Electrical and optical properties of indium tin oxide thin films grown by pulsed laser deposition

Abstract

Indium tin oxide (ITO) thin films (200–400 nm in thickness) have been grown by pulsed laser deposition (PLD) on glass substrates without a post-deposition anneal. The electrical and optical properties of these films have been investigated as a function of substrate temperature and oxygen partial pressure during deposition. Films were deposited at substrate temperatures ranging from room temperature to 300 °C in O2 partial pressures ranging from 0.1 to 100 mTorr. For 300 nm thick ITO films grown at room temperature in oxygen pressure of 10 mTorr, the electrical conductivity was 2.6×10-3 Ω-1cm-1 and the average optical transmittance was 83% in the visible range (400–700 nm). For 300 nm thick ITO films deposited at 300 °C in 10 mTorr of oxygen, the conductivity was 5.2×10-3 Ω-1cm-1 and the average transmittance in the visible range was 87%. Atomic force microscopy (AFM) measurements showed that the RMS surface roughness for the ITO films grown at room temperature was ∼7 A, which is the lowest reported value for the ITO films grown by any film growth technique at room temperature.