High resistivity iron-based, thermally stable magnetic material for on-chip integrated inductors
An on-chip magnetic structure includes a palladium activated seed layer and a substantially amorphous magnetic material disposed onto the palladium activated seed layer. The substantially amorphous magnetic material includes nickel in a range from about 50 to about 80 atomic % (at. %) based on the total number of atoms of the magnetic material, iron in a range from about 10 to about 50 at. % based on the total number of atoms of the magnetic material, and phosphorous in a range from about 0.1 to about 30 at. % based on the total number of atoms of the magnetic material. The magnetic material can include boron in a range from about 0.1 to about 5 at. % based on the total number of atoms of the magnetic material.
1. An on-chip magnetic structure, comprising:
a semiconductor substrate comprising at least one of gallium arsenide, indium phosphide, and silicon carbide;
a seed layer arranged directly on the semiconductor substrate, the seed layer comprising a nickel iron alloy;
an activated layer arranged directly on the seed layer, the activated layer comprising palladium nanoparticles; and
an electroless plated layer arranged directly on the palladium nanoparticles, the electroless plated layer comprising amorphous magnetic material disposed directly onto the palladium nanoparticles to form a Pd/NiFeP material comprising nickel in a range from 20 to 71 atomic % (at. %) based on a total number of atoms of the magnetic material, iron in a range from 10 to 50 at. % based on the total number of atoms of the magnetic material, and phosphorous in a range of about 20 at. % based on the total number of atoms of the magnetic material, wherein the palladium nanoparticles pin a microstructure of the amorphous magnetic material to maintain an amorphous state at a temperature of about 250° C.;
wherein the amorphous magnetic material has a thickness in a range from about 50 nanometers to about 5 micrometers.
2. The on-chip magnetic structure of claim 1 , wherein the magnetic material further comprises boron in an amount in a range from about 0.1 to about 5 at. % based on the total number of atoms of the magnetic material.
3. The on-chip magnetic structure of claim 1 , wherein the magnetic material has a resistivity of at least 100 micro-ohm·centimeters (μΩ·cm).
4. The on-chip magnetic structure of claim 1 , wherein the on-chip magnetic structure is a yoke or a coil.
5. The on-chip magnetic structure of claim 1 , wherein the palladium nanoparticles are formed by immersing the seed layer in a palladium-containing solution in a presence of an acid.
6. The on-chip magnetic structure of claim 5 , wherein the palladium-containing solution is palladium sulfate.
7. The on-chip magnetic structure of claim 5 , wherein the acid is sulfuric acid, hydrochloric acid, nitric acid, or any combination thereof.