Forming the Contact Surfaces of Micromechanical Switches
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
A contact fabrication process has been developed which produces a rounded contour on the plated contacting electrode of micromechanical switches. The complete process schedule is shown sequentially in Figs. 1a-1c. 1) Dope a (100) silicon wafer 10 heavily with boron in the regions 12 where a switch is desired. 2) Grow an epitaxial layer 14 over the entire substrate 10 to a thickness of 4 to 10 microns. 3) Deposit an insulating layer 16 to a thickness of 0.5 to 3 microns. 4) Deposit a thin metal film 18, typically Cr-Au, to a thickness of several hundred angstroms. 5) Apply a photoresist layer 20 and electroplate a thicker metal film 22 selectively through holes produced in the photoresist lithographically.