Spectroscopy of metal related levels in Ge by transient infrared and microwave absorption techniques

Spectral analysis of deep levels in n-Ge implanted with different fluences of Co, Fe, Ti, and Cr ions is presented using transient infrared and microwave absorption techniques at room temperature. The activation energy Ei of the deep levels observed with this novel approach, correlate rather well with those determined by capacitance-deep level transient spectroscopy (DLTS) and those extracted by simulation of the carrier recombination lifetime dependency on excitation level. It is shown that the synchronous variation of the carrier lifetime with deep level related parts of the microwave probed photo-conductivity spectrum reveals the recombination activity of specific centres.