Kavli Affiliate: Jia Liu
| First 5 Authors: Ruijun Zhang, Mingkun Zhang, Guoliang Zhang, Yujian Chen, Jia Liu
| Summary:
A minority carrier lifetime of 25.46 $mu$s in a P-type 4H-SiC epilayer has
been attained through sequential thermal oxidation and hydrogen annealing.
Thermal oxidation can enhance the minority carrier lifetime in the 4H-SiC
epilayer by reducing carbon vacancies. However, this process also generates
carbon clusters with limited diffusivity and contributes to the enlargement of
surface pits on the 4H-SiC. High-temperature hydrogen annealing effectively
reduces stacking fault and dislocation density. Moreover, electron spin
resonance analysis indicates a significant reduction in carbon vacancy defects
after hydrogen annealing. The mechanisms of the elimination of carbon vacancies
by hydrogen annealing include the decomposition of carbon clusters formed
during thermal oxidation and the low-pressure selective etching by hydrogen,
which increases the carbon content on the 4H-SiC surface and facilitates carbon
diffusion. Consequently, the combination of thermal oxidation and hydrogen
annealing eliminates carbon vacancies more effectively, substantially enhancing
the minority carrier lifetime in P-type 4H-SiC. This improvement is
advantageous for the application of high-voltage SiC bipolar devices.
| Search Query: ArXiv Query: search_query=au:”Jia Liu”&id_list=&start=0&max_results=3