Abstract: A method of forming a mask for bombardment of a semiconductor substrate with high energy particles and a mask formed thereby are provided. A patterned layer of a blocking material is formed over a mask substrate to define a high energy particle bombardment mask pattern. The blocking material has sufficient thickness in the mask pattern to substantially shield the semiconductor substrate from selected high energy particles in areas overlapped by the mask pattern when the mask is aligned over the semiconductor substrate. The mask includes a mask substrate having a patterned layer of blocking material formed thereon to define a high energy particle bombardment mask pattern. The blocking material has sufficient thickness in the mask pattern to substantially shield the semiconductor substrate from selected high energy particles in areas of the semiconductor substrate overlapped by the mask pattern when the mask is aligned over the semiconductor substrate.