These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. GaN RF Technology Qorvo Special Edition by Andrew Moore and Jose Jimenez These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. GaN RF Technology For Dummies,® Qorvo Special Edition Published by John Wiley & Sons, Inc. 111 River St. Hoboken, NJ 07030-5774 www.wiley.com Copyright © 2015 by John Wiley & Sons, Inc., Hoboken, New Jersey No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the Publisher. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Trademarks: Wiley, For Dummies, the Dummies Man logo, The Dummies Way, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission. John Wiley & Sons, Inc., is not associated with any product or vendor mentioned in this book. Qorvo and the Qorvo logo, and related trade dress, are trademarks or registered trademarks of Qorvo, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission. All other trademarks are the property of their respective owners. LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: QORVO, INC., THE PUBLISHER, AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICU- LAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT NEITHER QORVO NOR THE PUBLISHER IS ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFES- SIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPE- TENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER QORVO NOR THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PRO- VIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ. ISBN 978-1-119-13553-1 (pbk); ISBN 978-1-119-13554-8 (ebk) Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 For general information on our other products and services, or how to create a custom For Dummies book for your business or organization, please contact our Business Development Department in the U.S. at 877-409-4177, contact [email protected], or visit www.wiley.com/go/custompub. For information about licensing the For Dummies brand for products or services, contact BrandedRights&[email protected]. Publisher’s Acknowledgments Some of the people who helped bring this book to market include the following: Development Editor: Elizabeth Kuball Custom Publishing Project Specialist: Project Editor: Elizabeth Kuball Michael Sullivan Acquisitions Editor: Katie Mohr Project Coordinator: Melissa Cossell Editorial Manager: Rev Mengle Special Help: Jennifer Bingham, Douglas Reep, Candice Christensen Business Development Representative: Karen Hattan These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. Introduction allium nitride (GaN) transistors were first demonstrated Gin the 1990s and are now widely available for commer- cial and defense applications. GaN’s popularity is rooted in its high-current, high-voltage capabilities, which makes it highly valuable for microwave applications and power switching. Qorvo is a leader in the development of GaN transistors for radio frequency (RF) applications and their underlying process technology. Its latest devices support low-noise applications, as well as those at higher frequencies and power levels beyond 200 watts. Qorvo’s discrete GaN transistors, monolithic microwave inte- grated circuits (MMICs), and packaged solutions support a wide range of applications, including next-generation radar, electronic warfare (EW), base transceiver stations (BTS), instrumentation, and cable TV (CATV) infrastructures. GaN technology outperforms other RF technologies because it can simultaneously offer the highest power, gain, and efficiency combination at a given frequency, and because it operates at a higher operating voltage for a reduced system current. In this book, we fill you in on GaN semiconductors, the GaN field-effect transistor (GaN FET), and some practical considerations for deployment of GaN semiconductors. Foolish Assumptions This book is written for both technical and non-technical readers. If you’re an executive, salesperson, or design engineer, this book is for you. Unless of course, you’re looking for a book on indoor gardening! These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. 2 GaN RF Technology For Dummies, Qorvo Special Edition Icons Used in This Book Throughout this book, we occasionally use icons to call atten- tion to important information. You won’t see the typical cute grinning faces or other flashing emoticons, but you’ll definitely want to stop and pay attention! Here’s what you can expect. This icon points out information that you’ll want to put in storage, your memory, or whatever you use to keep track of important information like birthdays and phone numbers for later use. Anything marked with this icon is targeted toward your inner geek. Who knows? You may come away with some useful knowledge to increase your nerd status. No, this isn’t the thing you do to take care of your waitresses and bartenders. You should stop and take notice because there are nuggets of knowledge that could save you some aggravation later on. Beyond the Book Although this book is full of good information, we could only cover so much in 24 pages! So, if you find yourself wanting more after reading this book, just go to www.qorvo.com/gan, where you can get to more information about Qorvo’s GaN technologies and products. Where to Go from Here Whether you’re new to electrical design and GaN technology or a seasoned design engineer looking to use GaN technology in your designs, you’ll find this book useful. Each chapter in this book stands on its own, so you can skip around if you like. If you’re familiar with the topics in a chapter, you can skip it. We provide cross-references to information in other chapters of the book, so you can always find what you’re looking for. These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. Chapter 1 All about GaN In This Chapter ▶ Getting acquainted with GaN ▶ Seeing what makes GaN unique ▶ Understanding piezoelectricity ▶ Recognizing the benefit of GaN’s high power density allium nitride (GaN) is a binary III/V direct bandgap Gsemiconductor crystal that is most commonly used in general illumination (LED lights) and Blu-ray players. GaN is also used in radio frequency (RF ) amplifiers and in power electronics. GaN is a very hard material; its atoms are bonded by a very ionic gallium-nitrogen chemical bond that produces a bandgap of 3.4 electron volts (eV). In semiconductor physics, the bandgap refers to the energy required to free the electron from its orbit around the nucleus and allow it to move freely through the solid. The bandgap is an important material parameter that ultimately determines the mass of the freely moving electrons and the electric field that the solid is able to withstand. GaN has a bandgap of 3.4 eV, which is a big number. That’s why GaN is called a wide bandgap semiconductor. In comparison, gallium arsenide (GaAs) has a bandgap of 1.4 eV and silicon (Si) has a bandgap of only 1.1 eV. In this chapter, we fill you in on the basics of GaN and explain the unique characteristics that make GaN ideal for RF power amplifiers and other applications that operate at higher voltages and frequencies. These materials are © 2015 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. 4 GaN RF Technology For Dummies, Qorvo Special Edition The Basics of GaN Gallium (Ga) is a chemical element with atomic number 31. Gallium doesn’t exist freely in nature. Instead, it’s a byproduct in the production of zinc and aluminum. The GaN compound is formed by gallium and nitrogen atoms arranged, most commonly, in a wurtzite crystal structure. The wurtzite crystal structure (shown in Figure 1-1) is hexagonal and is characterized by two lattice constants (marked a and c in the figure). Figure 1-1: The GaN crystal structure. In the semiconductor world, GaN is usually grown at a high temperature (approximately 1,100°C) by metal organic chemi- cal vapor deposition (MOCVD) or molecular beam epitaxy (MBE) techniques on a foreign substrate (silicon carbide [SiC] for RF applications, or Si for power electronics applications). The GaN-on-SiC approach combines the high power density capabilities of GaN with the superior thermal conductivity and low RF losses of SiC.