Negative Field Reliability of ONO Gate Dielectric on 4H-SiC

Abstract

It was experimentally shown that an ONO gate dielectric carefully formed on 4H-SiC has extremely high reliability even under a negative electric field at least up to a junction temperature of 300°C, making it promising for power MOS and CMOS applications. Medium charge to failure of –30 C/cm2 was achieved for fully processed polycrystalline Si gate MONOS capacitors with an equivalent SiO2 thickness of teq = 44 nm and a 200-μm diameter. The medium time to failure of these capacitors projected for –3 MV/cm exceeds 86 and 6.3 thousand years at room temperature and 300°C, respectively. A parasitic memory action did not appear even when Eox of -6.6 MV/cm was applied for 5000 seconds.