Monolayer tungsten disulfide (WS₂) has recently attracted a great deal of interest as a promising material for advanced electronic and optoelectronic devices such as photodetectors, modulators, and sensors. Since these devices can be integrated in a silicon (Si) chip via back-end-of-line (BEOL) processes, the stability of monolayer WS₂ in BEOL fabrication conditions should be studied. In this work, the thermal stability of monolayer single-crystal WS₂ at typical BEOL conditions is investigated; namely (a) heating temperature of 300 C, (b) pressures in the medium- (10⁻³ mbar) and high- (10⁻⁸ mbar) vacuum range; (c) heating times from 30 minutes to 20 hours. Structural, optical and chemical analyses of WS₂ are performed via scanning electron microscopy, Raman spectroscopy, photoluminescence and X-ray photoelectron spectroscopy. It is found that monolayer single-crystal WS₂ is intrinsically stable at these temperature and pressures, even after 20 h of thermal treatment. The thermal stability of WS₂ is also preserved after exposure to low-current electron beam (12 pA) or low-fluence laser (0.9 mJ μm⁻²), while higher laser fluencies cause photo-activated degradation upon thermal treatment. These results are instrumental to define fabrication and inline monitoring procedures that allow the integration of WS₂ in device fabrication flows without compromising the material quality.

单层二硫化钨（WS ₂）作为一种先进的电子和光电设备（例如光电探测器，调制器和传感器）的有前途的材料，最近引起了广泛的关注。由于这些设备可以通过后端（BEOL）工艺集成到硅（Si）芯片中，因此应研究单层WS ₂在BEOL制造条件下的稳定性。在这项工作中，研究了在典型的BEOL条件下单层单晶WS ₂的热稳定性。即（a）300°C的加热温度，（b）中真空（10 ^-3 mbar）和高真空（10 ^-8 mbar）范围内的压力；（c）加热时间从30分钟到20小时。WS的结构，光学和化学分析₂通过扫描电子显微镜，拉曼光谱法，光致发光和X射线光电子光谱法进行。发现即使在热处理20小时后，单层单晶WS ₂在这些温度和压力下本质上也是稳定的。WS的热稳定性₂也被保留暴露于低电流的电子束（12 PA）或低能量激光（0.9毫焦耳之后μ米^-2），而较高的激光fluencies原因光活化降解后热处理。这些结果有助于定义制造和在线监控程序，这些程序允许将WS ₂集成到设备制造流程中，而不会影响材料质量。