PAM-XIAMEN offers (20-2-1) Plane Semi-insulating Freestanding GaN Substrate, which is semiconductor material for the development of iii-nitride device, microelectronic devices and optoelectronic devices. The following specification of free standing GaN crystal substrate is for sale.
1. Semi-insulating Freestanding GaN Substrate Specification
|Dimension||5 x 10 mm2 or 5 x 20 mm2|
|Orientation||(20-21)/(20-2-1) plane off angle toward A-axis 0 ±0.5°
(20-21)/(20-2-1) plane off angle toward C-axis -1 ±0.2°
|Resistivity (300K)||>106 Ω·cm|
|TTV||≤ 10 µm|
|BOW||BOW ≤ 10 µm|
|Surface Roughness:||Front side: Ra<0.2nm, epi-ready;
Back side: Fine Ground or polished.
|Dislocation Density||≤5 x 106 cm-2|
|Macro Defect Density||0 cm-2|
|Useable Area||> 90% (edge exclusion)|
|Package||each in single wafer container, under nitrogen atmosphere, packed in class 100 clean room|
2. Freestanding Gallium Nitride Substrate Growth
Although GaN has excellent properties, it has been constrained by the lack of matching substrate materials and high dislocation density. At present, there are three main research directions to prepare semi-insulating freestanding GaN substrate materials: GaN bulk single crystal preparation method, heteroepitaxial technology, HVPE and other methods to grow GaN thick film and peel off prepared substrate. HVPE growth technology has the characteristics of fast growth rate (the highest growth rate can reach 300μm/h) and uniform growth, so it can easily obtain large-area thick GaN bulk substrate. In addition, HVPE technology also has the characteristics of simple equipment and low cost, so HVPE has become the mainstream technology for preparing semi-insulating freestanding GaN substrate materials.
HVPE grows a bulk GaN substrate, usually by epitaxial 0.5~1mm thick film on a substrate, usually on sapphire, and then remove the substrate by laser lift-off, grinding or etching, and finally polish the obtained GaN to form the GaN free-standing substrate.
Moreover, HVPE technology can be used to directly grow a GaN film with a thickness of 10mm to form a quasi-bulk single crystal. Then, the gallium nitride single crystal is cut, ground, and polished to form a SI freestanding GaN single crystal substrate. The dislocation density of the prepared bulk single crystal decreases greatly with the increase of film thickness, from ~109/cm2 at the thickness of 10um to ~107/cm2 at 300um, and to ~105/cm2 at the thickness of 3mm. The XRD half-width of the low gallium nitride semiconductor substrate dislocation density region is 55 arcsec.