Forming sidewall spacers using isotropic etch
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Ting Ko, Kuang-Yuan Hsu
Life of this patent
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Abstract
A method includes etching a dielectric layer to form an opening, with a component of a transistor being exposed through the opening. A spacer layer is formed, and includes a horizontal portion at a bottom of the opening, and a vertical portion in the opening. The vertical portion is on a sidewall of the dielectric layer. An isotropic etch is performed on the spacer layer to remove the horizontal portion, and the vertical portion remains after the isotropic etch. The remaining vertical portion forms a contact plug spacer. A conductive material is filled into the opening to form a contact plug.
Claims20
A method comprising:
- etching a dielectric layer to form an opening, wherein a component of a transistor is exposed through the opening;
- forming a spacer layer comprising:
- a horizontal portion at a bottom of the opening;
- and
- a vertical portion in the opening, wherein the vertical portion is on a sidewall of the dielectric layer;
- performing an isotropic etch on the spacer layer to remove the horizontal portion, and the vertical portion remains after the isotropic etch, and the remaining vertical portion forms a contact plug spacer;
- and
- filling a conductive material into the opening to form a contact plug.
A method comprising:
- etching a dielectric layer to form an opening, wherein a component of a transistor is exposed through the opening;
- forming a spacer layer comprising a plurality of cycles, and each of the cycles comprises:
- depositing a sub-layer of the spacer layer;
- and
- bombarding the sub-layer to loosen a horizontal portion of the sub-layer, wherein the horizontal portion is at a bottom of the opening;
- removing the horizontal portions of the sub-layers formed by the plurality of cycles;
- and
- filling a conductive material into the opening to form a contact plug, wherein a vertical portion of the spacer layer encircles the contact plug.
A method comprising:
- forming an Inter-Layer Dielectric (ILD) to cover a gate stack;
- etching the ILD to form a source/drain contact opening;
- implanting a semiconductor substrate through the source/drain contact opening to form a source/drain region;
- forming a blanket spacer layer to extend into the source/drain contact opening;
- performing an isotropic etch on the blanket spacer layer to remove a portion of the blanket spacer layer in the source/drain contact opening, and a remaining portion of the blanket spacer layer in the source/drain contact opening forms a contact plug spacer;
- and
- filling a conductive material into the source/drain contact opening to form a source/drain contact plug, wherein the source/drain contact plug is encircled by the contact plug spacer.
Dependencies are inferred from the claim text.