Abstract: Radiation hardened integrated circuit devices may be fabricated using conventional designs and process, but including specialized structures to reduce or eliminate detrimental effects caused by various forms of radiation. An exemplary BGR structure includes a high-dose buried guard ring (HBGR) layer which is contacted to ground through the backside of the wafer or circuit die, thus forming a Backside BGR (BBGR) structure. In certain embodiments, the starting wafer may be highly doped to reduce the resistance from the HBGR to the back of the wafer, which is then further contacted to ground through the package. The performance of such devices may be further improved by using an electrically conductive adhesive to attach the die and to electrically connect the silicon substrate region to the package's conductive header, substrate, or die attach pad, which in turn is typically connected to one or more package pins/balls.

Abstract: A tool for etching at least one selected area of a silicon dixoide layer on a wafer. The tool includes a container which is partially filled with hydrofluoric (HF) acid. The tool further includes a template having an aperture extending between each selected area and the container. Vapors of the HF acid pass through each aperture to contact and etch each selected area in order to expose a test die on the wafer. An O-ring is associated with each selected area for sealing each of the selected areas from the remaining areas on the silicon dioxide layer such that substantially only the selected areas are etched by the vapors.