Method of manufacturing a layer structure having partially sealed pores

Patent metadata

Field	Value
Publication number	US-9929111-B2
Application number	US-201715461500-A
Country	US
Kind code	B2
Filing date	Mar 17, 2017
Priority date	Nov 30, 2015
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A method of manufacturing a layer structure includes: forming a first layer over a substrate; planarizing the first layer to form a planarized surface of the first layer; and forming a second layer over the planarized surface; wherein a porosity of the first layer is greater than a porosity of the substrate and greater than a porosity of the second layer; wherein the second layer is formed by physical vapor deposition; and wherein the first layer and the second layer are formed from the same solid material.

First claim

What is claimed is:

1. A method of manufacturing a layer structure, the method comprising:
forming a first layer over a substrate;
planarizing the first layer to form a planarized surface of the first layer; and
forming a second layer over the planarized surface;
wherein a porosity of the first layer is greater than a porosity of the substrate and greater than a porosity of the second layer;
wherein the second layer is formed by physical vapor deposition; and
wherein the first layer and the second layer are formed from the same solid material.

2. The method of claim 1 ,
wherein the second layer seals at least one pore of the first layer.

3. The method of claim 1 ,
wherein the first layer protrudes from an exposed surface of the substrate.

4. The method of claim 1 ,
wherein at least one of the following pore-characteristics of at least one of the substrate or the second layer is substantially zero:
a pore-density;
a pore-size; and
a porosity.

5. The method of claim 1 ,
wherein the first layer is formed by depositing solid particles over the substrate.

6. The method of claim 5 ,
wherein forming the first layer comprises sintering the solid particles.

7. The method of claim 6 ,
wherein the first layer is planarized after having been sintered.

8. The method of claim 6 ,
wherein the first layer is planarized at least one of before and during sintering.

9. The method of claim 1 ,
wherein a stress-temperature-gradient of the first layer is smaller than a stress-temperature-gradient of at least one of the second layer and the substrate.

10. The method of claim 1 ,
wherein a density of the first layer is smaller than a density of at least one of the second layer and the substrate.

11. The method of claim 1 ,
wherein a thickness of the second layer is at least one of: greater than half of a spatial pore-size of the first layer and smaller than twice the spatial pore-size of the first layer.

12. The method of claim 1 ,
wherein the first layer comprises an open-pored surface at least one of before planarizing the first layer and after planarizing the first layer.

13. The method of claim 1 ,
wherein the first layer comprises at least one of copper, silver and nickel.

14. The method of claim 1 ,
wherein planarizing the first layer comprises forming a gradient in at least one of the following pore-characteristics of the first layer:
a pore-density;
a pore-size; and
a porosity.

15. The method of claim 1 ,
wherein planarizing the first layer comprises at least one of the following: machining, mechanical polishing, electrochemical polishing, and chemical mechanical polishing.

16. The method of claim 1 , further comprising:
forming at least one of a solder joint and a bonding joint over the second layer for electrically contacting the second layer.

17. The method of claim 1 ,
wherein planarizing the first layer reduces a roughness of the first layer.

18. The method of claim 1 ,
wherein planarizing first layer comprises forming a pore characteristic of the first layer proximate the substrate greater than distant from the substrate.

19. The method of claim 1 ,
wherein planarizing the first layer comprises thinning the first layer.

20. A method of manufacturing a layer structure, the method comprising:
disposing solid particles over a substrate and sintering the solid particles to form a first layer having a greater porosity than the substrate;
planarizing the first layer to form a planarized surface of the first layer; and
forming a second layer having a lower porosity than the first layer over the planarized surface;
wherein the second layer is formed by sputtering.

Assignees

• Infineon Technologies Ag

Inventors

• Mischitz Martin
• Heinrici Markus
• Eichinger Barbara
• Schneegans Manfred
• Krivec Stefan

Classifications

• H10W72/5524

  comprising aluminium [Al] · CPC title

• H10W72/552

  comprising metals or metalloids, e.g. silver · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/536

  the connected ends being ball-shaped · CPC title

• H10W72/953

  not comprising solid metals or solid metalloids, e.g. polymers, ceramics or liquids · CPC title