Bipolar device having buried contacts
View Patent ↗The invention, in one aspect, provides a semiconductor device that includes a collector for a bipolar transistor located within a semiconductor substrate and a buried contact, at least a portion of which is located in the collector to a depth sufficient that adequately contacts the collector.
1. A semiconductor device, comprising:
a collector for a bipolar transistor located within a semiconductor substrate, wherein a collector tub is not present in the collector;
a diffusion buried contact region, at least a portion of which is located in a trench that extends into the collector to a depth sufficient to adequately contact the collector and that makes electrical connection within the collector, wherein the diffusion buried contact region extends along sidewalls of the trench;
a base region located within the collector;
at least first and second bipolar transistor emitter structures located on a surface of the semiconductor substrate and over the base and the collector and having a common base contact region located in the base and between the at least first and second bipolar transistors; and
a contact plug that extends into the collector to the depth to contact the diffusion buried contact region within the trench.
2. The device recited in claim 1 , wherein the diffusion buried contact region extends to a depth of at least about 0.05 microns into the collector.
3. The device recited in claim 1 , wherein the diffusion buried contact region further includes a contact junction located within the collector at the depth and the device further includes a dielectric layer located over the at least first and second bipolar transistor emitter structures and wherein a portion of the dielectric layer is located in the trench.
4. The device recited in claim 3 , wherein the diffusion buried contact region extends to a peak concentration region of the collector.
5. The device recited in claim 1 , wherein the diffusion buried contact region extends through an oxide isolation region located over the collector.
6. The device recited in claim 1 , further including a plurality of the bases and the emitter structures that form a plurality of bipolar transistors wherein the plurality of bipolar transistors form a portion of an integrated circuit, and the device further comprising:
non-bipolar transistors located over the semiconductor substrate;
dielectric layers located over the non-bipolar transistors and bipolar transistors; and
interconnects located in the dielectric layers that electrically connect to the non-bipolar and bipolar transistors, wherein a portion of the interconnects forms a portion of each of the buried contacts associated with each of the plurality of bipolar transistors.
7. A semiconductor device, comprising:
a collector for a bipolar transistor located within a semiconductor substrate, wherein a collector tub is not present in the collector;
a diffusion buried contact region, at least a portion of which is located in a trench that extends into the collector to a depth sufficient to adequately contact the collector and that makes electrical connection within the collector, wherein the diffusion buried contact region extends along the bottom and sidewalls of the trench;
a base region located within the collector;
at least a first biploar transistor emitter structure located on a surface of the semiconductor substrate and over the base and the collector; and
a contact plug that extends into the collector to the depth to contact the diffusion buried contact region within the trench.
8. The device recited in claim 7 , wherein the diffusion buried contact region extends to a depth of at least about 0.05 microns into the collector.
9. The device recited in claim 7 , wherein the diffusion buried contact region further includes a contact junction located within the collector at the depth and the device further includes a dielectric layer located over the at least first emitter structure and wherein a portion of the dielectric layer is located in the trench.
10. The device recited in claim 9 , wherein the diffusion buried contact region extends to a peak concentration region of the collector.
11. A semiconductor device, comprising:
a collector for a bipolar transistor located within a semiconductor substrate, wherein a collector tub is not present in the collector;
a diffusion buried contact region having a width less than about 1.6 microns and at least a portion of which is located in a trench that extends into the collector to a depth sufficient to adequately contact the collector and that makes electrical connection within the collector, wherein the diffusion buried contact region extends along the bottom and sidewalls of the trench;
a base region located within the collector;
at least a first biploar transistor emitter structure located on a surface of the semiconductor substrate and over the base and the collector; and
a contact plug that extends into the collector to the depth to contact the diffusion buried contact region within the trench.
12. The device recited in claim 11 , wherein the diffusion buried contact region extends to a depth of at least about 0.05 microns into the collector.
13. The device recited in claim 12 , wherein the depth of the diffusion buried contact region is about 1 micron.
14. The device recited in claim 11 , wherein the diffusion buried contact region further includes a contact junction located within the collector at the depth and the device further includes a dielectric layer located over the at least first emitter structure and wherein a portion of the dielectric layer is located in the trench.
15. The device recited in claim 11 , wherein the diffusion buried contact region extends to a peak concentration region of the collector.
16. The device recited in claim 15 , wherein a depth of the peak concentration ranges from about 4 microns to about 9 microns.