Patent ID: 9041126
Filing Date: 2015-05-26
Classification: H01L

Abstract:
1. A semiconductor transistor structure formed on a silicon substrate, comprising: a transistor gate on a top surface of the silicon substrate, the transistor gate having an effective gate length Lg, the transistor gate having two sides and a bottom with a bottom corner on each side defining a physical outer boundary of the gate; a source and drain extension region on either side of the transistor gate extending a distance inward from each side of the transistor gate, the source and drain extension regions defining two inner edges that form the effective gate length Lg, the source and drain extension regions being doped with a predefined dopant polarity; a deep source/drain doped region adjacent each of the source and drain extension regions, the deep source/drain doped regions being doped with a predefined dopant polarity that is the same as the dopant polarity for the source and drain extension regions, the deep source/drain doped regions having a dopant profile that includes a heavily doped portion therewithin; wherein the source/drain doped region and the source and drain extension region on each side of the transistor gate are in electrical contact with each other, the location of the electrical contact forming an interface; a substantially undoped channel portion that defines the space between the source and drain extension regions and the deep source/drain doped regions; and a screening region comprising a highly doped region of opposite polarity from the polarity of the deep source/drain doped regions and the source and drain extension regions, the screening region being immediately below the substantially undoped channel portion, the screening region extending laterally between the deep source/drain doped regions, the screening region having a dopant concentration of 5×10 wherein the screening region is located a vertical depth below the substrate surface, the screening region being no closer to the gate than the interface and wherein the screening region is positioned to be either above or below the heavily doped portion of the deep source/drain doped regions; and further including an outer portion defining a substantially undoped space region that substantially follows the combined shape of the deep source/drain doped regions and the source and drain extension regions, the outer portion having an outer edge that abuts the substantially undoped channel portion, the outer edge defining the interface, the screening region extending substantially to the outer edge of the outer portion.