Journal of Materials Research

Articles

Thermal Degradation Behavior of Indium Tin Oxide Thin Films Deposited by Radio Frequency Magnetron Sputtering

Yong-Nam Kima1 c1, Hyun-Gyoo Shina1, Jun-Kwang Songa1, Dae-Hyoung Choa1, Hee-Soo Leea1 and Yeon-Gil Junga2

a1 Material Testing Team, Korea Testing Laboratory, Guro-gu, Seoul 152-848, Republic of Korea

a2 Department of Materials Science and Engineering, Changwon National University, Changwon, Kyungnam 641-773, Republic of Korea

Abstract

The thermal degradation behavior of indium tin oxide (ITO) thin films coated on glass substrates using radio frequency (rf) magnetron sputtering was investigated over the temperature range of 100–400 °C in air. The resistivity of ITO films increases abruptly after the thermal degradation temperature of 250 °C is reached, with a slight increase from 200 to 250 °C. The x-ray photoelectron spectrometry intensity ratio of O/(In + Sn) in thermally degraded ITO films is higher than that in normal films. The carrier concentration gradually decreases up to 200 °C, sharply drops between 200 and 250 °C with increasing temperature, and then saturates from 275 °C. The Hall mobility drops suddenly at 275 °C. The diffusion of oxygen into oxygen interstitials and oxygen vacancies and the chemisorption of oxygen into grain boundaries decrease the carrier concentration and the Hall mobility, respectively. The former mainly affects the resistivity of ITO films below 250 °C, and the later above 250 °C.

(Received January 26 2005)

(Accepted March 24 2005)

(Online publication June 2005)

Key Words:

  • Ceramic;
  • Hall effect;
  • Thin film

Correspondence:

c1 Address all correspondence to this author. e-mail: eternity@ktl.re.kr

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