Sapphire is the material most widely used in the capacity of substrates for technical devices based on the nitrides GaN, InN, AlN and  their solid solutions. However, the method of heteroepitaxy of the nitrides on sapphire substrates results in high dislocation density and other structure defects, due to discrepancy in the crystal lattice parameters and thermal expansion coefficients of these materials. This essentially complicates the obtaining of heterostructures with high functional characteristics. Since the commercial production of the substrates for homoepitaxial growth is expensive, much attention is being paid nowadays to the use of modified sapphire substrates with buffer nitride layers (GaN/sapphire or AlN/sapphire templates) which play the role of inherent nitride quasi-substrates. We have developed a new method for the obtaining of AlN/sapphire templates based on nitridation of sapphire in a gaseous mixture containing N2, СО, СО2, Н2, Н2О with low concentration of СО2 and Н2О.

This method allows to obtain polar AlN//Al2O3, AlN//Al2O3), semipolar (AlN// Al2O3) and nonpolar ( AlN// Al2O3) crystalline AlN layers on the surface of sapphire. Their thickness ranges between 20-30nm and several microns, the rocking curve half-width is less than 1º. In contrast to well-known deposition methods in which epitaxial films are obtained using external source, in the given method AlN layer is formed due to dissolution of nitrogen in anion-deficient corundum followed by crystal-chemical transformations in the surface-adjacent layer of sapphire substrate. Therefore, the nitride layer is to be formed after the stage of corundum reduction followed by etching of the substrate surface. The goal of the present work was to establish regularities of the influence of reducing annealing of sapphire substrate on the morphology of the surface of AlN/sapphire templates.


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Recently, GaN-based blue and near-UV LEDs are extensively studied in the emerging solid-state lighting industry as a key technology. The light extraction efficiency (LEE) is very important factor in fabricating high brightness, high efficiency GaN-based light-emitting diode (LED). As well known, the large difference in the refractive index between the GaN(2.40) and air caused a narrow escape cone for the light in GaN crystal. One most used method is roughness or texture on interfaces, such as the patterned sapphire substrate (PSS) recently and the increasing efficiency of PSS LED is considered as a consequence of the light scattering by the PSS. Huang, etc developed the side wall shaping and truncated inverted pyramid (TIP) shaping technology to increase the external quantum efficiency (EQE) of GaN LED.

The flip-chip technology is also wildly studied because of its excellent performance in thermal conductivity and EQE these years. But the influence of sapphire substrate processes in the back-end process is few considered. In this work, the relation between extraction efficiency of GaN-based LED and several parameters of the sapphire substrate is studied, including thickness, roughness and package method. Firstly, the thickness of sapphire substrate in the back-end processes is studied. After choose a better sapphire thickness, we develop the roughness method using just a grinding process and the bottom face periodic pattern by dry etching technique to improve the external quantum efficiency. The different surface structure on the bottom surface of sapphire substrates are analyzed basis on geometry ray tracing simulation, and compared with experiments.


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This 2013 Deep Research Report is a professional and in-depth research report on the Global and Chinese sapphire substrate industry. The report begins by discussing the industry giving details on definition, classification, manufacturing process and product specifications.

The report then examines 17 Global and 12 Chinese manufacturers presenting information on capacity, production cost, selling price, profit, production value, profit margin, products, customers, raw materials and equipment sources.

The report also gives statistics on market shares, production market shares, global and Chinese demand, supply and shortage. It also offers details on price, cost, profit, production values and profit margins. Finally, the report also analyses the 3 million pieces sapphire substrate project feasibility analysis and related research conclusions.


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Sapphire semiconductor substrates are manufactured at sapphire products from high quality optical grade Czochralski sapphire, integrated facilities allow regulation of the production of substrates from crystal growth to fabrication and to accommodate special requests on very short notice.

Sapphire semiconductor substrates are available in all orientations including R-axis (10-12), C-axis (0001), A-axis (11-20), and M-axis (11-10). Substrates are available in various shapes (circular, rectangle, or square), from a few mm up to 100mm in size, and finishes according to customer specification. Primary flats(as per industry standards) are provided on circular substrates for orientation purposes; secondary flats are available on request. Substrate thickness' range from 0.013" (0.25mm) to 0.025" (0.675mm), depending on your particular application requirements.


Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
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