Influence of thermal processing on the electrical characteristics of MOS capacitors on strained-silicon substrates

Abstract

In this work the influence of thermal oxidation and subsequent thermal processing on the electrical characteristics of strained-Silicon (s-Si), MOS capacitors was studied. Strained-Si/Si1 − xGex/Si substrates of two different strain levels (10% and 22% Ge content) were oxidized within the temperature range of 800 °C to 900 °C for various time intervals. Capacitance-Voltage measurements reveal that the response of the MOS capacitors depends mainly upon two factors: a) the extend of the s-Si layer oxidation, i.e. the remaining s-Si thickness and b) the duration of the post-oxidation annealing in inert ambient. Both factors influence the interfacial properties of the structures. Additional oxidation experiments in N2O ambient indicate a significant influence of the process conditions on the quality of the oxidized structures.