Process chamber arrangement

According to various embodiments, a process chamber assembly (100) may comprise: a process chamber (102) for processing a substrate (120) within the process chamber (102); an optically transparent region (106) in a chamber wall (102W) of the process chamber (102); an outside of the process chamber (102) arranged optical sensor assembly (108), wherein the optically transparent region (106) and the optical sensor assembly (106) for detecting a position of a substrate (120) within the process chamber (102) are arranged.