Interfacial Heat Transport in Semiconducting Heterostructures
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-03-01 |
| Journal | Proceedings of the World Congress on Momentum, Heat and Mass Transfer |
| Authors | Zhixiong Guo |
| Institutions | Rutgers, The State University of New Jersey |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Interfacial Heat Transport in Semiconducting Heterostructures
Section titled âTechnical Documentation & Analysis: Interfacial Heat Transport in Semiconducting HeterostructuresâThis document analyzes the requirements for advanced thermal management in GaN-on-Diamond devices, as outlined in the research abstract, and maps these needs directly to 6CCVDâs capabilities in high-purity MPCVD diamond manufacturing.
Executive Summary
Section titled âExecutive SummaryâThe research addresses the critical challenge of Interfacial Thermal Boundary Resistance (TBR) in high-power GaN-on-Diamond electronics, a key limitation to device performance and longevity.
- Core Challenge: Dissipating large amounts of heat generated by GaN devices using diamond as a superior heat spreader.
- Focus Area: Analyzing and minimizing the TBR across the diamond/GaN interface, particularly the effect of inherent epilayers.
- Key Finding 1 (Epilayers): The thickness and material choice of the epilayer significantly impact overall thermal dissipation.
- Key Finding 2 (c-BN Potential): Cubic Boron Nitride (c-BN) is identified as a promising intermediate material due to its diamond-like thermal properties and compatibility.
- Breakthrough Result: Replacing the diamond cap or GaN substrate with c-BN reduces TBR, and direct growth of c-BN on diamond eliminates the need for an epilayer, achieving an unprecedented low TBR interface.
- 6CCVD Value Proposition: 6CCVD provides the necessary high-purity Single Crystal Diamond (SCD) and large-area Polycrystalline Diamond (PCD) substrates, along with custom metalization and polishing, essential for fabricating and testing these advanced heterostructures.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table summarizes the critical material requirements and performance metrics inferred from the research context of high-power GaN-on-Diamond thermal management.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Primary Application | High-Power RF/Power Electronics | N/A | Requires rapid heat dissipation to prevent thermal runaway. |
| Desired Thermal Property | Low Interfacial TBR | K*cm2/W (Inferred) | The primary metric for interface efficiency; minimization is the goal. |
| Ideal Heat Spreader Material | MPCVD Diamond (SCD/PCD) | N/A | Chosen for thermal conductivity (k) typically > 2000 W/m*K. |
| Interface Optimization Material | Cubic Boron Nitride (c-BN) | N/A | Used to replace traditional epilayers (e.g., AlN) for improved phonon matching. |
| Interface Goal | Direct Growth / Epilayer Elimination | N/A | Achieves the lowest possible TBR by maximizing interface quality. |
| Required Substrate Quality | High Purity, Low Defect Density | N/A | Essential for maintaining maximum intrinsic thermal conductivity in the diamond layer. |
Key Methodologies
Section titled âKey MethodologiesâThe successful replication and extension of this research require precise control over material deposition, interface engineering, and thermal measurement.
- Substrate Preparation: Utilizing high-quality, polished MPCVD diamond substrates (SCD or PCD) to ensure a low surface roughness (Ra < 1nm for SCD) critical for subsequent epitaxial growth.
- Heterostructure Fabrication: Depositing or bonding GaN onto the diamond substrate, often requiring an intermediate epilayer (e.g., AlN, SiC) to manage lattice mismatch.
- Interface Modification: Implementing c-BN layers, either as a cap or as a replacement for the GaN substrate, to study its effect on phonon transport and TBR.
- Direct Interface Engineering: Developing advanced CVD recipes to achieve direct, high-quality growth of c-BN onto the diamond surface, bypassing the need for traditional epilayers.
- Thermal Characterization: Employing advanced metrology (e.g., Time-Domain Thermoreflectance, TDTR) to accurately measure the TBR across the various diamond/epilayer/GaN and diamond/c-BN interfaces.
- Thickness Variation Study: Systematically varying the thickness of the intermediate epilayer or c-BN layer to quantify the thickness effect on overall thermal resistance.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-specification MPCVD diamond materials and custom engineering services required to advance research in GaN-on-Diamond and c-BN heterostructures.
Applicable Materials for Thermal Management
Section titled âApplicable Materials for Thermal Managementâ| Research Requirement | 6CCVD Material Solution | Key Technical Benefit |
|---|---|---|
| Ultra-Low TBR Interface | Electronic Grade SCD | Highest thermal conductivity (> 2000 W/m*K) and lowest defect density, maximizing heat flow away from the device. |
| Large-Scale Integration | High Thermal Grade PCD | Available in custom plates/wafers up to 125mm, ideal for scaling up GaN-on-Diamond manufacturing processes. |
| Interface Conductivity | Boron-Doped Diamond (BDD) | Can be used as a conductive layer or sensor element within the heterostructure for integrated thermal monitoring. |
Customization Potential & Interface Engineering
Section titled âCustomization Potential & Interface EngineeringâThe complexity of diamond/GaN/c-BN interfaces demands highly customized substrates and precise surface preparation, which are core competencies of 6CCVD.
- Custom Dimensions: We provide SCD and PCD plates in custom sizes and shapes, including inch-size wafers (up to 125mm for PCD), ensuring compatibility with standard semiconductor processing equipment.
- Precision Thickness Control: 6CCVD offers SCD and PCD layers with precise thickness control from 0.1”m up to 500”m, allowing researchers to accurately study the thickness effects of the diamond heat spreader on TBR, as highlighted in the paper.
- Advanced Polishing: Achieving an âunprecedented low TBRâ requires an atomically smooth interface. We guarantee ultra-low surface roughness:
- SCD: Ra < 1nm
- Inch-size PCD: Ra < 5nm
- Custom Metalization Services: For bonding, electrical contact, or creating measurement transducers (e.g., for TDTR), 6CCVD offers in-house deposition of critical metals, including Au, Pt, Pd, Ti, W, and Cu, tailored to the specific heterostructure stack.
Engineering Support
Section titled âEngineering SupportâThe integration of novel materials like c-BN with MPCVD diamond requires specialized knowledge of lattice matching and phonon transport.
- Expert Consultation: 6CCVDâs in-house PhD engineering team specializes in diamond growth parameters and material selection for similar GaN-on-Diamond High-Power Electronics projects. We assist clients in optimizing diamond purity and surface orientation to facilitate the direct growth of c-BN or other epilayers, minimizing interfacial defects.
- Global Supply Chain: We ensure reliable, global shipping (DDU default, DDP available) of high-value diamond substrates directly to your fabrication facility or research lab.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Heat dissipation through semiconducting heterostructures is of technological importance and fundamental research interest.Diamond is a desirable heat spreader, for integrating with semiconductors to dissipate quickly large amount of heat generated in electronics.The rapid development of GaN-on-diamond devices holds much promise for thermal management of high-power electronics and devices.Hitherto, the interfacial effect of an inherent epilayer between GaN and diamond to thermal dissipation is less investigated.One aim of this study is to understand and analyze the interfacial thermal boundary resistance (TBR) across a diamond/GaN heterostructure with an epilayer of different substrates.The thickness effect of epilayer is also revealed.Besides, c-BN is drawing increasing attention because it not only owns diamond-like thermal properties but also is a promising material for fabricating optoelectronic devices.It was found that the interfacial TBR reduced when the diamond cap or the GaN substrate was replaced by the c-BN.Further, c-BN can be directly grown on diamond without use of epilayer, resulting in an unprecedented low TBR in the diamond/c-BN interface.