[17a-PB1-1~32] 6.3 Oxide electronics

[17a-PB1-10] Phase transformation of SnO_x thin films induced by post-annealing for enhancement of p-channel thin-film transistor characteristics

〇(M2)Motonori Taki¹, Yoshiaki Hattori¹, Masatoshi Kitamura¹ (1.Kobe Univ.)

Keywords:

thin film transistor,PMOS,SnO

Achieving p-channel oxide thin-film transistors is an important challenge for complementary oxide semiconductor circuits, mainly due to the metastable nature of SnO and the difficulty of phase control. In this study, SnO_X thin films were fabricated by reactive sputtering using a Sn metal target, followed by post-annealing in air. The relationship between annealing temperature, optical appearance, chemical states, and TFT characteristics was investigated. Optical microscopy revealed a clear color change in the channel region from brown to light blue with increasing annealing temperature. TFTs annealed at 200 C exhibited p-channel operation with an on/off current ratio of approximately 10³ and a field-effect mobility of 2.3 cm² V^-1 s^-1. X-ray photoelectron spectroscopy confirmed that the Sn²⁺ fraction increased after annealing, indicating the formation of SnO-rich films. These findings suggest the possibility of achieving more detailed phase control of SnO_X thin films.