Wafer-Scale Growth of Ultrauniform 2D PtSe<sub>2</sub> Films with Spatial and Thickness Control through Multi-step Metal Conversion
Minseung Gyeon, Jae Eun Seo, Saeyoung Oh, Gichang Noh, Chang‐Wook Lee, Minhyuk Choi, Seongdae Kwon, Tae Soo Kim, Hu Young Jeong, Seungwoo Song, Jiwon Chang, Kibum Kang
Abstract
Metal conversion processes have been instrumental in advancing semiconductor technology by facilitating the growth of thin-film semiconductors, including metal oxides and sulfides. These processes, widely used in the industry, enhance the semiconductor manufacturing efficiency and scalability, offering convenience, large-area fabrication suitability, and high throughput. Furthermore, their application to emerging two-dimensional (2D) semiconductors shows promise in addressing spatial control and layer number control challenges. In this work, we designed a multi-step metal conversion process for 2D materials to synthesize a high-quality and ultrauniform film. PtSe 2 is introduced to utilize its wide-band-gap tunability, which exhibits both semiconductor and metallic properties. Our multi-step-grown PtSe 2 film shows extremely low roughness ( R a = 0.107 nm) and improved interlayer quality compared to the single-step PtSe 2 film. Additionally, we explored the growth mechanism of the metal conversion process and how the multi-step method contributes to the thickness uniformity of the film. We demonstrated a thin PtSe 2 channel field-effect transistor (FET) array with p-type behavior with a maximum on/off ratio ∼10 3 . The FET fabricated by the MoS 2 channel with the semimetallic multi-step PtSe 2 electrode shows an enhanced performance in mobility and contact resistance compared to the conventional single-step PtSe 2 electrode FET.