Non-Invasive Wide-Field Imaging of Chip Surface Temperature Distribution Based on Ensemble Diamond Nitrogen-Vacancy Centers

At a Glance

Metadata	Details
Publication Date	2025-03-20
Journal	Sensors
Authors	Zhenrong Shi, Ziwen Pan, Qinghua Li, Wei Li
Institutions	Changchun University
Citations	2
Analysis	Full AI Review Included

Technical Documentation & Analysis: Wide-Field NV Center Thermometry

This document analyzes the research paper “Non-Invasive Wide-Field Imaging of Chip Surface Temperature Distribution Based on Ensemble Diamond Nitrogen-Vacancy Centers” and outlines how 6CCVD’s advanced MPCVD diamond materials and customization capabilities can support, replicate, and scale this critical quantum sensing technology.

Executive Summary

Core Achievement: Successful demonstration of non-contact, wide-field temperature imaging of electronic chip surfaces using ensemble Nitrogen-Vacancy (NV) centers in diamond.
Ultra-High Sensitivity: Achieved a temperature sensitivity of 10 mK/Hz^1/2, enabling precise monitoring of thermal characteristics and defect identification.
High Resolution: Demonstrated a high spatial resolution of 1.3 µm over a wide field of view (500 µm x 500 µm), crucial for micro-scale electronic device analysis.
Material Innovation: Utilized a hybrid diamond-quartz device, integrating a thin (200 nm) NV-doped diamond layer bonded to a quartz substrate to mitigate thermal diffusion effects.
Quantum Optimization: Sensitivity was enhanced by 40% by precisely aligning the bias magnetic field along the diamond’s <111> crystal axis, suppressing off-axis lattice strain.
Application: Provides a powerful, non-invasive tool for real-time thermal monitoring, chip aging assessment, and high-speed fault diagnosis in micro-electromechanical systems (MEMS).

Technical Specifications

Parameter	Value	Unit	Context
Temperature Sensitivity (η)	10	mK/Hz^1/2	Achieved with optimized B
Spatial Resolution (r)	1.3	µm	Calculated based on optical setup (λ = 670 nm, NA = 0.3).
Field of View (FOV)	500 x 500	µm²	Wide-field imaging area.
NV-Doped Layer Thickness	200	nm (0.2 µm)	Thin film retained after polishing for surface sensitivity.
NV Concentration	5	ppm	High concentration achieved via ion implantation.
Diamond Crystal Phase	(110)	N/A	Crystal orientation of the diamond wafer.
Optimized Bias Field Alignment	<111>	N/A	Alignment direction yielding 40% sensitivity increase.
Zero-Field Splitting Shift (β_T)	-73	kHz/K	Highest linearity achieved at B
Microwave Frequency Range	2.6 to 2.9	GHz	Sweep range for ODMR spectrum acquisition.
Operating Temperature Range	300 to 400	K	Range tested for ODMR spectral shift analysis.
Temporal Resolution	2.4	s	Time required for one thermal image acquisition.

Key Methodologies

The high-sensitivity, wide-field temperature imaging was achieved through the precise integration of specialized diamond material and synchronized quantum control systems:

Hybrid Diamond Device Fabrication:
- A high-concentration NV center layer (5 ppm) was generated approximately 50 nm below the surface of a 3 mm x 3 mm x 1 mm (110) diamond wafer using ion implantation.
- The diamond was polished to retain a 200 nm thick NV-doped layer.
- The diamond wafer was bonded to a quartz substrate (thermal conductivity three orders of magnitude lower than diamond) using crystal bonding wax to create a hybrid device that minimizes thermal diffusion.
Optical Excitation and Collection:
- A 532 nm laser was used for NV center initialization.
- Fluorescence (~670 nm) was collected via a 10x objective lens (NA = 0.3) and filtered (650 nm high-pass) to eliminate background light.
- A CCD camera (1000 x 1000 pixels) captured images at 250 FPS.
Microwave and Magnetic Field Control:
- A microwave source generated a signal (~2.87 GHz), amplified to ~30 dBm, and transmitted via a horn antenna to manipulate the electron spin states.
- A three-axis adjustable electromagnet (0 to 500 mT range) was used to align the bias magnetic field precisely along the diamond’s <111> axis, maximizing the linearity and sensitivity of the ODMR signal.
Data Processing:
- An Arbitrary Waveform Generator (AWG) synchronized the laser, microwave sweep (0.5 MHz step frequency), and CCD camera.
- Fluorescence intensity data was processed using Lorentz fitting to determine the zero-field splitting value (D), which correlates linearly with temperature.

6CCVD Solutions & Capabilities

This research highlights the critical need for highly customized, ultra-thin, and precisely oriented Single Crystal Diamond (SCD) materials for advanced quantum sensing applications. 6CCVD is uniquely positioned to supply the necessary materials to replicate and scale this wide-field NV thermometry system.

Research Requirement	6CCVD Solution & Capability	Technical Advantage
Material Base	High-Purity SCD Wafers	Provides the low-strain, high-quality lattice structure essential for stable NV center formation and long spin coherence times, maximizing temperature sensitivity.
Thin Film Requirement (200 nm)	Custom SCD Thickness Control	We offer SCD films from 0.1 µm up to 500 µm. We can deliver wafers pre-thinned or ready for precise ion implantation and subsequent polishing to achieve the required 200 nm layer depth.
Crystal Orientation	Custom SCD Orientation	While the paper used (110), 6CCVD supplies SCD in standard (100) and (111) orientations, and can provide custom (110) wafers necessary for replicating the experimental setup.
Surface Quality	Precision Polishing (Ra < 1 nm)	Our internal polishing capability ensures the SCD surface roughness (Ra) is < 1 nm, minimizing optical scattering and maximizing fluorescence collection efficiency for ODMR imaging.
Hybrid Device Integration	Custom Substrate Handling	We can supply the SCD layer ready for bonding or assist in integrating the diamond film onto various substrates (e.g., Quartz, Silicon, Sapphire) to facilitate the hybrid thermal management structure.
Scaling & Dimensions	Large Area PCD/SCD	We offer custom dimensions, including PCD wafers up to 125 mm, allowing researchers to scale the current 3 mm x 3 mm device to larger formats for industrial chip testing.
Advanced Functionality	Custom Metalization Services	Although not used in this specific paper, 6CCVD offers in-house metalization (Au, Pt, Pd, Ti, W, Cu) for integrating microwave antennas or electrical contacts directly onto the diamond surface for enhanced ODMR control.

Engineering Support

6CCVD’s in-house team of PhD material scientists specializes in optimizing MPCVD growth parameters for quantum applications. We provide comprehensive engineering support for projects involving:

NV Center Optimization: Tailoring nitrogen doping levels (ppm) and post-growth processing (e.g., annealing, irradiation) to achieve optimal ensemble NV concentration and depth profile for high-sensitivity thermal monitoring.
Strain Management: Selecting the optimal crystal orientation and polishing technique to minimize lattice strain, which is critical for maintaining ODMR spectral linearity, as demonstrated by the 40% sensitivity gain achieved in this study.
Thermal Management: Consulting on material selection and integration strategies for hybrid devices used in high-power electronic testing and chip reliability assessment.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

With the development of chip technology, the demand for device reliability in various electronic chip industries continues to grow. In recent years, with the advancement of quantum sensors, the solid-state spin (nitrogen-vacancy) NV center temperature measurement system has garnered attention due to its high sensitivity and spatial range. However, NV centers are not only affected by temperature but also by magnetic fields. This article analyzes the impact of magnetic fields on temperature detection. By combining the wide-field imaging platform of optically detected magnetic resonance (ODMR) with a temperature-sensitive structure of thin ensemble diamond overlaid on a quartz substrate, high-sensitivity temperature detection has been achieved. And obtains a sensitivity of approximately 10 mK/Hz1/2. By combining a CCD camera imaging system, it realizes a wide field of view of 500 μm2, a high spatial resolution of 1.3 μm. Ultimately, this study demonstrates the two-dimensional actual temperature distribution on the chip surface under different currents, achieving wide-field, non-contact, high-speed temperature imaging of the chip surface.

Tech Support

Original Source

DOI: https://doi.org/10.3390/s25061947

References

2022 - Thermoelectric Coolers for On-Chip Thermal Management: Materials, Design, and Optimization [Crossref]
2013 - Nanometre-Scale Thermometry in a Living Cell [Crossref]
2021 - Ultra-Thin Temperature Controllable Microwell Array Chip for Continuous Real-Time High-Resolution Imaging of Living Single Cells [Crossref]
2019 - Lanthanide-Based Thermometers: At the Cutting-Edge of Luminescence Thermometry [Crossref]
2011 - Determining Intracellular Temperature at Single-Cell Level by a Novel Thermocouple Method [Crossref]
2016 - Micro/Nanoscale Thermometry for Cellular Thermal Sensing [Crossref]
2012 - Intracellular Temperature Mapping with a Fluorescent Polymeric Thermometer and Fluorescence Lifetime Imaging Microscopy [Crossref]
2010 - Temperature Dependence of the Nitrogen-Vacancy Magnetic Resonance in Diamond [Crossref]