ZnO thin films prepared by atomic layer deposition and rf sputtering as an active layer for thin film transistor

• Published in: Thin solid films 2008-02, Vol.516 (7), p.1523-1528
• Main Authors: Lim, S.J., Kwon, Soonju, Kim, H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Atomic layer deposition; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Materials; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; rf sputtering; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Transistors; Transparent TFT; Vapor phase epitaxy; growth from vapor phase; ZnO
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2007.03.144

Recently, the application of ZnO thin films as an active channel layer of transparent thin film transistor (TFT) has become of great interest. In this study, we deposited ZnO thin films by atomic layer deposition (ALD) from diethyl Zn (DEZ) as a metal precursor and water as a reactant at growth temperatures between 100 and 250 °C. At typical growth conditions, pure ZnO thin films were obtained without any detectable carbon contamination. For comparison of key film properties including microstructure and chemical and electrical properties, ZnO films were also prepared by rf sputtering at room temperature. The microstructure analyses by X-ray diffraction have shown that both of the ALD and sputtered ZnO thin films have (002) preferred orientation. At low growth temperature Ts≤125 °C, ALD ZnO films have high resistivity (>10 Ω cm) with small mobility (