On the relationship between the feedback charge method, charge transient spectroscopy and C-V measurements of semiconductors and insulators

Abstract

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 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 higher order filtering of the transient response, advanced to that current in charge transient spectroscopy. The knowledge of relative contributions of individual relations to the total transient charge is a a requisite for a meaningful interpretation of capacitance data. Finally, the relations of equivalence between the small-signal time-dependent capacitance and its frequency domain counterpart measured by standard ways are derived and their applicability discussed.