Comparative Study of Indium Oxide Films for High‐Mobility TFTs: ALD, PLD and Solution Process

Abstract

Abstract Deposition of indium oxide base films for high‐mobility thin film transistors (TFTs) has been an important part in the implementation of high‐resolution and high‐frequency display back panels. In this study, three types of In 2 O 3 (InO) films have been fabricated for TFTs using atomic layer deposition (ALD), pulsed laser deposition (PLD), and solution process, respectively. ALD‐derived InO films show controllable grain formation and optimized TFTs show the field effect mobility of ≈100 cm 2 V −1 s −1 in both the conventional transistor measurements and critical four‐probe measurements, reaching the level of low‐temperature polycrystalline silicon (LTPS). Combined spectroscopy investigations show that the ALD‐derived InO film features advantages as compared to those of the PLD‐deposited and solution‐processed InO film in providing a smoother surface morphology, good crystallinity, and more orderly atomic growth mode. Moreover, the bias‐stress stability of ALD‐derived TFTs can be improved with further passivation.