WS₂-Based Photosensing Devices: Process Scalability and Impact of Sulfurization

Process scalability, reproducibility, and reliability are the key components for the semiconducting manufacturing industries for mass production of any devices. This article presents the impact of the synthesis process and microfabrication techniques on the photosensing devices performance metrics. The CMOS compatible standard wafer scale microfabrication techniques are used to fabricate the photosensing devices based on tungsten disulfide (WS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>). The WS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> synthesis, device fabrication, and process scalability were verified by testing multiple devices from the processed silicon wafers. The optimized WS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>-based photosensing device offers a responsivity and detectivity of 1.94 A/W and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.3\times 10^{{11}}$ </tex-math></inline-formula> Jones at 950 nm, respectively. This optimized device has offered 38 times improved responsivity than the other tested devices. The optimized device has shown the rise/fall time of 81.5/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$79.9~\mu $ </tex-math></inline-formula>s at 950 nm. In addition, the stability test was performed by stimulating the device with different modulating frequencies.