Process for producing an integrated circuit device with substrate via hole and metallized backplane

Claim 1

A process for providing a metallic backplane on a body of semiconductor material having a first side which includes integrated circuit devices and a second side, wherein said backplane provides electrical connection to a contact pad on said first side and provides heat conduction from a region on said first side, comprising the steps of: depositing a first mask material on said second side of said body opposite to said contact pad and said region; deposition a second mask material on said first mask material; removing said first and second mask materials in an area opposite said contact pad; etching said second body side to remove a portion of said body below the unprotected area; removing said first and second mask materials in an area opposite said region; etching said second body side for a time sufficient to remove substantially all of the body material to said contact pad but for a time less than that which removes the body material to said region; removing said first and second mask materials; and depositing a metal on said second side of said body.