Hall effect of different textured CVD diamond films
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | Acta Physica Sinica |
| Authors | Su Qing-Feng, Liu Chang-Zhu, Linjun Wang, Yiben Xia |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Hall Effect in Textured CVD Diamond Films
Section titled âTechnical Documentation & Analysis: Hall Effect in Textured CVD Diamond FilmsâExecutive Summary
Section titled âExecutive SummaryâThis research investigates the electrical transport properties of high-quality polycrystalline CVD diamond (PCD) films with distinct crystallographic textures ([100] vs. [111]) using the Hall effect.
- Core Achievement: Successful fabrication and characterization of high-quality [100] and [111] textured PCD films via Hot Filament CVD (HFCVD).
- Material Type: Both tested samples (L1: [100] and L2: [111]) exhibited stable p-type semiconductor behavior across the tested temperature range (100 K to 500 K).
- Superior Performance: The [100] textured film (L1) demonstrated superior electrical characteristics, achieving a room temperature mobility of 76.5 cm2/V·s.
- Texture Impact: Film texture significantly influences carrier mobility and concentration; the [100] orientation, known for lower grain boundary density, yields better transport properties.
- Temperature Dependence: Carrier concentration increases, and mobility decreases, as the measurement temperature decreases (100 K to 500 K).
- Relevance to 6CCVD: The findings confirm the critical role of crystal quality and texture controlâa core strength of 6CCVDâs MPCVD technologyâfor advanced diamond microelectronic and optoelectronic applications.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Material Type | p-type | N/A | Both L1 ([100]) and L2 ([111]) films |
| Film Thickness | ~200 | ”m | Deposited PCD films |
| Substrate Material | p-type [100] Single Crystal Silicon | N/A | 20 mm x 20 mm |
| Measurement Range (Temperature) | 100 - 500 | K | Hall effect testing range |
| Annealing Temperature | 500 | °C | Post-deposition treatment |
| Annealing Atmosphere | Argon (Ar) | N/A | 45 minutes duration |
| L1 (Room Temp) Carrier Concentration | 4.3 x 104 | cm-3 | [100] Textured PCD |
| L1 (Room Temp) Mobility | 76.5 | cm2/V·s | [100] Textured PCD (Highest Mobility) |
| L2 (Room Temp) Carrier Concentration | 8.9 x 104 | cm-3 | [111] Textured PCD |
| L2 (Room Temp) Mobility | 51.5 | cm2/V·s | [111] Textured PCD |
| L1 Resistivity (Room Temp) | 1.97 x 1011 | Ω·cm | After annealing |
| L2 Resistivity (Room Temp) | 6.25 x 1011 | Ω·cm | After annealing |
Key Methodologies
Section titled âKey MethodologiesâThe polycrystalline diamond films were synthesized using the Hot Filament Chemical Vapor Deposition (HFCVD) method, followed by structural and electrical characterization.
- Substrate Preparation: p-type [100] single crystal silicon wafers (20 mm x 20 mm) were used as substrates.
- HFCVD Deposition (L1: [100] Texture):
- Gas Flow: Ethanol (15 sccm), H2 (800 sccm).
- Substrate Temperature: 750 °C.
- Filament Temperature: 2200 °C.
- Pressure: 4.0 kPa.
- Bias Voltage: -150 V.
- HFCVD Deposition (L2: [111] Texture):
- Gas Flow: Ethanol (20 sccm), H2 (800 sccm).
- Substrate Temperature: 850 °C.
- Filament Temperature: 2400 °C.
- Pressure: 4.2 kPa.
- Bias Voltage: 0 V.
- Post-Deposition Annealing: Films were annealed at 500 °C for 45 minutes under an Argon (Ar) protective atmosphere to improve film quality and ohmic contact characteristics.
- Structural Characterization: X-ray Diffraction (XRD) was used to confirm the crystallographic texture and quality (high [100] texture confirmed by R > 99% calculation).
- Electrical Characterization:
- I-V curves were measured using a Keithley 4200 SCS system.
- Hall effect parameters (carrier concentration, mobility) were measured using the Van der Pauw method with an Accent HL5500 PC Hall effect test system across 100 K to 500 K.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research highlights the critical need for precise control over crystallographic texture and film quality to optimize diamondâs performance in microelectronics. 6CCVD specializes in high-purity MPCVD diamond, offering superior control and scalability compared to the HFCVD method used in this study.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research into high-performance electronic devices, 6CCVD recommends the following materials:
| 6CCVD Material Recommendation | Description & Advantage | Application Relevance |
|---|---|---|
| High-Purity Polycrystalline Diamond (PCD) | Wafers up to 125mm diameter, offering superior purity and reduced non-diamond carbon content compared to HFCVD. | Ideal for high-power, high-frequency devices requiring large area coverage and controlled texture (e.g., [100] or [111]). |
| Electronic Grade Single Crystal Diamond (SCD) | For ultimate performance, SCD offers zero grain boundaries, leading to significantly higher carrier mobility (potentially > 1000 cm2/V·s) and lower defect density. | Necessary for fundamental research, quantum applications, and high-voltage/high-temperature electronics where maximizing mobility is critical. |
| Boron-Doped Diamond (BDD) | For controlled p-type doping, 6CCVD offers BDD films with precise boron incorporation, allowing engineers to tune carrier concentration far beyond the intrinsic levels achieved in this study. | Essential for creating active device layers (e.g., p-type contacts, transistors) with predictable and stable electrical properties. |
Customization Potential
Section titled âCustomization Potentialâ6CCVDâs in-house manufacturing capabilities directly address the specific requirements of advanced Hall effect testing and device fabrication:
- Custom Dimensions and Thickness:
- The paper used 20 mm x 20 mm samples (~200 ”m thick). 6CCVD provides custom plates and wafers up to 125mm (PCD), with thickness control from 0.1 ”m to 500 ”m (SCD/PCD) and substrates up to 10mm.
- Surface Finish:
- High-quality electrical measurements require ultra-smooth surfaces. 6CCVD offers polishing services achieving roughness Ra < 1nm (SCD) and Ra < 5nm (Inch-size PCD).
- Integrated Metalization:
- The Van der Pauw method requires four precise ohmic contacts. 6CCVD offers internal metalization services, including common diamond contact stacks such as Ti/Pt/Au, W, or Cu, tailored to specific annealing requirements.
- Texture Control:
- 6CCVDâs MPCVD process allows for precise control over growth parameters to maximize the desired crystallographic orientation ([100] or [111]), ensuring optimal electrical performance as demonstrated by the superior L1 sample.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team provides expert consultation to accelerate research and development. We can assist engineers and scientists with:
- Material Selection: Determining the optimal diamond grade (SCD, PCD, or BDD) and orientation for specific Hall effect measurements or microelectronic device fabrication.
- Process Optimization: Advising on post-growth treatments, such as the annealing step used in this paper, and selecting appropriate metalization schemes for stable ohmic contacts.
- Global Logistics: Ensuring reliable, fast global shipping (DDU default, DDP available) for time-sensitive projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Due to its smoothest surface, fewer defects, and better crystal quality, [100] textured diamond film is well suited for the application of optoelectronic and microelectronic devices. Carrier concentration and mobility are very important parameters of semiconductor materials. In order to further broadening the application of diamond films in optoelectronics and microelectronics, it is necessary to made a research on Hall effect characteristics of [100] textured and [111] textured films. In this paper, different textured polycrystalline diamond films are deposited on silicon substrates by hot filament chemical vapor deposition (HFCVD) method under different conditions. Microstructures of diamond films are characterized by X-ray diffraction (XRD). High quality [100] textured and [111] textured diamond films are obtained. Dark current-voltage (I-V) characteristics of different-oriented films after annealing are investigated at room temperature. The carrier concentration and mobility of diamond films are measured by Hall effect test system as the temperature changing from 100 to 500 K. Results indicate that the textures of diamond films affect the value of carrier mobility:carrier concentration increases and mobility decreases with the decrease of temperature; and the deposited films are of p-type materials. The carrier concentration and mobility of polycrystalline [100]-textured diamond films at room temperature are 4.3Ă104 cm-3 and 76.5 cm2/V·s, respectively.