Method of making a semiconductor device with a metallic layer coupled to a lower region of a substrate and metallic layer coupled to a lower region of a semiconductor device

Claim 1

A method of fabricating a semiconductor device, comprising the steps of: forming a mesa comprised of a layer of a first conductivity of semiconductor material and a layer of second conductivity of semiconductor material, wherein the mesa resides on a substrate of a wafer of a third conductivity of semiconductor material; forming a first trench in an upper region of the substrate; forming a second trench in the upper region of the substrate between the mesa and the first trench, wherein the second trench is deeper than the first trench; covering the mesa, a top of the substrate, and the first and second trenches with a layer of glass; forming an opening through the layer of glass to the top of the mesa; forming an opening through the layer of glass to the bottom of the first trench; forming a metallic interconnecting structure that electrically couples the bottom of the first trench to the top of the mesa over a portion of the layer of glass between the mesa and the first trench; forming a module that includes the metallic interconnecting structure, said portion of the layer of glass, the mesa, the first trench, the second trench, and a portion of the substrate of the wafer; removing the semiconductor material residing below a bottom of the second trench in order to form a first discrete region of semiconductor material that includes the first trench and a second discrete region of semiconductor material that includes the mesa; applying metal or metal alloy to a bottom of the first discrete region and a bottom of the second discrete region.

Claim 2

A method of fabricating a semiconductor device, comprising the steps of: forming a mesa comprised of a layer of a first conductivity of semiconductor material and a layer of second conductivity of semiconductor material, wherein the mesa resides on a substrate of a wafer of a third conductivity of semiconductor material; forming a first trench in an upper region of the substrate; forming a second trench in the upper region of the substrate between the mesa and the first trench, wherein the second trench is deeper than the first trench; covering the mesa, a top of the substrate, and the first and second trenches with a layer of glass; forming an opening through the layer of glass to the top of the mesa; forming an opening through the layer of glass to the bottom of the first trench; forming a metallic interconnecting structure that electrically couples the bottom of the first trench to the top of the mesa over a portion of the layer of glass between the mesa and the first trench; forming a module that includes the metallic interconnecting structure, said portion of the layer of glass, the mesa, the first trench, the second trench, and a portion of the substrate of the wafer; removing the semiconductor material residing below a bottom of the second trench in order to form a first discrete region of semiconductor material that includes the first trench and a second discrete region of semiconductor material that includes the mesa; applying metal or metal alloy to a bottom of the first discrete region and a bottom of the second discrete region.