Title :
Successful enhancement of lifetime for SiO2 on 4H-SiC by N2O anneal
Author :
Fujihira, Keiko ; Miura, Naruhisa ; Shiozawa, Katsuomi ; Imaizumi, Masayuki ; Ohtsuka, Ken-ichi ; Takami, Tetsuya
Author_Institution :
Adv. Technol. R&D Center, Mitsubishi Electr. Corp., Hyogo, Japan
Abstract :
Time-dependent dielectric breakdown (TDDB) measurement by constant current stress has been performed to investigate the oxide (SiO2) reliability grown on n-type 4H-SiC. At 300K, the intrinsic injected charge to breakdown (QBD) of thermally grown SiO2 in wet O2 ambience is about 0.1 C/cm2, whereas N2O anneal after the thermal oxidation results in the drastic improvement of the reliability. The intrinsic QBD of N2O annealed SiO2 is found to be 10 C/cm2, which is two orders of magnitude larger than that of the oxide without N2O anneal, suggesting that the quality of SiO2 and/or SiO2/SiC interface is improved. TDDB measurement has been also performed at high temperatures up to 423 K. The activation energy of oxide lifetime estimated from time to failure of 80% is 0.35 and 0.10 eV for the oxide with and without N2O anneal, respectively.
Keywords :
MIS devices; annealing; nitrogen compounds; oxidation; power MOSFET; semiconductor device breakdown; semiconductor device reliability; silicon compounds; wide band gap semiconductors; 0.10 eV; 300 K; 423 K; 4H-SiC; MOS devices; N2O; SiC-SiO2; activation energy; constant current stress; intrinsic injected charge; lifetime enhancement; oxide lifetime; oxide reliability; reliability improvement; semiconductor device reliability; thermal oxidation; time-dependent dielectric breakdown; Annealing; Current measurement; Dielectric breakdown; Dielectric measurements; Electric breakdown; Oxidation; Performance evaluation; Silicon carbide; Stress measurement; Thermal stresses; Dielectric breakdown; MOS devices; oxidation; semiconductor device reliability;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2004.837533
