Beveled overburden for vias and method of making the same

Patent metadata

Field	Value
Publication number	US-12207405-B2
Application number	US-202117923624-A
Country	US
Kind code	B2
Filing date	Apr 29, 2021
Priority date	May 8, 2020
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

A substrate including a via with a beveled overburden is disclosed. The substrate can include a substrate having a first surface, a second surface opposite the first surface, and a via passing from the first surface to the second surface. The via can be coated with a metallic layer that includes a first beveled overburden on the first surface, and the first beveled overburden can include a first outer edge that forms a first bevel angle greater than 95° with the first surface. The substrate can include a second beveled overburden that includes a second outer edge that forms a second bevel angle greater than 95° with the second surface. Methods of making the beveled overburdens are also disclosed.

First claim

What is claimed is:

1. A substrate, comprising:
a first surface, a second surface opposite the first surface, and a via passing from the first surface to the second surface; and
a metallic layer coating the via,
wherein the metallic layer comprises a first beveled overburden on the first surface and the first beveled overburden comprises first outer edge,
wherein the first outer edge forms a first bevel angle greater than 95° with the first surface,
wherein the substrate exhibits a lower probability of crack formation when heated to temperatures less than or equal to 600° C. than a substrate having an equivalent metallic layer with a patterned overburden.

2. The substrate as claimed in claim 1 , wherein the first bevel angle is 120° or greater.

3. The substrate as claimed in claim 1 , wherein a maximum thickness of the first beveled overburden is less than 50 microns.

4. The substrate as claimed in claim 1 , wherein the metallic layer comprises at least one of copper, aluminum, or tungsten.

5. The substrate as claimed in claim 1 , wherein a length of the first beveled overburden on the first surface is less than 500 microns.

6. The substrate as claimed in claim 1 , wherein the first outer edge comprises a linear bevel, stepped bevel, or concave bevel.

7. The substrate as claimed in claim 1 , wherein the substrate comprises a material selected from glass, glass-ceramic, ceramics, silicon, quartz, sapphire and combinations thereof.

8. The substrate as claimed in claim 1 , wherein the via is selected from a through hole via, a blind via, and a buried via.

9. The substrate as claimed in clam 1 , wherein the substrate has a coefficient of thermal expansion of less than or equal to 10e −6 /° C.

10. The substrate as claimed in claim 1 , wherein the via has a form selected from the group consisting of hour-glass, tapered, and cylindrical.

11. The substrate as claimed in claim 1 , wherein the metallic layer is conformal over the via, pinched over the via, or fills the via.

12. The substrate as claimed in claim 1 , wherein the metallic layer fills the via and a diameter of the via at the first surface is less than or equal to 25 microns.

13. The substrate as claimed in claim 1 , wherein a length of a first lateral overburden surface is at least 1 micron.

14. The substrate as claimed in claim 1 , wherein the metallic layer comprises a second beveled overburden on the second surface and the second beveled overburden comprises second outer edge.

15. The substrate as claimed in claim 14 , wherein the second outer edge forms a second bevel angle greater than 95° with the second surface.

16. A method of forming a via, comprising:
forming a metallic layer with a first beveled overburden on a via, the via being formed in a substrate, the first beveled overburden disposed over a first surface of the substrate, and wherein the first beveled overburden comprises a first outer edge forming a first bevel angle greater than 95° with the first surface, wherein the depositing comprises:
depositing an initial overburden; and
etching an outer portion of the initial overburden to form a first step.

17. The method as claimed in claim 16 , wherein the forming comprises:
forming a photoresist mask with an undercut over the first surface; and
depositing the metallic layer.

18. The method as claimed in claim 16 , wherein the depositing further comprises:
etching a portion of the initial overburden adjacent to the first step to a thickness between a thickness of the first step and a thickness of the initial overburden to form a second step.

Assignees

• Corning Inc

Inventors

• Joshi Dhananjay
• Okoro Chukwudi Azubuike
• Pollard Scott Christopher

Classifications

• H10W20/2125

  Top-view shapes · CPC title

• H10W20/0261

  characterised by the filling method or the material of the conductive fill · CPC title

• H10W20/435

  Cross-sectional shapes or dispositions of interconnections · CPC title

• H10W70/635

  Through-vias · CPC title

• H10W20/20

  Interconnections within wafers or substrates, e.g. through-silicon vias [TSV] · CPC title