Halftone phase shift photomasks are provided including a substrate configured to transmit light; a shift pattern on the substrate, the shift pattern including a pattern area on a center portion of the substrate and a blind area disposed on a periphery of the substrate, the shift pattern of the blind area having a greater thickness than a thickness that of the pattern area, and being configured to partially transmit the light; and a light shielding pattern formed on the shift pattern in the blind area and being configured to shield the light. Related methods are also provided herein.