| 1. |
|
|
| 2. |
- Rashid, S. J., et al.
(författare)
-
Numerical Parameterization of Chemical-Vapor-Deposited (CVD) Single-Crystal Diamond for Device Simulation and Analysis
- 2008
-
Ingår i: IEEE Transactions on Electron Devices. - 0018-9383 .- 1557-9646. ; 55:10, s. 2744-2756
-
Tidskriftsartikel (refereegranskat)abstract
- High-quality electronic-grade intrinsic chemical-vapor-deposited (CVD) single-crystal diamond layers having exceptionally high carrier mobilities have been reported by Isberg et al. This makes the realization of novel electronic devices in diamond, particularly for high-voltage and high-temperature applications, a viable proposition. As such, material models which can capture the particular features of diamond as a semiconductor are required to analyze, optimize, and quantitatively design new devices. For example, the incomplete ionization of boron in diamond and the transition to metallic conduction in heavily boron-doped layers require accurate carrier freeze-out models to be included in the simulation of diamond devices. Models describing these phenomena are proposed in this paper and include numerical approximation of intrinsic diamond which is necessary to formulate doping- and temperature-dependent mobility models. They enable a concise numerical description of single-crystal diamond which agrees with data obtained from material characterization. The models are verified by application to new Schottky m-i-p(+) diode structures in diamond. Simulated forward characteristics show excellent correlation with experimental measurements. In spite of the lack of impact ionization data for single-crystal diamond, approximation of avalanche coefficient parameters from other wide-bandgap semiconductors has also enabled the reverse blocking characteristics of diamond diodes to be simulated. Acceptable agreement with breakdown voltage from experimental devices made with presently available single-crystal CVD diamond is obtained.
|
|
| 3. |
- Gabrysch, Markus, et al.
(författare)
-
Formation of secondary electron cascades in single-crystalline plasma-deposited diamond upon exposure to femtosecond x-ray pulses
- 2008
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 103:6
-
Tidskriftsartikel (refereegranskat)abstract
- Secondary electron cascades were measured in high purity single-crystalline chemical vapor deposition (CVD) diamond, following exposure to ultrashort hard x-ray pulses (140 fs full width at half maximum, 8.9 keV energy) from the Sub-Picosecond Pulse Source at the Stanford Linear Accelerator Center. We report measurements of the pair creation energy and of drift mobility of carriers in two CVD diamond crystals. This was done for the first time using femtosecond x-ray excitation. Values for the average pair creation energy were found to be 12.17 +/- 0.57 and 11.81 +/- 0.59 eV for the two crystals, respectively. These values are in good agreement with recent theoretical predictions. The average drift mobility of carriers, obtained by the best fit to device simulations, was mu(h)= 2750 cm(2)/V s for holes and was mu(e)= 2760 cm(2) / V s for electrons. These mobility values represent lower bounds for charge mobilities due to possible polarization of the samples. The results demonstrate outstanding electric properties and the enormous potential of diamond in ultrafast x-ray detectors.
|
|
| 4. |
- Rashid, S. J., et al.
(författare)
-
Modelling of single-crystal diamond Schottky diodes for high-voltage applications
- 2006
-
Ingår i: Diamond and related materials. - : Elsevier BV. - 0925-9635 .- 1879-0062. ; 15, s. 317-323
-
Tidskriftsartikel (refereegranskat)abstract
- The modelling of Schottky m-i-p(+) (SMIP) diodes fabricated on chemical vapour deposited (CVD) single crystal (SC) diamond intrinsic layers grown on highly boron doped CVD diamond Substrates is reported. Variations in intrinsic layer thickness, Schottky metal type and operating temperature have been included in the analysis. Numerical models that take into account the activation of dopants, concentration and temperature dependant mobility and avalanche coefficients have been derived to successfully simulate experimental diamond devices.
|
|
| 5. |
|
|
| 6. |
- Twitchen, D.J., et al.
(författare)
-
High Voltage Single Crystal Diamond Diodes
- 2004
-
Ingår i: IEEE Transactions on Electron Devices. - 0018-9383 .- 1557-9646. ; 51:5, s. 826-828
-
Tidskriftsartikel (refereegranskat)abstract
- Demonstration of a 2.5-kV diamond diode is provided by electrical measurements using a circular gold Schottky contact, with an area > 1 mm(2), on large area freestanding single-crystal diamond consisting of a thin high purity layer (< 1 X 10(13) [B]/cm(3)) on a thicker heavily boron-doped (> 1 X 10(19) [B]/cm(3)) substrate with an ohmic back contact. The diode structures were fabricated using a microwave-assisted chemical vapor deposition process. The forward properties of the diode show a space charge limited current, with a forward-voltage drop of 2 V and a hole mobility of 4100 +/- 400 cm(2) /Vs at room temperature. For temperatures between 300 K < T < 380 K the mobility show T-312 dependence. This is consistent with acoustic phonon scattering, emphasizing the high purity quality of the top layer in which carrier transport is phonon rather than defect limited.
|
|
