MINORITY-CARRIER TRANSPORT PARAMETERS IN N-TYPE SILICON

Minority-carrier diffusion length, lifetime and diffusion coefficient in n-type Si are measured at 296 K in the doping range from 1018 cm−3 to 7 × 1019 cm−3. The measurement is based on a lateral collection of carriers generated by a spatially uniform light. The distance between the illumination edge and collection junction is defined by photolithography. This allows simultaneous and independent determination of all transport parameters in the same material. A self-consistency and accuracy check is provided by the relation L2 = Dτ. Details of experimentai procedures are described. Empirical best-fit relations for the three parameters are given. The extraction of lifetime and diffusion coefficient was done in the frequency domain, which allows for straightforward elimination of parasitic effects in the nanosecond and subnanosecond range. © 1990 IEEE