High-performance Ge MOS capacitors by O₂ plasma passivation and O₂ ambient annealing

Very promising capacitance-voltage (C-V) characteristics of capacitors on both p- and n-type Ge substrates are demonstrated by using an in situ O-2 plasma passivation and an O-2 ambient annealing. The capacitors exhibited a small equivalent oxide thickness of similar to 1.5 nm and a low D-it ( 0.51 eV). The surface potential modulation efficiency was estimated to be similar to 80% from flatband to strong inversion on both types of Ge. C-V hysteresis was less than 10 mV with positive bias up to 1.5 V. A low gate leakage current density of 0.51 eV). The surface potential modulation efficiency was estimated to be similar to 80% from flatband to strong inversion on both types of Ge. C-V hysteresis was less than 10 mV with positive bias up to 1.5 V. A low gate leakage current density of < 9 * 10(-8) A/cm(2) at V-FB +/- 1 V indicates high quality of the HfO2/GeO2 gate stacks. Excellent comprehensive properties suggest that a combination of O-2 plasma passivation and O-2 ambient annealing provides a promising technology for GeO2-based CMOS devices.A