The Right Cut with New Offering Opportunities from New LED Competition How to Stay Competitive Sapphire Approach
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CS Front Cover vFinal DR 26/4/10 10:55 Page 1 Optical switching Faster and smaller QCLs The leap from toys to tools Taiwan LEDs Back lit displays and street lighting fuels growth LED yield EPI defect and MOCVD control Vacuum and Abatement Integrated solution SemiLeds Vertical architecture boosts performance Brighter and cheaper LED start up company The right cut with new offering Opportunities from new LED competition How to stay competitive sapphire approach An Angel Business Communications publication April/May 2010 Volume 16 Number 3 Temescal is now a division of Ferrotec It’s Elemental Temescal’s Elemental Knowledge™ Brings Pure Precision to Compound Semi Metallization Temescal process scientists have developed a library of Elemental Knowledge™, leading to 3D vapor cloud modeling that enables Temescal to optimize your metallization process. A Temescal system is more than a mere evaporator. The Temescal Control System o ers the process engineer the most sophisticated recipe making tools while providing push-button control for operators. For more information, visit us at www.temescal.net Comment vFINAL 27/4/10 09:51 Page 3 CONNECTING THE COMPOUND SEMICONDUCTOR COMMUNITY editorialview April/May 2010 Volume 16 Number 3 Editor-in-Chief David Ridsdale [email protected] +44 (0)1923 690210 Consultant Editor Richard Stevenson PhD [email protected] +44 (0)1291 629640 News Editor Dr. Su Westwater [email protected] Director of SOLAR & IC Publishing Jackie Cannon [email protected] +44 (0)1923 690205 Account Managers Shehzad Munshi [email protected] Quantum cascade lasers +44 (0)1923 690215 Tommy Beazley [email protected] +44 (0)1923 690222 USA Representatives shake off the R&D tag Brun Media Tom Brun E: [email protected] Tel: 724 539-2404 Janice Jenkins E: [email protected] The quantum cascade laser represents the pinnacle of bandgap engineering. Tel: 724-929-3550 By controlling of the thickness and composition of hundreds of very thin layers, Director of Logistics Sharon Cowley [email protected] engineers are able to tweak the wavefunctions of the electrons and holes that +44 (0)1923 690200 skitter through this structure, and ultimately fine-tune its emission. Design & Production Manager Mitchell Gaynor [email protected] +44 (0)1923 690214 Thanks to this control, quantum cascade lasers can span a range of wavelengths that are outside the grasp of their more conventional, III-V Circulation Director Jan Smoothy [email protected] cousins. This includes vast swathes of the infrared spectrum with energies that +44 (0)1923 690200 can be used to probe the absorption lines of various gases, and far longer Subscriptions Manager wavelengths close to a terahertz. Debbie Higham [email protected] +44 (0)1923 690220 If powerful enough, easy-to-use and affordable quantum cascade lasers were Chief Operating Officer Stephen Whitehurst [email protected] available, then these sources would have a great chance of finding application +44 (0)2476 718970 in detecting gases, distracting heat-seeking missiles and aiding the Directors construction of terahertz imaging systems. But for many years this class of Bill Dunlop Uprichard – CEO Stephen Whitehurst – COO laser, which was invented in the mid-1990s, has produced relatively feeble Jan Smoothy – CFO powers and been caged in a cryostat. But now the tide is turning … Haroon Malik, Jackie Cannon, Scott Adams, Sharon Cowley, Sukhi Bhadal Published by In the Fall of 2008, this magazine covered the effort of Manijeh Razeghi’s Angel Business Communications Ltd, group at Northwestern University, which had realized continuous-wave outputs Hannay House, 39 Clarendon Road, Watford, Herts WD17 1JA, UK of more than one tenth of a Watt at room temperature. T: +44 (0)1923 690200 F: +44 (0)1923 690201 Back then these researchers were starting to look at new devices geometries, Angel Business Communications Ltd Unit 6, Bow Court, Fletchworth Gate, such as those that incorporating a buried ridge. Initial efforts showed that Burnsall Road, Coventry CV5 6SP refinements such as that could lead to outputs of several Watts. However, at T: +44 (0)2476 718 970 F: +44 (0)2476 718 971 that time of writing the output was multi-mode - no good for gas sensing. Compound Semiconductor is published eight times a year on a controlled circulation basis. More recently, the US firm Pranalytica has produced quantum cascade lasers Non-qualifying individuals can subscribe at: £105.00/€158 pa (UK & Europe), £138.00 pa (air mail), $198 pa (USA). that deliver several Watts at room temperature via single-mode emission. This Cover price £4.50. All information herein is believed to be correct at time of advance has come through a radical change in the structure of the laser: a going to press. The publisher does not accept responsibility for any errors and omissions. The views expressed in this change in the way that phonons are used to help to drive electrons to their publication are not necessarily those of the publisher. Every effort has been made to obtain copyright permission for the material contained in this publication. lowest energy level within the laser. Angel Business Communications Ltd will be happy to acknowledge any copyright oversights in a subsequent issue of the publication. Like Razeghi and her co-workers, the team at Pranalytica have detailed their Angel Business Communications Ltd © Copyright 2010. All rights reserved. Contents may not be efforts in an exclusive feature for Compound Semiconductor. If you want to reproduced in whole or part without the written consent of the publishers. The paper used within this magazine is read about the details of this new type quantum cascade structure, and the produced by chain of custody certified manufacturers, guaranteeing sustainable sourcing. performance that it has realized, you can find their feature on p. 22. US mailing information: Compound Semiconductor (ISSN 1096-598X) is published 8 times a year Jan/Feb, March, April/May, June, July,August/September, October, Richard Stevenson PhD November/December for a subscription of $198 by Angel Business Communications Ltd, Hannay House, Consultant Editor 39 Clarendon Road, Watford, Herts WD17 1JA, UK. Periodicals postage paid at Rahway, NJ. POSTMASTER: send address changes to: Compound Semiconductor, c/o Mercury International Ltd, 365 Blair Road, Avenel, NJ 07001 Printed by: Pensord Press. ISSN 1096-598X April/May 2010 www.compoundsemiconductor.net 3 Project5 26/4/10 10:43 Page 4 Joining CS Mantech for the first time Manu tor fac uc tu d ri n n o g ic T e m c e h S C d o n n u f e o r p e n m c o e C Ɣ 1 Ɣ 986 - 2010 The Premier Semiconductor Conference focused on the practical “nuts and bolts” of Compound Semiconductor Device Production. www.csmantech.org Full details on workshops, technical sessions and exhibits th April 20 Early Registration Deadline Contents CS Final 26/4/10 13:03 Page 5 CONNECTING THE COMPOUND SEMICONDUCTOR COMMUNITY contents Volume 16 Number 3 industry & technology Optical switches need to consume less power, cut their footprint and speed up if they are to stand a 13 good chance of serving future needs. One way to realize all this and more is to turn to switches that employ microdisk or photonic crystal lasers. Sapphire can form the bedrock forthe growth of relatively thick, single crystal epitaxial films of 18 rhombohedral SiGe. This material has much higher carrier mobility than single crystal silicon, and could spur the development of ultra-fast chipsets. A revolutionary active region is the driver behind the record single-facet output powers emanating from a 22 new quantum cascade lasers (QCLs). Tawian’s LED industry has weathered the global economic storm, and it is now recovering fast thanks 26 to increased deployment of this chip in street lighting and display backlights. LED device yield is impacted by epi defect correlation and MOCVD process control. Challenges 13 31 that are assisted with in line inspection techniques. HBLED manufacturers are faced with many challenges including vacuum and abatement. There 36 are benefits of combination technologies. Combining a metallic foundation with a vertical current path creates an LED that prevents current 39 crowding, realizes excellent thermal management, and delivers high efficacies and long lifetimes. A UK start-up is claiming to have developed a novel device treatment technology that paves the way for 18 26 42 the manufacture of brighter, lower-cost LEDs news Flexible OLEDs from 07 Fraunhofer CIGS efficiency records. 11 JV for CIGS project LETI shows off CMOS laser. 12 GaN growth predicted April/May 2010 www.compoundsemiconductor.net 5 Project11 14/1/10 12:58 Page 44 Your premier choice for III-V and Ge substrates and related strategic raw materials. VGF STRENGTH. PERFORMANCE. INNOVATION. AXT, Inc. is the only supplier in the world to offer materials for the inverted metamorphic, CIGS, and CPV Ge markets We offer Ga metal for CIGS and Ge substrates for CPV applications We also have GaAs and InP substrates as well as metamorphic and starting materials USA Headquarters 4281 Technology Drive T: 510-438-4700 E: [email protected] Fremont, CA, USA 94538 F: 510-353-0668 W: axt.com News vFinalDR 26/4/10 15:48 Page 7 led news with a barrier layer system, patented by the Dr. Nicolas Schiller, head of the business Fraunhofer FEP, without compromising its unit Coating of Flexible Products at the FEP Flexible luminosity. adds, “The coating processes opens up potential to reduce costs.” OLEDs from Dr. Christian May, head of the business unit, Organic Materials and Systems at the The technology developed marks a Fraunhofer IPMS stated, “Developing the milestone towards industrial manufacturing Fraunhofer flexible OLED, experience from both of flexible OLEDs.