A digital pattern generator has a MEMS substrate with a plurality of doping layers and a plurality of insulating layers between respective doping layers. A plurality of lenslets are formed as holes through the substrate. A charge drain coating is applied to the inner surfaces of the lenslets. The charge drain coating drains electrons that come into contact with the charge drain coating so that the performance of the digital pattern generator will not be hindered by electron charge build-up. The charge drain coating includes a doping material that coalesces into clusters that are embedded within a high dielectric insulating material.