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

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 × 10 − 2 Ω 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 Sn and oxygen atoms and a lower initial carrier concentration, ~ 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 °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.