Structural and Physical Characterization of Nanodiamond Composite Thin Films Synthesized by Pulsed-Laser Ablation Method (A Review)

At a Glance

Metadata	Details
Publication Date	2021-10-21
Journal	Proceedings of International Exchange and Innovation Conference on Engineering & Sciences (IEICES)
Authors	Lama Osman, Abdelrahman Zkria, Tsuyoshi Yoshitake
Institutions	Kyushu University
Citations	1
Analysis	Full AI Review Included

Technical Documentation & Analysis: Nanodiamond Composite Thin Films

Executive Summary

This review highlights the successful synthesis and characterization of Ultrananocrystalline Diamond Composite (NDC) thin films using Pulsed-Laser Deposition (PLD). 6CCVD leverages its expertise in high-purity MPCVD diamond to support and extend research in this critical materials space.

Low-Temperature Synthesis: NDC films were optimally grown at a relatively low substrate temperature of 550 °C under controlled hydrogen ambient (53.3 Pa), demonstrating compatibility with diverse solid-state substrates.
High sp³ Content: Structural analysis confirmed high diamond purity, with sp³ bonding fractions reaching 68% (undoped) and significantly enhanced up to 74% in Boron-doped films.
Precise Doping Control: The research successfully incorporated Nitrogen (up to 7.9 atm. %) and Boron (up to 13 atm. %) to tailor the electronic and structural properties of the NDC films, crucial for semiconductor applications.
Electronic and Optical Potential: The films exhibit a direct optical band gap of 2.2 eV, positioning them as splendid candidates for advanced electronic, optical, and biomedical device integration.
Methodological Advantage: PLD is confirmed as an effective physical vapor deposition technique for producing high-quality UNCD films under conditions often inaccessible to conventional CVD methods.
6CCVD Relevance: While this review focuses on PLD thin films, 6CCVD provides the necessary high-purity, large-area, and precisely doped MPCVD diamond substrates (SCD and PCD) required for subsequent device fabrication and commercial scaling.

Technical Specifications

The following hard data points were extracted from the review detailing the synthesis and material properties of the Nanodiamond Composite (NDC) films.

Parameter	Value	Unit	Context
Optimum Substrate Temperature (T_sub)	550	°C	PLD deposition condition
Hydrogen Ambient Pressure	53.3 (or 4)	Pa (or Torr)	Optimal growth environment
Film Thickness Range	1 - 5	µm	Single phase diamond films
NDC Crystallite Diameter	< 10	nm	Embedded in amorphous carbon matrix
Laser Wavelength	193	nm	ArF excimer laser
Laser Pulse Duration	24	ns	ArF excimer laser
Laser Fluence	5	J/cm²	Irradiance: 1.5 x 10⁹ W/cm²
Deposition Rate Range	5 - 80	nm/min	Depending on repetition rate (10 Hz or 50 Hz)
Undoped sp³ Fraction	68	%	Measured via XPS C1s spectra
Boron-Doped sp³ Fraction (13 atm. %)	74	%	Highest sp³ content reported
Direct Optical Band Gap	2.2	eV	Characteristic for NDC composite
Indirect Optical Band Gap	1.0	eV	Attributed to the a-C matrix

Key Methodologies

The Nanodiamond Composite (NDC) films were synthesized using the Pulsed-Laser Deposition (PLD) technique, a physical vapor deposition method.

Target Material: Solid graphite target utilized for ablation.
Laser Source: ArF excimer laser (193 nm, 24 ns pulse duration) focused onto the rotating target.
Energy Parameters: Laser fluence maintained at 5 J/cm² (Irradiance: 1.5 x 10⁹ W/cm²). Pulse repetition rates varied, typically 10 Hz or 50 Hz.
Substrate & Temperature: Films were deposited on diverse substrates (e.g., Si, Sapphire) maintained at an optimum temperature of 550 °C.
Ambient Atmosphere: Hydrogen gas ambient pressure maintained at 53.3 Pa (4 Torr) to facilitate the selective etching of sp² bonds, promoting high sp³ content.
Doping: Nitrogen or Boron doping was achieved by introducing controlled inflow ratios of the dopant gas into the ambient atmosphere during deposition.
Characterization: Comprehensive structural and physical characterization utilized High-Resolution TEM, Raman Spectroscopy, FTIR, X-ray Photoemission Spectroscopy (XPS), and Near-Edge X-ray Absorption Fine Structure (NEXAFS) to analyze bonding configuration and crystallite size.

6CCVD Solutions & Capabilities

The research demonstrates the potential of nanodiamond composites for advanced electronic and optical applications. 6CCVD specializes in providing high-quality, large-area MPCVD diamond materials that are essential for scaling these laboratory findings into commercial devices.

Applicable Materials for Replication and Extension

While the review focuses on PLD thin films, 6CCVD offers superior MPCVD materials necessary for high-performance device integration, especially where high purity, large area, or controlled conductivity is paramount.

6CCVD Material	Relevance to NDC Research	Key Advantage
Electronic Grade PCD	Ideal substrate for large-area electronic devices utilizing NDC films.	Wafers up to 125mm in diameter; excellent thermal management.
Heavy Boron Doped PCD (BDD)	Replicates and extends the Boron doping research (up to 13 atm. % reported).	Provides highly conductive, large-area electrodes (p-type semiconductor) with precise doping control.
Optical Grade SCD	Required for high-purity optical or quantum applications where defects must be minimized.	SCD thickness control from 0.1µm to 500µm; Ra < 1nm polishing.
Nitrogen-Doped SCD	Supports research into Nitrogen-Vacancy (NV) centers, a key application for nanodiamonds.	Precise control over nitrogen incorporation for quantum sensing and computing applications.

Customization Potential for Advanced Research

6CCVD’s in-house manufacturing capabilities directly address the needs of researchers working on Nanodiamond Composite films and related devices:

Custom Dimensions: We provide Polycrystalline Diamond (PCD) plates and wafers up to 125mm in diameter, significantly exceeding typical lab-scale substrates used in PLD.
Thickness Control: We offer precise thickness control for both SCD and PCD materials, ranging from 0.1µm to 500µm for films and up to 10mm for bulk substrates.
Surface Preparation: For optimal film adhesion and device performance, 6CCVD provides ultra-smooth polishing, achieving Ra < 1nm on Single Crystal Diamond (SCD) and Ra < 5nm on inch-size PCD.
Custom Metalization: The integration of diamond films into electronic devices often requires specific contact layers. 6CCVD offers internal metalization services, including Au, Pt, Pd, Ti, W, and Cu, tailored to the researcher’s specific device architecture.

Engineering Support

6CCVD’s in-house PhD team specializes in the growth and characterization of MPCVD diamond. We offer authoritative professional support for projects involving:

Material Selection: Assisting researchers in selecting the optimal diamond substrate (SCD, PCD, or BDD) to maximize the performance of their Nanodiamond Composite thin films.
Doping Optimization: Consulting on precise Boron and Nitrogen doping recipes to achieve specific electronic properties, extending the findings reported in this review.
Interface Engineering: Providing expertise on surface termination and polishing requirements necessary for subsequent thin-film deposition techniques like PLD.

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

View Original Abstract

Ultrananocrystalline diamond/hydrogenated amorphous carbon composite (so called Nanodiamond composite) thin films were deposited on diverse substrate materials at optimum substrate temperature of 550℃ and ambient hydrogen pressure of 53.3 Pa by pulsed-laser deposition technique. The structural and physical characterization of the undoped, nitrogen-doped and boron-doped films were well-discussed through this review.

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Original Source

DOI: https://doi.org/10.5109/4738587