About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Journal of Applied Physics
Paper
Dominant surface electronic properties of SiO2-passivated Ge surfaces as a function of various annealing treatments
Abstract
The metal-oxide-semiconductor (MOS), capacitance vs applied voltage (C-V) measurement technique was used to investigate SiO2-passivated Ge surfaces as a function of high-temperature annealing treatments in H 2, O2, N2, and H2O. Capacitance measurements were made at high frequencies (100 MHz) and/or reduced temperatures (145°, 77°K) to eliminate the capacitive contribution of fast surface states to the ac signal. Since the surface states did equilibrate with the superimposed applied dc voltage, is was possible to determine surface-state type, energy, and densityfrom voltage shifts in the C-V traces. Hydrogen annealing at 600°C or above introduces a high density (>10 13/cm2) of fast acceptor states. These states are located at the center of the Ge energy gap. In addition, hydrogen annealing at 700°-800°C introduces acceptors close to the valence band or fixed negative charge. Most of these hydrogen-induced states are removed by annealing in oxygen or water vapor at 230°-440°C. At the same time the oxygen or water vapor exposure introduces an effective positive charge density of 1-5×1012/cm2. This positive charge is due either to donors lying close to the conduction band edge or to fixed positive charge. The above effects are reversible. © 1968 The American Institute of Physics.