Enhanced mobility and stability in evaporated p-type TeOx/Te transistors via UV-O3-treated substrates

Recently, tellurium (Te), a p-type semiconductor material, has attracted tremendous interest in electronics and large-scale integrated circuits owing to its high hole mobility and excellent air stability. Although evaporated Te thin films have shown great potential for large-scale p-type transistors, further research is needed to improve the quality of Te thin films and enhance their electrical performance. In this work, we demonstrate that a simple ultraviolet/ozone (UV-O 3 ) pretreatment of Si/SiO 2 substrates can significantly reduce surface roughness and improve crystallinity in TeO x /Te films, as confirmed by grazing-incidence X-ray diffraction (GIXRD), Raman spectroscopy and atomic force microscopy (AFM). The improved structural properties lead directly to a remarkable improvement in device electrical performance. The hole mobility of devices fabricated on UV-O 3 -pretreated substrates increases markedly from 27.4 cm 2 /V·s to 75.8 cm 2 /V·s compared with those on untreated substrates. In addition, the subthreshold swing, hysteresis, contact resistance, interface trap state density and threshold-voltage stability under both negative bias stress (NBS) and positive bias stress (PBS) are all substantially improved. This work provides a simple and easily implementable approach to enhance the electrical performance of p-type Te-based transistors, offering valuable guidance for their application in next-generation electronics.