System and method to align a substrate under a shadow mask. A substrate holder has alignment mechanism, such as rollers, that is made to abut against an alignment straight edge. The substrate is then aligned with respect to the straight edge and is chucked to the substrate holder. The substrate holder is then transported into a vacuum processing chamber, wherein it is made to abut against a mask straight edge to which the shadow mask is attached and aligned to. Since the substrate was aligned to an alignment straight edge, and since the mask is aligned to the mask straight edge that is precisely aligned to the alignment straight edge, the substrate is perfectly aligned to the mask.