# US 11,993,864 B2 · Silicon carbide magnetometer and associated material formation methods

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,993,864 B2
- Document ID: US11993864B2
- Status: Granted
- Kind: B2
- Application number: 17/516,956
- Filed: 2021-11-02
- Published: 2022-05-05
- Granted: 2024-05-28
- Earliest claimed: 2020-11-04
- Assignees: The Johns Hopkins University
- Applicants: The Johns Hopkins University
- Inventors: John B. Abraham; Brian D. Clader; Robert Osiander; Cameron A. Gutgsell; Dalibor J. Todorovski; Scott A. Sperling; Jacob E. Epstein; Timothy M. Sweeney; Elizabeth A. Pogue; Tyrel M. McQueen
- Web page: https://patentgrep.com/patent/US11993864B2

## CPC

- C30B 33/02: Heat treatment (C30B33/04, C30B33/06 take precedence)
- C30B 29/36: Carbides
- C30B 33/04: using electric or magnetic fields or particle radiation
- G01R 33/0052: {Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85)}
- G01R 33/032: using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect}
- G01R 33/26: using optical pumping
- G01R 33/323: {Detection of MR without the use of RF or microwaves, e.g. force-detected MR, thermally detected MR, MR detection via electrical conductivity, optically detected MR}
- G01R 33/007: {Environmental aspects, e.g. temperature variations, radiation, stray fields (G01R33/025 takes precedence)}
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A method for forming a silicon carbide material with a plurality of negatively charged silicon mono-vacancy defects includes irradiating a silicon carbide sample, annealing the irradiated silicon carbide sample in an annealing operation, and quenching the annealed silicon carbide sample. Quenching may include heating the annealed silicon carbide sample to a maximum temperature and quenching the annealed silicon carbide sample to form the silicon carbide sample with the plurality of negatively charged silicon mono-vacancy defects.

## Claims

### Claim 1

A method for forming a silicon carbide material with a plurality of negatively charged silicon mono-vacancy defects, the method comprising:
irradiating a silicon carbide sample to form an irradiated silicon carbide sample;
annealing the irradiated silicon carbide sample in an annealing operation to form an annealed silicon carbide sample; and
quenching the annealed silicon carbide sample, wherein the quenching comprises heating the annealed silicon carbide sample to a maximum temperature and quenching the annealed silicon carbide sample to form the silicon carbide sample with the plurality of negatively charged silicon mono-vacancy defects;
wherein the silicon carbide sample exhibits a photoluminescence spectra with zero photon lines at about 1445, 1440, and 1354 millielectronvolts at temperatures below 10 Kelvin.

### Claim 2 (depends on 1)

The method of claim 1, wherein the n-type SiC wafer is a four layer hexagonal polytype.

### Claim 3 (depends on 1)

The method of claim 1, wherein the plurality of negatively charged silicon mono-vacancy defects are point defects in a crystalline material of the silicon carbide sample the plurality of negatively charged silicon mono-vacancy defects.

### Claim 4 (depends on 1)

The method of claim 1, wherein irradiating the silicon carbide sample comprises neutron irradiating the silicon carbide sample.

### Claim 5

A method for forming a silicon carbide material with a plurality of negatively charged silicon mono-vacancy defects, the method comprising:
irradiating a silicon carbide sample to form an irradiated silicon carbide sample;
annealing the irradiated silicon carbide sample in an annealing operation to form an annealed silicon carbide sample; and
quenching the annealed silicon carbide sample, wherein the quenching comprises heating the annealed silicon carbide sample to a maximum temperature and quenching the annealed silicon carbide sample to form the silicon carbide sample with the plurality of negatively charged silicon mono-vacancy defects,
wherein the silicon carbide sample with the plurality of negatively charged silicon mono-vacancy defects exhibits a shot noise sensitivity in a range of about 3.5 nT/√{square root over (Hz)} to 2.0 nT/√{square root over (Hz)}.

### Claim 6 (depends on 1)

The method of claim 1, wherein the annealing operation comprises cooling the irradiated silicon carbide sample to room temperature.

### Claim 7 (depends on 1)

The method of claim 1 further comprising cutting or dicing a SiC substrate comprising a purity layer with a nitrogen doping below 5.0×1014 cm−3 disposed on an n-type SiC wafer to form the silicon carbide sample prior to irradiating.

### Claim 8 (depends on 1)

The method of claim 1, wherein the silicon carbide sample with the plurality of negatively charged silicon mono-vacancy defects responds to a presence of a magnetic field with a change in photoluminescence.