Photosensitive Glass for Producing Recessed Metallurgy, Eliminating Need for Planarization
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
A photosensitive glass, after exposure to appropriate radiation (light, X-rays, electrons, etc.), can be crystallized by heat treatment into a desired pattern. Selective etching can then produce the pattern in three dimensions. Different exposure conditions (time/intensity/temperature) yield different etch structure depths. The application of this technique to formation of recess metallurgy is shown in Figs. 1 to 4. A photosensitive glass is coated on a substrate (Fig. 1), is selectively exposed and etched to produce, where required, multidepth recesses, as shown in Fig. 2. After deposition of a thin precoat of chromium, the unit is blanket coated with copper into the structure of Fig. 3. In the next step (Fig.