Diamond Immersion Photodetector for 193 nm Lithography

Abstract At present, most photodetectors work in atmospheric or vacuum environments, which leaves a large gap for detection under liquid conditions. However, this kind of research is of great significance, especially for the monitoring of 193 nm vacuum UV (VUV) light in the immersion lithography system underwater. Here, the p‐type diamond single crystal (PDSC) is applied as the photoelectrode for the construction of a VUV immersion photodetector with a PDSC‐ultra‐pure water‐Pt structure and a high response to 193 nm light. Under 193 nm excitation (@8 µW) and at 0 V, the PDSC immersion photodetector demonstrates a favorable characteristic of having a high responsivity of 5 mA·W⁻¹. Due to its exceptional performance, this device has been proven to function as a highly‐sensitive and self‐powered VUV detector, with significant potential for utilization in the monitoring of 193 nm light in immersion lithography systems.