Abstract A semiconductor device having an expanded guard ring overlying substantially the entire surface of a region except for at least one island therein. A relatively thin protective coating overlies the guard ring and a relatively thick protective coating overlies the island. A terminal connector contact for a wire-bonded or flip-chip device is formed on the relatively thick island portion of the protective coating, which is more suitable for withstanding bonding pressure. One form of this device includes a PNP transistor having an expanded P+ guard ring overlying a substantial portion of the collector surface noncontiguously closely surrounding the base region of the transistor. Islands of original P-type material having a relatively thick oxide coating thereon are left within the expanded P+ guard ring to support wire-bonding or flip-chip contact pads.
A method for making a face-bonding silicon transistor which comprises: oxidizing a major surface of a silicon wafer of a first conductivity type; removing said oxide from a first preselected area of said surface; diffusing a conductivity determining impurity of a second conductivity type into said first preselected area to form a PN junction; reforming said oxide over said first preselected area and the balance of said surface thereby increasing the oxide thickness on the balance of said surface; removing a portion of said reformed oxide overlying a second preselected area within said first preselected area and substantially the balance of said thicker oxide spaced from said first preselected area thereby defining a third preselected area, while preserving the thicker oxide coating over the PN junction and two discrete island portions spaced outside said PN junction within said third preselected area; diffusing a conductivity determining impurity of said first conductivity type into said second and third preselected areas; reforming said oxide over said second and third preselected areas and the balance of said surface including said islands thereby producing a thick oxide layer over said islands and a thin oxide layer over said second and third preselected areas; opening contact windows through said oxide to said surface within said first and second preselected areas; forming overlay contacts on said surface including terminal contact pads on said thick oxide layer over said islands; forming terminal connector bumps on said contact pads; pressure bonding a solder coated terminal connector lead to each of said bonding pads; and reflowing said solder to enhance bonding to said contact bumps.