High-performance TaN/HfSiON/Si metal-oxide-semiconductor structures prepared by NH3 post-deposition anneal

Abstract

Electrical and chemical characteristics of metal-oxide semiconductorfield-effect transistors(MOSFETs) prepared by low-thermal-budget (∼600 °C) NH 3 post-deposition annealing of HfSiON gate dielectric have been investigated. Compared to control Hf-silicate, HfSiON showed excellent thickness scalability, low leakage current density (J), and superior thermal stability. With proper annealing-time optimization, effective oxide thickness as low as 9.2 Å with J<100 mA/cm 2 at gate voltage V g =−1.5 V has been achieved. C–V hysteresis of HfSiON MOSFET was found to be small (<20 mV). Unlike NH 3 surface nitridation ( NH 3 pre-treatment prior to Hf-silicate deposition), no degradation in G m (transconductance), I d –V g (drain current–gate voltage), or I d –V d (drain current–drain voltage) characteristics has been observed.