SPECTRAL RESPONSE OF A PHOTODIODE USING 3C-SIC SINGLE-CRYSTALLINE FILM

3C-SiC/Si heterojunction photodiodes and 3C-SiC homojunction photodiodes have been fabricated by atmospheric chemical vapor deposition. The maximum quantum efficiency of heterojunction photodiodes with a window layer of 10 mum thick is 80% at 550 nm. An increase in the thickness of the SiC layer reduces the responsivity in wavelength regions shorter and longer than 500-550 nm. 3C-SiC self supported films of 20 mum thick, epitaxially grown on Si, have been used as substrates for homojunction photodiodes. The responsivity of the homojunction photodiode with a window layer thickness of 0.5 mum is 72 mA/W at 250 nm with a quantum efficiency of 36%. When the thickness of the window layer is decreased, the peak responsivity increases and the peak wavelength shifts to a shorter wavelength. These spectral responsivities are discussed together with the results of calculations using a one-dimensional model.