piezoelectric strain constant
Lead zirconate titanate -4: 289m/V
Lead zirconate titanate -5:372 m/V
Lead zirconate titanate -8: 225m/V
Piezoelectric voltage constant
Lead zirconate titanate -4:2.6 μ m/nm
Lead zirconate titanate -5:2.48 μ m/nm
Lead zirconate titanate -8: 2.5Vm/N\
Academic papers published by Microelectronics Institute 1999
I. Instrument Research Room
Germanium-silicon microwave power heterojunction bipolar transistor
, Jia Hongyong, Chen
China Electronics, 1 1, 1999.
We have developed a simple planar process compatible with silicon technology, and successfully developed a SiGe heterojunction bipolar transistor (HBT) suitable for microwave power applications. Its current gain is 50-320, and the breakdown voltage of collector and emitter reaches 28V and 5V respectively. Under the condition of * * * emitter connection and class C operation, the continuous wave power output reaches 5W and the collector conversion efficiency is 63%. On this basis, the power gain reaches 7.4dB when working at 900M MHz.
MEMS devices used in communication field
, Li Zhijian, Liu
Electronic Science and Technology Herald, 7, 1999
Micro-electro-mechanical system (MEMS) technology is widely used in the future communication field. This paper introduces several MEMS devices used in communication lines. Such as micro-capacitors, micro-inductors, micro-resonators, filters and micro-switches, and their main performances.
Preparation of P- Si micro-mold for depositing glass-British alloy microstructure array by plasma dry etching
, Liu, Tan Zhimin, Li Zhijian.
The 2nd Asia-Europe International Conference on Plasma Surface Engineering, 1999.9, Beijing.
In this paper, a micro-mold is made on P-type silicon by plasma dry etching, and then the mold is filled by electrochemical method. Thereby obtaining the microstructure of Pomo metal (80% nickel, 20% iron). As a soft magnetic material, microstructure bimo alloy has been widely used in MEMS research. In order to obtain the microstructure with the transverse dimension of 100mm× 100mm, a square deep groove with mask pattern was etched on the silicon wafer by plasma method. CF4 and SF6 are mixed as corrosive gases. 10 minutes can get 10 mm deep groove. This process shows a high etching rate of monocrystalline silicon. The deep groove is then used as a mold for selective electrodeposition. In order to realize the charge transfer between the electrolyte and the silicon electrode, the bottom of the square battery is doped with boron atoms and a special fixture is used. In this way, DC electroplating current can be applied to the electroplating substrate from the back of the silicon wafer, thus obtaining a highly uniform microstructure. By this method, the microstructure of Bohm alloy with high permeability (1700) was successfully obtained.
Research on Fabrication of High Performance Dual-axis Micro-acceleration Sensor
, Liu, Li Zhijian
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
In this paper, the research results of combining integrated circuit technology with LIGA technology to fabricate high-performance micro-acceleration sensor with nickel metal as structural material on silicon-based materials are given. Due to the use of metal materials, the device can obtain higher sensitivity in a smaller size. Special structure is adopted to make the device in the best damping state. The manufacturing process mainly includes thick glue lithography, electroplating seed layer deposition, electrochemical deposition of sacrificial layer and X-ray exposure.
Study on fabrication of back-aligned X-ray lithography mask
, Liu, Li Zhijian
10 national annual meeting of electron beam, ion beam and photon beam, 1 1 month 1999, Changsha, Hunan.
Deep X-ray lithography is an important method to fabricate MEMS structures with high aspect ratio. Due to the optical opacity of most LIGA mask support films, it is difficult to make multiple exposures that require repeated alignment. We solved this problem well by using the X-ray lithography mask with reverse alignment. The research results of mask manufacturing process are given. The whole process includes deposition of silicon nitride, ultraviolet lithography, electrochemical deposition of gold absorber, bulk silicon etching to form supporting film and so on. The alignment accuracy can reach 2mm by using Karsus double-sided quasi-exposure machine.
Design of silicon photoelectric integrated micromotor with mesa structure
Qi, Tan Zhimin, Liu, Li Zhijian.
Journal of Tsinghua University, 39(S 1), 1999.4.
In order to solve the problems of short service life and difficult speed measurement of electrostatic vibration micromotor with salient-pole flange structure, a photoelectric integrated vibration micromotor with mesa structure is proposed. Replacing the suspended polysilicon flange with the thickness of 1. 1 mm with the single-crystal silicon mesa flange has the advantages of high mechanical strength, low friction coefficient, wear resistance and no collapse. The hollow shaft of 2 mm is also replaced by a solid shaft, which overcomes the problem that the shaft is deformed due to wear and stress. Thereby greatly prolonging the service life of the motor. On the other hand, the photoelectric speed measuring circuit is integrated in the motor, which can accurately measure the motor speed. Can also form a closed-loop control system, or as a chopper, become a real MEMS electronic system. The new motor is simple in process, completely compatible with IC process, and can be manufactured in batches.
Photoelectric integrated speed measuring silicon electrostatic micromotor
Qi, Hou Yi and Liu
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
In this paper, micro-motor and photodiode are integrated to form a photoelectric speed measurement system. Several photodiodes are integrated under the rotor of the motor, and the rotation speed of the motor is measured by the change of dark current and bright current of the reverse bias diodes. The speed measuring range of the motor is improved, and the problem of slow speed measuring of the camera speed measuring system is solved. In addition, it also has the advantages of convenient test, compatibility and accurate technology. It can also be made into a kitchen knife. Become an optical, mechanical and electrical MEMS system.
Ferroelectric-silicon micro-integrated system
Li Zhijian, Ren and Liu.
Acta Semiconductors, 20(3), 1999
Ferroelectric-silicon micro-integrated system FSMIS is the product of the combination of ferroelectric materials and silicon technology, which has extremely important application value in MEMS, memory and so on. In this paper, several important preparation methods and typical application directions of silicon-based ferroelectric thin films are introduced, and their development prospects are prospected.
Research on ferroelectric-silicon integrated microphone and speaker
Ren, Liu and Li Zhijian
Journal of Tsinghua University, 39(S 1), 1999.
The purpose is to lay a foundation for realizing high-sensitivity integrated microphone and speaker. Based on the excellent mechanical and electrical coupling characteristics of lead zirconate titanate (PZT) ferroelectrics, the cantilever ferroelectric-silicon integrated microphone and speaker were developed by combining PZT ferroelectric thin film with silicon technology. The PZT diaphragm structure is optimized by using the double diaphragm model, and its technological process is preliminarily designed, which lays the design foundation for the final realization of integrated microphone and speaker. Ferroelectric-silicon integrated microphone and speaker are expected to be used in multimedia voice input and mobile communication.
2 1 century information storage technology-silicon-based ferroelectric memory.
Ren, Liu and Li Zhijian
Electronic Science and Technology Herald, 9, 1999
Silicon-based ferroelectric memory is a new type of memory that integrates ferroelectric materials into semiconductor integrated circuits through silicon processing technology to take advantage of this material in information storage. This emerging memory is an important application of the ferroelectric-silicon micro-integrated system FSMIS, which is expected to surpass the simple semiconductor memory in many aspects such as low working voltage, low power consumption, high storage density and excellent non-volatile storage performance, and may become an important information storage technology in 2 1 century.
Diaphragm design of silicon-based PZT microphone and speaker
Ren, Zhao Yang, Liu, Li Zhijian.
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
The purpose of this paper is to lay a foundation for the realization of ——PZT cantilever diaphragm, the core structure of microphone and speaker with high sensitivity and integration. Based on the excellent mechanical and electrical coupling characteristics of lead zirconate titanate (PZT) ferroelectrics, the cantilever ferroelectric-silicon integrated microphone and speaker were developed by combining PZT ferroelectric thin film with silicon technology. The multi-diaphragm model is used to optimize the design of PZT diaphragm structure, which lays the design foundation for the final realization of the core structure of integrated microphone and speaker.
Composite compensation of defects in p-type ZnSe
Ren, Zhu Jialin, Zhu Tianzhu, Yao
Journal of Applied Physics, 86(3), 1999
The defect complexes in nitrogen-doped and arsenic-doped ZnSe were studied by discrete variable local density functional method and cluster model. Based on the difference of formation energy of the two complexes, it is found that NSe-Zn-VSe is a more effective acceptor compensator in N-doped ZnSe, while AsSe-Znint is more effective in As-doped ZnSe. The complex of NSe-Zn-NSe with acceptor energy level of 65438±070 meV and NSe-NZn with donor energy level of 88 meV was determined. The concept of donor state of n molecule is confirmed.
Monolithic integration of HIP infrared detector and silicon MOS readout circuit
Wang Hechen
Journal of Tsinghua University, 39(S 1), 1999.
In order to prove the possibility of monolithic integration of P+-Gex/Si 1-x/P-Si HIP infrared detector and silicon MOS readout circuit, the technological compatibility between P+-Gex/Si1-X/P-Si HIP Shore infrared detector and silicon CMOS readout circuit is analyzed, and a feasible scheme is put forward. A monolithic integrated test chip for P+-Gex/Si 1-x/P-Si HIP infrared detector and NMOS readout switch circuit has been successfully developed by silicon 3 mm NMOS process. At 77K, the blackbody detection rate of the P+-Gex/Si 1-x/P-Si HIP device grown by molecular beam epitaxy (MBE) method without dielectric cavity and antireflection film reaches11/2. W- 1。
Study on Cr-AlN interface by secondary ion mass spectrometry
Yue ruifeng
Journal of Analytical Testing, 18(3), 1999.
Cr thin films with a thickness of 200 nm were deposited on AlN ceramic substrates polished at 200℃ by electron beam evaporation and annealed in high vacuum. MCs+-SIMS technology (detecting MCs+ type secondary ions under the bombardment of CS+primary ions) was used to analyze the samples in depth, and the relationship between the distribution of interface components and annealing temperature and time was given. The results show that MCs+-SIMS technology is an effective method to study the interfacial diffusion and reaction of cermet.
Discussion on thermal oxidation behavior of AlN ceramic substrate in air
Rebecca Yueruifeng
Applied Surface Science, (148), 1999
The initial oxidation behavior of AlN ceramic substrate after annealing in air at 850- 1 100℃ was studied by secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD). The results show that there is a thin oxygen-rich layer on the surface of the unannealed AlN ceramic substrate. Under the annealing condition of 10min, the oxygen-rich layer thickens rapidly with the increase of annealing temperature. After annealing at 1 100℃ for 20min minutes, a continuous oxide layer was formed on the surface of AlN ceramic substrate. Finally, combined with chemical thermodynamics, the initial oxidation mechanism of AlN ceramic substrate surface was discussed.
SIMS and XRD Studies on AlN and mullite ceramic Substrates
Yue ruifeng
Silicate bulletin, (4), 1999
The phase composition and surface composition, especially surface impurities, of AlN substrate with Dy2O3 and CaO as additives and mullite ceramic substrate with cordierite and BaCO3 as additives for electronic packaging were studied by secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD), and the thermal oxidation of AlN surface was discussed by SIMS. The results show that the surfaces of AlN and mullite ceramic are polluted by impurity elements such as lithium, carbon, fluorine, sodium, potassium, chlorine, titanium and rubidium. There is an oxygen-enriched layer on the surface of AlN, which is obviously widened after annealing at 850oC 10 minute in air.
SIMS, RBS and XRD Studies on Ti/AlN Interface Reaction
Rebecca Yueruifeng
Surface and Interface Analysis, 27(2), 1999
Ti film with thickness of 200nm was deposited on polished AlN ceramic substrate at 200℃ by electron beam evaporation and annealed in high vacuum. The solid-state interfacial reaction of Ti and AlN in the range of 200 ~ 850℃ was studied by secondary ion mass spectrometry (SIMS), Rutherford backscattering spectroscopy (RBS) and X-ray diffraction analysis (XRD), and the relationship between the distribution of interfacial components and annealing temperature and time was given. Ternary aluminides were found in the interface region, and the formation and development process of aluminides were observed. It is pointed out that aluminide is composed of titanium aluminum binary compound and titanium aluminum nitrogen ternary compound. Finally, the experimental results are explained by thermodynamic theory.
Research and design of a new integrated pressure sensor with double bridge structure
Yue Ruifeng, Liu, Li Zhijian
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
Based on the finite element analysis of the stress distribution of silicon cup structure, two new integrated pressure sensors with double-bridge structure are designed. Among them, the piezoresistive bridge is located in the high stress area on the diaphragm, and the compensation bridge is located in the gradually thickening bulk silicon area on the diagonal of the diaphragm or near the diaphragm, and the four resistors forming each bridge are concentrated in the same area. Subtracting the output signals of the piezoresistive bridge and the compensation bridge can obviously reduce the misalignment and temperature drift of the pressure sensor. The pressure sensor is also equipped with on-chip signal processing circuit, and integrated manufacturing is realized by PMOS process.
Research on fuzzy neural network and its VLSI implementation
Chen, Dong myung Kim, Li Zhijian
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
In order to overcome the shortcomings of fuzzy logic and neural network, fuzzy neural network has become one of the hot research fields. This paper reviews the proposal and development of fuzzy neural network, and discusses two main methods and achievements of model research: one is called fuzzy logic system based on neural network, and the other is called fuzzy neural network. VLSI implementation of fuzzy neural network is a relatively new topic. This paper first introduces the VLSI implementation of fuzzy logic and neural network, and then discusses the research results and development of VLSI implementation of fuzzy neural network.
Development of a Practical Fuzzy Controller
Wang Chun, Dong myung Kim
Journal of Tsinghua University, 39(S 1), 1999.
Aiming at the control problem of suspended metal ball in magnetic field, a nine-rule fuzzy controller with dual input and single output is designed. The controller adopts a new fuzzy and deblurring method, which overcomes the information loss caused by the classification of precise quantities in the usual fuzzy methods. The simulation results show that this method has the characteristics of short transition time, small overshoot and good stability. A CMOS current mode circuit is designed and an improved CMOS process is adopted. The results show that the circuit meets the design requirements well. The whole circuit has nearly 300 MOS transistors, with an area of 1. 1 mm2 and a power consumption of 10.7mw. ..
Design of Programmable Fuzzy Logic Controller Chip
Shen Jie, Dong myung Kim, Li Zhijian
Journal of Electronics, 27(8), 1999
This paper presents a general programmable fuzzy logic controller (PFLC) realized by analog circuits. For a control object with two input variables and one output variable, 8 1 control rules are allowed. The controller is composed of current-mode CMOS multivalued devices, which are manufactured by 2mm standard CMOS process. PFLC has a convenient input/output interface, and its fuzzy reasoning process is parallel, which is completed once every clock cycle, and the highest clock frequency can reach 1MHz.
Equivalent resistance of dual MOS transistor *
Shen Jie, Dong myung Kim, Li Zhijian
Journal of Tsinghua University, 39(S 1), 1999.
An equivalent resistor can be composed of two MOS transistors with grounded source and connected drain, so that they can work in the saturated region and unsaturated region respectively, that is, the function of the resistor is realized by active devices. The simulation and test results show that the working voltage is in the range of 1 ~ 4 V, and the resistance change is within 5%. In fact, the resistance of double MOS tube is a supplement and improvement of the resistance of single MOS tube. The structure is simple, the resistance value ranges from 1 kW to tens of kW, and the adjustment is convenient. It is manufactured by standard CMOS process.
Research progress of Si 1-xGex materials and bipolar devices
Jia Hongyong, Sun Zimin, Chen,
Semiconductor information, 36(3), 1999
Si 1-xGex materials have many excellent properties, and high-quality strained epitaxial layers can introduce the concept of energy band engineering into group IV devices. Heterojunction bipolar transistor (HBT) with epitaxial Si 1-xGex base region has achieved excellent performance and is compatible with silicon technology. BiCMOS technology integrating Si 1-xGex and Si has made great progress and reached the level of industrial application. The development of Si 1-xGex technology and the improvement of circuit speed also promote the progress of microwave integrated circuits and improve the application frequency band of Si MMIC. At present, it has been widely used in radio frequency (RF) communication.
Si 1-xGex HBT technology: a newcomer in RF and microwave fields
Jia Hongyong, Chen, Qian Peixin
Integrated Circuit Design, (8), 1999
This paper summarizes the development of Si 1-xGex materials and devices in recent years, and introduces its application in microwave circuits. Epitaxial Si 1-xGex base heterojunction bipolar transistor (HBT) promotes the progress of microwave integrated circuits and improves the application frequency band of Si MMIC due to its excellent performance and compatibility with silicon technology. At present, it has been widely used in radio frequency (RF) communication.
Study on SiGe/Si Ultra-high Vacuum Chemical Vapor Epitaxy Process
Jin Xiaojun, Jia Hongyong, Qian Wei, Han Yong, Lin, Chen and Qian Peixin.
Journal of Tsinghua University, 39(S 1), 1999.
In order to develop high-performance Si 1-xGex/Si heterojunction devices and grow strained Si 1-xGex materials suitable for device applications, the heteroepitaxial growth process of Si 1-xGex/Si was studied by using ultra-high vacuum chemical vapor deposition (UHV/CVD) equipment developed by ourselves. The growth rate and composition changes of Si 1-xGex with GeH4 flow rate were studied. The experimental results show that the growth rate of Si 1-xGex increases obviously with the increase of GeH4 flow rate, and the Ge component in the epitaxial layer is about 2.5 times of the GeH4 concentration in the gas phase. A simple growth kinetic model is proposed to explain the relationship between composition and flow rate. Raman spectrum analysis results show that the epitaxial layer is completely strained. The diode made of this material has good performance.
Design and Fabrication of a New Silicon Micro-acceleration Sensor
Li, Liu and Yang Jingming
Journal of Tsinghua University, 39(S 1), 1999.
In this paper, a new type of resonant silicon micro-acceleration sensor is studied, its structure and technology are designed, and a series of devices with different structures and sizes are made. At the same time, the acceleration sensor and the supporting beam make a resonant beam to detect the signal, and the signal output is obtained by the method of resistance thermal driving and piezoresistive bridge synchronous detection. The design scheme adopts piezoresistive sensing technology and bulk silicon micromachining technology, which has the advantages of high resolution, high stability and easy combination with signal processing circuit brought by resonance principle, and obtains high device performance at low cost. Its structural dimensions range from 3mm× 4mm to 6mm× 6mm. ..
Influence of quantization effect on subthreshold characteristics of deep submicron MOSFET
, Liu, Li Zhijian
Journal of Tsinghua University, 39(S 1), 1999.
In this paper, classical and quantum mechanical carrier distribution models of MOSFET subthreshold region are established by solving Schrodinger equation under triangular barrier approximation and applying Fermi statistics. Starting from the turn-on nature of devices, the definition of turn-on voltage suitable for quantum mechanical theory is proposed, and then the carrier distribution and subthreshold region current under classical theory and quantum mechanical theory are calculated. The influence of quantization effect on the characteristics of deep submicron MOSFET subthreshold region is systematically studied for the first time. The calculation results show that at high substrate doping concentration, the quantization effect leads to a significant decrease in carrier concentration and subthreshold current, and an increase in turn-on voltage, but has no significant effect on subthreshold slope factor. The work in this paper shows that the influence of quantization effect must be considered in the modeling and device design of sub-threshold characteristics of deep submicron MOSFET devices.
Modified model of quantum mechanical effect of turn-on voltage of multi-subband MOS devices
, Liu, Li Zhijian
Acta Semiconductors, 20(3), 1999
With the increase of substrate concentration and the decrease of gate oxide thickness, the influence of quantum mechanical effect on the characteristics of deep submicron MOSFET becomes more and more obvious. The experimental results show that the quantum mechanical effect will lead to the obvious shift of the turn-on voltage. In this paper, by comparing the numerical solution of Schrodinger equation under parabolic barrier with the analytical solution under triangular barrier, the correctness of triangular barrier approximation of quantum mechanical effect in weak inversion region of MOS structure is verified. By calculating the sub-band structure of the quantized layer in the weak inversion region, the concepts of quantized effective state density and classical effective state density are put forward, the distribution of carriers in the sub-band is analyzed, and two factors affecting the turn-on voltage by quantum mechanical effect are discussed. On this basis, a quantum mechanical correction model of turn-on voltage is given. The model accurately reveals the physical essence of quantum mechanical effect affecting the turn-on voltage, and gives the results consistent with the experimental data.
Discussion on global consistency of mobility of MOSFET inversion layer
, Liu, Li Zhijian
IEEE Trans。 Editor, 146(9), 1999
In the existing research on the global uniformity of carrier mobility in MOSFET inversion layer [1-4], the conclusions about the doping of non-uniform channel are obviously inconsistent. By carefully studying the data in document [1] and the parameter extraction method in document [2], we find that this inconsistency is only because the definition of depletion layer charge in document [1] is different from other documents. At the same time, we find that the method of extracting parameters from experimental data in reference [2] is not applicable. The research in this paper shows that the mobility of current has the same law as that of uniformly doped channel without doping channel.
Surface effective state density and its application in MOS structure modeling
, Liu, Li Zhijian
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
Based on the distribution characteristics of carriers in the inversion layer of MOS structure, the concept of surface effective density (SLED OS) is proposed. Based on the concept of surface effective state density, the charge distribution models under the framework of classical theory and quantum mechanics are established. This model introduces an efficient iterative method with high computational efficiency and strong stability. Based on this model, the influence of quantization effect on carrier concentration and surface potential of inversion layer is studied. In addition, a modified model of quantization effect of turn-on voltage is established by using the concept of SLEDOS.
Influence of quantization effect on carrier concentration in inversion layer of MOS structure at different temperatures
, Liu, Li Zhijian
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
Low-temperature MOS devices have attracted much attention because of their inherent high mobility and superior sub-threshold characteristics. The quantization effect will have a significant impact on the carrier concentration and turn-on voltage of MOSFET inversion layer. In this paper, the influence of quantization effect on carrier concentration in inversion layer of MOS structure at different temperatures is systematically studied for the first time. In a wide temperature range (77K~400K) and a large substrate doping concentration range (1016 cm-3 ~1018 cm-3), the relationship between the carrier concentration of the inversion layer and the gate voltage is calculated under the classical theoretical distribution and quantum theoretical distribution. The calculation results show that the influence of quantization effect on carrier concentration will increase obviously with the decrease of temperature. It is found that MOS devices can still maintain excellent subthreshold characteristics at low temperature after quantization effect is taken into account. In the weak inversion region, the quantization effect has a greater influence on the carrier concentration.
Comparative study on turn-on voltage of modern MOSFET devices
, Liu, Li Zhijian
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
Heterogeneous doped devices have become one of the essential structures in the structural design of MOSFET devices because of their good short channel effect. The influence of channel impurity distribution on turn-on voltage is very important. In this paper, the concepts of surface strong inversion turn-on voltage and constant carrier concentration turn-on voltage are proposed for MOSFET devices with uneven substrate doping, and the equivalence of these two definitions is verified on the basis of numerical solutions. Then, the turn-on voltages of three typical channel doping devices, namely, uniform distribution of substrate impurities, step distribution and Gaussian distribution, are systematically compared and studied. The calculation structure verifies the function of the stepped impurity distribution structure to reduce the turn-on voltage, and the characteristics of the non-uniform doping structure to reduce the turn-on voltage compared with the uniform doping structure. The calculation results show that for the stepped structure, when the width of the low doped region is less than the thickness of the depletion layer, the thickness of the depletion layer is basically independent of the width of the low doped region. At the same time, an analytical model of turn-on voltage of MOS devices suitable for step impurity distribution is given.
Research on integrated micro-flow control system
Pang, Liu, Li Zhijian
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
The miniaturized and integrated micro-flow control system, which combines micro-flow control devices with micro-flow sensors and related signal processing and control circuits, has become one of the hot spots in MEMS research. The structure, working principle and manufacturing technology of integrated micro-flow control system are introduced. The test results show that the manufacturing process of the system is simple and completely compatible with the standard MOS process, which lays a foundation for the practical application of the micro-flow control system.
Study on micro-flow control characteristics of micro-flow pump
Pang, Liu, Li Zhijian
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
Micro-flow pump is a typical micro-actuator, which has a wide application prospect in the fields of medicine, chemistry, bioengineering and electronic engineering. Different applications have different requirements for the flow control of micro-flow pump, among which the application of chemical analysis system requires the micro-flow pump to realize stable and controllable micro-flow. Therefore, it is necessary to study the flow control characteristics of micro-flow pump in depth. At present, micro-flow pumps working in various driving modes have been developed [1-7], among which aluminum-silicon bimetal driving mode has been deeply studied because of its simple manufacturing process and easy integration with circuits [8]. In this paper, the flow control characteristics of micro-flow pump driven by Al-Si bimetal, especially the micro-flow control characteristics, are studied. The analysis and experimental results show that frequency is the best micro-flow control method among various control factors.
Design and Fabrication of Resonant Micro Accelerometer
Li, Liu and Yang Jingming
The 6th National Conference on Sensitive Components and Sensors, 1999.438+00, Beijing.
This paper reports the design and fabrication of a novel resonant micro-acceleration sensor with bulk silicon structure. The device uses current thermal excitation and piezoresistive bridge synchronous detection to obtain signal output. Its sensitive structure adopts the form of highly symmetrical four-corner support, and four resonant beams are made between the four sides of the mass block and the support frame for signal detection. The acceleration sensor adopts three-layer silicon structure, all of which are manufactured by silicon micromachining technology. The chip samples are packaged and tested, and the performance test results of the resonator are given.
A New Piezoresistive Acceleration Sensor
Li, Liu and Yang Jingming
Proceedings of the 11th National Conference on Integrated Circuits and Silicon Materials, 1999.9, Dalian.
In this paper, the different structures of piezoresistive acceleration sensor are analyzed and compared. The stress concentration distribution of sensitive structures in acceleration field is obtained, and the optimization design criteria are given. On this basis, the pressure-sensitive bridge is designed, and a new structure with high performance and surrounded support is proposed. The packaging test of the successfully developed acceleration sensor shows that its performance is good.
Optimal design and compatible technology research of silicon integrated micropump system
Pang, Liu, Li Zhijian
Journal of Tsinghua University, 39(S 1), 1999.
The working principle, structural optimization, circuit design, manufacturing process and preliminary experimental results of a new silicon integrated micropump system are introduced. The system has a three-piece structure, two of which are formed by bulk silicon micromachining technology, and the other is an integrated aluminum-silicon bimetal drive structure. The structural parameters of the driving structure are optimized and the working efficiency is improved. According to the manufacturing process characteristics of aluminum-silicon bimetal drive structure, the micro-flow sensor and signal processing circuit are integrated on the drive structure, and the system integration is realized. The manufacturing process of the integrated system is simple, and the micro-machining process adopted is completely compatible with the standard MOS process. The overall dimension of the integrated micropump is 6mm×6mm× 1mm, the maximum output back pressure is 10 kPa, and the maximum flow rate can reach 44mL/min.