Limitations of the MOS capacitance method for the determination of semiconductor surface properties

摘要: For the use of MOS capacitance method in study surface properties, various approximations and assumptions, a purely conceptual an experimental nature, are usually made. These not always justified. In this paper applicability for studies is examined critically. It shown that limited its accuracy, that, most cases, it yields only gross features states. If there traps distributed spatially throughout oxide, effective state distribution can be found, may interpreted ambiguously as due either to right at interface, or both. Because consists essentially oxide series with semiconductor capacitances practical lower limit on magnitude which measured. Together difficulties interpreting measurements inversion layer regime, leads restriction portion forbidden gap states investigated. capacitors, produced by thermal oxidation silicon wet dry oxygen, were method. was found within range potential covered these measurements, total number occupied varies linearly if assumed all located interface. However, results also explained contains high density low lying trap sites uniformly oxide. some specimens monoenergetic level 0.7 eV below conduction band interface found.