Ultra-Small Test Probe
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
A method of making ultra-small test probes of 1-micrometer diameter that will allow smaller fan-out test patterns, test pads and closer spacing of some devices or chips in certain designs is described. This allows for increased packing density of structures, shorten test lines to improve electrical testing, and allows for direct testing of chip sites. In order to make very fine (about 1-micrometer wide) probes, there is used the unique property of metal under electromigration to create huge stresses and form the probes by extrusion. To get the desired shape, first a narrow thin film of metal 10, e.g., aluminum,is deposited over a diffused contact 12 on a silicon wafer 14. The contact to the silicon is very highly doped to provide high conductivity.