A comprehensive method combining deep-depletion profiling and capacitance transients to evaluate energy and depth distribution of MOS bulk defects

A measurement procedure is presented which combines deep-depletion profiling of MOS capacitors with transient analysis to simultaneously provide the doping profile and the bulk minority generation current. The evaluation of the transient yields the reverse current directly as a function of the depletion width, thus enabling depth profiling of the generation centers. The substrate temperature is an additional parameter that permits the activation energy of the generation mechanisms to be deduced and diffusion currents from the neutral bulk to be identified. Investigation of typical samples shows that the diffusion component is important in devices on lightly doped substrates, whereas it is not found in devices on heavily doped buried layers