferroelectric thin films. Capacitance, hysteresis loop, and switched charge versus time data are presented for metal-ferroelectric-metal c apacitors using platinum as the electrode material. Indications are th at the substitution of niobium for tantalum in the layered perovskite structure increases both the non-volatile polarization and the coerciv e field of the material. N-channel transistor characteristics of the l ow power gallium arsenide field effect transistor contained in the 1T- 1C memory bit are also presented. The results presented here imply tha t these materials warrant further research and process integration stu dies to realize low power non-volatile GaAs memory technology.