Patent ID: 8557045

Claim:
An apparatus for depositing material on a substrate, the apparatus comprising: a source block for exposing a substrate to sublimating vapor in a vacuum, the source block comprising: a first surface of the source block disposed proximate to a surface of the substrate; an open cavity formed into the first surface of the source block and extending into the source block to form a second surface, the second surface of the source block being substantially parallel to the first surface of the source block; a plurality of holes respectively formed into the second surface of the source block and respectively extending into the source block for a specified distance; and material positioned within each of the plurality of holes to be sublimated during exposure of the substrate, the material in each of the plurality of holes having a corresponding initial sublimation surface area, the material positioned such that the top of the material is below the second surface; wherein the plurality of holes are configured such that a sublimation surface area of the material within each of the plurality of holes is substantially equivalent to the corresponding initial sublimation source area as the material regresses into the plurality of holes; and the source block is configured such that radiative heat transfer between a portion of the surface of the substrate and the material within each of the plurality of holes is substantially constant as the material regresses into the plurality of holes.