Very narrow aspect ratio trapping trench structure with smooth trench sidewalls
AssigneeInternational Business Machines Corporation
InventorsKarthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
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Abstract
After forming a plurality of semiconductor fins that are separated from one another by trenches on a substrate, the semiconductor fins are fully or partially oxidized to provide semiconductor oxide portions. The volume expansion caused by the oxidation of the semiconductor fins reduces widths of the trenches, thereby providing narrowed trenches for formation of epitaxial semiconductor fins using aspect ratio trapping techniques.
Claims20
A method of forming a semiconductor structure comprising:
- forming a plurality of semiconductor fins on a substrate, wherein the plurality of semiconductor fins are separated from one another by first trenches having a first width;
- oxidizing at least a portion of each of the plurality of semiconductor fins to provide a semiconductor oxide portion, wherein the semiconductor oxide portions are separated from one another by second trenches having a second width less than the first width;
- and
- forming an epitaxial semiconductor layer within each second trench.
A method of forming a semiconductor structure, the method comprising
- forming a plurality of semiconductor fins on a substrate, wherein the plurality of semiconductor fins are separated from one another by first trenches having a first width;
- forming a bottom spacer layer around a bottom portion of each semiconductor fin;
- fully oxidizing each of the plurality of semiconductor fins to provide a semiconductor oxide portion, wherein the semiconductor oxide portions are separated from one another by second trenches having a second width less than the first width;
- etching the bottom spacer layer to form an opening underneath the second trench provided by the oxidizing;
- forming a faceted opening within the substrate and beneath each opening;
- forming an epitaxial semiconductor layer within each second trench and each opening;
- and
- recessing each semiconductor oxide portion to exposed an upper portion of each epitaxial semiconductor layer.
A method of forming a semiconductor structure, the method comprising
- forming a plurality of semiconductor fins on a substrate, wherein the plurality of semiconductor fins are separated from one another by first trenches having a first width;
- forming a bottom spacer layer around a bottom portion of each semiconductor fin;
- partially oxidizing each of the plurality of semiconductor fins to provide a semiconductor oxide portion, wherein the semiconductor oxide portions are separated from one another by second trenches having a second width less than the first width;
- etching the bottom spacer layer to form an opening underneath the second trench provided by the oxidizing;
- forming a faceted opening within the substrate and beneath each opening;
- forming an epitaxial semiconductor layer within each second trench and each opening;
- and
- recessing each semiconductor oxide portion to exposed an upper portion of each epitaxial semiconductor layer.
Dependencies are inferred from the claim text.