The spatial phase locked scanning electron beam lithography systems (SPLEBL) is a new lithography technique with a pattern placement precision of about 1 nm. The SPLEBL technique can solve the major problem of poor placement accuracy existed in the conventional scanning electron beam lithography for that it uses a Fourier technique to detect the beam position in real time during exposure. The fiducial grid plays a key role in SPLEBL. The two-dimensional global fiducial grid with a grid period of 250 nm placed on top of the e-beam resist used in SPLEBL with high contrast, high brightness, long-range spatial-phase coherence, large area and a pattern placement precision of about 1 nm is fabricated using optical interference lithography in this article. The detail fabrication process is described and the SEM images of the fabricated grid are also presented in this paper. Only one evaporation step and several spin-coating steps are required in the fabrication process, so it is simple and user friendly.