Study of the inductively coupled plasma assisted DC magnetron sputtering (ICPDMS) during ITO deposition

Abstract

An inductively coupled plasma (ICP) assisted DC magnetron sputtering (ICPDMS) method for the deposition of indium tin oxide (ITO) thin films was developed to satisfy the challenging requirements of a room temperature process and high temperature durability. The resistivity of ITO thin films deposited by ICPDMS at room temperature was improved to as low as 1.2 x 10(-2) Omega cm by increasing the RF power of the ICP source to 1200 W. Due to the additional dissociation and ionization by the high density plasma in ICPDMS system, the ITO thin films have a higher portion of Sri and oxygen atoms and a lower initial carrier concentration, similar to 10(18) #/cm(3), at room temperature than conventional ITO. However, the carrier concentration could be rapidly increased up to 10(20) #/cm(3) by post-annealing to temperatures as high as 500 degrees C for 1 h under high vacuum conditions. Unlike conventional ITO, the electrical properties of ICPDMS-ITO were relatively unchanged after high temperature heat cycles, which is a very attractive property for high performance photovoltaic solar cell applications. (C) 2009 Elsevier B.V. All rights reserved.