Patent ID: 7229669

Claim:
A method for providing reactive material enclosed by covering material on a substrate, the method comprising providing a substrate having a surface, providing a shadow mask, positioning the shadow mask and substrate in a fixture so the shadow mask is in a position to align an aperture of the shadow mask with a portion of the surface, positioning the shadow mask and substrate in a vacuum deposition chamber having a reactive material deposition source and a covering material deposition source, providing a vacuum in the vacuum deposition chamber, evaporating reactive material from the reactive material deposition source such that the reactive material passes through the aperture of the shadow mask and deposits on the surface to define an area of coverage of the reactive material, the reactive material comprising rubidium, cesium, or gallium, and evaporating covering material from the covering material deposition source to produce an area of coverage of the covering material that is greater than the area of coverage of the reactive material and that includes the area of coverage of the reactive material, to enclose the reactive material coated on the substrate, wherein when the reactive material comprises rubidium or cesium, the covering material comprises aluminum, and when the reactive material comprises gallium, the covering material comprises tungsten.