Tuesday, June 30, 2026

風姿花伝 (橫山光輝「三國誌」片頭曲)

風姿花伝 (橫山光輝「三國誌」片頭曲) 風姿花傳(ㄔㄨㄢˊ)

作詞：谷村新司作曲：谷村新司唄：谷村新司文言翻譯:sssn1 風は叫ぶ　人の世の哀しみを風號人世之哀星に抱かれた　靜寂の中で於群星簇擁萬籟俱寂中胸を開けば　燃ゆる血潮の赤は若敞心扉則沸血鮮紅共に混ざりて　大いなる流れに將混溶滾滾汩流而往人は夢みる　ゆえに儚く人夢故虛幻無常人は夢みる　ゆえに生きるもの人夢故得以生＊あ～あ～誰も知らない嗚呼無人知曉　あ～あ～明日散る花さえも嗚呼縱是明日凋蔫之花亦然固い契り　爛漫の花の下磐石之契花開爛漫之下月を飲み干す　宴の盃對月一飲而盡酒宴之盅君は帰らず　残されて佇めば君未歸獨駐足徘徊肩にあの日の　誓いの花吹雪憶起誓彼日散落肩上之花如吹雪人は信じて　そして破れて人信而衰頹破敗人は信じて　そして生きるもの人信而得以生 Repeat ＊國は破れて　城も破れて縱使國破城滅草は枯れても　風は鳴き渡る草枯遍野風颯聲依舊あ～あ～誰も知らない嗚呼無人知曉あ～あ～風のその姿を嗚呼風之姿あ～あ～花が伝える嗚呼花之是傳あ～あ～風のその姿を嗚呼風之姿

Thursday, May 28, 2026

AlN-Engineered Diamond/Aluminum Nitride Composite with Multiscale Interface Architecture for Ultra-High Thermal Conductivity and Electrical Insulation

Abstract

The integration of high thermal conductivity and electrical insulation in a single material system remains a critical challenge for advanced thermal management in high-power electronics. Here, we report a hierarchical diamond–AlN composite architecture enabled by multiscale interface engineering and additive manufacturing. Diamond particles are first activated via plasma-induced surface nano-roughening to enhance interfacial bonding. A conformal AlN interlayer is subsequently deposited by plasma-enhanced atomic layer deposition (PE-ALD), followed by the formation of a thick AlN shell via chemical vapor deposition (CVD). The resulting core–shell particles are consolidated with AlN matrix powder using selective laser melting and post-densification via hot isostatic pressing. The engineered interfaces significantly reduce thermal boundary resistance while preserving electrical insulation, yielding bulk composites with thermal conductivity up to 700 W m⁻¹ K⁻¹, high density (>99%), and dielectric breakdown strength up to 14 kV. This work demonstrates a scalable pathway for architected diamond-based composites for extreme thermal management applications.

1. Introduction

The rapid evolution of high-power and high-frequency electronic systems, including GaN-based power devices, radar modules, and laser arrays, has imposed stringent demands on thermal management materials. Conventional polymer-based substrates suffer from low thermal conductivity and limited thermal stability, while metallic composites, despite their excellent heat conduction, fail to meet electrical insulation requirements. Ceramic materials such as aluminum nitride (AlN) provide intrinsic electrical insulation but are limited by moderate thermal conductivity.

Diamond exhibits the highest known thermal conductivity among bulk materials; however, its integration into composite architectures is fundamentally constrained by interfacial thermal resistance and poor wettability with ceramic matrices. Consequently, engineering a thermally efficient and electrically insulating diamond-based composite remains a key materials challenge.

2. Materials Design Concept

We propose a multiscale interface engineering strategy to construct a hierarchical diamond/AlN composite system. The design is based on three synergistic components:

Diamond thermal core
High intrinsic phonon conductivity provides the primary heat transport pathway.
Conformal AlN interfacial layer (nanometer scale)
Deposited via PE-ALD, this layer ensures atomic-scale continuity, enhances phonon coupling, and suppresses interfacial scattering.
AlN outer shell (micrometer scale)
Formed via CVD, this layer provides structural continuity, electrical insulation, and compatibility with powder consolidation processes.

This multiscale architecture transforms discrete diamond particles into thermally integrated building blocks for bulk composites.

3. Surface Activation of Diamond Particles

Diamond powders (20–400 μm) are subjected to plasma-based surface activation using inductively coupled plasma (ICP) or an anode-layer ion source. Reactive oxygen or hydrogen plasma induces controlled surface etching, producing nano-scale roughness (Ra ≈ 5–100 nm). This process simultaneously removes organic contaminants and generates high-density surface anchoring sites.

The increased effective surface area enhances particle–coating adhesion and promotes mechanical interlocking at subsequent interface formation stages. Importantly, controlled roughening improves interfacial phonon coupling by increasing the real contact area between diamond and AlN.

4. Atomic-Scale Interface Engineering via PE-ALD

A conformal AlN interlayer is deposited using plasma-enhanced atomic layer deposition (PE-ALD) with trimethylaluminum (TMA) and NH₃ as precursors. The process yields an ultrathin (10–200 nm) yet dense AlN coating with near-unity conformality.

A graded deposition strategy is employed, wherein precursor-to-reactant ratios are systematically varied to produce a compositional gradient across the interlayer. This gradient reduces lattice and thermal mismatch between diamond and AlN, thereby minimizing interfacial thermal resistance.

The ALD-derived interlayer acts as a phonon coupling mediator, bridging the acoustic impedance mismatch between diamond and ceramic matrix.

5. Formation of Thick AlN Shell via CVD

A secondary AlN layer (>10 μm) is deposited using chemical vapor deposition (PECVD or hot-wire CVD). This layer ensures mechanical robustness and electrical insulation while preserving thermal continuity established by the ALD interface.

The CVD shell transforms individual diamond particles into electrically insulated thermally conductive units suitable for powder-based additive manufacturing.

6. Additive Manufacturing and Densification

Core–shell diamond particles are blended with AlN powder (1–40 μm) and processed via selective laser melting (SLM) under controlled inert atmosphere conditions (O₂ < 0.1%). Layer-wise laser consolidation is followed by:

Vacuum sintering (850–1100 °C)
Optional cold isostatic pressing
Hot isostatic pressing (50–200 MPa, 850–1050 °C)

This multi-step densification sequence ensures near-full density (>99%) while preserving the integrity of thermally engineered interfaces.

7. Thermal Transport Mechanism

The enhanced thermal performance originates from three coupled mechanisms:

Reduced interfacial phonon scattering due to ALD-mediated acoustic bridging
Increased real contact area from plasma-induced surface roughening
Continuous AlN matrix enabling percolative heat conduction pathways

The hierarchical architecture effectively suppresses thermal boundary resistance, which is typically the dominant bottleneck in diamond-based composites.

8. Results and Performance

The resulting bulk composites exhibit:

Thermal conductivity: 600–700 W m⁻¹ K⁻¹
Relative density: ≥99%
Dielectric breakdown strength: ~14 kV
Stable high-temperature thermal transport up to 500 °C

These values represent a significant improvement over conventional AlN or metal-based thermal substrates.

9. Conclusion

We demonstrate a multiscale interface engineering strategy for the fabrication of diamond–AlN composites with exceptional thermal and electrical performance. By integrating plasma-activated surface modification, atomic-scale ALD interface design, and CVD shell formation, we establish a scalable route to overcome long-standing interfacial limitations in diamond-based composites. This work provides a generalizable framework for designing next-generation thermal management materials for extreme electronic environments.

Saturday, May 23, 2026

Low Dielectric Constant Porous Diamond Film SEMIXICON DIASEMI

Low Dielectric Constant Porous Diamond Film

www.diasemi.us

Low dielectric constant porous diamond films are emerging as advanced functional materials for next-generation high-frequency electronics, microwave communication, photonics, and semiconductor packaging. By introducing nanoscale porosity into CVD diamond films, the effective dielectric constant can be significantly reduced while maintaining diamond’s exceptional thermal conductivity, chemical stability, and mechanical hardness.

Compared with dense diamond films, porous diamond structures exhibit lower dielectric constant and dielectric loss, enabling faster signal transmission, reduced RC delay, minimized capacitive coupling, and improved performance in high-speed and high-frequency electronic systems. These characteristics are especially important for 5G/6G communication, millimeter-wave devices, radar systems, microwave integrated circuits, and advanced RF packaging.

Porous diamond films are typically fabricated using MPCVD processes combined with template-assisted growth, selective etching, or nanostructured carbon precursor engineering to control pore size and distribution. The resulting material offers a unique combination of:

Low dielectric constant
Low tangent loss
Faster signal speed
Reduced crosstalk
Low parasitic capacity
Higher frequency
Excellent thermal stability

In advanced semiconductor and photonic applications, low-k porous diamond films provide an ideal platform for thermal management and electromagnetic performance optimization, supporting the development of faster, smaller, and higher-power electronic devices.

Sunday, May 17, 2026

DIASEMI™ TC4 / Diamond Composite

High-Performance Titanium Matrix Composite for Extreme Environments

1. Product Overview

DIASEMI™ TC4/Diamond Composite is an advanced titanium matrix composite engineered by integrating TC4 titanium alloy with high-purity diamond particles. The material is consolidated via spark plasma sintering and can be further functionalized with chemical vapor deposition.

This hybrid architecture delivers a unique combination of:

High strength-to-weight ratio
Exceptional hardness and wear resistance
Tunable thermal expansion
Enhanced thermal management capability

2. Key Features

Diamond Reinforcement
Improves hardness, wear resistance, and thermal conductivity
Engineered Interface (TiC Layer)
In-situ formation of TiC enhances bonding and load transfer
CTE Matching Capability
Adjustable coefficient of thermal expansion for system integration
CVD-Compatible Surface
Direct growth of diamond films for extreme surface performance
Enhanced Densification (Optional Cu Phase)
Improved consolidation without compromising microstructure

3. Typical Properties

4. Microstructure Description

The composite consists of:

TC4 matrix (continuous phase)
Dispersed diamond particles
Interfacial TiC transition layer

Functional Mechanism:

Diamond → load bearing + thermal conduction
TiC → interfacial bonding + stress transfer
TC4 → structural integrity

5. Surface Engineering Option

CVD Diamond Coating Capability

Continuous diamond film achievable after ~4 hours deposition
Strong adhesion via TiC interlayer
Uniform morphology with optimized filament tension

Performance Enhancement:

Ultra-low friction coefficient
Extreme wear resistance
Improved thermal flux handling

6. Manufacturing Process

Step 1 – Powder Preparation

TC4 powder + diamond powder
High-energy ball milling for uniform mixing

Step 2 – Consolidation

Spark plasma sintering (SPS)
Controlled temperature, pressure, and dwell time

Step 3 – Surface Functionalization (Optional)

Hot filament CVD diamond deposition
Stress-controlled filament alignment

7. Design Flexibility

8. Applications

Aerospace

Lightweight wear-resistant components
Thermal-structural parts

Semiconductor Equipment

Precision handling components
Vacuum-compatible structures

Tribology

Bearings and sliding interfaces
High-load wear systems

Biomedical

Biocompatible implants
Surgical tools

9. Competitive Advantages

Integrated bulk + surface engineering
Strong interfacial bonding via TiC
Scalable SPS + CVD manufacturing
Tunable thermal and mechanical properties

10. Customization Options

DIASEMI provides:

Diamond particle size & fraction tuning
Custom geometry (plates, discs, complex shapes)
Surface coating (thickness, roughness, grain size)
Hybrid structures (Cu-enhanced densification)

11. Ordering Information

Code	Description
DIA-TD-10	10% Diamond Composite
DIA-TD-20	20% Diamond Composite
DIA-TD-CVD	With CVD Diamond Coating
DIA-TD-CU	Cu-enhanced densification

12. Quality & Testing

SEM microstructure analysis
Raman spectroscopy (diamond quality)
Density & porosity measurement
Hardness and mechanical testing
Thermal expansion & conductivity characterization

13. Disclaimer

Values shown are typical and may vary depending on processing conditions and customization. DIASEMI recommends application-specific validation.

Thursday, May 14, 2026

Diamond Nanophotonic & Optomechanical Membrane

Enabling Next-Generation Photonics, Quantum Sensing, and Light-Driven Mechanics

Executive Summary

The rapid evolution of nanophotonics and optomechanics is redefining how light interacts with matter—not only as a carrier of information, but also as a mechanical actuator at the micro- and nanoscale. DIASEMI introduces a diamond-based nanophotonic membrane platform that enables simultaneous control of:

Optical phase, polarization, and spin–orbital states
Mechanical motion driven by radiation pressure and angular momentum
Quantum and sensing functionalities enabled by diamond’s unique material properties

Leveraging ultra-thin CVD diamond membranes (1–10 μm) combined with advanced subwavelength structuring and femtosecond laser machining, DIASEMI delivers a scalable solution for integrated photonics, optomechanical systems, and quantum devices.

Technology Overview

Light as a Mechanical and Optical Tool

Photons carry both linear momentum (radiation pressure) and angular momentum (spin and orbital), enabling:

Optical trapping and manipulation (optical tweezers)
Torque generation on birefringent microstructures
Light-driven actuation and switching
Nonlinear optical interactions (e.g., two-photon absorption)

DIASEMI’s platform harnesses these effects through engineered diamond nanostructures, enabling devices that both shape light and respond mechanically.

Form-Birefringent Diamond Nanostructures

Subwavelength grating structures induce form birefringence (Δn = nₑ − nₒ), allowing precise control of:

Polarization states
Spin–orbital coupling (q-plates)
Spectral filtering and dichroism
Phase retardation across wide wavelength ranges

These structures enable advanced optical functionalities across UV → IR → THz regimes, leveraging diamond’s broadband transparency.

Why Diamond? (DIASEMI Advantage)

DIASEMI’s platform is built on high-quality CVD diamond membranes with unmatched properties:

Property	Value / Benefit
Thermal conductivity	Up to 2000 W/m·K
Optical transparency	X-ray to far-IR
Refractive index	~2.4 (ideal for photonics)
Bandgap	5.45 eV (deep UV compatibility)
Mechanical strength	ieal for MEMS/NEMS
Quantum compatibility	NV⁻ centers for sensing

Key Advantage:
Diamond uniquely combines optical, mechanical, and quantum functionalities in a single material platform.

DIASEMI Fabrication Platform

1. Lithography-Based Nanostructuring (High Precision)

Electron-beam lithography (EBL)
Reactive ion etching (RIE)
Subwavelength gratings (Λ: 0.8–7 μm)
Aspect ratios up to ~15

Applications:

Infrared birefringent optics
Polarization control elements
Photonic crystal structures

2. Femtosecond Laser Micro-Machining (High Flexibility)

230 fs pulse duration @ 1030 nm
Sub-micron precision over cm-scale areas
Graphitization-assisted cutting & ablation
Direct structuring of 1 μm membranes

Capabilities:

Suspended optomechanical structures
Stress-relief patterning
Rapid prototyping without masks

Optomechanical Structures

DIASEMI enables fabrication of ultra-sensitive suspended diamond devices, including:

Micro-bridges (≤10 μm width)
Membrane-supported platforms
Resonant mechanical elements

These structures exhibit:

High sensitivity to optical forces
Tunable mechanical resonance
Strong coupling to light fields

Result: Ideal for precision sensing, actuation, and quantum optomechanics.

Optical Performance

Infrared Birefringent Response

Tunable dichroism (positive ↔ negative)
Polarization-dependent absorption and transmission
Quarter-wave phase control via structural design
Broadband operation (2.5–15 μm demonstrated)

Subwavelength Effects

Λ ≈ λ regime enables:
- Enhanced light–matter interaction
- Diffraction-controlled transmission
- Field localization at diamond–air interfaces

Key Innovations

DIASEMI’s platform introduces:

Thin (<10 μm) free-standing diamond photonic membranes
Hybrid fabrication (EBL + fs-laser)
Integrated opto-mechanical functionality
Spectral tunability via geometry-controlled birefringence
Stress-engineered flatness for high-yield fabrication

Applications

Photonics & Optics

IR windows and filters
Polarization converters (q-plates)
Photonic crystal devices
Beam shaping and phase control

Quantum Technologies

NV-based sensing platforms
Quantum photonics integration
Spin–photon interfaces

Optomechanics

Light-driven MEMS/NEMS
Precision force and torque sensors
Levitated particle systems

Thermal & Harsh Environments

High-power laser systems
Aerospace and defense optics
Extreme environment sensing

Manufacturing Challenges Solved by DIASEMI

Challenge	DIASEMI Solution
Membrane warping	Stress-relief laser patterning
Substrate non-flatness	Adaptive fabrication workflows
Fragility of thin diamond	Controlled thinning + support design
Large-area nanopatterning	fs-laser scalability
Multi-physics integration	Unified material platform

Future Roadmap

DIASEMI is advancing toward:

Wafer-scale diamond photonic platforms
Integrated quantum–photonic–mechanical systems
AI-designed nanophotonic structures
Hybrid diamond–Si/SiC/AlN/GaN integration

Conclusion

DIASEMI’s diamond nanophotonic membrane platform represents a paradigm shift in photonics and optomechanics, enabling:

Light to control matter
Structures to control light
And diamond to unify both

This technology unlocks new possibilities in precision sensing, quantum systems, and high-performance photonic devices, positioning DIASEMI at the forefront of next-generation photonics innovation.

Wednesday, May 13, 2026

Standard Diasemi diamond and copper composite heatsink

1. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 15x15x0.3 ±0.1mm

Ra: 0.5um

2. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 15x15x0.5 ±0.1mm

Ra: 0.5um

3. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 15x15x1.0 ±0.1mm

Ra: 0.5um

4. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 15x15x1.5 ±0.1mm

Ra: 0.5um

5. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 15x15x2.0 ±0.1mm

Ra: 0.5um

6. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 20x20x0.3 ±0.1mm

Ra: 0.5um

7. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 20x20x0.5 ±0.1mm

Ra: 0.5um

8. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 20x20x1.0 ±0.1mm

Ra: 0.5um

9. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 20x20x1.5 ±0.1mm

Ra: 0.5um

10. Copper Diamond Composite Cu Coated

Dimensions Tolerances: 20x20x2.0 ±0.1mm

Ra: 0.5um

Tuesday, May 12, 2026

DIASEMI Ultra-Thin AlN Insulated Diamond–Copper Heat Spreader

DIASEMI presents an advanced diamond–copper composite heat spreader featuring an ultra-thin aluminum nitride (AlN) ceramic coating (1–2 μm) for high-performance thermal management with electrical insulation.

Unlike conventional thick ceramic layers, the sub-micron AlN coating is deposited via precision thin-film processes, dramatically reducing thermal resistance while maintaining excellent dielectric strength and interface reliability.

Key Features

Ultra-thin AlN insulation: 1–2 μm (minimized thermal barrier)
Exceptional thermal conductivity: up to 600–900 W/m·K (composite core)
High dielectric strength: suitable for power electronics isolation
Low thermal resistance interface: optimized for high heat flux devices
Robust adhesion: engineered interfacial layer for long-term stability
CTE matching: tailored for GaN, SiC, and advanced semiconductor packages

Performance Advantage

By reducing the ceramic coating thickness from conventional tens of microns to 1–2 μm, DIASEMI achieves:

>30–50% reduction in interfacial thermal resistance
Improved heat dissipation efficiency under >1 kW/cm² heat flux
Enhanced reliability under thermal cycling

Applications

GaN / SiC power modules
High-power laser diode packages
RF and microwave systems
AI and high-density computing hardware

Positioning

The DIASEMI solution bridges the gap between high thermal conductivity materials and electrical insulation, enabling next-generation compact, high-power semiconductor systems where both heat removal and dielectric isolation are critical.

DIASEMI Ceramic Coating Insulated Diamond–Copper Heatsink

www.diasemi.us

DIASEMI introduces an advanced insulated diamond–copper composite engineered for next-generation high-power electronic and photonic systems. By integrating a dense Al₂O₃ ceramic layer via aerosol deposition, the inherently conductive Cu/diamond composite is transformed into a high-performance, electrically insulating thermal management platform.

The Al₂O₃ coating preferentially anchors onto the ductile copper matrix, forming a continuous, conformal insulating layer while progressively extending across diamond surfaces from the Cu–diamond interface. This unique deposition mechanism enables full electrical isolation without compromising thermal pathways. A ~9 μm-thick ceramic layer delivers ultra-high electrical resistivity (~10¹² Ω·cm), increasing bulk resistance by more than 14 orders of magnitude.

Critically, the composite retains an ultra-high thermal conductivity of ~800 W/m·K—far exceeding conventional ceramic-based solutions. Compared with diamond–SiC composites, the DIASEMI insulated diamond–copper platform provides superior thermal conductivity, improved thermal spreading efficiency, and comparable thermal expansion matching.

This work establishes insulated Cu/diamond as a breakthrough material platform that bridges the gap between metals and ceramics, enabling high-voltage, high-heat-flux applications.

Introduction (DIASEMI Technical Positioning)

Thermal Management Challenge in High-Power Systems

The continuous scaling of power density in semiconductor devices—such as IGBTs, RF amplifiers, and high-energy laser systems—has pushed thermal management materials beyond traditional limits. Materials must simultaneously deliver:

Ultra-high thermal conductivity
Electrical insulation
Coefficient of thermal expansion (CTE) compatibility
Mechanical reliability under thermal cycling

Material Landscape: Diamond-Based Composites

Two leading material systems have emerged:

1. Diamond–SiC (Ceramic Matrix Composite)

Diamond/SiC composites are widely adopted due to their intrinsic electrical insulation and good thermal stability. However:

Thermal conductivity typically ranges 200–800 W/m·K
Phonon scattering at diamond–SiC interfaces limits performance
Limited tunability of properties due to ceramic processing constraints

2. Diamond–Copper (Metal Matrix Composite)

Cu/diamond composites offer:

Exceptional thermal conductivity (>800 W/m·K)
Excellent thermal spreading due to metallic matrix
Tunable CTE via diamond loading and interface engineering

However, their electrical conductivity prohibits direct use in high-voltage environments, historically limiting their application scope.

DIASEMI Breakthrough: Insulated Diamond–Copper Composite

DIASEMI overcomes this fundamental limitation by introducing a ceramic insulation layer (Al₂O₃) via aerosol deposition (AD):

Room-temperature process → preserves interface integrity
Dense, pinhole-free ceramic coating
Conformal coverage across heterogeneous Cu–diamond surface
No degradation of thermal pathways

Deposition Mechanism Insight

Al₂O₃ preferentially deposits on the soft Cu matrix, smoothing surface roughness
Growth initiates at Cu–diamond interfaces, ensuring strong anchoring
Coating propagates across diamond surfaces, forming a continuous insulating layer
Smaller diamond particles enhance coating uniformity due to higher interfacial area

Performance Comparison: DIASEMI vs Diamond–SiC

Property	DIASEMI Insulated Cu/Diamond	Diamond/SiC Composite
Thermal Conductivity	500~850 W/m·K	200–800 W/m·K
Electrical Property	Insulating (Al₂O₃ layer)	Intrinsically insulating
Thermal Spreading	Excellent (metal matrix)	Moderate
CTE (ppm/K)	5–8 (tunable)	3–6
Processing Temperature	Room temperature (AD coating)	High-temperature sintering
Interface Control	Engineered carbide + coating	Limited
Power Device Suitability	Excellent (IGBT, RF, laser)	Good

Key Advantages of DIASEMI Insulated Cu/Diamond

3–4× higher thermal conductivity vs Diamond/SiC
Maintains electrical insulation without sacrificing heat dissipation
Superior thermal spreading → reduced hot spots
Scalable, low-temperature coating process
High reliability under thermal cycling

Application Positioning

The DIASEMI insulated diamond–copper platform is optimized for:

High-voltage power modules (IGBT, SiC MOSFET)
High-power laser diode packaging
RF and microwave systems
Advanced photonics and optical platforms
Aerospace and defense thermal systems

Saturday, May 9, 2026

DIASEMI DICU Diamond and copper composite heatsink

DIASEMI™ DICU Ultra Thermal™ Series

Diamond / Copper High Thermal Conductivity Composite

Engineered Heat Spreader Platform for Extreme Power Density

1. Product Overview

DIASEMI™ D-Cu Ultra Thermal™ is a next-generation diamond-reinforced copper composite designed for ultra-high heat flux applications.

By integrating engineered carbide interlayers (TiC / WC / ZrC) with optimized diamond architecture, the material achieves exceptional thermal conductivity with tailored thermal expansion, enabling reliable operation in next-generation semiconductor and photonics systems.

2. Key Features

Ultra-high thermal conductivity: up to 850 W·m⁻¹·K⁻¹
CTE matching to semiconductors: 6–8 ×10⁻⁶ K⁻¹
Low interfacial thermal resistance via engineered carbide bonding
High density (>99%) for maximum heat transport efficiency
Excellent thermal stability under high power cycling
Customizable geometry and thickness

3. Typical Applications

Semiconductor & Electronics

GaN / SiC RF power devices
Laser diode heat spreaders
High-performance CPUs / GPUs
Power modules (IGBT, MOSFET)

Photonics

High-power laser packaging
Optical benches
IR / EUV systems thermal platforms

Advanced Systems

Aerospace electronics
Fusion / high-energy systems
Microwave and RF components

4. Material Specifications

Property	Typical Value	Test Method
Thermal Conductivity	700 – 850 W·m⁻¹·K⁻¹	Laser Flash
Coefficient of Thermal Expansion (CTE)	6 – 8 ×10⁻⁶ K⁻¹	Dilatometry
Density	> 99% theoretical	Archimedes
Specific Heat	~385 J·kg⁻¹·K⁻¹	DSC
Electrical Resistivity	2–4 µΩ·cm	Four-point probe
Bending Strength	250–350 MPa	ASTM C1161
Operating Temperature	up to 500°C (air)	—

5. Interface Engineering Options

(A) WC Interface (Standard Industrial Grade)

Interlayer: 180–220 nm WC
Thermal conductivity: 750–820 W·m⁻¹·K⁻¹
Best for: scalable production, cost-performance balance

(B) TiC Interface (High-End Performance Grade)

Interlayer: 200–250 nm TiC
Thermal conductivity: 800–850 W·m⁻¹·K⁻¹
Best for: extreme heat flux, premium devices

(C) ZrC Interface (High Reliability Grade)

Interlayer: 150–250 nm ZrC
Thermal conductivity: 600–750 W·m⁻¹·K⁻¹
Best for: harsh environments, long lifetime systems

6. Microstructure Design

Parameter	Specification
Diamond Type	Synthetic (HPHT / CVD compatible)
Particle Size	100 – 200 µm (optimized)
Volume Fraction	60 – 70%
Distribution	Uniform / bimodal optional
Interface Layer	Continuous carbide coating

7. Available Formats

Plates: up to 100 × 100 mm
Thickness: 0.3 – 5 mm
Custom shapes:
- Laser cut
- CNC machined
- Metallized (Ni/Au optional)

8. Surface & Finishing Options

Polished (Ra < 50 nm available)
Double-side lapping
Metallization:
- Ni / Au
- Ti / Pt / Au
Direct bonding ready surfaces

9. Process Technology

DIASEMI utilizes a hybrid manufacturing platform:

Diamond surface metallization
- Magnetron sputtering
- Salt bath / diffusion coating
Composite formation:
- Pressure melt infiltration (preferred)
- Vacuum hot pressing
- SPS (R&D / prototyping)

10. Performance Benchmark

Material	Thermal Conductivity (W·m⁻¹·K⁻¹)	CTE (×10⁻⁶ K⁻¹)
Copper	~400	17
AlN	170–200	4.5
SiC	180–270	4
CVD Diamond	1200–2000	1–2
DIASEMI D-Cu Ultra Thermal™	700–850	6–8

11. Design Advantages

✔ Compared to Copper

2× higher thermal conductivity
50% lower CTE

✔ Compared to Ceramics (AlN / SiC)

3–4× higher thermal conductivity
Better heat spreading capability

✔ Compared to CVD Diamond

Lower cost
Easier machining
Better CTE matching

12. Reliability

Thermal cycling stability: >1000 cycles (−40°C to 200°C)
No delamination at interface
مقاومة عالية للتعب الحراري (high thermal fatigue resistance)

13. Design Guidelines

Optimal interlayer thickness: ~200 nm
Avoid excessive coating thickness (>300 nm)
Maintain high diamond volume fraction (~65%)
Ensure high Cu purity (≥99.99%)

14. Ordering Information

Product Code Format:


DIASEMI-Dcu-[Interface]-[Size]-[Thickness]-[Finish]

Example:
DIASEMI-Dcu-WC-50x50-1.0mm-NiAu

15. Customization Options

Tailored CTE for specific chips (GaN / Si / SiC)
Gradient interface design
Microchannel integration for liquid cooling
Large-area substrates

16. Summary

DIASEMI™ D-Cu Ultra Thermal™ provides:

The optimal balance between ultra-high thermal conductivity, manufacturability, and system compatibility

It bridges the gap between:

CVD diamond (performance)
Copper (cost & processability)

www.diasemi.us

Tuesday, May 5, 2026

DIASEMI Pre-AR Coated CVD Diamond Window Dies for the Photonics Industry

Enabling the Next Generation of Miniaturized Optical Systems

As photonics systems continue to scale toward higher power densities, smaller footprints, and harsher operating environments, the demand for advanced optical window materials has intensified. Applications in optical communications, high-power lasers, and sensing technologies require materials that simultaneously deliver:

High optical transmission
Exceptional thermal conductivity
Mechanical robustness
Long-term environmental stability

Conventional optical materials—such as fused silica or sapphire—often fail to meet all these requirements simultaneously. This limitation has driven increasing interest in CVD diamond, a material uniquely positioned at the intersection of optics, thermal management, and extreme durability.

DIASEMI introduces a breakthrough solution:

Pre-AR Coated CVD Diamond Window Dies

A Fundamental Shift in Optical Coating Architecture

Traditional approaches rely on depositing anti-reflective (AR) coatings after the diamond substrate has been fabricated and polished. While effective for large optics, this method becomes impractical for micro-scale window dies (sub-millimeter dimensions), where handling, alignment, and coating uniformity present major challenges.

DIASEMI’s innovation reverses this paradigm.

Instead of post-processing, we implement a pre-deposition architecture, where the optical coating is engineered before diamond growth. This approach integrates thin-film optics directly into the material synthesis process, leveraging principles of thin film interference at the earliest stage of fabrication.

Technology Overview

1. Pre-Engineered Optical Coating Layer

A precisely designed anti-reflective coating is deposited onto a sacrificial substrate using advanced thin-film deposition techniques (PVD or CVD). Material systems are selected based on wavelength requirements:

SWIR (0.8–1.5 µm): SiO₂, Si₃N₄
MWIR / LWIR: Y₂O₃, HfO₂, ZrO₂, rare-earth oxides

Layer thickness is optimized according to optical interference conditions to minimize surface reflection.

2. Direct CVD Diamond Growth

High-quality diamond is then grown directly on the AR-coated surface using chemical vapor deposition (CVD). During this process:

Diamond inherits the optical interface
The AR coating undergoes in-situ thermal stabilization (~800–900°C)
A robust, low-defect interface is formed

This step also ensures compatibility with high-power photonic environments.

3. Precision Microfabrication

Following growth, the diamond surface is:

Mechanically polished to optical grade (Ra ≤ 10 nm)
Laser diced into micro-scale dies (down to <500 µm)
Plasma treated to remove graphitic residues

4. Sacrificial Substrate Removal

The original substrate is selectively removed via chemical or plasma etching, leaving behind a self-supported diamond window with an integrated AR coating.

Key Advantages

Native Integration of Optical Functionality

The AR coating is not an add-on—it is structurally integrated into the diamond window. This eliminates interface weaknesses associated with post-deposition coatings.

Wafer-Level Manufacturing of Micro Windows

DIASEMI’s process enables batch fabrication of ultra-small optical dies, overcoming the limitations of conventional coating techniques.

Superior Thermal and Mechanical Stability

Because the coating is exposed to the full CVD growth environment, it achieves:

High thermal stability
Strong adhesion
Reduced residual stress

Enhanced Optical Performance

Optimized AR coatings significantly reduce Fresnel reflection at the diamond interface, improving transmission efficiency across target wavelengths.

Reduced Processing Complexity and Cost

By eliminating post-growth coating steps, the process:

Simplifies manufacturing flow
Improves yield
Enables scalable production

Performance Characteristics

Typical DIASEMI Pre-AR Diamond Window Dies offer:

Transmission: >98% (design-dependent)
Surface roughness: ≤ 10 nm
Thickness: 5–50 µm
Die size: down to 0.3–0.5 mm
Thermal conductivity: up to 2000 W/m·K (diamond bulk)

Application Areas

DIASEMI’s pre-AR coated diamond windows are engineered for demanding photonics applications, including:

Optical communication modules (SWIR band ~1.0–1.5 µm)
High-power laser systems (e.g., ~1 µm wavelength platforms)
Infrared sensing and imaging systems
Harsh-environment optical sensors
MEMS and micro-photonic packaging