Near-interface concentration reduction in n-type Au/CrGaAs Schottky contacts

• Published in: Vacuum 1990, Vol.40 (1), p.201-203
• Main Authors: Horváth, ZsJ, Gyúró, I, Németh-Sallay, M, Tüttö, P
• Format: Article
• Language: English
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/0042-207X(90)90156-S

Recently discrepancies were obtained between the barrier heights evaluated from the I-V and C-V measurements of Au/CrGaAs Schottky contacts and between the experimental and theoretical concentration dependences of the built-in potential obtained for the same devices. In this paper the possible causes of these discrepancies are analyzed. It is shown that the capacitance values at zero bias and the obtained built-in potentials are consistent with the concentrations evaluated from the C-V measurements of the finished contacts, but they are not consistent with the concentrations obtained on the eptitaxial layers before the device preparation by electrochemical C-V profiling. It is also shown that the above discrepancies may be explained by errors in the evaluation of the built-in potential. These errors are due to the concentration-dependent reduction of the electron concentration near the M-S interface. The possible mechanisms of the concentration reduction are outlined briefly.