Investigation on origin of Z[1/2] center in SiC by deep level transient spectroscopy and electron paramagnetic resonance

Abstract

The Z[1/2] center in n-type 4H-SiC epilayers—a dominant deep level limiting the carrier lifetime—has been investigated. Using capacitance versus voltage (C-V) measurements and deep level transient spectroscopy (DLTS), we show that the Z[1/2] center is responsible for the carrier compensation in n-type 4H-SiC epilayers irradiated by low-energy (250 keV) electrons. The concentration of the Z[1/2] defect obtained by C-V and DLTS correlates well with that of the carbon vacancy ( Vc ) determined by electron paramagnetic resonance, suggesting that the Z[1/2] deep level originates from Vc.