A silicon photodiode detector can be used for position sensing of the electron beam in the Scanning Electron Microscope (SEM). In order to validate the implementation of the multi-beam detector array, the silicon photodiode was made thin and fitted within a small working distance. The performance of drift detection of the electron beam as time varies is investigated. Besides, a backscattered electron image can be created by scanning the electron beam. It may allow the development of a massively parallel electron beam direct-write lithography system with electron imaging capability.