GaN epitaxy template on Sapphire substrate with N-type, P-type or semi-insulating is available for the preparation of semiconductor optoelectronic devices and electronic devices. GaN epitaxial layer on sapphire substrate refers to a composite structure composed of a gallium nitride single crystal thin film material and the supporting sapphire substrate, that after a series process operations such as epitaxial deposition, diffusion, and ion implantation. Especially pointed out that non-PSS (so-called SSP) templates are to co-load with PSS wafers for planar runs, which can help to more clearly see reflectance. The GaN on sapphire lattice mismatch from PAM-XIAMEN is relatively low. For more specifications of the GaN material epitaxy on Sapphire, please see the followings:
1. Wafer Specifications of GaN Epitaxy Template on Sapphire Substrate
1.1 Undoped GaN Template on Sapphire
GaN Template on Sapphire, C plane 5×5 mm x 30 micron Thickness,1sp
GaN Template on Sapphire, R- plane, 5 x 5 mm x 5 micron,1sp
GaN Template on Sapphire, C plane, 10 x 10 mm x 5 micron,1sp
GaN Template on Sapphire, M plane,10 x 10 mm x 5 micron,1sp
GaN Template on Sapphire, C plane,10×10 x0.5 mm , Film: 30 micron Thick
GaN Template on Sapphire (C plane), N type, undoped, 4″x 4- 5 micron,1sp
GaN Template on Sapphire (C plane), N type, undoped, 4″x 5 micron, 2sp
GaN Template on Sapphire (C plane), N type, undoped, 4″x 30 micron,1sp( Production Grade)
GaN Template on Sapphire (C plane), N type, undoped, 2″x 4- 5 micron,1sp
GaN Template on Sapphire (C plane), N type, undoped, 2″x 5 micron, 2sp
GaN Template on Sapphire (C plane), N type, undoped, 2″x 30 micron,1sp( Production Grade)
Semi-Insulting GaN Template on Sapphire (C plane), N type, undoped, 4″x 5 micron,1sp
Semi-Insulting GaN Template on Sapphire (C plane), N type, undoped, 3″x 5 micron,1sp
GaN Template on Sapphire ( Semi-insulated) 4″x 20 Micron–Production Grade
GaN Template on Sapphire ( Semi-insulated) 4″x 5 Micron–Research Grade
GaN Template on Sapphire ( Semi-insulated) 2″x 20 Micron–Production Grade
GaN Template on Sapphire ( Semi-insulated) 2″x 5 Micron–Research Grade
1.2 Doped GaN Template on Sapphire
GaN (0001) Template( N+ ,Si-doped) on Sapphire , 4″x 5um,1sp
GaN (0001) Template( N+ ,Si-doped) on Sapphire, 4″x 5um,2sp
GaN (0001) Template( N-type ,Fe-doped) on Sapphire, 4″x 5um,1sp
GaN (0001) Template( N+ ,Si-doped) on Sapphire , 2″x 5um,1sp
GaN (0001) Template( N+ ,Si-doped) on Sapphire, 2″x 5um,2sp
GaN (0001) Template( N-type ,Fe-doped) on Sapphire, 2″x 5um,1sp
Si-doped GaN (0001) Template on Sapphire N+type, 4″x 5 micron,1sp
FLAAT GaN (0001) Template( N+ ,Si-doped) on Sapphire N+ , 2″x 15um,1sp
Mg-doped P-type GaN (0001) Template on Sapphire 10x10x 2 micron,1sp，Doping Concentration: 5E17/cc
Mg-doped P-type GaN (0001) Template on Sapphire 4″x 2 micron,1sp，Doping Concentration: 5E17/cc
Mg-doped P-type GaN (0001) Epitaxial Template on Sapphire 4″x 2 micron,2sp
Mg-doped P-type GaN (0001) Template on Sapphire 2″x 2 micron,1sp，Doping Concentration: 5E17/cc
Mg-doped P-type GaN (0001) Epitaxial Template on Sapphire 2″x 2 micron,2sp
2. Industry Criteria for Epitaxy GaN Films on Sapphire
This standard applies to the preparation of templates of GaN epi-layer on sapphire for semiconductor optoelectronic devices and electronic devices.
2.1 Warpage of GaN Epitaxial Growth on Sapphire
Note for Y, Z, H in the table:
“Y” – a gallium nitride epitaxy template on sapphire with a thickness not exceeding 20um (inclusive);
“Z” – a sapphire-based GaN epitaxial wafer with a thickness exceeding 20um but not exceeding 50um (inclusive);
“H” – GaN on sapphire wafer with a thickness of more than 50um.
The warp of GaN epiwafer on sapphire should meet the requirements of Table 1.
Table 1 Warp of GaN Epitaxial film on Sapphire
2.2 Thickness for the Sapphire based GaN Epitaxial Growth
The thickness of N-polar GaN on sapphire epitaxy should comply with the requirements in the Table 2.
Table 2 GaN Layer Thickness and Total Thickness Variation
|Thickness Code||Thickness Deviation||TTV|
|y||±2 um||≤2 um|
|Z||±5 um||≤5 um|
|H||±10 um||≤10 um|
2.3 Surface Quality of Gallium Nitride Epitaxy on Sapphire Substrate
The surface of sapphire based gallium nitride epitaxial growth should be a mirror-like, no yellowing, no blackening, and no chromatic aberration. And surface defects of SSP template should meet the requirements of Table 3.
Table 3 Maximum Allowable Value of Surface Defects
|Item||Maximum Allowable Value|
|2 Inch||4 Inch|
|Scratches (Quantity: strips; Scratch length: mm)||≤2: ≤5mm||≤5: ≤5mm|
|Cracks, Duck Claws, Ripples, Orange Peel, Fog, Chipped Edges||None||None|
|Small hills and pits (Dia≥0.5mm, unit: pcs/cm2)||None||None|
|Small Hills and Pits (0.2mm≤diameter<0.5mm, unit: pcs)||1||2|
|Note: The surface defect area refers to the entire surface of the 2mm ring area removed from the edge.|
The surface roughness of epitaxy of gallium nitride on sapphire wafer should be less than 0.6nm.
If the customer has special needs for certain items, it should be decided by the supplier and the buyer.
2.4 GaN Epi Wafer on Sapphire Electrical Parameters
The electrical parameters of single crystal GaN epitaxy on Sapphire template should meet the requirements of Table 4.
Table 4 Electrical Parameters
|Conductivity Type||Carrier concentration cm-3||Mobility cm3/v1– s1||Resistivity ohm- cm|
2.5 GaN Epitaxy on Sapphire Peak Position and Half-Width
The allowable value of peak position and half-width for GaN epitaxy template should meet the requirements of Table 5.
Table 5 Peak Position and Half-Width
|Crystal Plane||Peak Position (Bragg Angle)||FWHM(arcsec)|
|( 10-12)||24.04°+/- 0.6° (determined by the deflection angle of the product demand)||≤250|
|(0002)||17.28°+/- 0.6° (determined by the deflection angle of the product demand)||≤250|
3. FAQ of GaN on Sapphire Template
Q1: Why you have carrier concentration less than dopant density of GaN on sapphire epitaxy?
A: For GaN epitaxy on sapphire wafer, Mg and H will be combined, about 1/1000 will be activated, and the activation energy is higher, so the doping concentration is greater than the carrier concentration.
Q2: Since I will be doing high-temperature solar cells with your p-GaN, will the carrier concentration be stable at 400 degree-C?
A: The 400 degree is high a bit, and I think it can be affordable at a short time at 400 degrees,but the efficiency will decline for a long time.Of course, it also depends on your device structure. If it’s just a very simple PN structure, no quantum well may be better. In addition, the Mg activation of the P type can also be achieved by annealing at high temperature.
Q3: Can you please inform me what is the minimum thickness of p-GaN you can provide? Can I get at least 5-7micro-meter of p-GaN?
A: The constant thickness is as below we mentioned: in the market, when people say 5um p type GaN, actually it includes all the layers p-gan, u-gan, and GaN buffer, here clearly say the market 5um p gan is just our wafers.
2/GaN epitaxy on sapphire, p type
2″ dia, p-type, Mg doped ,
Total thickness :>4.5um+/-0.5um
GaN Buffer layer
Surface Finish :Single Side Polished,epi-ready
Usable Area ≥ 90 %
Q4: I want to know if you cut the wafer from undoped GaN template on sapphire wafer of make it in 10x10mm size? and how you clean it ? because I used chemical solution and it increase the roughness, so how can I clean GaN epitaxy template without any damage for surface or when I receive it from you it clean and I can used it? this information very important for my research.
A: The regular process for undoped GaN on Sapphire template after cutting them by laser:
- put the substrate in the cleaning container.
- pour acetone, the capacity of acetone should be soaked at 2mm and ultrasonic cleaning for 10 minutes.
- the acetone is poured into the waste liquid bucket and poured into the anhydrous ethanol. The capacity of the anhydrous ethanol should be immersed in the height of 2mm, and the ultrasonic cleaning is 10 minutes.
- will be used back into the waste liquid bucket and deionized water for 10 times.
- preparation of No. 1 liquid (H2O2:NH3.H2O:H2O=2:1:7), deionized water for boiling water, cleaning for 5 minutes;
- deionized water rinse 10 times;
- blow dry (100 grade clean table);
Q5: Please tell me the roughness of the undoped GaN epitaxy template on sapphire, and how can I order 1x1cm samples from your company. And its growth by HVPE?
A: The roughness of undoped GaN epitaxy on Al2O3: Ra<2nm, it is natural growth surface, by MOCVD.