Features of Manufacturing the Element Base of High-Temperature Electronics Using Laser Radiation
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-04-29 |
| Journal | Doklady BGUIR |
| Authors | E. Đ. Shershnev |
| Institutions | Francisk Skorina Gomel State University |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Thermal Laser Separation of Diamond
Section titled âTechnical Documentation & Analysis: Thermal Laser Separation of DiamondâExecutive Summary
Section titled âExecutive SummaryâThis research validates the use of Thermal Laser Separation (TLS) as a kerf-free, high-precision method for manufacturing diamond-based components for high-temperature electronics. The findings directly support the need for high-quality, precisely oriented MPCVD diamond materials supplied by 6CCVD.
- Core Achievement: Demonstrated controlled brittle fracture of diamond crystals using localized thermal stress induced by a 1064 nm diode-pumped laser and aerosol cooling.
- Mechanism: The process relies on generating Critical Thermoelastic Microstresses (KTM) at a specific depth (modeled 0.5-0.8 mm) to initiate and guide cleavage.
- Material Physics: Controlled separation exploits the anisotropy of diamondâs elastic properties, favoring fracture along the crystallographic plane with the minimum free surface energy, specifically the (111) plane (10.6 J/m2).
- Processing Advantage: TLS offers a significant advantage over traditional mechanical methods by achieving narrow, kerf-free cuts with minimal thermal influence zone, crucial for microelectronics.
- 6CCVD Relevance: The success of this technique is highly dependent on the quality, purity, and precise crystallographic orientation of the diamond wafers, which are core specialties of 6CCVDâs MPCVD Single Crystal Diamond (SCD) catalog.
- Application: This technology is essential for scaling the production of high-voltage, high-power diamond devices, particle detectors, and other components for high-temperature environments.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the modeling and experimental verification of the Thermal Laser Separation (TLS) process:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Laser Wavelength | 1064 | nm | Diode-pumped, Infrared (IR) source |
| Thermal Source Power Density (Modeled) | 2 * 106 | W/cm2 | Used for calculating temperature and stress fields |
| Optimal KTM Depth (Modeled) | 0.5 - 0.8 | mm | Depth where maximum thermoelastic stress ($\sigma_{33}$) concentrates |
| Processing Depth (Experimental) | ~250 | ”m | Achieved depth of controlled cleavage |
| Pulse Repetition Rate (Experimental) | 5 | kHz | Used for 7.5 W average power |
| Pulse Duration (Experimental) | 3 | ”s | At 5 kHz repetition rate |
| Average Laser Power (Experimental) | 7.5 | W | Used for thermal separation |
| Preferred Cleavage Plane | (111) | N/A | Plane of minimum free surface energy (Griffiths criterion) |
| Free Surface Energy F (111) | 10.6 | J/m2 | Minimum value, driving brittle fracture |
| Diamond Melting Temperature (Tm) | 3700 - 4000 | °C | Context for high-temperature stability |
| Microcrack Initiation Size | Up to 100 | ”m | Linear size of the initial defect formed by ablation |
Key Methodologies
Section titled âKey MethodologiesâThe controlled thermal laser separation (TLS) process is a two-stage method combining precise thermal modeling with localized heating and rapid cooling:
- Thermal Modeling: The non-stationary thermal conductivity problem was solved using the classical parabolic heat equation, utilizing MATLAB (pde-toolbox) to calculate temperature distributions and resulting thermoelastic microstresses ($\sigma$) within the diamond volume.
- Initial Defect Creation: A primary microcrack is intentionally formed on the surface using an ablative pulsed laser. This defect acts as the predetermined starting point for the controlled fracture line.
- Localized Heating: A focused, quasi-continuous wave (QCW) 1064 nm diode-pumped laser (operating in TEM00 mode) scans the material surface along the desired separation path. The laser geometry (elliptical Gaussian beam) is optimized for localized heating.
- Rapid Cooling (Stress Induction): Immediately following the laser heating spot, an aerosol coolant (chiller) is applied. This rapid temperature gradient generates critical thermoelastic microstresses (KTM).
- Controlled Cleavage: The induced KTM concentrates at a specific depth (0.5-0.8 mm modeled), causing controlled brittle fracture. The fracture path follows the crystallographic plane corresponding to the minimum free surface energy, ensuring precise separation along the (111) plane.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe successful implementation of Thermal Laser Separation (TLS) for high-temperature electronics requires diamond material with exceptional purity, precise crystallographic orientation, and high surface qualityâall core competencies of 6CCVD.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research, 6CCVD recommends the following MPCVD diamond materials:
| Material Grade | Application Relevance | Key 6CCVD Specification |
|---|---|---|
| Optical Grade SCD | High-power/high-voltage electronics, requiring maximum thermal conductivity and minimal defects. | SCD thickness from 0.1 ”m up to 500 ”m. Ra < 1 nm polishing standard. |
| High-Quality PCD | Cost-effective alternative for large-area element bases where single-crystal purity is not strictly required. | Wafers up to 125 mm diameter. Ra < 5 nm polishing standard for inch-size plates. |
| Custom Oriented SCD | Essential for optimizing anisotropic processes like TLS, which relies on the (111) cleavage plane. | SCD available in precise crystallographic orientations (<100>, <110>, <111>). |
Customization Potential
Section titled âCustomization PotentialâThe research focuses on manufacturing the element base, which often requires specific dimensions and integration features. 6CCVD provides comprehensive customization services to meet these needs:
- Custom Dimensions: We supply plates and wafers up to 125 mm (PCD) and offer custom laser cutting services to achieve the precise geometries required for high-temperature electronic components.
- Thickness Control: The modeling suggests optimal stress concentration occurs 0.5-0.8 mm below the surface. 6CCVD can provide SCD and PCD substrates tailored to this depth range, up to 10 mm thick, ensuring optimal material interaction with the laser process.
- Metalization Services: For subsequent device integration, 6CCVD offers in-house deposition of critical metal layers, including Au, Pt, Pd, Ti, W, and Cu, ensuring compatibility and high adhesion on the diamond surface.
- Surface Preparation: The integrity of the TLS process depends on minimizing surface defects. Our ultra-high-quality polishing (Ra < 1 nm for SCD) ensures minimal pre-existing flaws that could lead to uncontrolled fracture initiation.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers specializes in the unique thermal and mechanical properties of MPCVD diamond. We offer expert consultation to assist researchers and engineers in optimizing material selection for similar Thermal Laser Separation projects.
- Anisotropy Consultation: We assist in selecting the optimal crystallographic orientation and surface finish to maximize the efficiency and control of anisotropic processing techniques like TLS.
- Global Logistics: We ensure reliable global shipping (DDU default, DDP available) for time-sensitive research and manufacturing projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The paper presents the results of research on laser processing of natural and artificial diamond crystals in microelectronics technologies by thermal laser separation. An analysis of physical-chemical phenomena observed as a result of the thermal effect of laser radiation on anisotropic materials in various crystallographic directions is conducted. Based on the Griffiths criterion, the mechanics of brittle fracture as a result of the formation of critical micromechanical stresses caused by the thermal action of laser radiation are analyzed. The non-stationary problem of thermal conductivity was solved, temperature distributions in the volume of the material were calculated, on the basis of which information on the change of elastic properties of crystals leading to its controlled destruction in given directions was obtained. The simulation results were confirmed experimentally in the processes of thermal laser separation of rough diamonds by forming localized areas of critical thermoelastic microstresses at a given depth in the crystal volume, which are the starting point of the line of controlled crystal separation. Optimal modes of controlled separation of crystals of natural and artificial diamonds using a diode-pumped laser with a radiation wavelength of 1064 nm have been identified.