FinFET with etch-selective spacer and self-aligned contact capping layer
In the manufacture of a FinFET device, an isolation architecture is provided between gate and source/drain contact locations. The isolation architecture may include a low-k spacer layer and a contact etch stop layer. An upper portion of the isolation architecture is removed and replaced with a high-k, etch-selective spacer layer adapted to resist degradation during an etch to open the source/drain contact locations. The high-k spacer layer, in conjunction with a self-aligned contact (SAC) capping layer disposed over the gate and overlapping a sidewall of the isolation layer, forms an improved isolation structure that inhibits short circuits or parasitic capacitance between the gate and source/drain contacts.
1. A fin-type field effect transistor (FinFET) device, comprising:
a semiconductor fin having a source/drain region and a channel region adjacent to the source/drain region;
a conductive contact disposed over the source/drain region;
an etch stop layer positioned over and directly contacting an upper surface of the source/drain region of the semiconductor fin, and contacting a sidewall of the conductive contact, wherein a sidewall of the etch stop layer directly contacts the sidewall of the conductive contact;
a gate stack disposed over the channel region;
a capping layer formed from an insulating material disposed as a single-layer structure over the gate stack;
an isolation layer including a low-k dielectric disposed between the gate stack and the conductive contact, wherein a sidewall of the capping layer overlaps at least a portion of a sidewall of the isolation layer and wherein a top surface of the conductive contact is co-planar with a top surface of the capping layer, and a top surface of the isolation layer is substantially coplanar with a top surface of the etch stop layer; and
a high-k spacer layer positioned, at least partially over a drain region of the source/drain region, the high-k spacer layer disposed over the isolation layer and the etch stop layer, and disposed between the conductive contact and the capping layer, wherein the bottommost surface of the high-k spacer layer directly contacts the top surface of the isolation layer and the top surface of the etch stop layer, and an upper surface of the high-k spacer layer is substantially co-planar with the top surface of the conductive contact and the top surface of the capping layer, and wherein at least a portion of a sidewall of the high-k spacer layer directly contacts and is vertically aligned with the sidewall of the etch stop layer.
2. The FinFET device of claim 1 , wherein a bottom surface of the capping layer is below the top surface of the isolation layer.
3. The FinFET device of claim 1 , wherein the capping layer includes silicon nitride.
4. The FinFET device of claim 1 , wherein a top surface of the gate stack is below the top surface of the isolation layer.
5. A fin-type field effect transistor (FinFET) device, comprising:
a semiconductor fin having a source/drain region and a channel region adjacent to the source/drain region;
a conductive contact disposed over the source/drain region;
an etch stop layer positioned over and directly contacting an upper surface of the source/drain region of the semiconductor fin, wherein a sidewall of the etch stop layer directly contacts a sidewall of the conductive contact;
a gate stack disposed over the channel region;
a capping layer formed from an insulating material disposed as a single-layer structure over the gate stack, wherein a top surface of the conductive contact is co-planar with a top surface of the capping layer;
an isolation layer including a low-k dielectric disposed between the gate stack and the conductive contact, wherein a sidewall of the capping layer overlaps at least a portion of a sidewall of the isolation layer, and a top surface of the isolation layer is substantially coplanar with a top surface of the etch stop layer; and
a high-k spacer layer positioned, at least partially over a drain region of the source/drain region, the high-k spacer layer over the isolation layer and the etch stop layer, and disposed between the conductive contact and the capping layer, wherein the bottommost surface of the high-k spacer layer directly contacts the top surface of the isolation layer and the top surface of the etch stop layer, and an upper surface of the high-k spacer layer is substantially co-planar with the top surface of the conductive contact and the top surface of the capping layer, and wherein at least a portion of a sidewall of the high-k spacer layer directly contacts and is vertically aligned with the sidewall of the etch stop layer.
6. The FinFET device of claim 5 , wherein the capping layer includes silicon nitride.
7. The FinFET device of claim 5 , wherein the conductive contact includes a metal that forms an ohmic contact with the source/drain region.
8. The FinFET device of claim 5 , wherein the etch stop layer has a thickness of at most ten nanometers.
9. The FinFET device of claim 5 , wherein the high-k spacer layer, the isolation layer and the capping layer form a continuous barrier between the conductive contact and the gate stack.
10. The FinFET device of claim 5 , wherein a top surface of the gate stack is below the top surface of the isolation layer.
11. The FinFET device of claim 1 , wherein the conductive contact includes a metal that forms an ohmic contact with the source/drain region.
12. The FinFET device of claim 1 , wherein the etch stop layer has a thickness of at most ten nanometers.
13. The FinFET device of claim 1 , wherein the high-k spacer layer, the isolation layer and the capping layer form a continuous barrier between the conductive contact and the gate stack.