Angled ion implantation in a semiconductor device
View Patent ↗Angled ion implants are utilized to form doped regions in a semiconductor pillar formed in an opening of a mask. The pillar is formed to a height less than the height of the mask. Angled ion implantation can be used to form regions of a semiconductor device such as a body tie region, a halo region, or current terminal extension region of a semiconductor device implemented with the semiconductor pillar.
1. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes forming an opening in the mask layer;
forming a semiconductor layer in the opening to a distance below a top surface of the mask layer; and
performing an angled ion implantation in the semiconductor layer within the opening wherein the angled ion implantation is performed while the substrate is rotated a predetermined amount, wherein during the performing, the mask layer inhibits ions from implanting into specific regions of the semiconductor layer;
removing the mask layer after performing an angled ion implantation.
2. The method of claim 1 , wherein performing the angled ion implantation further comprises rotating the substrate by an amount in a range of between 0-270 degrees around an axis orthogonal to a major surface of the substrate.
3. The method of claim 1 , wherein the semiconductor layer comprises a first current terminal region and a second current terminal region, wherein performing the angled ion implantation further comprises performing the ion implantation to form a current terminal extension region in the semiconductor layer.
4. The method of claim 1 , wherein forming the semiconductor layer further comprises epitaxially growing silicon in the opening to form a pillar, and wherein performing the angled ion implantation further comprises forming an annular shaped doped region in a portion of the pillar.
5. The method of claim 4 , comprising doping the pillar to form a source region, a drain region, and a body region.
6. The method of claim 1 , further comprising:
forming a layer of control terminal material over the substrate after removing the mask layer;
forming a control terminal structure, wherein the control terminal structure includes a patterned portion of the layer of control terminal material.
7. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes forming an opening in the mask layer;
forming a semiconductor layer in the opening to a distance below a top surface of the mask layer; and
performing an angled ion implantation in the semiconductor layer within the opening wherein the angled ion implantation is performed while the substrate is rotated a predetermined amount, wherein during the performing, the mask layer inhibits ions from implanting into specific regions of the semiconductor layer;
wherein the semiconductor layer comprises a source region, a body region, and a drain region, wherein performing the angled ion implantation further comprises performing the ion implantation to form a conductive body tie between the body region and the substrate.
8. The method of claim 7 , further comprising:
removing the mask layer after performing an angled ion implantation.
9. The method of claim 7 , further comprising:
forming a layer of control terminal material over the substrate after performing the angled ion implantation;
forming a control terminal structure, wherein the control terminal structure includes a patterned portion of the layer of control terminal material.
10. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes forming an opening in the mask layer;
forming a semiconductor layer in the opening to a distance below a to surface of the mask layer; and
performing an angled ion implantation in the semiconductor layer within the opening wherein the angled ion implantation is performed while the substrate is rotated a predetermined amount, wherein during the performing, the mask layer inhibits ions from implanting into specific regions of the semiconductor layer;
removing the mask layer;
forming a dielectric on a side of the semiconductor layer; and
forming a charge storage structure on the dielectric.
11. The method of claim 10 , further comprising:
forming an insulating layer on the charge storage structure; and
forming a layer of control terminal material over the insulating layer.
12. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes patterning the mask layer to form an opening in the mask layer;
epitaxial growing a semiconductor pillar in the opening, a top surface of the semiconductor pillar being a predetermined distance below a top surface of the mask layer; and
performing an angled ion implantation in the semiconductor pillar to form an annular doped region in a portion of the semiconductor pillar, wherein during the performing, the mask layer inhibit ions from implanting into specific regions of the semiconductor pillar;
removing the mask layer after the performing.
13. The method of claim 12 , wherein performing the angled ion implantation further comprises rotating the substrate around an axis orthogonal to a major surface of the substrate.
14. The method of claim 12 , further comprising:
forming a layer of control terminal material over the substrate after removing the mask layer;
forming a control terminal structure, wherein the control terminal structure includes a patterned portion of the layer of control terminal material.
15. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes patterning the mask layer to form an opening in the mask layer;
epitaxial growing a semiconductor pillar in the opening, a top surface of the semiconductor pillar being a predetermined distance below a top surface of the mask layer; and
performing an angled ion implantation in the semiconductor pillar to form an annular doped region in a portion of the semiconductor pillar;
wherein the semiconductor pillar is doped to form a first current terminal region, a second current terminal region, and a body region;
wherein performing the angled ion implantation further comprises performing the ion implantation to form a conductive body tie between the body region and the substrate.
16. The method of claim 15 wherein during the performing, the mask layer inhibit ions from implanting into specific regions of the semiconductor pillar, the method comprising:
removing the mask layer after the performing.
17. The method of claim 15 , further comprising:
forming a layer of control terminal material over the substrate after performing the angled ion implantation;
forming a control terminal structure, wherein the control terminal structure includes a patterned portion of the layer of control terminal material.
18. A method comprising:
forming a mask layer over a substrate;
forming an opening, wherein the forming the opening includes patterning the mask layer to form an opening in the mask layer;
epitaxial growing a semiconductor pillar in the opening, a top surface of the semiconductor pillar being a predetermined distance below a top surface of the mask layer; and
performing an angled ion implantation in the semiconductor pillar to form an annular doped region in a portion of the semiconductor pillar;
removing the mask layer;
forming a dielectric on a side of the semiconductor pillar; and
forming a charge storage structure on the dielectric.
19. The method of claim 18 , further comprising:
forming an insulating layer on the charge storage structure; and
forming a layer of control terminal material over the insulating layer.
20. The method of claim 18 , further comprising:
forming a layer of control terminal material over the substrate after removing the mask layer;
forming a control terminal structure, wherein the control terminal structure includes a patterned portion of the layer of control terminal material.