Method for forming rectangular-shaped spacers for semiconductor devices
AssigneeAdvanced Micro Devices, Inc.
InventorsHuicai Zhong, Srikanteswara Dakshina-Murthy
Life of this patent
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Abstract
A semiconductor device and method of making the same forms a spacer by depositing a spacer layer over a substrate and a gate electrode and forms a protective layer on the spacer layer. The protective layer is dry etched to leave a thin film sidewall on the spacer layer. The spacer layer is then etched, with the protective layer protecting the outer sidewalls of the spacer layer. This etching creates spacers on the gate that have substantially vertical sidewalls that extend parallel to the gate electrode sidewalls. The I-shape of the spacers prevent punch-through during the source/drain ion implantation process, providing an improved source/drain implant dose profile.
Claims11
A method of forming a semiconductor device comprising the sequential steps:
- forming source/drain extensions in a substrate;
- depositing a spacer layer over the substrate and a gate electrode having a top surface and vertically extending sidewalls;
- forming a protective layer on the spacer layer;
- etching the protective layer to remove the protective layer from the spacer layer over the top surface of the gate electrode and maintain the protective layer on the spacer layer parallel to the sidewalls of the gate electrode;
- etching the spacer layer to remove the spacer layer from the substrate and over the top surface of the gate electrode to form spacers on the gate electrode with each spacer having two substantially vertical sidewalls extending parallel to the gate electrode sidewalls;
- and
- performing a source/drain implantation with the gate electrode and the spacers masking the substrate.
A method of forming a semiconductor device, comprising the sequential steps:
- forming a gate electrode having vertically extending sidewalls on a substrate;
- forming source/drain extensions in the substrate;
- forming first sidewall spacers on the gate electrode, each first sidewall spacer having a pair of vertically extending planar sidewalls that are substantially parallel to the gate electrode sidewalls;
- and
- performing a source/drain implantation with the gate electrode and the first sidewall spacers masking the substrate;
- wherein the step of forming first sidewall spacers includes:
- depositing a spacer layer over the substrate and the gate electrode after the forming of the source/drain extensions in the substrate;
- forming a protective layer on the spacer layer;
- and
- etching the protective layer and the spacer layer to form the first sidewall spacer.
Dependencies are inferred from the claim text.