Status LED chip manufacturing equipment and technology introduced

First, the growth of epitaxial wafers upstream localization of equipment status

LED industry chain is usually defined as the growth of epitaxial wafers upstream, midstream and downstream of making a chip packaging and testing and application of the three links. From upstream to downstream industries, gradually reduce the barriers to entry, in which epitaxial growth of LED industry chain the highest technical content, the maximum density of capital investment, is the most intense international competition, the largest area of ​​operational risk. In the LED industry chain, epitaxial growth and the chip manufacturing industry profits accounted for about 70%, LED packaging accounts for about 10% to 20%, while the LED application also accounted for about 10% to 20%.

All sectors of the industry chain of production equipment from technology used to follow the same principles of investment, growth in our upstream and midstream wafer chip manufacturing more than 60 enterprises, the core device basically imported technology controlled by others, and the technology is still can not be compared with the international mainstream manufacturers. This means that our high-end LED epitaxial wafers, chip supply capacity can not meet the needs, require a lot of imports, thus greatly restricting the domestic LED industry development and profitability.



Table 1 LED industry chain and Key Equipment Overview

Upstream of epitaxial growth, as extension of the film determines the final performance and quality LED light source, is the core of LED production process for MOCVD growth of epitaxial films also because of technical difficulty, complex process to become the most attention in recent years, global markets monopoly of the most serious equipment. Therefore, the equipment in China has been favorable for the domestic industry, some companies and research institutes have initiated the development of MOCVD, but when it can achieve industrial application is unknown.

In addition, with the LED epitaxial technology innovation, especially in sapphire substrate processing technology widely used sapphire substrate etching equipment is becoming the core of LED epitaxial wafer manufacturing technology is one key process equipment, directly affects their level of film performance, more and more industry attention. As the star of the semiconductor equipment industry, with many years in the north of semiconductor microelectronics, solar energy equipment manufacturing high-end technology, LED production areas for the application of specially developed ELEDETM330ICP etching etching equipment, and has successfully carved a PSS substrate erosion in the large-scale production line applications, which can be called the field of LED production equipment made the breakthrough LED equipment at home is bound to play to promote and lead.

Second, the middle chip manufacturing status of major equipment

LED chip manufacturing for the middle reaches of the performance requirements based on device structure and process design. Major equipment includes etching machines, lithography, evaporation of Taiwan, Taiwan sputtering, laser scribing machines.

1, the etching process and equipment

Etching chips in the middle has a wide application field, and as graphic substrate LED technology more and more companies are recognized on the graphic substrate demand to ICP etching etching machines in the LED industry improved significantly the proportion of the chain. Greater capacity, higher performance LED ICP etching machine as the needs of mainstream business objectives, in terms of capacity requirements of a single batch etching machine capacity of over 20 per plate, higher machine utilization and automatic Cassette to Cassette of the production process; the increasing number of single-batch, inter-chip and batch uniformity between the more stringent control; In addition, longer maintenance cycle and convenient interactive user interface is necessary for large-scale production line equipment Preparation Conditions. The development of the north of Microelectronics ELEDETM330 etching machines, integrated a number of advanced technologies, the semiconductor etching process is more precise with the design requirements of the field to achieve higher performance LED etching process, fully meet the large-scale production lines engraved on the dry etching process the request.

2, the lithography process and equipment

Lithography process is the solution of the photoresist coated wafer, exposed after a certain pattern on the wafer process. LED chip production in the PSS through the lithography process to achieve the desired patterned etching mask formation and preparation of electrodes in the chip manufacturing. LED mainly uses projection lithography lithography, nanoimprint lithography and contact the three technologies. Contact lithography due to low prices, is currently the mainstream, but popular with the PSS substrate, graphics, fine size, projection lithography has become mainstream. Nanoimprint resist because no simple process, lower overall costs, but because of poor reproducibility, is still in development stage.



Table 2 LED on the middle reaches of the application of etching equipment

China LED production contact lithography machine is mainly dependent on imports, mostly projection lithography machine used refurbished semiconductor lithography. The view of the lithography equipment manufacturers of domestic technological base and gained in the renovation business experience, I believe over time the development of LED-made prospects for the future of lithography equipment. Nanoimprint technology through the hot nano template class graphics in the United States and Taiwan have a more in-depth research, industrial application is not mature, but there are still great potential.

3, the evaporation process and equipment

Evaporation process is defined as one or chip surface coated with ITO transparent electrode layers and Cr, Ni, Pt, Au and other metal, generally placed in high-temperature vacuum wafer, the molten metal vapor on the wafer. LED chip production in the evaporation process using a welding electrode on the chip and the chip through the evaporation of metal to increase the current conduction area.

Evaporation source of energy is divided into units by thermal evaporation and electron beam evaporation Taiwan Taiwan, in view of the high melting point metal as an electrode, the metal for better adhesion, LED industry, the widespread use of e-beam evaporator. LED deposition current domestic production of import-based units still present. Although Taiwan has acquired the domestic principle of evaporation, and evaporation can be used to manufacture laboratory units, but because of the degree of automation, process repeatability, uniformity, etc., and do not enter the production line. View of the LED electrodes deposited by PVD deposition of semiconductor equipment sets the difficulty of lower than this situation, the country with experience in the development of semiconductor PVD equipment, equipment manufacturers, will have the ability to achieve LED evaporation units domestically.

4, PECVD technology and equipment

PECVD process is completed after the epitaxial process, the chip surface coated with a layer of SiO2 or SiNx, as the electrode etching requires a hard mask in order to increase the mask and the GaN epitaxial layer etching selectivity, better moment eclipse profile morphology.

LED current mainstream use of PECVD is generally flat with 13.56MHz PECVD, is about 250 ~ 300 ℃ in the temperature of film, a film can reach more than 40 films, PECVD is currently used in the production of domestic LED is still the main imports. LED using the same PECVD PECVD and traditional technical difficulties, the key technology is still in the temperature control, plasma technology, vacuum systems, software systems. China has successfully developed crystalline silicon solar cells with plate PECVD equipment, the equipment and LED devices with PECVD great similarities between, after the local hardware to improve the design, relatively easy to achieve localization of LED with PECVD.

Third, the downstream packaging status of major equipment manufacturing

And downstream packaging and testing industry chain and application, refers to the outer lead connected to the middle electrode on the production of LED chip to form LED devices, and then used to make these devices a large LED display, LED backlight and other end-product process. Used in this part of the production equipment is relatively simple, and the electronics industry have a certain commonality, such as the solid crystal, wire machines.

In addition, the chain in each industry, but also used a variety of film properties, parameters, testing equipment, such as X-ray diffraction, photoluminescence spectroscopy, Hall effect detector, ellipsometry, transmission electron microscopy, scanning electron microscopy, resistance tester, testing equipment, most of these general-purpose equipment for the electronics industry, domestic and international production and application has been very mature.

LED for the LED industry, the rapid development of equipment to bring a broad development space for China's development by leaps and bounds LED equipment provides an unprecedented historical opportunity, as the demand for high-brightness LED chip market continues to rise, as its technical support for the equipment industry will get more and more space for development. LED equipment in view of domestic enterprises has been achieved and the basis of available technologies, we have reason to believe, domestic equipment suppliers through to sharpen their technical strength and sense of service, we will able to achieve the same stage with foreign equipment vendors, and use their own price, geographic and service advantages, LED, and the broader microelectronics equipment industry, firmly stand firm.