Water absorption in thermally grown oxides on SiC and Si: Bulk oxide and interface properties

We combine nuclear reaction analysis and electrical measurements to study the effect of water exposure (D₂O) on the n-type 4H-SiC carbon face (000 1¯) MOS system and to compare to standard silicon based structures. We find that: (1) The bulk of the oxides on Si and SiC behave essentially the same with respect to deuterium accumulation; (2) there is a significant difference in accumulation of deuterium at the semiconductor/dielectric interface, the SiC C-face structure absorbs an order of magnitude more D than pure Si; (3) standard interface passivation schemes such as NO annealing greatly reduce the interfacial D accumulation; and (4) the effective interfacial charge after D₂O exposure is proportional to the total D amount at the interface.