Shaped metal edge for galvanic or capacitive isolator
The disclosed technology generally relates to lithographically defined conductive lines for integrated circuit devices formed by plating, and more particularly to conductive lines shaped to reduce the magnitude of electric field in the electric field distributions around conductive lines of integrated and monolithic transformers and isolators.
1. An integrated circuit device comprising:
a substrate having a main surface;
a core layer disposed over the substrate; and
a lithographically patterned primary coil, the primary coil comprising one or more windings wound around a winding axis parallel to the main surface, wherein each of the windings comprises:
a top conductive line arranged over the core layer, the top conductive line having a first thickness along a vertical axis perpendicular to the main surface, wherein a cross-section of the top conductive line in a plane parallel to the winding axis and perpendicular to the main surface comprises a rounded convex portion of a side surface of the top conductive line, the rounded convex portion having a radius of curvature larger than 1 micron,
a bottom conductive line arranged under the core layer, the bottom conductive line having a second thickness along the vertical axis, wherein a cross-section of the bottom conductive line in the plane comprises a rounded convex portion of a side surface of the bottom conductive line, the rounded convex portion having a radius of curvature larger than 1 micron,
a first conductive via extended along the vertical axis electrically connecting the top and bottom conductive lines, and
a second conductive via extended along the vertical axis electrically connecting one but not the other of the top and bottom conductive lines to a conductive line of another winding of the primary coil.
2. The integrated circuit device of claim 1 , wherein the rounded convex portion of the side surface of the top conductive line has a radius of curvature exceeding 15% of the first thickness.
3. The integrated circuit device of claim 1 , wherein the bottom conductive line and the top conductive line are formed at a bottom metallization layer and an upper metallization layer, respectively, wherein the upper and bottom metallization layers are distinct metallization layers of the integrated circuit device each comprising at least a metallized portion formed by electroplating and an intermetal dielectric portion embedding the metallized portion.
4. The integrated circuit device of claim 3 , wherein the first conductive via comprises at least a lower segment electroplated on the bottom conductive line and an upper segment on which the top conductive line is electroplated.
5. The integrated circuit device of claim 1 , wherein the side surface of top conductive line further comprises a stepped portion having one or more side surface sections, and wherein an individual side surface section is a flat surface substantially perpendicular to the main surface.
6. The integrated circuit device of claim 5 , wherein the top conductive line further comprises a top vertical section having a third thickness along the vertical axis and a bottom vertical section having a fourth thickness along the vertical axis, the top vertical section comprising the rounded convex portion of the side surface and the bottom vertical section comprising the stepped portion of the side surface, and wherein an average width of the top vertical section is larger than a width of the bottom vertical section.
7. The integrated circuit device of claim 6 , wherein the fourth thickness of the bottom vertical section is equal to half of a difference between the width of the bottom vertical section and a width of the top vertical section at an interface between the top vertical section and the bottom vertical section.
8. The integrated circuit device of claim 1 , wherein the radius of curvature of the rounded convex portion of the side surface of one or both of the top and bottom conductive lines is greater than 3 microns.
9. The integrated circuit device of claim 1 , further comprising a lithographically patterned secondary coil, the secondary coil comprising:
one or more windings wound around the winding axis, wherein each of the windings comprises:
a second top conductive line arranged over the core layer, the second top conductive line having a third thickness along the vertical axis, wherein a cross-section of the second top conductive line in the plane comprises a rounded convex portion of a side surface of the second top conductive line, the rounded convex portion having a radius of curvature larger than 1 micron,
a second bottom conductive line arranged under the core layer, the second bottom conductive line having a fourth thickness along the vertical axis, wherein a cross-section of the second bottom conductive line in the plane comprises a rounded convex portion of a side surface of the second bottom conductive line, the rounded convex portion having a radius of curvature larger than 1 micron,
a third first conductive via extended along the vertical axis electrically connecting the second top and second bottom conductive lines, and
a fourth conductive via extended along the vertical axis electrically connecting one but not the other of the second top and second bottom conductive lines to a conductive line of another winding of the secondary coil,
wherein the primary coil and the secondary coil are magnetically coupled.
10. The integrated circuit device of claim 9 , wherein the rounded convex portion of the side surface of the second top conductive line has a radius of curvature exceeding 15% of the third thickness.
11. The integrated circuit device of claim 9 , wherein the primary coil and the secondary coil are interlaced with each other and wound around the winding axis such that the windings of the primary coil alternate with the windings of the secondary coil along the winding axis.
12. The integrated circuit device of claim 9 , wherein the top conductive line and the second top conductive line are lithographically co-patterned at a top metallization level.
13. The integrated circuit device of claim 9 , wherein the rounded convex portions of the bottom and second bottom conductive lines are formed on one or both of top and bottom corner portions of the side surfaces of the bottom and second bottom conductive lines that directly face each other.
14. An integrated circuit device comprising:
a substrate having a main surface;
a core layer disposed over the substrate; and
a lithographically patterned primary coil, the primary coil comprising one or more windings wound around a winding axis parallel to the main surface, wherein each of the windings comprises:
a top conductive line arranged over the core layer, wherein an acute angle between a negatively sloped side surface and a top surface of the top conductive line is less than 75 degrees,
a bottom conductive line arranged under the core layer, wherein an acute angle between a positively sloped side surface and a bottom surface of the bottom conductive line is less than 75 degrees,
a first conductive via extended along a vertical axis perpendicular to the main surface and electrically connecting the top and the bottom conductive lines, and
a second conductive via extended along the vertical axis and electrically connecting the top or the bottom conductive lines to a conductive line of another winding of the primary coil.
15. The integrated circuit device of claim 14 , wherein the acute angle between the negatively sloped side surface and the top surface of the top conductive line, and the acute angle between the positively sloped side surface and the bottom surface of the bottom conductive line, are less than 70 degrees.
16. The integrated circuit device of claim 14 , wherein a width of the top conductive line, along a lateral axis parallel to the main surface, decreases from the top surface to a bottom surface of the top conductive line along a vertical axis perpendicular to the main surface.
17. The integrated circuit device of claim 16 , wherein a width of the bottom conductive line along a lateral axis parallel to the main surface, increases from a top surface to the bottom surface of the bottom conductive line along the vertical axis.
18. The integrated circuit device of claim 14 , wherein the bottom conductive line and the top conductive line are formed at a bottom metallization layer and an upper metallization layer, respectively, wherein the upper and bottom metallization layers are distinct metallization layers of the integrated circuit device each comprising at least a metallized portion formed by electroplating and an intermetal dielectric portion embedding the metallized portion.