The LED chip manufacturing process

The basic principle of epitaxial growth is: in a substrate substrates of heating to proper temperature ( Mainly include sapphire and, SiC, Si) InGaAlP, gaseous substances have control to the substrate surface, grow a particular single crystal thin film. LED growth of epitaxial wafer technology at present mainly adopts organic chemical vapor deposition of metals.

MOCVD is introduced:

metal organic chemical vapor deposition ( 金属- 有机化学气相沉积,简称金属 Rockwell company proposed in 1968 by the United States, a new technology of preparation of compound semiconductor sheet is tasted membranes. The device set precision machinery, semiconductor materials and vacuum electronics, fluid mechanics, optics, chemistry, computer co. , LTD. Is a multi-disciplinary, is a high degree of automation, the price is expensive, high technology integration of cutting-edge optoelectronic specialized equipment, mainly used in GaN ( Gallium nitride) Epitaxial growth of semiconductor materials and blue, green or ultraviolet light emitting diode chip manufacturing, development of optoelectronic industry is also the most promising one of special equipment.

LED chip manufacturing process:

the epitaxial wafer - cleaning - plating transparent electrode layer and the transparent electrode lithography graphics - corrosion - to glue to platform graphics lithography, and dry etching to stripping, annealing SiO2 deposition - window graphics lithography - SiO2 corrosion - stripping - N extremely graphic lithography to pre cleaning, coating to peel, annealing to P extremely graphic printing, coating to peel, grinding and cutting to chip, finished product testing.

actually epitaxial wafer production process is very complex, in the exhibition after the epitaxial wafer, electrode (LED epitaxial wafer began to do next P, N) And then began to use laser machine for cutting the LED epitaxial wafer ( Before cutting LED epitaxial wafer mainly use diamond cutter) , made into a chip, in different locations on the wafer extract nine points to do parameter test, as shown:

1, the main wavelength, intensity and voltage test, the shipment can conform to the normal standard parameters of the wafer to continue to do the next step of operation, if the test does not conform to the requirements of the wafer at 9 o 'clock, just put aside the other processing.

2, wafer cut into chips, 100% of the visual inspection ( VI/VC） , the operator to use 30 multiples of the microscope magnified visual analysis.

3, then the use of automatic sorting machine according to the different voltage, wavelength, intensity of prediction parameters for automatic selection of the chip, testing and classification.

4, the final inspection on the LED chip ( VC) And a label. Chip area in the center of the blue film, blue film on up to 5000 chip, but must ensure that each blue film on chip shall not be less than 1000, the number of the chip type, batch number, quantity, and photoelectric measurement data recorded on the label, attached to the back of the glossy paper. Blue chips will be the last item on the membranes of the testing and visual inspection standard is the same for the first time, to ensure the quality of chip neatly and qualified. So you made the LED chip ( Currently on the market generally referred to as the parties) 。

in the LED chip production process, some of the defective or damaged electrode chip, sorting out, these are the back of the crystal, this time on the blue film has some chips do not conform to the requirements of the normal shipment will naturally became edge or wool, etc.

talked about in different locations on the wafer extraction parameters testing, nine points do to do not conform to the requirements of the wafer for additional processing, these cannot be directly used to make the LED wafer square piece, also won't do any sorting, sold directly to customers, which is currently on the market of LED wafer ( But in the wafer have good things, such as party) 。