Electron doping of ALD-grown ZnO thin films through Al and P substitutions

• Published in: Journal of materials science Vol. 48; no. 7; pp. 2806 - 2811
• Main Authors: Tynell, T., Okazaki, R., Terasaki, I., Yamauchi, H., Karppinen, M.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.04.2013; Springer; Springer Nature B.V
• Subjects: Aluminum; Atomic layer epitaxy; Atomic properties; Carrier density; Characterization and Evaluation of Materials; Charge density; Chemistry and Materials Science; Classical Mechanics; Crystallization; Crystallography and Scattering Methods; Current carriers; Deposition; Dielectric films; Dopants; Doping; Electric properties; Electrical resistivity; Energy Materials & Thermoelectric; Film growth; Materials Science; Polymer Sciences; Seebeck effect; Solid Mechanics; Thin films; Zinc; Zinc oxide; Deposition Temperature; Dopant Content; Carrier Density; Seebeck Coefficient; Atomic Layer Deposition
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-012-6942-9

Several series of Al- and P-doped ZnO thin films have been deposited with atomic layer deposition at different temperatures using diethyl zinc, trimethyl aluminum, trimethyl phosphate, and H 2 O as the precursors. The optimal deposition temperature range is found at 160–220 °C where the film growth is stable and well-crystallized films with low resistivity are obtained. The effect of the dopant content on the charge carrier density of the films is evaluated based on optical reflectivity, Seebeck coefficient, and electrical resistivity data for the films. Both dopants are found to be effective in controlling the carrier density of ZnO; systematic increase in carrier density is demonstrated for Al-doping up to 2 at.% and for P-doping up to 5 at.%. The conductivity of the as-deposited films remains n -type.