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US 8,999,861 B1Granted
Semiconductor structure with substitutional boron and method for fabrication thereof
AssigneeSuVolta, Inc.
InventorsLance Scudder, Pushkar Ranade, Charles Stager, Lucian Shifren, Dalong Zhao, U.C. Sridharan, Michael Duane
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Abstract
A method for fabricating a semiconductor structure so as to have reduced junction leakage is disclosed. The method includes providing substitutional boron in a semiconductor substrate. The method includes preparing the substrate using a pre-amorphization implant and a carbon implant followed by a recrystallization step and a separate defect repair/activation step. Boron is introduced to the pre-amorphized region preferably by ion implantation.
Claims6
A method for fabricating a semiconductor structure on a semiconductor substrate, comprising:
- masking portions of the substrate to form a pattern of transistors;
- performing a pre-amorphization implant into selected open areas defining a channel stack underlying a gate for a plurality of transistor elements of a similar type;
- performing a carbon ion implantation into the selected open areas in addition to the pre-amorphization implant;
- performing a boron ion implantation into the selected open areas in addition to the carbon ion implantation so as to form a screening region for the transistor element;
- performing a solid phase epitaxy after the carbon and boron ion implantations to cause the amorphized portions to transform into crystalline structures;
- performing an activation anneal to activate the boron by rendering the boron substitutional;
- forming a threshold voltage control layer on the boron screening region of the transistor element;
- and
- forming an epitaxial channel layer on the threshold control layer of the transistor element.
6 more elements
Dependencies are inferred from the claim text.