China exploits technology
Although commercial activity is just emerging, various research groups have experience dating back more than 25 years. However, the majority of the research work had been concentrated on material development rather than device optimization. Holger Juergensen of Aixtron estimates that there are more than 40 groups in China working in the field of compound semiconductors, with more than 50 MBE and 70 MOCVD systems (including around 40 commercial MOCVD reactors) installed throughout the country. Until recently, the lack of financial resources and production equipment made it quite difficult for the researchers to exploit their work.
In the past, work has concentrated on the development of laser devices for telecommunication or military applications. Today, however, most new companies are jumping into the high-brightness LED market, and are especially focusing on nitride LEDs. Juergensen says that the situation is similar to the status of Taiwan six or seven years ago when it entered the AlGaInP LED market (which it now dominates), but he feels that China will catch up with the rest of the world very quickly.
China already has a fledgling compound semiconductor supply chain, with companies manufacturing metalorganic precursors, and GaAs substrates and epiwafers. In addition, it is one of the world s leading suppliers of gallium. LED manufacturingWhile Taiwan now dominates AlGaInP chip production, and is making rapid progress in the InGaN market, China has skipped the relatively mature AlGaInP field and is instead targeting GaN-based devices. Jiangxi Fangda Focus Information Material, a joint venture between China Fangda Group and Nanchang University, was formed in July 2000. Its main products are GaN-based epiwafers, and in late 2001 it ordered a series of MOCVD production systems from Thomas Swan for its facility in Nanchang. Shanghai LanBao Photoelectric Materials has ordered MOCVD machines from both Emcore and Aixtron. Established in September 2000, the company is a spin-off from the CAS Institute of Physics, and supplies blue and green GaN-based epiwafers and chips.
Shanghai Beida Blue Light is a spin-off company from Peking University supplying nitride epiwafers and UV, green and blue LED chips. The company is a customer of Aixtron and describes itself as the first specialized company for producing III-nitride semiconductors in China. Xiamen San an Electronics plans to establish a large R&D and manufacturing site for high-brightness LEDs in Xiamen. Typical of some of the Chinese companies that become involved in compound semiconductors without prior experience, San an Group is major producer of steel, pig iron and electricity. Telecom and laser suppliersA joint venture between Wuhan Research Institute (WRI) and Corning Lasertron, Wuhan Telecommunications Devices is the leading supplier of optoelectronic devices in China. Its products, which are almost all sold to Chinese telecom equipment manufacturers, include 850, 1310 and 1550 nm laser diodes; LEDs; detectors; transmitter, receiver and transceiver modules; and 980 nm pump lasers. The company estimates it has an annual capacity of 5.5 million pairs of optoelectronic devices and 1.5 million optoelectronic modules.
Hi-Tech Optoelectronics was established in 1999, and is a spin-off from CAS Institute of Semiconductors in Beijing with investment from China Energy Conservation Investment Corp. It manufactures laser diodes at a range of wavelengths from 635 to 1650 nm, as well as fiber-coupled CW modules and photodetectors, and recently introduced 20 W laser diode arrays operating at 780-830 nm. Tsinghua UniversityAn example of one of the many academic facilities looking at compound semiconductors, the State Key Laboratory on Integrated Optoelectronics in Tsinghua University (established in 1991) carries out epitaxial growth using MBE and MOVPE. The group investigates integrated optoelectronic devices and their applications in fiber-optic networks, and recently developed a 2.5 Gbit/s gain-coupled DFB laser integrated with an EA modulator.
The lab has made lots of important research achievements and grown into a major research base for optoelectronic materials, devices and their applications in optical fiber communication systems and networks in the Chinese mainland. It is not yet involved with commercial manufacturing or spin-offs related to compound semiconductors.
The lab also has a nitride program investigating blue LEDs and HEMTs. With funding from Shandong Incalcu Group, the university s "high-brightness blue LED" project developed high-brightness InGaN/GaN MQW blue LEDs with an optical power of 1.5 mW at 470 nm (Compound Semiconductor March 2002 p9). Material suppliersAs mentioned above, China has several commercial material suppliers. Jiangsu Nata Optoelectonic Material Co Ltd is a spin-off from Nanjing University, which began developing metalorganic precursors such as DEZn and TMI in 1986. The company was established at the end of 2000 and offers around 20 types of precursor, which are growth tested on the company s MOCVD system.
Also in late 2000, the CAS Institute of Semiconductors in Beijing announced plans to team up with four other investors to form Compound Crystal Technology to commercialize the institute s semi-insulating GaAs technology. The company has injected around RMB 540 million ($65 million) to establish a production line with a capacity of 100,000 wafers per year, and will also offer GaAs- and InP-based epiwafers.
A spin-off from the CAS Institute of Physics, Advanced Chinese Epitaxy is set to become the first company in China to offer GaAs-based epiwafers. The Beijing-based company, set up in partnership with Ningxia St Edenweiss, bought a V100 production MBE system from Thermo VG Semicon last year. "Our MBE work started here over 20 years ago," said Junming Zhou, head of the MBE laboratory at the Institute of Physics and president of Advanced Chinese Epitaxy. "Initially, the V100 will be used to prepare microwave device material for which there is an ever-increasing demand in our country."
