화학공학소재연구정보센터
Applied Surface Science, Vol.301, 19-23, 2014
Characterization of 4H-SiC surfaces by non-destructive techniques based on capacitance voltage measurements
Two recently developed characterization techniques for doping density profiling of SiC structures are introduced and compared. One is the in situ mercury contact capacitance-voltage (C-V) method realized without surface preparation, the other is the corona charge-voltage technique (Q-V) which is not only no-preparation but non-contact as well. It is shown that accurate measurements can be performed by both techniques even in the absence of any passivation layer (bare surface). While in the case of the C-V technique the standard measurement routine and evaluation process is applicable and provides a satisfactory result for SiC, a significantly revised and modified method is used for the Q-V measurement based on the long lasting, stable deep-depletion state of the SiC surface due to the very low intrinsic carrier concentration and thus a very long generation lifetime. Despite the different nature of the two techniques, doping density values determined by them have excellent correlation, which indicates the reliability and accuracy of both methods. The industrial applicability of the two techniques is compared in terms of reproducibility of the results. (C) 2014 Elsevier B.V. All rights reserved.