Study on N type 4H-SiC minority carrier lifetime by microwave photoconductivity decay technology

Microwave photoconductivity decay technology is used to measure the minority carrier lifetime of N type 4H SiC.Respectively setting the excitation intensity to 100%, 50%, 25% and 5% the minority carrier lifetime is measured. The results indicated that the minority carrier lifetime of N type 4H SiC sample is about 0.138μs and the incident laser intensity is not the main factor to increase or decrease the lifetime. But when the incident laser intensity is weakening, the signal wave amplitude is lessened and the noise is correspondingly increased. This means some weak signal measurement technology such as filter or smooth window must be used. The experiment indicated that Microwave photoconductivity decay technology is convenient and efficient to measure the N type carrier lifetime which have a great significance to 4H-SiC.