Thin-film resistor (TFR) with displacement-plated TFR heads
A thin film resistor (TFR) module may be formed in copper interconnect in an integrated circuit device. A pair of displacement-plated TFR heads may be formed by forming a pair of copper TFR head elements (e.g., damascene trench elements) spaced apart from each other in a dielectric region, and displacement plating a barrier region on each TFR head element to form a displacement-plated TFR head. A TFR element may be formed on the pair of displacement-plated TFR heads to define a conductive path between the pair of TFR head elements through the TFR element and through the displacement-plated barrier region on each metal TFR head. Conductive contacts may be formed connected to the pair of displacement-plated TFR heads. The displacement-plated barrier regions may protect the copper TFR heads from copper corrosion and/or diffusion, and may comprise CoWP, CoWB, Pd, CoP, Ni, Co, Ni—Co alloy, or other suitable material.
1. An integrated circuit (IC) structure, comprising:
a thin film resistor (TFR) module, comprising:
a pair of spaced-apart displacement-plated TFR heads, comprising:
a pair of TFR head elements spaced apart from each other in a dielectric region; and
a displacement-plated barrier region at a top of each of the pair of TFR head elements;
a TFR element formed on the pair of spaced-apart displacement-plated TFR heads to define a conductive path between the pair of TFR head elements through the TFR element and through the displacement-plated barrier region at the top of each metal TFR head;
a TFR dielectric cap formed on the TFR element, the TFR dielectric cap having an etched perimeter corresponding with an etched perimeter of the underlying TFR element; and
conductive contacts coupled to the pair of spaced-apart displacement-plated TFR heads.
2. The IC structure of claim 1 , wherein the TFR element comprises SiCr or SiCCr.
3. The IC structure of claim 1 , wherein the pair of TFR head elements comprise copper damascene structures.
4. The IC structure of claim 1 , wherein the displacement-plated barrier region at the top of each of the pair of TFR head elements comprises cobalt tungsten phosphide (CoWP).
5. The IC structure of claim 1 wherein the TFR element fully covers a top area of each of the pair of spaced-apart displacement-plated TFR heads.
6. The IC structure of claim 1 , wherein the TFR film includes (a) a pair of head regions, each covering a top area of one of the displacement-plated TFR heads and (b) a connecting region connecting the pair of head regions, the connecting region having a smaller width than the head regions.
7. The IC structure of claim 1 , wherein the TFR element has a thickness in the range of 50-1000 Angstroms.
8. The IC structure of claim 1 , wherein the TFR dielectric cap comprises silicon nitride or silicon oxide.
9. An integrated circuit (IC) structure, comprising:
a thin film resistor (TFR) module comprising:
a pair of spaced-apart displacement-plated TFR heads, comprising:
a pair of TFR head elements formed in a first metal layer; and
a pair of first displacement-plated barrier regions formed on the pair of TFR head elements, respectively; and
a TFR element formed on the pair of spaced-apart displacement-plated TFR heads to define a conductive path connecting the pair of TFR head elements through the TFR element and through the displacement-plated barrier region formed on each TFR head element;
a TFR dielectric cap formed on the TFR element, the TFR dielectric cap having an etched perimeter corresponding with an etched perimeter of the underlying TFR element; and
a first interconnect structure comprising:
an interconnect element formed in the first metal layer; and
a second displacement-plated barrier region formed on the interconnect element;
a TFR layer region on the second displacement-plated barrier region, the TFR layer region and the TFR element comprising respective portions of a TFR layer;
a dielectric cap on the TFR layer region, the dielectric cap having an etched perimeter corresponding with an etched perimeter of the TFR layer region, the dielectric cap and the TFR dielectric cap comprising respective portions of a dielectric cap layer.
10. The IC structure of claim 9 , wherein the TFR element comprises SiCr or SiCCr.
11. The IC structure of claim 9 , wherein the pair of TFR head elements and the interconnect element comprise copper damascene structures.
12. The IC structure of claim 9 , wherein the pair of first displacement-plated barrier regions and the second displacement-plated barrier region comprise cobalt tungsten phosphide (CoWP).
13. The IC structure of claim 9 , wherein the TFR film includes (a) a pair of head regions, each covering a top area of one of the displacement-plated TFR heads and (b) a connecting region connecting the pair of head regions, the connecting region having a smaller width than the head regions.
14. The IC structure of claim 9 , further comprising a second metal layer comprising:
a respective TFR contact connected to each displacement-plated TFR head by a respective TFR contact via; and
an upper interconnect structure connected to the first interconnect structure by an interconnect via.
15. The IC structure of claim 9 , wherein the dielectric cap layer comprises silicon nitride or silicon oxide.