Amorphous In-Si-O Films Fabricated via Solution Processing

We report the characteristics of an amorphous oxide semiconductor In-Si-O fabricated via solution processing. In-Si-O thin films with nominal silicon concentration of 0 at.%, 1 at.%, 3 at.%, 5 at.%, 9 at.%, 50 at.%, and 100 at.% were fabricated via spin coating. The films were characterized via thermal desorption spectroscopy (TDS), x-ray reflectivity, x-ray diffraction (XRD), extended x-ray absorption fine structure (EXAFS), and electrical resistance measurements. TDS analysis suggested that organic residues, such as organic functional groups from raw materials and solvents, were almost completely desorbed from the films at approximately 400°C. The XRD and EXAFS analyses confirmed that pure In2O3 crystallizes at approximately 350°C and that the crystallization temperature increases with the silicon concentration. In-Si-O films with silicon concentration above 3 at.% exhibited high electrical resistance, indicating that films fabricated via spin coating contain few oxygen vacancies. These results suggest that In-Si-O thin films have significant potential for use as channels in field-effect transistors designed for next-generation flat-panel displays.