Compound semiconductors come to Silicon Valley
CS-MAX is the industry s largest event, having drawn more than 900 attendees to the inaugural event in Boston last year. Its mission statement is to encourage productive interchanges among engineers and managers engaged in high-volume manufacturing of compound semiconductor devices, and to provide a showcase for new ideas from semiconductor equipment and materials companies that can increase the productivity of compound semiconductor fabs. CS-MAX is intended to fill the role for compound semiconductors that the Semicon shows play for silicon - namely, an annual forum for new ideas that will bring economic benefit to the industry. Technical program highlights Manufacturing compound semiconductors requires specialized knowledge at almost every process step. CS-MAX will explore production-related issues that are unique to the industry. It is the first conference that brings together all of the compound semiconductor device types and materials systems that are currently in production. Papers will be presented in several areas, including:
• GaAs and InP ICs;
• LEDs and other III-V optoelectronics;
• wide-bandgap semiconductors;
• silicon heterostructures;
• fab management;
• front- and back-end processing;
• epitaxy;
• characterization;
• environmental health and safety.
More than 100 papers will be presented in 28 sessions over two and a half days. The speakers, who are drawn from 80 different organizations, will focus on manufacturing-related issues, with special emphasis on productivity and yield enhancements, and cost-saving techniques. LEDs Three full sessions will be dedicated to topics that are unique to LED manufacturing. Back-end issues will be addressed by AXT Optoelectronics in a paper entitled "Challenges in low cost flip chip LEDs for solid state lighting". GELcore will make a presentation discussing their die attach process for power LEDs. And there will be two presentations, from Emcore and JPSA, on the alternatives to scribe-and-break for separating InGaN-on-sapphire die, demonstrating higher die yield and throughput, but with lower operating costs.
The testing of LED die remains a challenging aspect of LED production. Eric Bretschneider of Uniroyal Optoelectronics will present a paper on the spectroradiometric measurements of LED die, comparing the overall performance of photodiode and CCD array approaches. Op-Test will discuss how angular variation in fiber-optic probes impacts the measurement accuracy of LED die in production environments. The results of measurements on GaN and AlInGaP devices, and the implications for the design of measurement systems, will be discussed. There will also be a presentation from Kelvin Shih of Lawrence Technological University on a new LED junction-temperature measurement technique. This technique uses the LED junction itself as a sensor, and shows how the relative brightness of the LED at different currents and ambient temperatures can be calculated and plotted. In addition, several LED-related papers will also feature in the epitaxy and characterization sessions. Microelectronics Presentations on the production of III-V ICs will include the following:
• Anadigics - automated inspection for monitoring InGaP HBT backside via processes;
• Agere Systems - high-speed and large output voltage swing InP-based DHBT driver ICs;
• Anadigics - the effects of gold concentration temperature and agitation on the cross-wafer resistance uniformity of electroplated backside vias in thinned GaAs wafers;
• Filtronic Compound Semiconductors - manufacturable microwave power FET technology;
• Skyworks Solutions - throughput optimization of HBT ion implant isolation using doubly charged helium;
• Sumitomo Electric Industries - InGaAs/InP single-HBT fabrication process with high uniformity and high yield for multi-10 Gbit/s optical communication applications.
There will also be a number of presentations on InP processing, as well as the continuing evolution of the metamorphic approach as an alternative to the use of InP substrates. Raytheon RF Components will report on the qualification of a production MHEMT process for low-noise and high-frequency applications. IQE will present a comparison of metamorphic buffer layers for M-HBT applications. And United Monolithic Semiconductors will present a paper that is entitled "Selective double recess technology on metamorphic HEMTs: improving the on-state breakdown behavior". Optoelectronic components Presentations in the optoelectronics area will include those by:
• LuxNet Corporation - high-performance, high-yield and throughput VCSEL process technology;
• JDS Uniphase - cost-effective short design cycle approach to monolithically integrated photodiode lenses;
• Alfalight - the impact of GaAs substrate quality on laser diode lifetime.
In addition, there will be a presentation from the University of Ulm on the development of a new chemically assisted ion-beam etching process for the fabrication of high-quality dry-etched laser mirrors in the GaAs/AlGaAs material system. Results will be presented showing that the process produces lasers with a performance comparable to that of lasers with cleaved facets fabricated from the same epitaxial material.
Unaxis will present the results of a systematic study of GaAs/AlGaAs non-selective etch using BCl3/Cl2 chemistry, for the purpose of establishing an optimized non-selective dry etch for VCSELs.
RSoft Design Group will present an overview of simulation techniques for photonic semiconductors. There will also be presentations from Palomar Technologies on optimal eutectic bonding techniques for enhanced laser reliability, and a paper from Taiwan s PROWTech on estimating optical thickness errors in VCSEL structures from optical reflection spectra.
