Wannier-Stark localization in 6H-SiC JFETs

The paper presents Wannier-Stalk localization related phenomena investigated in 6H-SiC JFET structures. The p-type, 2 μm thick layer doped to N_d-N_a=1.5×10¹⁷ cm^-3 was grown onto the p-layer. Two step photolithography was performed with evaporated Al/Ni combination to form metal contacts. Subsequent dry etching process was performed to produce JFET devices. In experiments the JFET structures were illuminated by a light with different wavelengths ranging from 0.25 to 0.40 μm. The light penetrates into the channel through the open surface of the n-layer. Using the exciting light with different wavelengths, the diffusion lengths of the electron in the p⁺-layer and holes in the n-layer were determined to be L_n=0.4 μm and L_h=0.3 μm respectively.