臺灣博碩士論文加值系統

This study aims to design and develop a CMOS sensor chip for measuring thermal conductivity of liquids. The CMOS sensor chip is realized by VIS 0.5 μm 2P3M CMOS process with maskless post-CMOS micromachinings. The procedure used to measure thermal conductivity of liquids here is utilized to replace conventional methods which require a great deal of specimen and cost a long measurement time.
The measurement system consists of a heater at the center, four pairs of temperature sensors, specimen of liquid drop and a cavity for thermal insulation. Once a heat flux is applied by the heater, it will cause temperature variations of the sensor. Different kinds of tested liquids will result in different temperature variations of the sensor. The temperature variation will correspond to the resistance variation of temperature sensors.
Four kinds of liquids are used to measure in the thesis. The conclusions of experiment results are as follows: a liquid with higher thermal conductivity results in a smaller resistance variation of the temperature sensor. In addition, an experiment system will have a larger time constant as a liquid with higher thermal conductivity is tested.
Thermal conductivities of other liquids could be measured as well based on a relation between thermal conductivity and time constant was established by the measuring procedure in the thesis.

Table of Contents
Acknowledgement I
Abstract II
Table of Contents IV
List of Tables VII
List of Figures VIII
Chapter 1 Introduction 1
1.1 General Remarks 1
1.1.1 Thermal conductivities of liquids 1
1.1.2 CMOS-MEMS fabrication technology 1
1.2 Literature Survey 2
1.2.1 A transient hot-wire method 3
1.2.2 A transient hot-disk method 4
1.2.3 CMOS-MEMS fabrication technologies 6
1.3 Motivation and Objectives 6
1.4 Thesis Organization 8
Chapter 2 Design Principle 10
2.1 Principles of the CMOS Sensor 10
2.2 Design of the CMOS Sensor Chip 11
2.2.1 CMOS 0.5μm 2P4M whole chip layout 12
2.2.2 Subsystems of the CMOS sensor chip 12
Chapter 3 Post-CMOS Micromachining 16
3.1 Post-CMOS Micromachining Process Flow of the CMOS Sensor Chip 16
3.2 Isotropic Wet Etching for Removing Metal Layers 18
3.3 Anisotropic Dry Etching for Removing Silicon Dioxide 19
3.4 Anisotropic Wet Etching for removing silicon substrate 21
3.5 Anisotropic Dry Etching for opening pads 23
3.6 Wire bonding 24
Chapter 4 Experimental Apparatus and Procedures 25
4.1 Experimental Apparatus 25
4.2 Tested Liquids 26
4.3 Experimental Procedures 27
4.3.1 Procedure of resistance versus temperature calibration 27
4.3.2 Procedures of measuring thermal conductivity of tested Liquids 28
Chapter 5 Experimental Results and Discussions 30
5.1 Experimental Results of Different Tested Liquids 30
5.2 Experimental Results Comparison of Different Tested Liquids 32
5.3 Uncertainty Analysis 33
Chapter 6 Conclusions and Future Prospects 35
References 60

Luo, H., Fedder, G.K., and Carley, L.R., 2000 “A 1 mG lateral CMOS-MEMS accelerometer,” IEEE Micro Electro Mechanical Systems (MEMS`00) , pp. 502-507.
Gustafsson, S.E., Karawacki, E., and Khan, M.N., 1979, “Transient hot-strip method for simultaneously measuring thermal conductivity and thermal diffusivity of solids and fluids,” J Phys D: Appl Phys, 12, pp. 1411.
Hsieh, C.M., “Study and Application of TMAH Anisotropic Wet Etching,” Master thesis, Dept. of Mechanical Engineering, NTU, Taipei, Taiwan.

Kaltsas, G., and Nassiopoulou, A. G.., 1998, “Frontside bulk silicon micromachining using porous-silicon technology,” Sensors and Actuators A, 65, pp. 175-179.

Kaltsas, G., and Nassiopoulou, A. G.., 1999, “Novel C-MOS compatible monolithic silicon gas flow sensor with porous silicon thermal isolation,” Sensors and Actuators A, 76, pp. 133-138.

Moser, D., Lenggenhager, R., and Baltes, H., 1991, “Silicon gas flow sensor using industrial CMOS and bipolar IC technology,” Sensors and Actuators A, 27, pp. 591-595.

Moser, D., and Baltes, H., 1993, “A high sensitivity CMOS gas flow sensor on a thin dielectric membrane,” Sensors and Actuators A, 37-38, pp. 33-37.

Senturia, S.D., 2001, Microsystem Design, Kluwer Academic Publishers, Massachusetts, US, pp. 61-65

Tabata, O., 1996, “pH-controlled TMAH etchants for silicon micromachining,” Sensors and Actuators A, 53, pp.335-339

VIS, 2004, VIS 0.5μm Mixed Singal 2P3M Polyicide 3.3V Design Rule.

Witch, H., llling, M., Wechsung., R., 2002, “The Microsystem Market in Automotive: Insights from the NEXUS Market Study 2001,” Witch Technologie Consulting, http://www.wtc –consult.de/deutsch/publika/abstratct/mst-automotive.pdf

Wakeham, W.A., Nagashime, A., and Sengers, J.V., 1991, Measurement of transport properties of fluids, Blackwell Scientific, Oxford, UK, pp. 459-460.

Yamasue, E., Susa, M., Fukuyama, H., Nagata, K., 2001, “Thermal conductivities of silicon and germanium in solid and liquid states measured by non-stationary hot wire method with silica coated probe,” Journal of CRYSTAL GROWTH, 234, pp. 121-131.