Effect of the Schottky Barrier Height on the Detection of Midgap Levels in 4H-SiC by Deep Level Transient Spectroscopy
The effect of the Schottky barrier height on the detection of the midgap defects EH6 and EH7 in 4H-SiC by deep level transient spectroscopy (DLTS) is systematically studied. The results show that the DLTS peak height - and as a consequence the observed defect concentration - increases with the increasing barrier height and saturates above 1.5 eV for EH6 and above 1.7 eV for EH7, while below 1.1 eV the DLTS peak height completely disappears. A model is applied, which determines the position of the quasi-Fermi level in the space charge region as a function of the barrier height and of the reverse bias applied and which explains the variation of the DLTS peak height.
Akira Suzuki, Hajime Okumura, Tsunenobu Kimoto, Takashi Fuyuki, Kenji Fukuda and Shin-ichi Nishizawa
S. A. Reshanov et al., "Effect of the Schottky Barrier Height on the Detection of Midgap Levels in 4H-SiC by Deep Level Transient Spectroscopy", Materials Science Forum, Vols. 600-603, pp. 417-420, 2009