Electronic device including an insulating structure
An electronic device can include a substrate and an insulating structure. In an aspect, an anchor can include a portion of the substrate that extends into the insulating structure or a portion of the insulating structure that extends into the substrate. In another aspect, a process of forming an electronic device can include patterning a substrate to define a trench and a first anchor; and forming an insulating structure within the trench and adjacent to the first anchor. In a further aspect, a process of forming an electronic device can include patterning a substrate to define a trench having a sidewall and a first pillar spaced apart from the sidewall; doping the first pillar to change a conductivity type of the first pillar; and forming an insulating structure that surrounds the first pillar.
1. A process of forming an electronic device comprising:
patterning a substrate to define a trench and a first anchor having a proximal portion and a distal portion, wherein
the first anchor extends from a sidewall of the trench,
the sidewall is closer to the proximal portion than to the distal portion, and
the proximal portion has a width that is less than a width of the distal portion; and
forming an insulating structure within the trench and adjacent to the first anchor.
2. The process of claim 1 , wherein:
patterning the substrate further defines a first pillar within the trench; and
forming the insulating structure comprises:
forming a first insulating layer within the trench;
removing at least a portion of the first pillar after forming the first insulating layer to create a cavity; and
forming a second insulating layer to at least partly fill the cavity.
3. The process of claim 2 , wherein a combination of the first and second insulating layers forms a second anchor that has a complementary shape to the first anchor.
4. The process of claim 2 , wherein the first pillar has an I-beam shape that includes a first flange, a second flange, and a web disposed between the first and second flanges.
5. The process of claim 4 , wherein a section of the web is wider and spaced apart from the first and second flanges.
6. The process of claim 4 , wherein the insulating structure has clipped outer corners.
7. The process of claim 1 , further comprising doping the first anchor to change a conductivity type of the first anchor.
8. The process of claim 1 , further comprising thinning the substrate to expose at least a portion of the insulating structure along a backside of the substrate.
9. A process of forming an electronic device including a termination region, the process comprising:
patterning a substrate to define a trench having a sidewall and a first pillar spaced apart from the sidewall;
doping the first pillar to change a conductivity type of the first pillar; and
forming an insulating structure that surrounds the first pillar,
wherein the first pillar and the insulating structure are within the termination region.
10. The process of claim 9 , wherein:
patterning the substrate further defines a second pillar spaced apart from the first pillar and the sidewall; and
the process further comprises removing at least a portion of the second pillar to create a cavity.
11. The process of claim 10 , wherein forming the insulating structure comprises:
forming a first insulating layer within the trench;
removing at least a portion of the second pillar is performed after forming the first insulating layer, wherein a cavity is not formed immediately adjacent to the first pillar; and
forming a second insulating layer to at least partly fill the cavity.
12. The process of claim 9 , wherein:
patterning the substrate further comprises patterning the substrate to define an anchor extending from the sidewall of the trench; and
doping the anchor to change a conductivity type of the anchor, wherein the anchor and the first pillar have a same conductivity type after the anchor and first pillar are doped.
13. The process of claim 12 , wherein forming the second insulating layer within the cavity is performed such that the second insulating layer seals the cavity.
14. The process of claim 9 , further comprising:
doping a surface doped region along an upper surface of the substrate outside the trench and within the termination region; and
forming a molding compound over the substrate and termination region,
wherein the substrate has a conductivity type that is an opposite conductivity type of the surface doped region and the first pillar after doping the first pillar.
15. A process of forming an electronic device comprising:
patterning a substrate to define a trench having a sidewall and a first pillar, wherein the first pillar is a part of the substrate and spaced apart from the sidewall;
forming a first insulating layer within the trench;
removing at least a portion of the first pillar after forming the first insulating layer, wherein a cavity is formed where the at least a portion of the first pillar is removed, and the cavity is immediately adjacent to the first insulating layer where the at least a portion of the first pillar is removed; and
forming a second insulating layer within the cavity.
16. The process of claim 15 , wherein patterning the substrate further defines a first anchor and a second anchor pillar, wherein:
the first and second anchors extend from the sidewall of the trench,
each of the first and second anchors and the first pillar includes a middle portion and an end portion, and
the end portion of the of the first pillar is disposed between and extends toward the middle portions of the first and second anchors, and
the middle portion of the first pillar is disposed between the end portions of the first and second anchors, and the end portions of the first and second anchors extend toward the middle portion of the first pillar.
17. The process of claim 15 , wherein patterning the substrate further defines an anchor and a second pillar spaced apart from the anchor and the first pillar, wherein:
the anchor extends from the sidewall of the trench,
each of the anchor and the first and second pillars includes a middle portion and an end portion, and
the end portion of the of the anchor is disposed between and extends toward the middle portions of the first and second pillars, and
the middle portion of the anchor is disposed between the end portions of the first and second pillars, and the end portions of the first and second pillars extend toward the middle portions of the anchor.
18. The process of claim 17 , wherein patterning the substrate is performed such that:
the anchor has an T-shape, and the first and second pillars have I-beam shapes, and
ends of the I-beam shapes of the first and second pillars are adjacent to and along opposite sides of a stem of the T-shape of the anchor, and
the ends of the I-beam shapes of the first and second pillars are disposed between the sidewall of the trench and a cross-bar of the T-shape of the anchor.
19. The process of claim 15 , wherein patterning the substrate further defines an anchor extending from the sidewall of the trench, wherein the anchor has a T-shape, a Y-shape, a square cross shape, a bulb-and-stick shape, a hook shape, or a dovetail shape.
20. The process of claim 15 , wherein:
patterning the substrate further defines an anchor extending from the sidewall of the trench and spaced apart from the first pillar, and
removing at least a portion of the first pillar does not remove any part of the anchor.