5 x 10 mm, A plane (11-20) Fe-doped semi-insulating, non-polar, free-standing Gallium Nitride (GaN)
MSE Supplies offers premium quality GaN crystal substrates with low dislocation density (on the order of 105 /cm2) and uniform surface with no periodic defects. These high quality GaN crystals have an usable area of more than 90%.
We sell directly from the factory, and therefore can offer the best price on the market for high quality GaN crystal substrates. Customers from all over the world have trusted MSE Supplies as their preferred supplier of GaN crystal substrates.
- Product #: WA0211
- Conductivity type: semi-insulating
- Dimension: 5 mm x 10 mm +/- 0.2 mm
- Thickness: 350 +/- 25 um
- Usable surface area: > 90% substrate surface
- Orientation: A plane (11-20) off angle toward C-Axis -1 +/- 0.2 deg
- Total Thickness Variation (TTV): <10 um
- Bow: <10 um
- Resistivity (at 300K): > 106 Ohm-cm
- Fe-doping concentration: ~ 3 × 1018 cm−3
Dislocation Density: < 5x105 cm-2
- Polishing: front surface Ra < 0.5 nm. Epi-ready polished. Back surface: fine ground.
- Package: packaged in a class 100 clean room environment in single wafer containers under a nitrogen atmosphere.
1. Emission properties of a-plane GaN grown by metal-organic chemical-vapor deposition
We report on the emission properties of nonpolar a-plane
GaN layers grown on r-plane sapphire. Temperature-, excitation-density-, and polarization-dependent photoluminescences and spatially resolved microphotoluminescenceand cathodoluminescence are employed in order to clarify the nature of the different emission bands in the 3.0-3.5 eV spectral range. In the near band-edge region the emission lines of the donor-bound excitons 3.472eV and free excitons 3.478eV are resolved in the polarized low-temperature spectra,indicating a good quality of the layers. At low energies two other emissions bands with intensity and shape varying with the excited area are observed. The 3.42eV emission commonly attributed to the excitons bound to basal plane stacking faults shows thermal quenching with two activation energies (7 and 30meV) and an S-shaped temperature dependence of the peak position. This behavior is analyzed in terms of hole localization in the vicinity of the stacking faults. The emission band that peaked at 3.29eV is found to blueshift and saturate with increasing excitation intensity. The spatially resolved cathodoluminesence measurements show that the emission is asymmetrically distributed around the triangular-shaped pits occurring at the surface. The 3.29eV emission is suggested to involve impurities, which decorate the partial dislocation terminating the basal stacking faults.
2. GaN grown in polar and non-polar directions
In this paper, defects formed in GaN grown by different methods are reviewed. Thin GaN films were grown on c-, m-, and a-planes on a number of substrates and typical defects as characterized by transmission electron microscopy are described. For polar epilayers grown on c-plane sapphire the typical defects are dislocations (edge, screw and mixed). The lowest dislocation density was obtained for homoepitaxial growth using molecular beam epitaxy (MBE) or hydride vapour phase epitaxy (HVPE). In these cases, the core structure of screw dislocations were studied in detail. In both cases, the cores are full. In the layers grown by HVPE the dislocations are decorated by pinholes stacked on top of each other. These pinholes are empty inside and their formation is attributed to impurities (oxygen) present in these layers. In these layers Ga-rich cores have been found. These were not observed in the layers grown by MBE on the top of the HVPE templates. Epilayers grown in non-polar directions (m- or a-plane) have a high density of planar defects (stacking faults) terminated by partial dislocations. Only low energy faults were found. The majority of these faults are formed at the interface with the substrate and propagate to the sample surface.
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