High resistivity soft magnetic material for miniaturized power converter

Patent metadata

Field	Value
Publication number	US-2018076275-A1
Application number	US-201715817858-A
Country	US
Kind code	A1
Filing date	Nov 20, 2017
Priority date	Mar 24, 2015
Publication date	Mar 15, 2018
Grant date	—

Abstract

An on-chip magnetic structure structure includes a magnetic material comprising cobalt in a range from about 80 to about 90 atomic % (at. %) based on the total number of atoms of the magnetic material, tungsten in a range from about 4 to about 9 at. % based on the total number of atoms of the magnetic material, phosphorous in a range from about 7 to about 15 at. % based on the total number of atoms of the magnetic material, and palladium substantially dispersed throughout the magnetic material.

First claim

What is claimed is:

1 . A method for forming an on-chip magnetic structure, the method comprising:
activating a magnetic seed layer with palladium, the magnetic seed layer being positioned over a semiconductor substrate; adding a lead salt to a plating solution; electrolessly plating, with the plating solution, a magnetic alloy onto the palladium to form a Pd/CoWP layer; and annealing the substrate; wherein the Pd/CoWP layer comprises cobalt in a range from about 80 to about 90 at. % based on the total number of atoms of the magnetic material, tungsten in a range from about 4 to about 9 at. % based on the total number of atoms of the magnetic material, phosphorous in a range from about 7 to about 15 at. % based on the total number of atoms of the magnetic material, and palladium substantially dispersed throughout the magnetic material.

2 . The method of claim 1 , wherein the magnetic seed layer comprises nickel and iron.

3 . The method of claim 1 , wherein the on-chip magnetic structure is an inductor.

4 . The method of claim 1 , wherein the Pd/CoWP layer is amorphous.

5 . The method of claim 1 , wherein the magnetic seed layer is at least 40 nm thick.

6 . The method of claim 1 , wherein the Pd/CoWP layer is magnetically stable to at least 200° C. for at least 1 hour.

7 . The method of claim 1 , wherein the cobalt is in a range from about 81 to about 86 at. %.

8 . The method of claim 1 , wherein the lead salt is lead acetate, lead nitrate, or a combination thereof.

9 . The method of claim 1 , wherein the lead salt is present in the plating solution in an amount in a range from about 0.01 to about 0.5 ppm.

10 . The method of claim 1 , wherein the lead salt is present in the plating solution in an amount in a range from about 0.05 to about 10 ppm.

11 . A method for forming an on-chip magnetic structure, the method comprising:
activating a magnetic seed layer with palladium, the magnetic seed layer being positioned over a semiconductor substrate; adding a cadmium salt to a plating solution; electrolessly plating, with the plating solution, a magnetic alloy onto the palladium in the presence of a magnetic field bias to form a film; and annealing the film at a temperature of at least 200° C. wherein the film comprises cobalt in a range from about 80 to about 90 at. % based on the total number of atoms of the magnetic material, tungsten in a range from about 4 to about 9 at. % based on the total number of atoms of the magnetic material, phosphorous in a range from about 7 to about 15 at. % based on the total number of atoms of the magnetic material, and palladium substantially dispersed throughout the magnetic material.

12 . The method of claim 11 , wherein the phosphorous is in a range from about 9 to about 14 at. %.

13 . The method of claim 11 , wherein the tungsten is in a range from about 4 to about 7 at. %.

14 . The method of claim 11 , wherein the film's resistivity is at least 110 μΩ·cm.

15 . The method of claim 11 , wherein the film is a soft magnetic material.

16 . The method of claim 11 , wherein the cadmium salt is cadmium acetate and cadmium nitrate, or any combination thereof.

17 . The method of claim 11 , wherein the cadmium salt is present in the plating solution in an amount in a range from about 0.01 to about 0.5 ppm.

18 . The method of claim 11 , wherein the cadmium salt is present in the plating solution in an amount in a range from about 0.05 to about 10 ppm.

19 . The method of claim 11 , wherein annealing is at a temperature of 250° C.

20 . The method of claim 11 , wherein the magnetic seed layer comprises nickel and iron.

Assignees

• IBM

Inventors

• Deligianni Hariklia
• Gallagher William J
• Kellock Andrew J
• O'Sullivan Eugene J
• Romankiw Lubomyr T
• Wang Naigang

Classifications

• H10P14/47

  Electrolytic deposition, i.e. electroplating; Electroless plating · CPC title

• H10P14/46

  using a liquid · CPC title

• H10W20/497

  Inductive arrangements or effects of, or between, wiring layers · CPC title

• H01F27/00

  Details of transformers or inductances, in general · CPC title

• H01F41/26

  using electric currents {, e.g. electroplating} · CPC title