Instrument measuring temperature dependence of minority-carrier lifetime without contact

An instrument measuring the temperature dependence of minority-carrier lifetimes without contacts is described. The temperature range is 100 to 420 K, and the shortest decay time observed is about 2 μs. The instrument utilizes the photo decay of microwave power reflected from the sample, therefore, it is a contactless method. As an example, the instrument was applied to high-quality silicon crystals used in very large scale integrated circuit fabrication. The measured temperature dependence could be explained by the Shockley–Read–Hall theory by assuming a level for the recombination centers at 0.18 eV from the valence band.