High-Performance Ge MOS Capacitors by $\hbox{O}_{2}$ Plasma Passivation and $\hbox{O}_{2}$ Ambient Annealing

Qi Xie,Matty Caymax,Yulong Jiang,Shaoren Deng,Xinping Qu,Davy Deduytsche,Annelies Delabie,Dennis Lin,Marc Schaekers,Christophe Detavernier

doi:10.1109/led.2011.2166993

Abstract

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 ~1.5 nm and a low D it (<; 6 * 10 11 cm -2 eV -1 ) energy distribution covering the major part of the Ge bandgap (>; 0.51 eV). The surface potential modulation efficiency was estimated to be ~80% from Hatband 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 HfO 2 /GeO 2 gate stacks. Excellent comprehensive properties suggest that a combination of O 2 plasma passivation and O 2 ambient annealing provides a promising technology for GeO 2 -based CMOS devices.

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