Sensor Technology. Summer School: Advanced Microsystems Technologies for Sensor Applications

Transcription

1 Sensor Technology Summer School: Universidade Federal do Rio Grande do Sul (UFRGS) Porto Alegre, Brazil July 12 th 31 st,

2 Outline of the Lecture: Philosophy of Sensing Thermal Sensors Chemical Sensors Semiconductor Basics Biological Sensors Radiation Sensors Environmental Sensor Systems Mechanical Sensors Nanosensors Magnetic Sensors Recitatives 2

3 Introduction: Comparative scale of semiconductor sensors S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 1, Fig. 1, p. 2 3

4 Introduction: Block diagram of the general measurement system S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 1, Fig. 2, p. 4 4

5 Classification Scheme for Semiconductor Sensors: Measurands input quantities, properties or conditions that are detected or measured by sensors acoustic measurands biological measurands closely related to the chemical measurands six types of signals: electric measurands chemical signals magnetic measurands electrical signal magnetic signals mechanical measurands mechanical signals optical measurands radiant signals radiant measurands thermal signals thermal measurands 5

6 Introduction: For decades we face a rapid progress in semiconductor technology microelectronics today many control / instrumentation systems can be realized as monolithic or hybrid modules Microprocessors allow system operation defined by software substantial increase in features for signal-processing user-interface 6

7 System Architecture: Overall system architecture of a measurement / control system (I) external physical and/or chemical parameters measured and converted into an electrical format (array of sensors) c S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 1, p

8 System Architecture: Overall system architecture of a measurement / control system (I) external physical and/or chemical parameters measured and converted into an electrical format (array of sensors) sensed data collected, processed, digitized using in-module circuitry (integrated or hybrid) transmitted over a digital bus to a host controller 8 S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 1, p. 474

9 System Architecture: Overall system architecture of a measurement / control system (II) host controller uses information makes appropriate decisions feeds control information back to the external environment c S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 1, p

10 System Architecture: Overall system architecture of a measurement / control system (II) host controller uses information makes appropriate decisions feeds control information back to the external environment array of actuators output action c S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 1, p

11 System Architecture: Overall system architecture of a measurement / control system increasingly needed in a large variety of applications automotive health care manufacturing environmental monitoring industrial processing avionics defense 11 S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 1, p. 474

12 Sensing Systems: Sensors are the most critical system element most determining factor concerning system accuracy weakest link in the developing of most emerging, next-generation instrumentation, data-acquisition and control systems sometimes (often?) unreliable sometimes do not offer adequate accuracy often the reason for expensive system maintenance and repair costs sensors have been identified as a rather weak link in automotive control systems concerning long-term reliability & fail-safe operation Solid-state microsensors (semiconductor sensors) have significantly improved some of the critical performance characteristics 12

13 Sensing Systems: Integrated sensors & smart sensors go far beyond simple sensor possibilities provide features like standard interfaces self-testing fault-tolerance digital compensation overall systems accuracy, dynamic range and reliability is much improved development of novel sensor systems and instrumentation became more easy 13

14 Sensing Systems: Solid-state sensor evolution (I) 1 st generation devices contain essentially no electronics produced the end effect with virtually no signal processing example: bimetal strip 2 nd generation devices contained amplification and perhaps temperature compensation all electronics was typically remote from the sensor data was analog one-way data flow from the sensor to the display 14

15 Sensing Systems: Solid-state sensor evolution (II) 3 rd generation devices some amplification and signal buffering occurs in-module discrete or hybrid electronics sensor operates in a remote signal-processing package which consists of analog-to-digital converter (ADC) and µ-computer S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 2, p

16 Sensing Systems: Solid-state sensor evolution (III) 4 th generation devices higher level of integration sensor electronics (partly or completely) monolithically integrated on the sensor chip addressable from the processor feature control inputs and (usually) processed analog outputs two-way communication using digital address and analog high-level voltage or time-analog pulse-rate-modulated output data compensation either at the sensor or remotely 16

17 Sensing Systems: Solid-state sensor evolution (III) 4 th generation devices S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 2, p

18 Sensing Systems: Solid-state sensor evolution (IV) 5 th and 6 th generation devices high performance features only attainable at a system level development of system components (not simple devices) data conversion to digital format performed at the sensor itself linked to the host controller over a bidirectional sensor bus self-testing sensor and addressable data compensation remote (5 th generation) local (6 th generation) 18

19 Sensing Systems: Solid-state sensor evolution (IV) 5 th and 6 th generation devices S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 2, p

20 Bus Organized Sensing Systems: System architecture of a high-performance distributed sensing system 4 principle components: host computer bus structure µ-processor driven sensing nodes sensor front-end S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 3, p

21 Bus Organized Sensing Systems: Four principle components of a bus organized sensor system host computer overall system control bus structure transmits addresses of nodes, host commands and data bidirectional (to and from sensor nodes) µ-processor driven sensing node interfaces with its sensors and host computer interprets and executes commands provides the requested information to the host computer sensor front-end contains sensors and necessary circuitry 21

22 Bus Organized Sensing Systems: Example: diagram & organization of the Michigan Parallel Bus Standard (MPS) bus contains 16 lines: 8 bidirectional data lines (D0 D7) 1 parity line 4 control lines for synchronizing the message transfers 3 power lines S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 4, p

23 Bus Organized Sensing Systems: Example: diagram & organization of the Michigan Serial Bus Standard (MSS) bus contains 4 lines (1 bidirectional data line and 3 power lines) S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 5, p

24 Sensing Nodes: Hybrid 5 th -generation sensor design Sensor node partitioned into 3 chips: sensor chip including transducers front-end interface electronics signal processing / interface chip including amplification data conversion µ-processor based µ-controller interfacing external sensor bus PROM including node identification information (node address, etc.) S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 6, p

25 Interface Standards: Block diagram of a VLSI interface design S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 12, p

26 Sensor Compensation: Sensor structure & design might be not optimal digital signal-processing techniques can be used for accuracy improvement Example: piezoresistive pressure sensor uncompensated and compensated data nonlinearity at 21.5 C S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 13, p

27 Technologies for Solid-State Integrated Sensors: Sensors fabricated using pn-junction electrochemical etch-stop S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 18, p. 506 Sensors fabricated using boron etch-stop S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 18, p

28 Technologies for Solid-State Integrated Sensors: Surface micro-machined integrated sensors S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 18, p. 507 CMOS foundry-compatible integrated sensor fabrication technology S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 18, p

29 Integrated Sensors: Important application for solid-state sensors and actuators health care biomedicine biological research Miniature, high-performance stable sensors and actuators are required accurate and reliable interface with the biological environment areas of interest, e. g. recording the electrical activity from the nervous system deliver electrical signals to nervous or muscular tissue for a activation of paralyzed muscles 29

30 Integrated Sensors: Micro-machined Si-microprobe designed for both electrical recording stimulation of the central nervous system array of conductors interconnect recording and/or stimulation sites located at the tip on-chip signal-processing housed on the back-end of the probe substrate S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 19, p

31 Integrated Sensors: Block diagram of 10-electrode recording microprobe S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 20, p

32 Integrated Sensors: On-chip circuitry which is designed for electronically configurable 32-electrode recording microprobes block diagram S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 21, p

33 Integrated Sensors: SEM* and optical photographs of multichannel recording microprobes * ) scanning electron microscope S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 22, p

34 Integrated Sensors: 16-channel stimulating microprobe used in stimulation of the central systems block diagram S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 23, p

35 Integrated Sensors: 16-channel stimulating microprobe used in stimulation of the central systems photograph S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 24, p

36 Integrated Sensors: Gas detectors basic structure of thin-film gas detectors gas sensors are in a high demand numerous automotive, medical or process control applications S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 25, p

37 Integrated Sensors: Gas detectors photograph of a dual-detector gas sensing chip fabricated using bulk micro-machining techniques S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 26, p

38 Integrated Sensors: Gas detectors block diagram of a three-chip hybrid 4-element gas analyzer 38 S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 27, p. 520

39 Integrated Sensors: Gas detectors photograph of a multi-chip hybrid gas analysis module S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 28, p

40 Integrated Sensors: Gas detectors block diagram of the interface between the control chip and a gas detector S. M. Sze (Editor): Semiconductor Sensors, John Wiley and Sons, Inc. (1994), Chapter 10, Fig. 29, p