Image based in situ electron-beam drift detection by silicon photodiodes in scanning-electron microscopy and an electron-beam lithography system

Abstract

► Silicon-photodiode detector for in-situ beam position sensing in an scanning electron microscope (SEM). ► Applying image processing technique to the backscattered-electron image to reach nanometer resolution. ► The performance in detecting the drift of the electron beam over time was analyzed. ► This detection mechanism is useful for beam position feedback in the electron-beam direct-write lithography system. A silicon-photodiode detector can be used to sense the position of the electron beam in a scanning-electron microscope. In order to validate the implementation of a electron beam drift detector, a silicon photodiode was constructed with a low profile and small working distance. The performance in detecting the drift of the electron beam over time was analyzed. It was also shown that a back scattered-electron image can be created with electron scanning, which allows the development of highly sensitive in situ beam position feedback in the electron-beam direct-write lithography system.