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US 12,588,244 B2Granted
Semiconductor devices and methods of fabrication thereof
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Wei Chang, Shahaji B. More, Chi-Yu Chou, Yueh-Ching Pai
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Abstract
Embodiments of the present disclosure provide a method of forming a contact opening using selective ALE operations to remove ILD layer along an upper profile of a source/drain region, and then form a source/drain contact feature having a concave bottom profile with increased contact area.
Claims20
A method for fabricating a semiconductor device, comprising:
- forming a fin structure along a first direction;
- forming two or more sacrificial gate structures along a second direction over the fin structure, wherein the second direction is perpendicular to the first direction;
- etching back the fin structure between the two or more sacrificial gate structures;
- forming a source/drain region between the two or more sacrificial gate structures, wherein a profile of the source/drain region along the second direction includes a top surface and two sloping side surfaces;
- depositing a CESL (contact etch stop layer) layer over the source/drain region, wherein the CESL layer covers the top surface and two side surfaces of the source/drain region;
- depositing a first ILD (interlayer dielectric) layer over the CESL layer;
- forming replacement gate structures in place of the two or more sacrificial gate structures;
- performing a planarization process to form a planar surface including the replacement gate structures, the first ILD layer and the CESL layer;
- depositing a second ILD layer over the top surface;
- form a source/drain contact opening in a mask layer to expose a portion of the second ILD layer;
- performing a first etch process through the source/drain contact opening to remove the second ILD layer and a portion of the first ILD layer;
- terminating the first etch process when the second ILD layer is removed and the first ILD layer is etched at a first distance below the planar surface;
- performing a second etch process to remove the first ILD layer and the CESL layer exposed in the source/drain contact opening;
- terminating the second etch process when to a first level to expose the CESL layer formed on the top surface of the source/drain region is exposed;
- selectively etching the first ILD layer along the side surfaces of the source/drain region to expose the CESL layer formed on the side surfaces of the source/drain regions;
- removing exposed portion of the CESL layers to expose the top surface and portions of the side surfaces of the source/drain region;
- forming a silicide layer on the top surface and the portions of the side surfaces of the source and drain region;
- and
- depositing a conductive material over the silicide layer.
16 more elements
A method for fabricating a semiconductor device, comprising:
- depositing a mask layer over a semiconductor substrate comprising:
- a fin structure along a first direction;
- a first and a second gate structures along a second direction over the fin structure, wherein the second direction is perpendicular to the first direction;
- a source/drain region between the first and second gate structures, wherein the source/drain region has a convex upper profile along the second direction, and the convex upper profile includes a top surface, a first side surface and a second side surface, the first side surface and the second side surface slope from the top surface towards a middle level, and the source/drain has a greatest width along the second direction at the middle level;
- a CESL layer over the top surface, the first side surface and the second side surface of the source/drain region;
- and
- an ILD layer over the CESL layer;
- forming a first opening through the mask layer;
- etching the ILD layer through the first opening to expose the CESL layer on the top surface of the source/drain region;
- selectively etching the ILD layer along the first side surface and second side surface of the source/drain region to a landing level, wherein the landing level is above the middle level;
- removing the exposed CESL layer;
- and
- forming a source/drain contact feature having a concave bottom profile matching the convex upper profile of the source/drain region.
10 more elements
A method for fabricating a semiconductor device, comprising:
- depositing a mask layer over a semiconductor substrate comprising:
- a fin structure along a first direction;
- a first and a second gate structures along a second direction over the fin structure, wherein the second direction is perpendicular to the first direction;
- a source/drain region disposed between the first and second gate structures;
- a CESL layer disposed over the source/drain region;
- a first ILD layer disposed over the CESL layer;
- and
- a second ILD layer disposed over a planar surface comprising the first ILD layer, the CESL layer and the first and second gate structures;
- forming a source/drain opening through the mask layer;
- performing a first etch process through the source/drain opening to remove the second ILD layer and a portion of the first ILD layer;
- terminating the first etch process when the second ILD layer is removed and the first ILD layer is etched to a first level, wherein the first level at a first distance below the planar surface;
- performing a second etch process to remove the first ILD layer and the CESL layer exposed in the source/drain contact opening;
- terminating the second etch process when the CESL layer on a top surface of the source/drain region is exposed;
- selectively etching back the first ILD layer along the source/drain region to a second level;
- removing exposed portion of the CESL layers to expose the source/drain region;
- forming a silicide layer on exposed portion of the source and drain region;
- and
- forming a source/drain contact feature in the source/drain opening.
15 more elements
Dependencies are inferred from the claim text.