Passivation and Generation of States at P-Implanted Thermally Grown and Deposited N-Type 4H-SiC/SiO2 Interfaces
In this work the effect of phosphorus on the electrical properties of n-type 4H-SiC MOS capacitors is studied. Phosphorus ions are implanted into the epitaxial layers prior to the deposition of SiO2 by PECVD, in shallow depths and at concentrations at the oxide-semiconductor interface in the range of (5 x 1017…1 x 1019) cm-3. Those samples are compared with 31P-implanted 4H-SiC MOS capacitors with thermally grown oxides, which were primarily investigated in the previous work of the authors. It is shown that independently of the oxide technology phosphorus may lead to decrease of the density of interface traps, whose response time to the AC voltage is longer than 1 µs. The side-effect of the implantation of phosphorus is generation of the very fast interface states, which are able to follow the frequencies over 1 MHz.
Fabrizio Roccaforte, Francesco La Via, Roberta Nipoti, Danilo Crippa, Filippo Giannazzo and Mario Saggio
T. Sledziewski et al., "Passivation and Generation of States at P-Implanted Thermally Grown and Deposited N-Type 4H-SiC/SiO2 Interfaces", Materials Science Forum, Vol. 858, pp. 697-700, 2016