Contact module for optimizing emitter and contact resistance
An advanced contact module for optimizing emitter and contact resistance and methods of manufacture are disclosed. The method includes forming a first contact via to a first portion of a first device. The method further includes filling the first contact via with metal material to form a first metal contact to the first portion of the first device. The method further includes forming additional contact vias to other portions of the first device and contacts of a second device. The method further includes cleaning the additional contact vias while protecting the first metal contact of the first portion of the first device. The method further includes filling the additional contact vias with metal material to form additional metal contacts to the other portions of the first device and the second device.
1. A structure, comprising:
a transistor on a substrate;
a bipolar transistor on the substrate, the bipolar transistor comprising an emitter region, a base region, and a collector region;
a dielectric layer on the transistor and the bipolar transistor;
a first contact extending from a top surface of the dielectric layer to a non-silicided region of the emitter region, wherein excess metal of the contact is on the top surface of the dielectric layer; and
plural second contacts extending over the excess metal on the top surface of the dielectric layer to respective silicide regions of the base region, the collector region, and the transistor.
2. The structure of claim 1 , wherein the plural second contacts extend through the excess metal on the top surface of the dielectric layer.
3. The structure of claim 1 , wherein the silicide region of the base region is directly on a top surface of an epitaxial layer that is directly on a top surface of the substrate.
4. The structure of claim 3 , wherein the bipolar transistor is an NPN transistor.
5. The structure of claim 4 , wherein the NPN transistor is provided on the epitaxial layer which comprises boron doped SiGe.
6. The structure of claim 1 , wherein the emitter region is polysilicon.
7. The structure of claim 1 , wherein the base region includes a base contact region and the collector region includes a collector contact region, both of nickel silicide.
8. The structure of claim 1 , wherein the base region includes a base contact region and the collector region includes a collector contact region, both of cobalt silicide.
9. The structure of claim 1 , wherein:
the substrate is a p-type substrate;
the base region has a base contact region which is formed on an epitaxial layer comprising boron doped SiGe; and
the collector region has a collector contact region which is formed over an n-type region on the p-type substrate that is electrically connected to the collector region of the bipolar transistor.
10. The structure of claim 1 , wherein each of the plural second contacts comprises a liner.
11. The structure of claim 10 , wherein the liner comprises TiN.
12. The structure of claim 1 , wherein the substrate is a p-type substrate.
13. The structure of claim 12 , wherein the bipolar transistor is isolated from the transistor by a shallow trench isolation structure.
14. The structure of claim 13 , wherein the bipolar transistor is formed on an epitaxial layer, which comprises a boron doped SiGe layer, and the emitter region is polysilicon material.
15. The structure of claim 14 , wherein silicide regions of the base region, the collector region and the transistor are nickel silicide or cobalt silicide.
16. The structure of claim 15 , wherein the base region has a base contact region formed on the boron doped SiGe layer and the collector region has a collector contact region formed over an n-type region on the p-type substrate that is electrically connected to the collector region.
17. The structure of claim 1 , wherein a silicide region of a collector region is on the top surface of the substrate.
18. The structure of claim 1 , further comprising a contact in direct electrical contact on a non-silicided region of the emitter region which is different than contacts of the collector region and the base region, the contacts of the collector region and the base region are in electrical contact with silicide regions of the collector region and the base region.
19. The structure of claim 18 , wherein the bipolar transistor and the transistor are formed on a same substrate, and the silicide region of the base region is directly on a top surface of an epitaxial layer that is directly on a top surface of the substrate.