Hall element for 3-D sensing 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 p-type well in a substrate; forming a first n-type well in a first region surrounded by the p-type well in top view; forming a second n-type well in a second region surrounding the p-type well; providing n-type dopant in the first and second n-type wells; and providing p-type dopant in the p-type well and the first n-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 n-type well surrounded by the p-type well and DTI region in top view;
providing n-type dopant in the n-type well;
providing p-type dopant in the p-type well;
forming the STI region and DTI region prior to forming the p-type well,
wherein the substrate comprises an n-type substrate (n-sub) implant,
wherein the substrate further comprises an n-epitaxial growth over the n-sub implant,
wherein the DTI region provides isolation between 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, and
wherein the second region is disposed between the DTI region and a second DTI region.
2. The method according to claim 1 , wherein the substrate comprises a p-type substrate.
3. The method according to claim 1 , comprising:
forming the n-type well prior to forming the p-type well.
4. The method according to claim 1 , comprising:
forming the n-type well after forming the p-type well.
5. The method according to claim 1 , further comprising:
forming an interlayer dielectric (ILD) over the n-type and p-type wells;
performing self-aligned silicidation to reduce resistance in the n-type and p-type wells;
forming contacts in the ILD; and
performing back-end-of-line (BEOL) processing.
6. 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 n-type well surrounded by the p-type well and DTI region in top view;
providing n-type dopant in the n-type well;
providing p-type dopant in the p-type well;
forming a cover layer over the n-type well, wherein the cover layer comprises a p-type cover, or STI region; and
forming a layer of local oxidation of silicon (LOCOS) over the cover layer or directly on the n-type well,
wherein the n-type well is formed as a cross-shaped pattern in top view.
7. The method according to claim 6 , comprising:
forming the p-type well to completely surround the cross-shaped n-type well.