Electrolessly formed high resistivity magnetic materials
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.
1. A magnetic material comprising:
a seed layer having a metal selected from the group consisting of: copper, cobalt, nickel, platinum, palladium, ruthenium, iron, a nickel alloy, a cobalt-iron-boron alloy, and any combination thereof; and
a magnetic layer consisting essentially of a cobalt-iron-boron alloy formed on the seed layer;
wherein the resistivity of the magnetic material is greater than or equal to about 1000 micro ohms centimeter.
2. The magnetic material of claim 1 , wherein the magnetic layer cobalt-iron-boron alloy comprises an amorphous or a nano-crystalline micro structure.
3. The magnetic material of claim 1 , wherein the cobalt-iron-boron alloy comprises boron in an atomic percentage in the range of between from about 25% to about 45%, and ranges therebetween.
4. The magnetic material 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.
5. The magnetic material of claim 1 , wherein the magnetic layer cobalt-iron-boron 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.
6. A chip comprising:
one or more on-chip magnetic structures, each of the one or more on-chip magnetic structures having:
a seed layer having a metal selected from the group consisting of: copper, cobalt, nickel, platinum, palladium, ruthenium, iron, a nickel alloy, a cobalt-iron-boron alloy, and any combination thereof; and
a magnetic layer consisting essentially of a cobalt-iron-boron alloy formed on the seed layer;
wherein each of the one or more on chip magnetic structures has a resistivity greater than or equal to about 1000 micro ohms centimeter.
7. The chip of claim 6 , wherein the magnetic layer cobalt-iron-boron alloy comprises boron in an atomic percentage range between from about 25% to about 45%, and ranges therebetween.
8. The chip of claim 6 , wherein each of the one or more on-chip magnetic structures has a magnetic coercivity in the range from about 0.1 to less than about 10 Oersted (Oe), and ranges therebetween.
9. The chip of claim 6 , wherein the magnetic layer cobalt-iron-boron 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.