Identification of Defects Limiting the Carrier Lifetime in n- Epitaxial Layers of 4H-SiC

The identification of defects limiting the carrier lifetime in n- epilayers of 4H-SiC is reviewed. The dominant electron traps, the Z1/2 and EH6/7 defects, believed to be VC-related, have been correlated to the lifetime in several studies. It was later shown that only one center, Z1/2 , actually controls the bulk lifetime. In recently-grown material with low Z1/2 concentration, other processes dominate. Recent measurements indicate that surface recombination controls the lifetime.