Quantum dot devices with multiple dielectrics around fins
Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a base; a fin extending away from the base, wherein the fin includes a quantum well layer; a first dielectric material around a bottom portion of the fin; and a second dielectric material around a top portion of the fin, wherein the second dielectric material is different from the first dielectric material.
1. A quantum dot device, comprising:
a base;
a fin extending away from the base, wherein the fin includes a quantum well layer;
a first dielectric material around a bottom portion of the fin;
a second dielectric material around a top portion of the fin, wherein the second dielectric material is different from the first dielectric material; and
a gate above the fin, wherein the gate is at least partially above the second dielectric material.
2. The quantum dot device of claim 1 , wherein the second dielectric material has a loss tangent that is less than a loss tangent of the first dielectric material.
3. The quantum dot device of claim 1 , wherein the quantum well layer is between different portions of the second dielectric material.
4. The quantum dot device of claim 1 , wherein a thickness of the second dielectric material is between 10 nanometers and 100 nanometers.
5. The quantum dot device of claim 1 , wherein the second dielectric material is a high-k dielectric material.
6. The quantum dot device of claim 1 , further comprising:
a third dielectric material around the top portion of the fin, wherein the third dielectric material is adjacent to the second dielectric material.
7. The quantum dot device of claim 6 , wherein portions of the second dielectric material and portions of the third dielectric material alternate along a length of the fin.
8. The quantum dot device of claim 6 , further comprising:
a first gate above the fin, wherein the first gate is at least partially above the second dielectric material; and
a second gate above the fin, wherein the second gate is at least partially above the third dielectric material.
9. The quantum dot device of claim 8 , further comprising:
a dielectric material between the first gate and the second gate.
10. The quantum dot device of claim 1 , wherein the second dielectric material extends down side faces of the fin to a depth between 10 nanometers and 100 nanometers.
11. The quantum dot device of claim 1 , wherein the second dielectric material has a tapered profile that narrows closer to the base.
12. The quantum dot device of claim 1 , wherein the fin is a first fin, and the quantum dot device further includes:
a second fin extending away from the base, wherein the second fin includes a quantum well layer; and
a third dielectric material around a top portion of the second fin;
wherein the first dielectric material is around the bottom portion of the fin.
13. The quantum dot device of claim 12 , wherein the third dielectric material has a loss tangent that is less than a loss tangent of the first dielectric material.
14. The quantum dot device of claim 12 , wherein the quantum well layer of the second fin is between different portions of the third dielectric material.
15. The quantum dot device of claim 1 , wherein the fin has a tapered shape that is widest proximate to the base.
16. A quantum computing device, comprising:
a quantum processing device, wherein the quantum processing device includes a fin, the fin includes a quantum well layer, the quantum processing device further includes a plurality of gates above the fin to control quantum dot formation in the fin, a bottom portion of the fin is between portions of a first dielectric material, a top portion of the fin is between portions of a second dielectric material different from the first dielectric material, and the portions of the second dielectric material are on the portions of the first dielectric material; and
a non-quantum processing device, coupled to the quantum processing device, to control voltages applied to the plurality of gates.
17. The quantum computing device of claim 16 , further comprising:
a memory device to store data generated by quantum dots formed in the quantum well layer during operation of the quantum processing device.
18. The quantum computing device of claim 16 , wherein the quantum processing device further includes a third dielectric material, a top portion of the fin is between portions of the third dielectric material, the third dielectric material is different from the second dielectric material, and the portions of the third dielectric material are on the portions of the first dielectric material.