ON THE RELATIONSHIP BETWEEN THE FEEDBACK CHARGE METHOD, CHARGE TRANSIENT SPECTROSCOPY AND C-V MEASUREMENTS OF SEMICONDUCTORS AND INSULATORS

The feedback charge method, originally proposed for quasi-static C-V measurements, is treated with regard to filtering of multi-exponential charge transients in both semiconductor devices and insulators. An intimate relationship between the feedback charge method and deep-level transient spectroscopy (DLTS) is established. The only condition to be applied is to use a unique and sufficiently small excitation voltage step DELTA-U from the region where the response is linear in DELTA-U in either case. Improved spectral resolution of time constants is mediated by a new higher order filtering of the transient response, advanced to that current in charge transient spectroscopy. The knowledge of relative contributions of individual relaxations to the total, transient charge is a requisite for a meaningful interpretation of C(x)(t) data. Finally, the relations of equivalence between the small-signal time-dependent capacitance? C(x)(t) and its frequency domain counterpart C(omega) measured by standard ways are derived and their applicability discussed.