Hall element for 3-D sensing using integrated planar and vertical elements and method for producing the same
A method of forming a 3D Hall effect sensor and the resulting device are provided. Embodiments include forming a shallow trench isolation (STI) region and a deep trench isolation (DTI) region in a substrate; forming a p-type well in the substrate surrounded by the STI region in top view; forming a first n-type well and a second n-type well surrounded by the p-type well and DTI region in top view; forming n-type dopant in the first n-type well and the second n-type well; and forming p-type dopant in the p-type well.
1. A method comprising:
forming a shallow trench isolation (STI) region and a deep trench isolation (DTI) region in a substrate;
forming a p-type well in the substrate surrounded by the STI region in top view;
forming a first n-type well and a second n-type well surrounded by the p-type well and DTI region in top view;
forming n-type dopant in the first n-type well and the second n-type well; and
forming p-type dopant in the p-type well.
2. The method according to claim 1 , wherein the substrate comprises a p-type substrate.
3. The method according to claim 1 , wherein the substrate further comprises a n-type substrate (n-sub) implant.
4. The method according to claim 3 , wherein the substrate further comprises an n-epitaxial growth over the n-sub implant.
5. The method according to claim 4 , further comprising:
forming the STI region and DTI region prior to forming the p-type well,
wherein the STI region, DTI region and p-type well provide isolation between a planar Hall element located in a first region of the n-epitaxial growth in top view, a vertical Hall element located in a second region of the n-epitaxial growth extending vertically in a device in cross section view or a combination thereof.
6. The method according to claim 5 , comprising:
forming the p-type well prior to forming the first n-type well or the second n-type well.
7. The method according to claim 5 , comprising:
forming the p-type well after forming the first n-type well or the second n-type well.
8. The method according to claim 1 , comprising:
forming the first n-type well as a cross-shaped pattern in top view; and
forming the second n-type well as a fragmented square-shaped pattern partially surrounding the cross-shaped pattern in top view,
wherein a fragment of the fragmented square-shaped pattern intersects an end-point of the cross-shaped pattern perpendicularly.
9. The method according to claim 8 , further comprising:
forming a cover layer over the first n-type well and the second n-type well,
wherein the cover layer comprises a p-type cover or STI region.
10. The method according to claim 9 , further comprising:
forming a layer of local oxidation of silicon (LOCOS) over the cover layer or directly on the first n-type well and the second n-type well.
11. The method according to claim 1 , comprising:
forming the p-type well to surround the second n-type well in top view.
12. The method according to claim 1 , further comprising:
forming an interlayer dielectric (ILD) over the first n-type well, the second n-type well and the p-type well;
performing self-aligned silicidation to reduce resistance in the first n-type well, the second n-type well and the p-type well;
forming contacts in the ILD; and
performing back-end-of-line (BEOL) processing.
13. A device comprising:
a shallow trench isolation (STI) region and deep trench isolation (DTI) region formed in a substrate;
a p-type well formed in the substrate between the STI region in top view;
a first n-type well and a second n-type well formed in the substrate and surrounded by the p-type well and DTI region in top view;
n-type dopant implanted in the first n-type well and the second n-type well; and
p-type dopant implanted in the p-type well,
wherein the device is configured to sense a magnetic field perpendicular and in-plane direction relative to the device.
14. The device according to claim 13 , wherein the substrate comprises a p-type substrate and a n-type substrate (n-sub) implant and an n-epitaxial growth formed over the n-sub implant.
15. The device according to claim 14 , further comprising:
a planar Hall element located in a first region of the n-epitaxial growth in top view; and
a vertical Hall element located in a second region of the n-epitaxial growth extending vertically in the device in cross section view,
wherein the p-type well is formed to surround the second n-type well and wherein the STI region, DTI region and p-type well provide isolation between the planar Hall element and the vertical Hall element.
16. The device according to claim 15 , wherein the planar Hall element and the vertical Hall element are configured to operate at different clock cycles.
17. The device according to claim 13 , wherein the first n-type well is formed as a cross-shaped pattern in top view, and the second n-type well is formed as a fragmented square-shaped pattern partially surrounding the cross-shaped pattern in top view.
18. The device according to claim 17 , wherein a fragment of the fragmented square-shaped pattern intersects an end-point of the cross-shaped pattern perpendicularly.
19. The device according to claim 13 , further comprising:
a cover layer formed over the first n-type well and the second n-type well,
wherein the cover layer comprises a p-type cover, STI region or a layer of local oxidation of silicon (LOCOS).
20. The device according to claim 13 , further comprising:
an interlayer dielectric (ILD) over the first n-type well, the second n-type well and the p-type well; and
contacts in the ILD,
wherein the device is configured for multiple terminal sensing.