Low temperature deposition of indium tin oxide thin films by low voltage sputtering in various rare gases

Indium tin oxide (ITO) films were deposited at a temperature below 50degreesC by a low-voltage sputtering system. The sputtering voltage was fixed at 100 V and At, Kr, and Xe were used as the sputtering gases. Compared with the sputtering in Ar gas, the sputtering in Kr or Xe gas caused a significant suppression of crystallization of the deposited film and resulted in the formation of amorphous films. These films had much lower resistivities than the films deposited using Ar gas, since the Hall mobility of the films had a larger value. Typical Hall mobility and carrier density are 50 cm(2)/V sec, and 5 x 10(20) cm(-3), respectively. This improvement was attributable to the reduction of high-energy particle bombardment to the film surface in the sputtering. These films are stable at a temperature below 150degreesC, and crystallization occurs at a temperature above 150degreesC.