Extraordinary hall effect sensors and arrays

An array of n EHE magnetic sensors, n being an integer >1, comprising

• an alloy Ry[MxN100−x]100−y, wherein 0≦x≦100, 0.00<y≦20.00, and M is selected from the group consisting of Fe, Co, Ni, FezCo100−z wherein 0<z<100, and all magnetic alloys containing Fe, Co, or Ni;
• the alloy formed into a Hall bar along which sense current is carried between points C1 and C2 located on the Hall bar;
• a plurality of n voltage wires for measuring Hall voltage between points H1n and H2n which are located along the nth voltage wire;
• and
• a plurality of n field sensors defined by an intersection of the nth voltage wire with the Hall bar.

An Extraordinary Hall Effect (EHE) magnetic sensor comprising:

• an alloy Ry[MxN100−x]100−y wherein 0≦x≦100, 0.00≦y≦20.00, the alloy defining a thickness t,
• whereby M is selected from the group consisting of Fe, Co, Ni, FezCo100−z wherein 0<z<100, and all magnetic alloys containing Fe, Co, or Ni;
• wherein N is selected from the group consisting of Pt, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Au, In, Sn, Te, TI, Pb and Bi;
• wherein R is a rare earth element if y>0.00, and
• wherein the alloy exhibits a temperature coefficient T.C. having an absolute value |T.C.|≦0.003 K−1 at least in the temperature range from 273 K to 350 K.

A method of making an EHE sensor comprising:

• providing a substrate;
• preparing the substrate by cleaning it in a vacuum using an ion beam;
• selecting an alloy Ry[MxN100−x]100−y wherein 0≦x≦100, 0.00<y≦20.00, M is selected from the group consisting of Fe, Co, Ni, FezCo100−z wherein 0<z<100, and all magnetic alloys containing Fe, Co, or Ni, wherein N is selected from the group consisting of Pt, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Au, In, Sn, Te, TI, Pb and Bi, and wherein R is a rare earth element defined by one of the atomic numbers 58-71 if y>0.00;
• selecting a thickness t for the alloy;
• and
• disposing the alloy onto the substrate at a thickness t.

A method of designing an EHE sensor comprising:

• selecting a first alloy Ry[MxN100−x]100−y wherein 0≦x≦100, 0.00≦y≦20.00, M is selected from the group consisting of Fe, Co, Ni, FezCo100−z wherein 0<z<100, and all magnetic alloys containing Fe, Co or Ni, wherein N is selected from the group consisting of Pt, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Au, In, Sn, Te, Tl, Pb and Bi, and wherein R is a rare earth element defined by one of the atomic numbers 58-71 if y>0.00;
• preparing a first and a second sensor sample wherein the first alloy is deposited at a first and a second thickness, respectively;
• selecting a second alloy that varies from the first in either only the relative concentration of R or only the relative concentration of M;
• preparing a third and a fourth sensor sample wherein the second alloy is deposited at the first and the second thickness, respectively;
• and
• comparing electrical and magnetic properties of at least two of the sensor samples at a selected temperature.

A method of determining a maximum acceptable sense current in an EHE sample sensor comprising:

• selecting an alloy Ry[MxN100−x]100−y wherein 0≦x≦100, 0.00≦y≦20.00, M is selected from the group consisting of Fe, Co, Ni, FezCo100−z wherein 0<z<100, and all magnetic alloys containing Fe, Co or Ni, wherein N is selected from the group consisting of Pt, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Au, In, Sn, Te, Tl, Pb and Bi, and wherein R is a rare earth element defined by one of the atomic numbers 58-71 if y>0.00;
• preparing a sample sensor by disposing the alloy on a substrate surface such that the alloy defines a thickness t;
• passing a first current through the alloy;
• measuring a first Hall voltage across the sample sensor at a first time;
• measuring a second Hall voltage across the sample sensor at a second time;
• passing a second current through the alloy;
• measuring a third Hall voltage across the sample sensor at a third time;
• measuring a fourth Hall voltage across the sample sensor at a fourth time;
• and
• evaluating voltage as a function of time for the first and the second currents.

A method of making an array of EHE sensors comprising:

• providing a substrate that defines a first surface, an opposing second surface, and a plurality of vias penetrating from the first surface to the second surface;
• filling the vias with a conductive material;
• polishing at least the first surface of the substrate;
• and
• disposing an alloy layer that exhibits EHE onto the first surface.

A method of co-depositing two targets M and N onto a substrate comprising:

• loading a first target M onto a first sputtering gun and loading a second target N onto a second sputtering gun;
• mounting a discharge end of the first sputtering gun in spaced relation from a discharge end of the second sputtering gun within a vacuum chamber;
• passing the substrate over the discharge end of the first sputtering gun for a first time interval so as to deposit a layer of the first target M at a thickness t1 onto the substrate;
• passing the substrate over the discharge end of the second sputtering gun for a second time interval so as to deposit a layer of the second target N at a thickness t2 onto the substrate;
• wherein the start of the second time interval is within one minute of the end of the first time interval.

A method of depositing an alloy film at a thickness t onto a plurality of substrates comprising:

• mounting a discharge end of a sputtering gun in a vacuum chamber;
• loading a target of the alloy onto a sputtering gun;
• mounting a first substrate at a first location spaced from a central pivot;
• mounting a second substrate at a second location spaced from the central pivot;
• moving the first substrate about the central pivot into alignment with the discharge end of the sputtering gun and a layer of alloy at a thickness tx is deposited thereon;
• subsequently moving the second substrate about the central pivot into alignment with the discharge end of the sputtering gun and a layer of alloy at a thickness tx is deposited thereon.