无视出售芯片业务传言，IBM升级RF芯片制程技术

在市场再度传言IBM将10亿美元出售其芯片部门给GlobalFoundries的同时，该公司正在加速量产新一代绝缘上覆硅(silicon-on-insulator，SOI)与硅锗(silicon germanium，SiGe)制程，以扩大在射频(RF)芯片代工市场的占有率；该类芯片传统上大多是采用更稀有的砷化镓(gallium arsenide，GaAs)制程。 IBM的两种新制程都在该公司只提供晶圆代工的 美国佛州Burlington晶圆厂运作，该座8吋晶圆厂以往曾生产IBM高阶服务器处理器以及相关芯片，不过那些芯片的生产已经移往位于纽约州East Fishkill的 12吋晶圆厂。Burlington晶圆厂为广泛的客户提供 CMOS、SOI与SiGe等多种制程，但现在打算将制程种类减少，集中资源在生产RF芯片的SOI制程等技术上；该种制程目前也是IBM晶圆代工业务中 成长最快的。 不过IBM并未透露该晶圆厂的产能规模以及营收，仅表示该公司自四年前开始生产SOI制程RF芯片迄今，该类芯片已经累计出货达70亿颗──光是去年出货量就达30亿颗；那些芯片主要是供应手机与无线通信基站应用。 接 受EETimes美国版编辑访问的IBM代表都不愿针对芯片部门出售传言发表意见，这些专家都是该公司模拟制造部门的资深人才，只谈技术。IBM专门生产 RF芯片的最新SOI制程代号为 7SW，以制造RF交换器为主，还有一些功率放大器；无论是蜂窝通信或是Wi-Fi设备，为因应对多重频段的支持，对这类组件需求越来越高。 在 IBM任职25年、五年前开始负责RF SOI业务的RF前端技术开发经理Mark Jaffe表示：“较新一代的智能型手机内含8~12颗RF交换器，RF前端的构造非常复杂，主要原因是我们现在有采用载波聚合(carrier aggregation)的 Advanced LTE 技术，支持很多载波路径以及频段。” IBM为RF芯片量身打造的SOI制程技术 7SW 是一种1.3微米/1.8微米混合制程，号称能提升RF交换器性能30%，同时将芯片面积尺寸缩小30%。“我们重新打造了交换器晶体管，将焦点集中在决 定漏电的导通电阻(resistance-on)与关断电容(capacitance-off)；”Jaffe表示：“其次我们提升了交换器晶体管的击穿 电压(breakdown voltage)，通常你得堆栈晶体管以承受高电压需求，但现在你可以建立一个短一点的堆栈以缩减芯片面积。” 此 外IBM也改善了晶体管的线性度，将三次谐波失真(the third harmonic distortion)降低了8dB。事实上7SW制程幕后的核心团队大概只有10个人、工作了18个月；该团队约是从 2006年开始研发RF芯片专用的SOI制程。而为了建立第二供应来源，IBM已将位于法国的一座旧晶圆厂独立为新公司Altis。 在IBM任职14年、负责向无线领域客户营销晶圆代工业务的Sara Mellinger表示，过去包括Skyworks等市场领导级RF芯片供货商，是采用砷化镓制程制造RF前端芯片，但现在该类芯片已经大幅转向采用SiGe或SOI制程。 目前在SOI制程RF芯片代工领域，Tower Jazz是IBM最大的竞争对手，此外CMOS制程晶圆代工大厂GlobalFoundries 与台积电(TSMC)也准备切入SOI制程抢相关商机。目前IBM的7SW制程已经在质量验证阶段，并为关键客户提供芯片样品，预计 2015年正式量产。 本文授权编译自EE Times，版权所有，谢绝转载 本文下一页：IBM的SiGe制程迈向90纳米节点

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{pagination} IBM的SiGe制程迈向90纳米节点 至于IBM代号 9HP的SiGe BiCMOS制程技术则是90纳米节点，能支持360 GHz最高振荡频率(Fmax)、300+ GHz截止频率(Ft)，因应60~80GHz运作频率的各种芯片所需阈值。而采用90纳米制程节点，则能实现接近SOI、媲美砷化镓制程之更紧密、低功 耗的设计，可生产包括60GHz的Wi-Fi芯片、蜂巢式骨干网络芯片组、高阶测试设备用芯片、光学收发器，以及规模虽小、成长快速的车用雷达芯片，还有 航天军事应用雷达芯片。 “这将会是被大幅应用的技术；”自1980年代就投入开发SiGe技术(当时应用于生产IBM服务器处理器芯片)的IBM院士David Harame表示，目前大多数SiGe技术都是采用0.18或0.13微米制程节点，IBM是最近才领先宣布进入90纳米节点。 9HP 制程是IBM的一个十人小组花了四年时间开发，目前已提供数家关键客户试用，预计8月能通过质量验证。如同SOI制程，IBM也将提供9HP制程的开发套件，此外该公司也提供客制化的介电质附加模块(dielectric add-on modules)以及毫米波工具组。Harame强调：“这并非是产业界常见的服务，你在其他先进CMOS晶圆厂或12吋晶圆厂就找不到这些东西。” 该团队也表示，SiGe制程市场正呈现成长态势，因为目前蜂窝骨干网络正迈向采用60GHz连结技术，此外车用雷达也预计将被产业界大幅采用。 本文授权编译自EE Times，版权所有，谢绝转载 编译：Judith Cheng 参考英文原文：IBM Upgrades RF Foundry Efforts，by Rick Merritt

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{pagination} IBM Upgrades RF Foundry Efforts Rick Merritt 90 nm SiGe process due in August SAN JOSE, Calif. — IBM is ramping up new silicon-on-insulator and silicon germanium processes, aiming to increase its share of the foundry business for RF chips. Many of the components are traditionally made in more exotic gallium arsenide processes. The efforts underscore IBM's deep expertise in process technology. But they come at a time when the unit is operating under the cloud of reports the corporation is considering a sale of its chip division. Both the new processes run in IBM's Burlington, Vt., fab that solely does foundry work. The 200 mm wafer fab once made processors and related chips for IBM's high-end servers, but that work has moved on to IBM's 300 mm facility in East Fishkill, N.Y. The Burlington fab supports many flavors of CMOS, silicon-on-insulator (SOI), and silicon germanium (SiGe) processes for a wide variety of customers. It is trying to focus on fewer recipes, like its SOI process for making RF chips, a process that now represents the majority and fastest-growing part of its business. IBM provides no details of the size of the fab or its revenues. However it does say it has sold a total of nearly 7 billion SOI RF chips for handsets and base stations since it started making the parts about four years ago -- 3 billion of them in the last year. In interviews with four technical and marketing experts from Burlington, none would comment on the impact of the rumored sale of the division. All are veterans of IBM, parts of small, elite teams doing deep technical work in the area of analog components for the rapidly growing mobile sector. Next page: Inside IBM's new SOI recipe Inside IBM's new SOI recipe IBM's so-called 7SW is its latest SOI recipe for making RF chips, mainly RF switches and some power amplifiers. Cellular and WiFi systems need a growing number of the components to handle the increasing number of frequency bands the standards support. "Newer smartphones have eight to 12 RF switches per phone. The architecture of the RF front end is getting very complicated because, as we get to things like Advanced LTE with carrier aggregation, there are a lot of carrier paths and frequencies," says Mark Jaffe, IBM's manager of RF front-end development. 7SW is a 130/180 nm hybrid tuned to deliver about 30% more performance and 30% smaller die area for RF switches. "We re-engineered the switch transistor completely, focusing on metrics such as resistance-on and capacitance-off, which determine leakage," says Jaffe, a 25-year IBM semiconductor veteran who has managed the RF SOI program for five years. "Secondly, we increased the breakdown voltage for the switch transistor. Typically you need to stack transistors to withstand high voltage requirements, but now you can build a shorter stack, and that provides a reduction in chip area." IBM also improved the linearity of the transistors, achieving about an 8 dB decrease in the third harmonic distortion. The core team behind 7SW comprised only about 10 people working 18 months. The group has been working on SOI for RF chips since about 2006. For a second source, they use an old IBM fab in France spun off as a separate company called Altis. In the past, companies such as Skyworks dominated the market for making RF front-end chips using gallium arsenide (GaAs). But today "the industry is going through a big shift," to SiGe and SOI processes, says Sara Mellinger, a 14-year IBM vet who markets the foundry service to wireless customers. Tower Jazz is one of IBM's biggest competitors here, using SOI for RF chips. CMOS giants such as GlobalFoundries and TSMC are said to be getting into SOI to capture some of the business as well. 7SW is still in qualification, with sample parts shipping to key customers. Volume production is expected next year. Next page: Silicon germanium moves to 90 nm Silicon germanium moves to 90 nm IBM's 9HP is a 90 nm SiGe BiCMOS process that can support a 360 GHz Fmax and 300+ GHz Ft. That provides the margin needed to handle a wide variety of chips using 60 to 80 GHz services. The 90 nm features sizes support denser designs with power consumption closer to SOI than competing GaAs processes. Applications include 60 GHz WiFi and cellular backhaul chipsets, high-end test gear, optical transceivers, automotive radar -- a small but rapidly growing segment -- and aerospace and defense radar. "This will be a heavily used technology," says David Harame, an IBM fellow who has been working on SiGe since the 1980s when it was used for IBM's server CPUs. "Most SiGe results published to date are for 180 to 130 nm processes" not 90 nm, which he claims currently only IBM supports. 9HP has been in development for four years by a 10-person team at IBM. A handful of key clients have had early access to the technology, which IBM expects to have qualified in August. As with its SOI process, IBM will offer enablement tools such as process development kits for 9HP. The SiGe group also offers custom dielectric add-on modules and millimeter wave tool kits. "That's not a common offering -- you don't find these things in advanced CMOS or 300 mm wafer fabs," says Harame. The group claims SiGE is in a growth mode. Sixty-gigahertz backhaul links are on the rise in cellular networks, and automotive radar is seen as one of the next big things for cars.