Semiconductor device and method
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYu-Lien Huang, Guan-Ren Wang, Ching-Feng Fu
Life of this patent
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Abstract
In an embodiment, a structure includes: a gate stack over a channel region of a substrate; a source/drain region adjacent the channel region; a first inter-layer dielectric (ILD) layer over the source/drain region; a silicide between the first ILD layer and the source/drain region, the silicide contacting a top surface of the source/drain region and a bottom surface of the source/drain region; and a first source/drain contact having a first portion and a second portion, the first portion of the first source/drain contact disposed between the silicide and the first ILD layer, the second portion of the first source/drain contact extending through the first ILD layer and contacting the silicide.
Claims20
A method comprising:
- depositing a contact etch stop layer (CESL) over a source/drain region;
- depositing an inter-layer dielectric (ILD) layer over the CESL;
- etching an opening in the ILD layer;
- extending the opening through the CESL with a first etching process, the first etching process being anisotropic;
- widening a lower portion of the opening by etching the CESL with a second etching process to form an undercut between the ILD layer and the source/drain region, the second etching process being isotropic;
- forming a silicide in the opening and the undercut, the silicide contacting the source/drain region;
- and
- forming a source/drain contact in the opening and the undercut, the source/drain contact contacting the silicide.
A method comprising:
- depositing a contact etch stop layer (CESL) on a source/drain region;
- depositing an inter-layer dielectric (ILD) layer on the CESL;
- etching the ILD layer to form an opening through the ILD layer;
- etching the CESL with a first etching process to extend the opening through the CESL;
- etching the CESL with a second etching process to form an undercut between the ILD layer and the source/drain region, the second etching process different from the first etching process;
- forming a silicide in the undercut and the opening, the silicide formed on the source/drain region;
- and
- forming a source/drain contact in the undercut and the opening, the source/drain contact formed on the silicide.
A method comprising:
- depositing a contact etch stop layer (CESL) having a first portion on an upper surface of a source/drain region and having a second portion on a lower surface of the source/drain region;
- depositing an inter-layer dielectric (ILD) layer on the CESL;
- removing the first portion of the CESL with an anisotropic etching process to expose the upper surface of the source/drain region;
- removing the second portion of the CESL with an isotropic etching process to expose the lower surface of the source/drain region, wherein removing the second portion of the CESL forms a first undercut and a second undercut, the first undercut between the ILD layer and the upper surface of the source/drain region, the second undercut between the ILD layer and the lower surface of the source/drain region;
- and
- after the anisotropic etching process and after the isotropic etching process, forming a silicide on the upper surface of the source/drain region and on the lower surface of the source/drain region.
Dependencies are inferred from the claim text.