GaAs Substrate for LED with Silicon Dopant

GaAs Substrate for LED with Silicon Dopant

The GaAs substrate (gallium arsenide substrate) doped with silicon, grown by VGF, is available from GaAs substrate supplier – PAM XIAMEN, which is for fabricating LED (light-emitting diodes). GaAs is zinc blende crystal structure. The GaAs substrate orentation is (100)150± 0.50 off toward (111)A with a thickness of 350±20µm.

The core of semiconductor lighting devices is LEDs, which are composed of substrate materials, luminescent materials, light conversion materials, and packaging materials. The substrate material for LED epitaxial wafer is very important for the technology development in the semiconductor lighting industry. Different substrates need different growth technology for LED epitaxy, processing technology for chip and packaging technology. So far, gallium arsenide substrate, sapphire substrate, silicon substrate, and silicon carbide substrate are the four commonly used substrate materials for making LED chips. More about the GaAs LED substrate, please see table below:

1. Specifications of GaAs Substrate for LED

Parameter Customer’s Requirements UOM
Growth Method: VGF
Conduct Type: S-C-N
Dopant: GaAs-Si
Diameter: 100.00± 0.2 mm
Orientation: (100)150± 0.50 off toward (111)A
OF location/length: EJ [ 0-1-1]± 0.50/32±1
IF location/length: EJ [ 0-1 1 ]± 0.50/0         
Ingot CC: Min: 0.4E18 Max: 4E18 /cm3
GaAs Substrate Resistivity: Min: 0.8E-3 Max: 9E-3 Ω·cm
SSMobility: Min: 1000 Max: cm2/v.s
EPD: Max: 5000 / cm2
GaAs Substrate Thickness: 350±20 µm
Laser Marking: N/A
TTV/TIR: Max: 10 µm
BOW: Max: 15 µm
Warp: Max: 15 µm
Surface Finish– front: Polished  
Surface Finish –back: Etched
Epi-Ready: Yes

 

2. Light-emitting Diode on GaAs Wafer Substrates

As a direct band gap material, the minimum of conductive band of GaAs is over the maximum of the valancy band. Transition between the valency band and conductive band only needs energy changing, and momentum do not need to change. Due to this property, the energy levels from the conductive band to the valency band through the electron movement will emit light. Therefore, N type GaAs substrate can be used for manufacturing the light-emitting diodes.

A Light-emitting diode is a semiconductor light source that generates light passing current through a PN junction. The energy for electrons movement determine the color of the light. Usually, the light color is monocolor due to the band structure. Generally, LED based on GaAs substrate emits the light between the red and yellow regions.

3. Inspection Standards for GaAs Substrates of LED Epitaxial Chips

GB/T 191 Packaging, storage and transportation icon sign
GB/T1555 Method for determining crystal orientation of semiconductor single crystal
GB/T 2828.1 Sampling inspection procedure by attributes Part 1: Sampling plan for batch-by-batch inspection retrieved by acceptance quality limit (AQL)
GB/T 4326 Extrinsic semiconductor single crystal Hall mobility and Hall coefficient measurement method
GB/T 6616 Semiconductor GaAs chip resistivity and GaAs film layer resistance test method: non-contact eddy current method
GB/T 6618 Test method for GaAs wafer thickness and total thickness change
GB/T 6620 Non-contact testing method for GaAs wafer warpage
GB/T 6621 Test method for surface flatness of GaAs wafer
GB/T 6624 Visual inspection method for surface quality of polished GaAs wafer
GB/T 8760 Method for measuring dislocation density of GaAs single crystal
GB/T 13387 Method for measuring the reference surface length of GaAs and other electronic material wafers
GB/T 13388 X-ray test method for crystallographic orientation of GaAs wafer reference plane
GB/T 14140 GaAs wafer diameter measurement method
GB/T 14264 Semiconductor material terminology
GB/T 14844 Semiconductor material designation method
SEMI M9.7-0200 Specification of 150mm diameter gallium arsenide single crystal round polished wafer (notch)

 

4. LED Gallium Arsenide Substrate Inspection

4.1 Surface Quality

There are no scratches, chipped edges, orange peel and cracks within 2mm of the edge of the GaAs substrate surface. No stains, solvent residues, wax residues on the entire surface or as stipulated in the contract

4.2 Electrical Properties Inspection of LED GaAs Substrate
  • Resistivity: The gallium arsenide substrate resistivity detection is carried out according to the measurement method specified in GB/T 4326;
  • Mobility: The GaAs substrate mobility is tested according to the measurement method specified in GB/T 4326;
  • Carrier concentration: The carrier concentration of the GaAs substrate is tested according to the measurement method specified in GB/T 4326.
4.3 Inspection conditions

Unless otherwise specified, the inspection of GaAs substrate for LED epitaxial chips shall be carried out under the following conditions:

Temperature: 23℃±5℃;

Relative humidity: 20%~70%;

Atmospheric pressure: 86 kPa ~106 kPa;

Cleanliness: Class 10000.

For more information, please contact us email at [email protected] and [email protected].

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