Electrolessly formed high resistivity magnetic materials

Patent metadata

Field	Value
Publication number	US-2017314136-A1
Application number	US-201715486744-A
Country	US
Kind code	A1
Filing date	Apr 13, 2017
Priority date	May 2, 2016
Publication date	Nov 2, 2017
Grant date	—

Abstract

Present disclosure relates to magnetic materials, chips having magnetic materials, and methods of forming magnetic materials. In certain embodiments, magnetic materials may include a seed layer, and a cobalt-based alloy formed on seed layer. The seed layer may include copper, cobalt, nickel, platinum, palladium, ruthenium, iron, nickel alloy, cobalt-iron-boron alloy, nickel-iron alloy, and any combination of these materials. In certain embodiments, the chip may include one or more on-chip magnetic structures. Each on-chip magnetic structure may include a seed layer, and a cobalt-based alloy formed on seed layer. In certain embodiments, method may include: placing a seed layer in an aqueous electroless plating bath to form a cobalt-based alloy on seed layer. In certain embodiments, the aqueous electroless plating bath may include sodium tetraborate, an alkali metal tartrate, ammonium sulfate, cobalt sulfate, ferric ammonium sulfate and sodium borohydride and has a pH between about 9 to about 13.

First claim

What is claimed is:

1 . A method of making a magnetic material comprising:
placing a seed layer in an aqueous electroless plating bath to form a cobalt-based alloy on the seed layer, wherein the aqueous electroless plating bath comprises sodium tetraborate, an alkali metal tartrate, ammonium sulfate, cobalt sulfate, ferric ammonium sulfate, and sodium borohydride, and the aqueous electroless plating bath has a pH in a range from about 9 to about 13, and ranges therebetween.

2 . The method of claim 1 , wherein the sodium tetraborate comprises a concentration in a range from about 0.005 moles per liter to about 0.02 moles per liter, and ranges therebetween, the alkali metal tartrate comprises a concentration in a range from about 0.222 moles per liter to 0.250 moles per liter, and ranges therebetween, the ammonium sulfate comprises a concentration in a range from about 0.150 moles per liter to about 0.200 moles per liter, and ranges therebetween, the cobalt sulfate comprises a concentration in a range from about 0.01 moles per liter to 0.04 moles per liter, and ranges therebetween, the ferric ammonium sulfate comprises a concentration in a range from about 0.005 moles per liter to about 0.040 moles per liter, and ranges therebetween, and the sodium borohydride comprises a concentration in a range from about 5 micromoles per liter to about 200 micromoles per liter, and ranges therebetween.

3 . The method of claim 1 , wherein the seed layer includes a metal selected from a group consisting of: copper, cobalt, nickel, platinum, palladium, ruthenium, iron, a nickel alloy, a cobalt-iron-boron alloy, a nickel-iron alloy, and any combination thereof.

4 . The method of claim 1 , wherein the cobalt-based alloy has a thickness in a range from about 100 to about 500 nanometers, and ranges therebetween, and the seed layer has a thickness in a range from about 50 to about 70 nanometers, and ranges therebetween.

5 . The method of claim 1 , wherein the aqueous electroless plating bath has a pH in a range from about 10.5 to about 12.5, and ranges therebetween.

6 . The method of claim 1 , wherein a temperature of the aqueous electroless plating bath is in a range from about 25° C. to about 45° C., and ranges therebetween.

7 . The method of claim 1 , wherein the cobalt-based alloy comprises an amorphous or a nano-crystalline microstructure.

8 . The method of claim 1 , wherein the cobalt-based alloy comprises a cobalt-iron-boron alloy.

9 . The method of claim 1 , wherein the cobalt-based alloy comprises boron in an atomic percentage in a range of between from about 25% to about 45%, and ranges therebetween.

10 . The method of claim 1 , wherein the magnetic material has a magnetic coercivity in the range from about 0.1 to less than about 10 Oersted (Oe), and ranges therebetween.

11 . The method of claim 1 , wherein the cobalt-based alloy has a thickness in the range from about 100 to about 500 nanometers, and ranges therebetween, and the seed layer has a thickness in the range from about 50 to about 70 nanometers, and ranges therebetween.

12 . The method of claim 1 , wherein a resistivity of the magnetic material is greater than or equal to about 200 micro ohms-centimeter.

13 . The method of claim 1 , wherein a resistivity of the magnetic material is greater than or equal to about 1000 micro ohms-centimeter.

14 . A method comprising:
forming a seed layer having a metal selected from a group consisting of: copper, cobalt, nickel, platinum, palladium, ruthenium, iron, a nickel alloy, a cobalt-iron-boron alloy, a nickel-iron alloy, and any combination thereof; and forming a cobalt-based alloy on the seed layer to form one or more on-chip magnetic structures.

15 . The method of claim 14 , wherein the cobalt-based alloy comprises boron in an atomic percentage range between from about 25% to about 45%, and ranges therebetween.

16 . The method of claim 14 , wherein each of the one or more on-chip magnetic structures has a magnetic coercivity in a range from about 0.1 to less than about 10 Oersted (Oe), and ranges therebetween.

17 . The method of claim 14 , wherein the cobalt-based alloy has a thickness in a range from about 100 to about 500 nanometers, and ranges therebetween, and the seed layer has a thickness in the range from about 50 to about 70 nanometers, and ranges therebetween.

18 . The method of claim 14 , wherein each of the one or more on-chip magnetic structures has a resistivity greater than or equal to about 200 micro ohms-centimeter.

19 . The method of claim 14 , wherein each of the one or more on-chip magnetic structures has a resistivity greater than or equal to about 1000 micro ohms-centimeter.

20 . The method of claim 14 , wherein the cobalt-based alloy comprises an amorphous or a nano-crystalline microstructure.

Assignees

• IBM

Inventors

• Deligianni Hariklia
• Gallagher William J
• Luo Yu
• Romankiw Lubomyr T
• Yoon Joonah

Classifications

• C23C18/50 Primary

  with alloys based on iron, cobalt or nickel · CPC title

• H01F1/14708

  Fe-Ni based alloys (pure Fe or Ni H01F1/14, H01F1/16 or H01F1/20) · CPC title

• C23C18/1637

  metallic substrate · CPC title

• C23C18/168

  Control of temperature, e.g. temperature of bath, substrate · CPC title

• H01F41/046

  structurally combined with ferromagnetic material · CPC title