Variable-temperature scanning capacitance microscopy: A way to probe charge traps in oxide or semiconductor

Abstract

The spatial distribution of carriers and an energy level of charge traps are measured with a newly built variable-temperature scanning capacitance microscope (VTSCM). The system has the spatial resolution of ∼20 nm, and the good energy resolution enough to measure the energy level and the capture cross section of electron or hole traps. By operating the VTSCM in an isothermal transient mode of capacitance spectroscopy, a hole trap that lies about 0.40 eV above the valence band maximum is identified in a SiO2/p-Si sample, and the result is compared to that taken with a conventional deep level transient spectroscopy.