Indium tin oxide (ITO), sometimes referred to as tin doped indium oxide, is a widely used transparent conductor due to its ability to offer higher conductance and better etch ability over other transparent conductors. ITO has been utilized as transparent electrodes in liquid crystal displays and heterojunction solar cells, as transparent heat reflecting films, as the sensing medium in gas sensors, and in optoelectronic device applications. In general, these films are characterized by high transparency in the visible spectra, high reflectance in the IR and absorption in the UV regions, and near metallic conductivity. Although the desired characteristics of the film depend strongly on the application, they (transparency and conductivity) should ideally be as high as possible. In this work DC reactive sputtering was used to deposit high quality ITO films on ambient temperature substrates with a resistivity of lxl0"3 ohm-cm and an average transmittance of 85% over the range of 400 to 800 nm. The results of a statistically designed experiment showed that with a high oxygen partial pressure and low the argon partial pressure the deposited film was near fully reacted with resistivities of 1x10^ ohm-cm and an average transmission of 85%. With low oxygen and high argon partial pressures the ITO films are more metallic in nature with resistivities of lxlO-2 ohm-cm and an average transmission of about 50%. The optical and resistive properties of the films were shown to improve with 200 C post deposition anneals in air on hot plates. Anneals of asdeposited films up to 200 C initially reduced the resistivities of the films due to grain growth and provided small improvements in transmission. Anneals over 200 C increased the average transmission and resistivity by incorporating more oxygen into the films.
Library of Congress Subject Headings
Thin films; Semiconductor films; Indium
Department, Program, or Center
Center for Materials Science and Engineering
Infante, Philip, "Characterization of DC reactive sputtered indium tin oxide thin films" (1994). Thesis. Rochester Institute of Technology. Accessed from
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