PAM-XIAMEN, one of LED wafer manufacturers, offers GaN Wafer for Fabricating LED Devices, which is GaN Epi Structure with InGaN MQWs on sapphire substrate, and can be blue or green emission:
1. Specification of GaN Wafers for LED Devices
PAM200614-GAN-LED
size : 2 inch
WD : 455 ± 10nm
brightness : > 90mcd
VF : < 3.3V
n-GaN Thickness : <4.1㎛
u-GaN thickness : <2.2㎛
substrate : patterned sapphire substrate (PSS)
without p-roughness
without ITO
Single-side polished
GaN LED Wafer Structure
| p-GaN | Mesa Etching Depth: ~10,000A |
| InGaN MQWs | |
| ESD protection Layer ( -06 μm) | — |
| n-GaN (~4 μm) | — |
| u-GaN (~2 μm) | — |
| Sapphire ( 430 μm) | — |
2. Standard of Gallium Nitride based Epitaxial Layer for LED Lighting
GaN Epitaxial wafers include LED full-structure GaN epitaxial wafers and GaN templates (including n-type and p-type GaN wafers according to conductivity types). Here we just list the criteria of GaN LED wafer with the full structure.
2.1 GaN LED Wafer Technical Parameters
The technical parameters of GaN wafer for LED should be complied with the parameters in Table 1.
Table 1
| Item | Requirements (mm) | |||
| 50,8 | 76.2 | 100 | 150 | |
| Diameter | 50.8±0.2 | 76.2±0.2 | 100±0.2 | 150±0.2 |
| Reference Surface Size | 16.0±1.0 | 24.0±1.0 | 32.0±1.0 | 48.0±1.0 |
| Center Point Thickness | 0.43±0.03 | 0.52±0.03 | 0.65±0.03 | 1.30±0.03 |
| Thickness Unevenness | ≤0.02 | ≤0.03 | ≤0.05 | ≤0.08 |
| Curvature | ≤0.04 | ≤0.05 | ≤0.06 | ≤0.08 |
| Warpage | ≤0.04 | ≤0.05 | ≤0.06 | ≤0.08 |
| Note: When the buyer has special requirements for the geometric dimensions of the epitaxial wafer, it shall be specified in the contract by both the supplier and the buyer. | ||||
2.2 GaN LED Wafer Epitaxial Surface Quality
The surface quality of GaN on Sapphire substrate should be meet the requirements in the Table 2.
Table 2
| Item | Test Conditions | Range | Requirements | |||
| 50.8 mm | 76.2 mm | 100 mm | 150 mm | |||
| Hexagonal defects | 200X | diameter ≥300 um | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer |
| diameter <300 um | 20 pcs/wafer | 30 pcs/wafer | 40 pcs/wafer | 60 pcs/wafer | ||
| Fine pits | 200X | diameter ≥ 20 um | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer |
| diameter <20 um | 100 pcs/wafer | 150 pcs/wafer | 200 pcs/wafer | 300 pcs/wafer | ||
| Small marks | 50X | length ≥ 5 mm | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer |
| length <5 mm | 3 pcs/wafer | 5 pcs/wafer | 10 pcs/wafer | 20 pcs/wafer | ||
| White point | 50X | length ≥ 3 mm | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer | 0 pcs/wafer |
| length <3 mm | 20 pcs/wafer | 30 pcs/wafer | 40 pcs/wafer | 60 pcs/wafer | ||
| Note: When the customer has special requirements for the surface quality of the epitaxial wafer, the supplier and the buyer shall determine in the contract. | ||||||
2.3 Emission wavelength of GaN LED Epi Wafer
The emission wavelength of the full-structure GaN epitaxial wafer is 200nm~430nm for ultraviolet (including violet light), 430nm to 490nm for blue light, and 490nm to 540nm for green light. The typical emission wavelength of the epitaxial wafer of gallium nitride should meet the requirements of Table 3.
Table 3
| Item | Requirement | ||
| UV LED Epitaxial Wafer | Blue LED Epitaxial Wafer | Green LED Epitaxial Wafer | |
| Typical Wavelength /nm | 280±10, 310±10, 380±10 | 450±10, 470±10 | 500±10, 520±10 |
| Note: When the buyer has special requirements for the wavelength of the epitaxial wafer or technological advancement changes the existing wavelength, it shall be specified in the contract by the supplier and the buyer. | |||
2.4 LED GaN Wafer Photoelectric Parameters
The photoelectric parameters such as the opening voltage (VF), peak wavelength, leakage current, electrostatic discharge sensitivity (ESD) of the GaN epi wafer for LED should meet the requirements of Table 4.
Table 4
| Item | Requirements | ||
| UV LED Epitaxial Wafer | Blue LED Epitaxial Wafer | Green LED Epitaxial Wafer | |
| Turn on Voltage / V | ≤5.0 | ≤3.0 | ≤3.0 |
| Peak Wavelength / nm | 280±10, 310±10, 380±10 | 450±10, 470±10 | 500±10, 520±10 |
| Leakage Current(-8V) / uA | ≤0.5 | ≤1 | ≤3 |
| ESD / V | ≥4000 | ≥4 000 | ≥4 000 |
| Note: When the buyer has special requirements for the photoelectric parameters of the GaN epitaxial film or the parameters are changed by technological progress, the supply and buyer shall determine in the contract. | |||
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