Realization and Characterization of Carbonic Layers on 4H-SiC for Electrochemical Detections
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2017-05-15 |
| Journal | Materials science forum |
| Authors | Julien Pézard, Véronique SouliÚre, Mihai Lazar, Naoufel Haddour, François Buret |
| Institutions | Institut National des Sciences Appliquées de Lyon, Laboratoire des Multimatériaux et Interfaces |
| Analysis | Full AI Review Included |
Technical Analysis and Material Sourcing Documentation: Carbonic Layers on SiC for Electrochemical Sensing
Section titled âTechnical Analysis and Material Sourcing Documentation: Carbonic Layers on SiC for Electrochemical SensingâDocument Reference: Realization and characterization of carbonic layers on 4H-SiC for electrochemical detections (Pezard et al.) Prepared For: Engineering and Scientific Clients Date: October 26, 2023 Prepared By: 6CCVD Technical Engineering Team
Executive Summary
Section titled âExecutive SummaryâThis research successfully demonstrates the integration of multiple advanced carbon thin filmsâspecifically Boron Doped Diamond (BDD), Graphene, and Pyrolyzed Photoresist Films (PPF)âonto 4H-SiC substrates for high-performance electrochemical biosensors. This approach aligns with the industry trend toward fully integrated, robust sensing platforms.
- Core Achievement: Successful synthesis of high-quality BDD films on 4H-SiC using Plasma-Assisted Chemical Vapour Deposition (PACVD), demonstrating feasibility for large-scale SiC technology integration.
- Performance Metrics: BDD electrodes exhibited high sensitivity (12.83 ”A/mM) and broad potential windows, confirming superior electroactivity compared to traditional glassy carbon electrodes.
- Biosensor Application: The BDD transducers were successfully functionalized with acetylthiocholinesterase for the detection of acetylthiocholine, yielding a clinically relevant limit of detection (22.8 ”M).
- Integration Potential: All carbon layers were shown to be compatible with high-temperature processing (up to 1650 °C) and possess high patternability, crucial for transitioning from macrometric to micrometric integrated devices.
- Material Strength: The intrinsic chemical robustness and reproducibility of BDD films make them ideal for long-term, high-reliability biosensing applications where resistance to high temperatures and aggressive environments is critical.
Technical Specifications
Section titled âTechnical SpecificationsâThe table below summarizes the critical electrochemical performance data for the Boron Doped Diamond (BDD) electrodes, essential for replicating or extending this research.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Synthesis Method (BDD) | PACVD | N/A | Deposition on 4H-SiC substrate |
| Electrode Area Tested | 1 | cm2 | Sample size for biosensor evaluation |
| BDD Sensitivity | 12.83 ±0.44 | ”A/mM | Highest sensitivity achieved among the three carbon films for acetylthiocholine detection |
| Limit of Detection (LOD) | 2.28 E-05 | M (22.8 ”M) | Lowest concentration detected (Diamond) |
| Linear Range | 2.28 E-05 to 0.45 E-03 | M (22.8 ”M to 0.45 mM) | Effective measurement range (Diamond) |
| Maximum Reaction Speed (Imax) | 8.31 E-06 ±2.08E-08 | A | Chronoamperometry result (Diamond) |
| Michaelis Menten Constant (KM) | 0.23 ±5.75 E-04 | mM | Enzyme affinity/activity (Diamond) |
| Potential Window (KCl 0.1M) | -1 to -1.37 | V | Electroactivity range (Diamond) |
| Potential Window (PBS 10X) | -1.1 to -1.25 | V | Electroactivity range (Diamond) |
| Graphene Synthesis Temperature | 1550 | °C | Silicon sublimation on SiC in Ar atmosphere |
| PPF Maximum Annealing Temperature | 1650 | °C | Optimized for maximum electrical conductivity |
Key Methodologies
Section titled âKey MethodologiesâThe synthesis of the carbon films required specific high-temperature and vacuum processing steps, demonstrating compatibility with SiC fabrication technologies.
- Substrate Preparation: Commercial 4H-SiC substrates featuring a low-doped n-type epilayer were used to isolate the electrochemical response of the carbon films from the substrate.
- Boron Doped Diamond (BDD) Deposition: BDD films were grown directly onto the SiC substrates using Plasma-Assisted Chemical Vapour Deposition (PACVD), yielding conductive, heavily boron-doped layers necessary for electrochemical activity.
- Pyrolyzed Photoresist Film (PPF) Synthesis:
- A 1 ”m thick AZ5214E photoresist layer was applied via spin coating.
- Annealing Step 1 (Pyrolysis): Primary pyrolysis was conducted under primary vacuum at 750 °C for 30 minutes.
- Annealing Step 2 (Graphitization): A second high-temperature annealing step was performed using an induction Rapid Thermal Annealing (RTA) furnace for 30 minutes, under Argon (Ar) gas, with temperature plateaus varied between 1150 °C and 1650 °C.
- Graphene Synthesis: Graphene was grown via Silicon sublimation from the SiC surface at 1550 °C under an Ar atmosphere, utilizing the same induction RTA furnace as the PPF process.
- Characterization: Four-point probe measurements determined conductivity. Electrochemical properties were studied using potentiostat characterization. Layer thickness was measured via alpha-step profilometer, and structural changes were analyzed via ”-Raman (633 nm HeNe laser).
- Biosensor Functionalization: Electrodes (1 cm2 samples) were functionalized for acetylthiocholine detection by adsorption using a 0.5% chitosan solution in acetic acid (pH 5).
6CCVD Solutions & Capabilities: Enabling Integrated Diamond Biosensors
Section titled â6CCVD Solutions & Capabilities: Enabling Integrated Diamond BiosensorsâThis research confirms the potential of Boron Doped Diamond (BDD) as a transducer material for high-sensitivity, integrated electrochemical sensors compatible with SiC technology. 6CCVD is an industry leader in manufacturing high-quality MPCVD Diamond, offering materials and engineering services perfectly matched to replicate, scale, and optimize this work.
Applicable Materials for Replication and Scaling
Section titled âApplicable Materials for Replication and ScalingâTo meet the high-performance and structural integration requirements outlined in the paper, 6CCVD strongly recommends the following materials:
| 6CCVD Material Specification | Application Match & Technical Advantage |
|---|---|
| Heavy Boron Doped PCD (BDD) | Directly addresses the need for conductive diamond electrodes. Our heavily doped polycrystalline diamond (PCD) films offer the high signal-to-noise ratio and wide potential range required for robust electrochemistry, exceeding standard glassy carbon performance. |
| PCD Thin Films (0.1”m - 500”m) | Provides the necessary thinness for integrated devices. Our PCD can be grown on customer-supplied substrates (e.g., 4H-SiC wafers) to guarantee compatibility with existing SiC processing steps. |
| Optical Grade SCD Substrates | While this paper used BDD on SiC, our high-purity SCD substrates (up to 10mm thickness) offer unparalleled thermal and chemical stability for highly sensitive applications demanding the lowest background noise or requiring optical transparency in the setup. |
Customization Potential for Micrometric Integration
Section titled âCustomization Potential for Micrometric IntegrationâThe paperâs conclusion stresses the need to transition electrodes from macrometric to micrometric dimensions for all-inclusive devices. 6CCVDâs specialized fabrication services are critical for achieving this next step:
- Custom Dimensions and Etching: 6CCVD offers high-precision laser micro-cutting and shaping services. We can produce complex electrode patterns and micro-structures down to the micron level on BDD films grown on up to 125mm wafers, perfectly suited for integrated SiC micro-systems.
- Custom Thickness Control: We offer precise control over BDD film thickness, ranging from 0.1 ”m to 500 ”m, allowing researchers to tune the electrode properties (conductivity, mechanical strength) as a function of device integration requirements.
- Metalization Services: Although not the focus of this specific paper, electrochemical sensors often require reliable electrical contacts. 6CCVD provides in-house multi-layer metalization capabilities (including Ti, Pt, Au, Pd, W, and Cu) applied directly to the diamond surface, ensuring robust contacts compatible with micro-device assembly.
- High-Quality Polishing: For applications requiring high-resolution imaging or highly reproducible surface chemistry, 6CCVD can polish large-area PCD/BDD wafers (up to inch-size) to an Ra < 5 nm finish, and Single Crystal Diamond (SCD) surfaces to Ra < 1 nm.
Engineering Support & Global Logistics
Section titled âEngineering Support & Global LogisticsâOur commitment extends beyond material supply. 6CCVDâs in-house PhD team, specializing in MPCVD synthesis and diamond characterization, can assist with material selection and deposition parameter optimization for similar SiC-integrated biosensing or high-temperature electrochemical projects.
We ensure seamless global procurement logistics. All 6CCVD materials are shipped Globally (DDU default, DDP available), providing reliable, secure delivery of sensitive materials worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We are ready to support your transition from lab-scale prototypes to fully integrated diamond micro-devices.
View Original Abstract
Carbon materials are considered building blocks for most of electrochemical sensors. Their biocompatibility allows their use as transducers for biosensors. Furthermore, they can be patterned, giving interest in all-inclusive bioelectrochemical detection devices. In particular, graphene, boron doped diamond, and pyrolyzed photoresist films are suitable for this kind of application, which would give the ability to use these working electrodes within a fully designed apparatus completed by counter and reference electrode. In this paper, a pioneer work is exposed on the synthesis of these materials for use as electrochemical sensors and as transducers for biodetection of acetylcholine by adsorption of acetylthiocholinesterase. The lowest limit of detection reaches 6.98 ÎŒM, sensitivity 5.91 ÎŒA/mM, and a linear range from 6.98 ÎŒM to 0.55 mM.