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Tungsten for Sapphire Growth Furnace  »

LED sapphire is to describe artificial sapphire(Al2O3 single crystal) for processing LED substrate sapphire. Artificial sapphire (Al2O3 single crystal) can be used for decoration (such as jewelry, glass etc.), industrial window material and semiconductor substrate, especially for LED substrate sapphire. But for LED substrate, sapphire should be with special crystal orientation, low dislocation density and so on, and it is that it belongs to the high-end products in the artificial sapphire.

LED wafer manufacture can be divided into two steps.

First of all, in the liner low fabricated on gallium nitride (GaN) epitaxial substrate, this process is mainly completed in the metal organic chemical vapor deposition of epitaxial furnace. After preparing the materials source and good fabrication of GaN based epitaxial wafer is required for high pure gas, according to the process requirements can be gradually the epitaxial wafer do. Commonly used substrate are mainly sapphire, silicon carbide and silicon substrate, and GaAs, AlN, ZnO and other materials. MOCVD is the use of gas phase reactants (precursor) organic metal and V and III of the NH3 reaction at the substrate surface, the required products deposited on the substrate surface. By controlling the temperature, pressure, concentration of reactants and the types of proportion, so as to control the coating composition, crystal phase of quality. MOCVD epitaxial furnace is the production of LED epitaxial films of the most commonly used equipment.

Next is the two electrodes of LED PN junction processing, key process of electrode processing but also the production of LED chip, including cleaning, vapor deposition, yellow light, chemical etching, fusion, grinding; then dicing, testing and grading of LED feather, you can get the LED chip required. If the wafer cleaning is not clean enough, evaporation system is not normal, the metal layer may lead to evaporation out (of the electrode after etching) will fall off, the metal layer appearance color, gold bubble anomaly. Evaporation process sometimes needs the spring clip fixed chip, it will produce a clip marks (in visual inspection must carry except). Yellow light work includes baking, photoresist, photographic exposure and development, if the developer does not completely and mask holes will have a light emitting region more metal residue. Wafer in the process, various process such as cleaning, vapor deposition, yellow light, chemical etching, fusion, grinding and other operations must use tweezers and a basket of flowers, carrier, so there will be grain electrode scratch occurs.  

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