Al Ohmic Contacts to HCl-Treated MgxZn1−xO
Authors: Sheng, H.; Saraf, G.; Emanetoglu, N.W.; Hill, D.H.; Lu, Y.
Source: Journal of Electronic Materials, Volume 34, Number 6, June 2005 , pp. 754-757(4)
Abstract:The Al nonalloyed ohmic contacts were fabricated on MgxZn1−xO (0 ≤ x ≤ 0.2) thin films. HCl surface treatment significantly reduced the specific contact resistances to value around 10−4 Ω cm2. X-ray photoelectron spectroscopy (XPS) analysis revealed that the HCl treatment increased the oxygen vacancy density and introduced chlorine to the semiconductor surface, resulting in a thin conductive layer and thus reduced specific contact resistance. A subsequent oxygen plasma treatment reduced the oxygen vacancy density, and correspondingly increased the specific contact resistance. Al-ZnO contacts were insensitive to the HCl treatment, due to the formation of a highly conductive Al-doped thin interface layer.
Document Type: Research Article
Publication date: June 2005