Research Review 2001
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Integrated Systems Laboratory Eidgenössische Technische Hochschule Zürich Swiss Federal Institute of Technology Zurich Microelectronics Design Center Research Review 2001 W. Fichtner Q. Huang H. Kaeslin N. Felber D. Aemmer Grid Adaptation for Device Simulation Automatic grid adaptation is a useful method to construct suitable simula- tion meshes, to control the solution accuracy, and to rllieve the user from manual work. The time-consuming and error-prone grid generation phase of a TCAD simulation suite can thus be shortened which reduces costs in commercial and industrial applications. Though state-of-the-art in many application areas, grid adaptation is not widely used within semiconductor device simulation because the mathematical nature of the underlying par- tial differential equations, expressed in terms of strong internal and bound- ary layers of the solutions, poses tremendous difficulties both for suitable adaptation criteria and the overall robustness of the adaptation module. In this project a novel anisotropic grid adaptation procedure for the stationary 2D drift-diffusion model has been de- veloped. It implements the Scharfetter- Gummel box method on quad-tree based boundary Delaunay grids. The major concern has been to meet practi- cal requirements by addressing the most interesting quantities as device terminal currents, to account for practi- cal simulation cases, to achieve suffi- cient robustness, and to respect cus- tomer’s use of reasonable but quite coarse simulation meshes. The ap- proach is based on estimates of the er- ror of the system dissipation rate, gained by the solution of local Dirichlet Adaptively generated mesh for a 0.18µm nMOSFET suitable for the problems or residual methods. The ro- extraction of Id(Vd)-characteristics. bust recomputation of the solution on The junction layers are unresolved, adaptively achieved grids is crucial for anisotropic refinement is visible in the practical adaptive simulations and has channel, and the grid size (1397 ver- been remarkably stabilized even for tices) is smaller than manually opti- mized simulation grids with compara- large avalanche generation (refer to the ble accuracy. contribution on page 64 left). Adaptively generated mesh for a power diode with several floating regions, com- plex geometrical features, and indicated jumps J(AGM-DR) of the element dissi- pation rate serving as error estimator. Left Figures: Effect of grid adaptation on simulation grids of a reverse-biased 2D pn-diode with curved junction: Sequence of grids with indicated element error distribution at a fixed bias. Bottom figure: Reduction of the relative error of the global dissipation rate (black) and estimated relative errors based on different criteria as a function of the number of vertices. Integrated Systems Laboratory Eidgenössische Technische Hochschule Zürich Swiss Federal Institute of Technology Microelectronics Design Center Research Review 2001 W. Fichtner Q. Huang H. Kaeslin N. Felber D. Aemmer Cover Image: World’s First RF Simulation of a Commercial Multi-Band Handset The trend toward mobility and the tremendous progress in communication technologies has created an exponen- tially growing market for wireless applications. Further advances in miniaturization and complexity require efficient and powerful tools in the R&Dphase of these products. A project jointly funded by industry and MINAST/KTI has the objective of creating the most advanced TCADtool for the analysis and optimization of the electromagnetic ra- dio-frequency near-field. This study incorporated the most detailed analysis of a re- al-world handset scenario ever conducted, based on one of the latest commercially available multi-band mobile phones. Simulations were performed on the Finite-Differ- ence Time-Domain (FDTD)-based platform SEMCAD. The detailed CADdataset of the phone (Figure 1) consists of about 40 distinguished electromechanical parts. More- over, the PCB was modeled by 5 PEC/dielectric layers in- terconnected by more than 50 vias. The application of combined graded meshing and subgridding enabled grid resolutions of 100µm, embedded within computational domains extended by 0.5m. All measurements were per- formed using the DASY4 near-field scanner equipped with the latest probes. The agreement between measurement and simulation (Figure 2) for all examined parameters was considerably better than what the uncertainty assessment of the meth- od would predict. Compared were all parameters signifi- cant for RF engineers, including impedance, efficiency, Fig. 1: Physical phone and its detailed CADequivalent within the 3-D far-field as well as near-field distributions (E, H, SAR) ACIS-based solid modeling environment of the SEMCADsimulation (Figure 3). An initial investigation of the antenna itself lead platform. to small deviations in gain and resonance frequencies (~1%), and for the averaged SAR, variations lower than 10% were obtained. Related subprojects are outlined on pages 80ff. Fig. 2: Comparison of simulation (SEMCAD) and measurement (DASY4) for the E- and H-fields in a plane at 10mm above the phone. Fig. 3: Assessment of near- and far-field data in a real-world configura- All fields are normalized to the same input power. tion (head-phone: SAR and radiation pattern). Address of the laboratory: Integrated Systems Laboratory Phone: +41 1 632 42 68 ETH Zentrum, ETZ Fax: +41 1 632 11 94 Gloriastrasse 35 e-mail: [email protected] CH-8092 Zürich WWW: http://www.iis.ee.ethz.ch Switzerland Contents Preface 9 Organization of the Integrated Systems Laboratory 12 Representative Figures 13 Staff 16 Former PhD Students 18 Academic Guests 23 Partners and Funding Agencies 26 Awards 36 Patents 37 History of the Integrated Systems Laboratory 38 Research Projects: IC and System Design and Test 43 GALS: Globally-Asynchronous Locally-Synchronous System Design 44 Multi-Point Interconnects for Globally-Asynchronous Locally-Synchronous Systems 44 Testability of Globally-Asynchronous Locally-Synchronous Wrapper Modules 45 Clock Generators for Globally-Asynchronous Locally-Synchronous Wrapper Modules 45 Multimedia Network Chips 46 Reconfigurable Hardware Accelerator for Real-time Multimedia Data Processing 46 Synchronization of an IEEE-1394 Network for Audio and Video 47 All-Digital Standardcell-Based PLL for Audio and Video 47 New Wireless Communication Systems 48 UMTS-MIMO-Transceiver 48 IP Core for Real-Time Solution of Least Squares Problems using CORDIC and QRD-RLS 49 Lower Bounds on Power Dissipation in Digital VLSI 49 Control of Combined Parallel/Series-Connected IGBTs 50 Research Projects: Analog and Mixed-Signal Design 51 Transmit I/Q Modulator for UMTS (Universal Mobile Telecommunications System) 52 Baseband Circuits for Direct Conversion UMTS Mobile Receiver 52 IQ Demodulator for Direct-Conversion UMTS Mobile Receiver 53 Baseband Circuit for UMTS Transmitter 53 A 33mW, 14-bit, 2.5Msample/s Sigma-Delta A/D Converter 54 A Low-Power 8-bit Folding and Interpolating Analog-to-Digital Converter 54 A High-Speed D/A Converter with Background Calibration 55 Broadband Sigma-Delta D/A Converter 55 Optimization of OTAs for Application in Sampled Data Systems 56 High-Speed Multibit Sigma-Delta Modulator for Telecom Applications 56 An 18mW 1800MHz Quadrature Demodulator in 0.18µm CMOS 57 Mobile Telemonitoring System for Biomedicine 57 5 Research Projects: Technology CAD 59 Modeling and Simulation of Quantum Effects in MOSFETs 60 Quantum Drift Diffusion (QDD) Modeling of Tunneling through Insulators 60 Simplified Model for Inelastic Acoustic Phonon Scattering 61 Hot-Carrier Degradation of MOSFETs 61 Conductance of Nano-Scale Silicon-On-Insulator (SOI) Single Electron Devices 62 3D Simulation of Noise in Bipolar Transistors 62 Monte Carlo Generated Noise Sources 63 Coulomb Enhancement of Radiative Recombination Rates 63 Robust Grid Adaptation in Device Simulation for Large Avalanche Generation 64 Process Simulation with "noffset3d" Meshes 64 "Moving Boundary" Algorithm with Volume Triangulations 65 Simulation of Substrate Leakage in Semiconductor Lasers 65 Calculation of the Spontaneous Emission Coupling for Edge-Emitting Lasers 66 Simulation of a Tunable Twin-Guide Distributed-Feedback Semiconductor Laser 66 Simulation of a Weakly Index-Guided Buried-Stripe Type Laser Diode 67 Self-Heating Effects in Multi-Dimensional Simulations of Quantum-Well Lasers 67 Temperature and Carrier Density Effects on Optical Modes in Quantum-Well Lasers 68 LUMI2 Optical Mode Solver 68 Numerical Simulation of InP/InGaAs High-Speed Photodetectors 69 Intraband Photon Absorption in Multi-Quantum-Well (MQW) Structures 69 Optoelectronics Characterization Laboratory (OptoLab) 70 Molecular Dynamics-Kinetic Monte Carlo Calculations of Ion Implantation 70 Ab-Initio Study of Arsenic Activation and Deactivation in Silicon 71 Diffusion Mechanisms of Highly Arsenic-Doped Silicon 71 Ab Initio Calculations for the Self-Interstitial in Silicon 72 Parallel Iterative Methods for Large Sparse Linear Systems from Semiconductor Simulation 72 Research Projects: Physical Characterization 73 Reliability of Power Semiconductors for Automotive Applications Thermal and Computational Fluid Dynamics Simulation of Integrated Modules 74 Electrical Characterization of Silicon at Very High Temperatures 74 Extraction of Doping Profiles by Scanning-Capacitance Microscopy 75 Characterization of the Offset Matching for MOS Transistor Structures 75 Measurements and Device Simulations of Transient Substrate Effect in Smart-Power ICs 76 Minimization of Transient Substrate