The fabrication of silicon microsystems

The subject of silicon microsystems is reviewed from a device manufacturing viewpoint. Techniques taken straight from the integrated-circuit industry were the starting point for this work. Because of the 3D nature of microsystems, different processes have been developed to fully exploit the potential of this field, particularly in substrate etching and lithography. The paper explores the developments that have been made in this area, and how it is likely that microelectronics and microsystems, from a manufacturing point of view, will diverge even further in the future     

Descrambling and data reading techniques for flash-EEPROM memories. Application to smart cards

The retention, reliability and security of data stored in Non Volatile Memories (NVM) are problems of utmost importance for the microelectronics industry. All these issues could be addressed by physically reading the memory content. A method to deduce memory organization and then to read data in Flash-EEPROM devices is presented. It is based on failure analysis techniques such as Focused Ion Beam (FIB), Scanning Kelvin Probe Microscopy (SKPM) and Scanning Capacitance Microscopy (SCM). An application is demonstrated on the Flash memory of a Programmable Integrated Circuit (PIC) from Microchip dedicated to smart card applications.     

Functional and technological integration of measurement microsystems

The field of measurement microsystems has progressed with advances in the fields of microelectronics, micromechanics, microoptics, and digital signal processing (DSP). In this article, the author summarizes a unified conceptual basis for measurement microsystems, discusses some specifics of integration, and describes an innovative approach to the development of a micro-opto-electrical system (MOEMS), a microspectrometer on a chip. This example highlights the complexity of the problem of transition from a successful laboratory concept proof to a product that can be manufactured.     

Automatized failure analysis of tungsten coated TSVs via scanning acoustic microscopy

In 3D integrated microelectronics, the failure analysis of through silicon vias (TSVs) represents a highly demanding task. In this study, defects in tungsten coated TSVs were analysed using scanning acoustic microscopy (SAM). Here, the focus lay on the realization of an automatized failure detection method towards rapid learning. We showed that by using a transducer of 100 MHz center frequency, established with an acoustical objective (AO), it is possible to detect defects within the TSVs. In order to interpret our analysis, we performed acoustic wave propagation simulations based on the elastodynamic finite integration technique (EFIT). In addition, high resolution X-ray computed tomography (XCT) was performed which corroborated the SAM analysis. In order to go towards automatized defect detection, firstly the commercially available software “WinSAM8” was enhanced to perform scans at defined working distances automatically. Secondly, a pattern recognition algorithm was successfully applied using “Python” to the SAM scans in order to distinguish damaged TSVs from defect-free TSVs. Besides the potential for automatized failure detection in TSVs, the SAM approach exhibits the advantages of fast and non-destructive failure detection, without the need for special preparation of the sample.     

Thermally driven reliability issues in microelectronic systems: status-quo and challenges

To meet the needs of future microelectronics and microsystems, we need a paradigm shift in the approach to system reliability. It is emphasized that the scientific success of many nano/micro-related projects will never lead to a business success without breakthroughs in the way industry is handling quality and reliability through the whole value chain. The paper discusses several reasons for these facts and offers a perspective for future improvements. The paper is essentially a mix between an overview paper and some personal observations in an editorial style.     

流星余迹通信中的智能天线技术研究

针对流星余迹通信原理及信道特点,建立了适用于流星余迹通信系统的智能天线系统模型。在热区跟踪上,使用波束切换技术;而对于可用流星余迹使用自适应数字波束形成技术。针对流星余迹持续时间短的特点,为了获得最佳接收性能,缩短等待时间,对自适应算法提出了收敛速度快、计算复杂度小的要求,这里采用变步长LMS算法与判决导向算法相结合的半盲自适应算法,并对半算法进行了仿真分析。     

Short-circuit robustness test and in depth microstructural analysis study of SiC MOSFET

The purpose of this paper is to describe an approach of short circuit ageing allowing further microstructural analysis that is needed for the identification of failure mechanisms. So far, few relevant studies on SiC MOSFET SC robustness tests have been described putting in light the need for complementary information on physical mechanisms involved in failure modes. A large part of this work is dedicated to a new approach of SC robustness tests. Following ageing, using PEM (Photo Emission Microscopy) technique, SEM (Scanning Electronic Microscopy), and FIB (Focus Ion Beam) cutting, the study successfully correlates electrical measurements and structural analyses for an elementary cell of SiC MOSFET power transistor.     

硅基异质集成技术发展趋势与进展

目前主流的异质集成技术有单片异质外延生长、外延层转移和小芯片微米级组装。硅基异质集成主要是指以硅材料为衬底集成异质材料(器件)所形成的集成电路技术。它首先在军用微电子研究中得到重视,并逐渐在民用领域扩展。硅基异质集成技术正处于芯片级集成向晶体管级集成的发展初期,已有关于晶体管级和亚晶体管级集成的报道。本文重点研究了单片三维集成电路(3D SoC)、太赫兹SiGe HBT器件、超高速光互连封装级系统(SiP)、单片集成电磁微系统等硅基异质集成技术前沿,展现了硅基异质集成技术的发展趋势,及其在军用和民用通信、智能传感技术发展中所具有的重要意义。     

Electrochemical Micromachining as an Enabling Technology for Advanced Silicon Microstructuring

Based on previous theoretical and experimental results on the electrochemical etching of silicon in HF‐based aqueous electrolytes, it is shown for the first time that silicon microstructures of various shapes and silicon microsystems of high complexity can be effectively fabricated in any research lab with sub‐micrometer accuracy and high aspect ratio values (about 100). This is well beyond any up‐to‐date wet or dry microstructuring approach and is achieved using a wet etching, low‐cost technology: silicon electrochemical micromachining (ECM). Dynamic control of the etching anisotropy (from 1 to 0) as the electrochemical etching progresses allows the silicon dissolution to be switched in real‐time from the anisotropic to the isotropic regime and enables advanced silicon microstructuring to be achieved through the use of high‐aspect‐ratio functional and sacrificial structures, the former being functional to the microsystem operation and the latter being sacrificed for accurate microsystem fabrication. World‐wide dissemination of the ECM technology for silicon microstructuring is envisaged in the near future, due to its low cost and high flexibility, with high‐potential impact on, though not limited to, the broad field of microelectronics and microfabrication.     

STEM role in failure analysis

The STEM is a technique used in failure analysis that solves the gap between conventional Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) and enables the acquisition of high resolution images of a sample mounted on a TEM grid. This paper explains the theory of STEM imaging and presents its application through some failure analysis works preformed with a FEI Strata Dual Beam 235 mounted with a STEM detector and an EDAX Energy dispersive X-ray detector.This technique is essentially used for failure root cause research and is particularly interesting when combined with elemental analysis, as it gives high resolution results when performed on thin samples.     

新一代微分析及微加工手段——聚焦离子束系统

聚焦离子束 (FIB)技术是 90年代发展起来的具有微细加工和微分析组合功能的新技术。随着集成电路线宽的不断减小 ,集成度不断提高 ,该技术已在微电子工业中被广泛应用 ,其优势也日益显现。文中主要对FIB系统的构成作较为详尽的介绍 ,同时也涉及该技术的应用和发展。     

发展中的GaN微电子(一)

GaN微电子是继GaAs微电子之后在21世纪新发展起来微电子领域的国际战略制高点.从功率密度、高频性能、增强型器件与数字电路等方面阐述了GaN微电子最新的关键技术突破,并介绍了GaN微电子从UHF频段到3 mm波段在通讯、雷达和电子对抗等领域的应用研究进展.从GaN HEMT器件的电流崩塌、栅漏电流、逆压电效应、热电子...     

1-V microsystems-scaling on schedule for personal communications

The authors predict that scaled-down, ultra-low-power ICs and shrinking form-factors will hasten the arrival of on-demand services. Thus in total, advances in the various device and system technologies for conserving energy will deliver enormous system benefits. At the end of this decade and early into the next century, most portable microsystems will operate at around 1 V. The energy will be supplied by a single battery cell or solar cells. Progress in microelectronics and I/O devices will encourage shrinking form factors. At the lower form factors, personal systems will become unobtrusive and truly personal. Highly energy-efficient, ultra-low power 1-V microsystems will make possible the low-cost, battery-operated, portable systems needed to propel personal communication, entertainment, and information services. For these services to gain market acceptance, however, their benefits must be commensurate with cost. In their discussion the authors place emphasis on the developments in integrated circuit technologies     

The use of the focused ion beam in failure analysis

Since the introduction of the Focused Ion Beam (FIB), many applications have been developed. This article deals with a stand alone FIB in a failure analysis laboratory where it is used for material characterisation and sample preparation. In this paper examples will be given of FIB applications as used for failure analysis and process monitoring of semiconductor devices.     

Application of layout overlay for failure analysis

New layout overlay techniques have been developed based on standard image correlation techniques to support failure analysis in modern microelectronic devices, which are critical to analyze because they are realized in new technologies using sub-μm design rules, chemical mechanical polishing techniques CMP and auto-routing design techniques. As the new techniques are realized as an extension of a standard CAD-navigation software using standard image format “TIFF”, which is available at all modern FA-equipment, these techniques can be used for all modern failure analysis methods. Examples of application are given for circuit modification using Focused Ion Beam (FIB), for supporting preparation from the backside and for fault localization using emission microscopy.     

Microactuators and micromachines

Research and development in microelectromechanical systems (MEMS) have made remarkable progress since 1988, when an electrostatic micromotor the size of a human hair was first operated successfully. Since then, many types of microactuators utilizing various driving forces and mechanisms have been developed. Distinctive features of MEMS (miniaturization, multiplicity of components, and the integration of microelectronics) have led to promising application areas such as fluidic microsystems. In the future, MEMS promises to make contributions to the society of the twenty-first century in three broad areas: (1) offering easier access to information, (2) making human lifestyles more compatible with the environment, and (3) improving people's social welfare. This paper will discuss some of the technological issues pertaining to microactuators, micromachines, and the future development of MEMS     

The Integration of On-Line Monitoring and Reconfiguration Functions into a Safety Critical Automotive Electronic Control Unit

This paper presents an innovative application of IEEE1149.4 and the Integrated Diagnostic Reconfiguration (IDR) method to an Automotive Electronic Control Unit implemented as a fully-integrated mixed-signal system. The IEEE1149.4 test structure has been embedded and used on-line for interconnect monitoring and signal analysis. This provides higher resolution failure diagnostics enabling localised fault compensation. A novel On-Line Monitoring architecture is presented, that supports real-time testing of the critical circuit nodes. The paper concludes that fault tolerance can be integrated into mixed-signal electronic systems to handle key failure modes.Carl Jeffrey is currently a research associate at Lancaster University. He received an M.Eng. Computer Systems Engineering in 1997 and a Ph.D. in March 2005 in the area of Built-in Test of Integrated Microsystems. Dr. Jeffrey has published 8 key conference and journal papers and is currently contributing to the European Network of Excellence in Design for Micro & Nano manufacture.Rueben Cutajar graduated in Mechanical Engineering from the University of Malta in 1997. Immediately started working for STMicroelectronics (Malta) Ltd, where, as a senior engineer, he was responsible for product and assembly process improvements as well as package failure analysis and reliability. Rueben moved to Lancaster University as a Research Associate in November 2001, where he carried out research and development work related to materials and assembly techniques used for packaging electronics and microsystems in harsh environments, especially automotive applications.Andrew Richardson is currently the Director of the Centre for Microsystems Engineering at Lancaster University. He is also the Scientific Director of Dolphin Integration, Grenoble. His interests are in the integration of Micro & Nano Technology into Heterogeneous systems and Design for Micro & Nano manufacture. Prof. Richardson initiated work on applied research contracts in the early 90’s that addressed test and design for manufacture problems in the field of Microelectronics and Microsystems Technology. To date he has initiated and taken responsibility for deliverables on a range of project, mainly industrial worth over £2.5M to date and published over 100 papers on his work. More recently he has launched a major new European Framework VI Network of Excellence involving 24 partners across Europe and £4.5M of funding to integrate and re-structure the European MNT Design for manufacture community.Steve Prosser graduated in 1979 from Oxford University with a degree in Chemistry and continued there to complete his doctorate in Physical Sciences in 1982. His industrial career started with THORN EMI Central Research Laboratories developing novel silicon-based chemical sensors. In 1985 he joined Lucas Industries (now TRW) and has led the development of advanced sensors for automotive and aerospace applications. Expatriate assignment with Lucas took him overseas for three years working as Engineering Manager for Lucas Control Systems (Schaevitz Sensors) in Virginia, USA. In 1998, he returned to the UK to become Chief Engineer—Technology within TRW Automotive Electronics. He is responsible for the technology development for advanced electronics and sensors. He is currently Chairman of the Institute of Physics Instrumentation Science and Technology Group and also Visiting Professor of Engineering at Lancaster University.Steve Riches joined Micro Circuit Engineering (MCE) in May 1999, after 16 years at The Welding Institute, where he worked on assembly and packaging techniques for microelectronics and laser processing. Since that time, he has worked as Business Development Manager for MCE, where he has been involved in establishing capabilities for the manufacture of ruggedised displays and packaging of microsystems.     

The Citizen Health System (CHS): a modular medical contact center providing quality telemedicine services.

In the context of the Citizen Health System (CHS) project, a modular Medical Contact Center (MCC) was developed, which can be used in the monitoring, treatment, and management of chronically ill patients at home, such as diabetic or congestive heart failure patients. The virtue of the CHS contact center is that, using any type of communication and telematics technology, it is able to provide timely and preventive prompting to the patients, thus, achieving better disease management. In this paper, we present the structure of the CHS system, describing the modules that enable its flexible and extensible architecture. It is shown, through specific examples, how quality of healthcare delivery can be increased by using such a system.     

Spectroscopic photon emission microscopy: a unique tool for failure analysis of microelectronics devices

Photon emission microscopy (PEM) is a technique used commonly for failure analysis of microelectronics chips. This technique has it limitations: it can only be used to indicate the place of the failure. In most cases, this is not enough to allow a definition of the failure, i.e. to find out whether it is due to a gate oxide breakdown, a metal short, a junction spiking, etc. In this paper spectral PEM is discussed. It is shown that the spectrum of the light emitted by the failure may offer valuable information about the identity of the failure.     

Evaluation of scanning capacitance microscopy sample preparation by focused ion beam

Due to the continuous reduction of the critical dimensions of semiconductor devices, it becomes very important to know the two dimensional (2D) doping profile for electrical performance of devices. Scanning Capacitance Microscopy (SCM) is a powerful technique for qualitative analysis of 2D doping species distribution, measuring small capacitance variations with high spatial resolution. For 2D carrier profiling, the region of interest must be accessible to the profiling instrument. SCM samples require cross-sectioning to expose the inner sample at a visible surface. In some analysis, the failure is localized at a very accurate address up to hundreds of nanometers. With the traditional polishing method of sample preparation it is very difficult to reach the exact location. For this reason we are investigating a new way to prepare SCM sample with Focused Ion Beam (FIB) and plasma etch in order to accurately choose the scanning zone. This paper presents a method to obtain SCM scans after a sample preparation by FIB and the influence of the FIB and the Plasma etcher on cross-sectioned SCM samples.