Authors: Gyuwon Yang, Junil Kim, Byeongmoon Lee, Jae Eun Jang, Hyuk‐Jun Kwon
Published: 2025-05-30
Source: Full article
AbstractThe lack of p‐type conductivity in metal oxide semiconductors presents the major limitation for their integration into complementary metal‐oxide‐semiconductor (CMOS) technology, which requires both n‐type and p‐type semiconductors for balanced and efficient operation. Titanium dioxide (TiO2) is known for its wide‐gap n‐type semiconductor characteristics, but it is challenging to convert it into a p‐type semiconductor. This study focuses on the semiconducting type conversion of TiO2 via laser‐assisted oxidation and doping integration, enabling simultaneous Ti oxidation to form TiO2 and type‐conversion‐friendly Al doping in a single step. When the laser power exceeds a specific threshold, Al cations from the underlying Al₂O₃ layer diffuse into the TiO₂ lattice. This selective incorporation of Al converts the intrinsic n‐type conductivity of TiO₂ to p‐type by substituting Ti⁴⁺ with Al3⁺. The formation of TiO2 and the incorporation of Al dopants are confirmed using X‐ray Photoelectron Spectroscopy and Energy Dispersive Spectroscopy Transmission Electron Microscopy. In addition, the fabrication of laser‐oxidized Al‐doped TiO2 thin‐film transistors confirms that Al doping improves hole current and photostability. The laser‐induced Al‐doped TiO2 offers an easy, simple, efficient, and controllable fabrication method for CMOS technology and advanced electronic devices.