Electrical characteristics and suppressed boron penetration behavior of thermally stable HfTaO gate dielectrics with polycrystalline-silicon gate

Abstract

The investigation of the thermal stability and electrical characteristics of HfTaO gate dielectric with polycrystalline-silicon gate was discussed. It was shown that the incorporation of Ta into HfO 2 enhances the crystallization temperature of film dramatically. It was confirmed by transmission electron micrographs that HfTaO with 43% Ta film remains amorphous even after activation annealing at 950°C for 30 s and the formation of low-k interfacial layer was observably reduced. It was shown that the capacitance-voltage curve of metal-oxide-semiconductor capacitor fits well with simulated curve, indicating good interface property between HfTaO and substrate, by using HfTaO gate dielectric.