Tri-gate devices and methods of fabrication

• US 7,514,346 B2
• Filed: 12/07/2005
• Issued: 04/07/2009
• Est. Priority Date: 08/23/2002
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chau, Robert S., Kavalieros, Jack, Doyle, Brian S., Hareland, Scott A., Datta, Suman, Barlage, Douglas
• Primary Examiner(s): Doan; Theresa T
• Application Number:
  US11/297,084
• Publication Number:
  US 20060228840A1
• Time in Patent Office: 1,217 Days
• Field of Search: 438/149, 438/184, 438/303, 438/591, 438/595, 257/E21.205, 257/E21.624, 257/E21.638, 257/E21.561, 257/E21.57, 257/E21.7, 257/E21.704, 257/E21.176, 257/E21.186
• US Class Current: 438/591
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01L 29/0665 the shape of the body defining a nanostructure nanotechnology per se B82B
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/1033 with insulated gate, e.g. characterised by the length, the width, the geometric contour or the doping structure with channel and gate aligned in the lengthwise direction H01L29/42376; with buried channel H01L29/7838
• CPC Class Codes: H01L 29/41791 for transistors with a horizontal current flow in a vertical sidewall, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/42392 fully surrounding the channel, e.g. gate-all-around
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/772 Field effect transistors
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7854 with rounded corners
• CPC Class Codes: H01L 29/78645 with multiple gate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H10K 10/482 the IGFET comprising multiple separately-addressable gate electrodes
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/842 for carbon nanotubes or fullerenes
• CPC Class Codes: Y10S 977/938 Field effect transistors, FETS, with nanowire- or nanotube-channel region

Abstract

The present invention is a semiconductor device comprising a semiconductor body having a top surface and laterally opposite sidewalls formed on a substrate. A gate dielectric layer is formed on the top surface of the semiconductor body and on the laterally opposite sidewalls of the semiconductor body. A gate electrode is formed on the gate dielectric on the top surface of the semiconductor body and adjacent to the gate dielectric on the laterally opposite sidewalls of the semiconductor body.

Claims

1. A method of forming a semiconductor device comprising:

forming a semiconductor body having a top surface and laterally opposite sidewalls;

masking the top surface of the semiconductor body;

roughening said laterally opposite sidewalls of said semiconductor body while the top surface remains unaltered to enhance the oxidation rate of said sidewalls of said semiconductor body relative to the top surface;

removing the mask from the top surface of the semiconductor body; and

growing an oxide on said sidewalls of said semiconductor body and on the top surface of said semiconductor body wherein the thickness of said oxide on said sidewalls of said semiconductor body is greater than the thickness of said oxide on said top surface of said semiconductor body due at least in part to the roughening of the sidewalls.

2. The method of claim 1 wherein said sidewalls of said semiconductor body are roughened by sputtering.

3. The method of claim 1 wherein said gate dielectric layer on said laterally opposite sidewalls of said semiconductor body is at least 1.3 times the thickness of said gate dielectric layer on the top surface of said semiconductor body.