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

The spatial distribution of carriers and an energy level of charge traps ar e measured with a newly built variable-temperature scanning capacitance mic roscope (VTSCM). The system has the spatial resolution of similar to 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 de ep level transient spectroscopy. (C) 2001 American Institute of Physics.