Microstructure evolution and grain orientation in ITO targets and their effects on the film characteristics

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 17; pp. 14620 - 14634
• Main Authors: Mei, Fangsheng, Yuan, Tiechui, Li, Ruidi, Qin, Kai, Huang, Jingwei
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2018; Springer Nature B.V
• Subjects: Adhesive strength; Characterization and Evaluation of Materials; Chemistry and Materials Science; Compressive strength; Crystal structure; Density; Evolution; Flat panel displays; Grain orientation; Grain size; Indium oxides; Indium tin oxides; Influence; Laboratories; Materials Science; Microstructure; Morphology; Optical and Electronic Materials; Phase transitions; Powder metallurgy; Sintering; Solid solubility; Surface roughness; Texture; Tin oxides
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9598-7

ITO targets sintered at 1560–1600 °C were selected to deposit ITO films at 25 and 150 °C with a purpose of investigating the relationship between microstructure evolution and grain orientation in ITO targets and the film characteristics. It is found that, with increasing the sintering temperature, the triangle grains of In 4 Sn 3 O 12 (secondary phase) transform into the dendritic grains of In 2 SnO 5 (secondary phase), following by the increase of the solid solubility of tin oxide in In 2 O 3 phase (main phase). Besides, the sintering temperature has a great influence only on the texture of secondary phase. More solid solubility of tin oxide in In 2 O 3 phase, stronger texture intensity of secondary phase and higher sputtering temperature were found to promote the crystallinity of ITO films resulting in the lower sheet resistance and obtain the films with lower compression stress and strong adhesion. The transmittance of ITO films deposited at 25 °C is closely related to the film surface roughness, while it is mainly associated with the crystal structure for ITO films deposited at 150 °C.