Modulation of Diamond PN Junction Diode with Double-Layered n-Type Diamond by Using TCAD Simulation
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2024-04-28 |
| Journal | Electronics |
| Authors | Caoyuan Mu, Genzhuang Li, Xianyi Lv, Qiliang Wang, Hongdong Li |
| Institutions | Jilin University |
| Citations | 1 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis study proposes and validates, via TCAD simulation, a novel double-layered n-type diamond structure (D-PND) designed to function as a highly effective Junction Termination Extension (JTE) for vertical diamond PN junction diodes.
- Core Achievement: The D-PND structure successfully modulates the electric field distribution, achieving a superior balance between breakdown voltage (Vbd) and on-resistance (Ron) compared to conventional single-layer (S-PND) designs.
- Performance Metric: The optimized D-PND achieved a peak Baligaâs Figure of Merit (BFOM = Vbd2 / Ron) of 0.42 GW/cm2, a significant increase from the baseline S-PND value of 0.035 GW/cm2.
- Optimal Parameters: The best performance was obtained with a Vbd of 1450 V and an Ron of 5.08 mΩ·cm2, simulated at an operating temperature of 550 K.
- Structural Design: The JTE consists of an n- diamond layer (100 nm thick, 5 x 1017 cm-3) and an n+ diamond layer (50 nm thick, 1 x 1018 cm-3), separated by an optimal distance (S1) of 1 ”m.
- Mechanism: The double-layer structure generates three balanced electric field peaks (at the electrode edge, n+-edge, and n--edge), effectively alleviating electric field crowding and preventing premature breakdown.
- Implication: These results provide critical design guidelines for realizing high-power, high-efficiency vertical diamond power electronics.
Technical Specifications
Section titled âTechnical SpecificationsâThe following specifications represent the optimized parameters and simulated performance metrics for the Double-Layered PND (D-PND) structure, unless otherwise noted.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Peak Baligaâs Figure of Merit (BFOM) | 0.42 | GW/cm2 | Optimized D-PND (S1 = 1 ”m) |
| Breakdown Voltage (Vbd) | 1450 | V | Optimized D-PND (Max BFOM) |
| On-Resistance (Ron) | 5.08 | mΩ·cm2 | Optimized D-PND (Max BFOM) |
| Forward Turn-On Voltage (Von) | 5.7 | V | Typical S-PND performance |
| Simulation Temperature (T) | 550 | K | Lattice temperature used for dopant activation |
| Critical Electric Field (Ec) | 6 | MV/cm | Value used for diamond impact ionization model |
| p- Drift Layer Thickness | 4 | ”m | Hole concentration: 1 x 1016 cm-3 |
| p+ Substrate Thickness | 1 | ”m | Hole concentration: 1 x 1019 cm-3 |
| n- Layer Thickness (D1) | 100 | nm | Electron concentration: 5 x 1017 cm-3 |
| n+ Layer Thickness (D2) | 50 | nm | Electron concentration: 1 x 1018 cm-3 |
| JTE Separation Distance (S1) | 1 | ”m | Distance between n+ and n- layers (Optimized) |
| Electron Lifetime (Ïn) | 2 x 10-9 | s | Used in Shockley-Read-Hall (SRH) model |
| Hole Lifetime (Ïp) | 2 x 10-9 | s | Used in Shockley-Read-Hall (SRH) model |
Key Methodologies
Section titled âKey MethodologiesâThe study utilized Technology Computer-Aided Design (TCAD) simulation to model and optimize the vertical diamond PND structures.
- Simulation Environment: Silvaco TCAD software (Version 5.0.10.R) was used to perform 2D device simulations, focusing on forward conduction and reverse breakdown characteristics.
- Operating Temperature: A lattice temperature of 550 K was selected for all simulations. This temperature is crucial because it enhances the activation of dopants in diamond, which typically have large activation energies, thereby reducing device resistance.
- Physical Models Implemented:
- Recombination: Shockley-Read-Hall (SRH) Recombination and Auger Recombination models were included to accurately describe carrier dynamics. Electron and hole lifetimes (Ïn, Ïp) were set to 2 x 10-9 s.
- Mobility: The Low-Field Mobility model was adopted, incorporating temperature dependence. Mobility values at 300 K were specified for p-type (”p = 200 cm2/Vs) and n-type (”n = 500 cm2/Vs) diamond.
- Doping: The incomplete ionization model was used to account for the temperature-dependent ionization of dopants.
- Breakdown: Impact ionization was modeled using a critical electric field of 6 MV/cm for diamond.
- Optimization Strategy (S-PND): Initial simulations focused on the single-layer structure (S-PND) to determine the sensitivity of performance to cathode size (S = 0 to 3 ”m), n-type layer thickness (D = 100 to 200 nm), and doping concentration (1 x 1017 to 1 x 1018 cm-3).
- Optimization Strategy (D-PND): The double-layer structure (n+/n-) was optimized by systematically varying:
- The relative distance (S1) between the n+ and n- layers (0 to 1.5 ”m).
- The doping concentrations of the n+ and n- layers.
- The individual thicknesses (D1 and D2) while maintaining a fixed total JTE depth (150 nm).
Commercial Applications
Section titled âCommercial ApplicationsâThe successful optimization of the diamond PN junction diode structure, achieving high Vbd and low Ron, positions this technology for use in demanding power electronics sectors.
- High-Voltage Power Conversion: Essential for utility-scale power grids, HVDC transmission systems, and industrial motor drives, requiring devices capable of blocking >1 kV.
- Electric Vehicles (EVs) and Hybrid Systems: Used in high-efficiency traction inverters and charging infrastructure where minimizing power loss (low Ron) and maximizing reliability (high Vbd) are paramount.
- Aerospace and Defense: Applications requiring robust, high-power density electronics that can operate reliably under extreme thermal conditions, leveraging diamondâs superior thermal conductivity.
- High-Temperature Electronics: Suitable for downhole drilling, geothermal energy systems, or engine control units where ambient temperatures exceed the limits of silicon or SiC devices (operating capability confirmed at 550 K).
- Pulsed Power Systems: Diamondâs high critical electric field (6 MV/cm) makes it ideal for fast, high-power switching in specialized pulsed power applications.
View Original Abstract
This study proposed a novel double-layer junction termination structure for vertical diamond-based PN junction diodes (PND). The effects of the geometry and doping concentration of the junction termination structure on the PNDsâ electrical properties are investigated using Silvaco TCAD software (Version 5.0.10.R). It demonstrates that the electric performances of PND with a single n-type diamond layer are sensitive to the doping concentration and electrode location of the n-type diamond. To further suppress the electric field crowding and obtain a better balance between breakdown voltage and on-resistance, a double-layer junction termination structure is introduced and evaluated, yielding significantly improved electronic performances. Those results provide some useful thoughts for the design of vertical diamond PND devices.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
Section titled âReferencesâ- 2014 - A Survey of Wide Bandgap Power Semiconductor Devices [Crossref]
- 2018 - Gallium nitride vertical power devices on foreign substrates: A review and outlook [Crossref]
- 2022 - Progress of structural and electronic properties of diamond: A mini review [Crossref]
- 2022 - Design of a 6 kV Beta-Ga2O3 PN Heterojunction Diode with Etched Double-Layered NiO with a Figure of Merit of 10 GW cmâ2 [Crossref]
- 2018 - Recent advances in diamond power semiconductor devices [Crossref]
- 2022 - Ultra-wide bandgap semiconductor Ga2O3 power diodes [Crossref]
- 2023 - Flexible Tactile Sensors Using AlN and MOSFETs Based Ultra-Thin Chips [Crossref]
- 2022 - AlN quasi-vertical Schottky barrier diode on AlN bulk substrate using Al0.9Ga0.1N current spreading layer [Crossref]
- 2002 - A Dawn for Carbon Electronics? [Crossref]