HIGH-RESOLUTION ELECTROLESS DEPOSITS ON ALUMINA FROM ULTRAVIOLET EXPOSURE OF A PT METALORGANIC

Photochemical and electroless metallization techniques have been combined to create metal patterns on alumina (Al2O3). In this positive imaging process, small amounts of an ultraviolet (uv) sensitive metalorganic (MO) Pt compound are first applied to the surface of the alumina by spin coating. A quartz photomask is then used to selectively expose the Pt MO to uv light in the areas that are to be metallized. After a xylene rinse removes the Pt MO from the unexposed areas, the substrate and xylene insoluble Pt MO are fired in air at 450-degrees-C for 5 min, followed by electroless deposition of Ni on the uv exposed surface. Total Pt consumption is to about 0.01-0.02 g/m2 of metallized surface-no Pt or Ni was detected in nonmetallized regions. The uv exposure time is brief, less-than-or-equal-to 0.75 s, and 0.3-mu-m-thick Ni/B deposits can be patterned on 96% pure alumina with resolution of nearly 28-mu-m line/spaces.