We discuss the technical rationale, challenges, and potential for achieving the intimate integration of photonics components such as lasers, detectors, and modulators with VLSI electronics and review the progress made towards commercializing this technology for high-density optical transceivers and switching products.

This paper presents the combination of "bottom-up" layer-by-layer (LbL) nano self-assembly and "top-down" micromanufacturing techniques for MEMS and microelectronics applications. Two approaches, modified lift-off and metal mask, were utilized to pattern nano-assembled thin films effectively. With nano self-assembly and surface micromachining, highly flexible nanoparticle-based magnetic cantilever platform for micro sensing and actuation was self-assembled. Self-assembled magnetic thin films on polymeric tunneling sensors were functional as a polymer actuators for the actuation of highly sensitive sensors. For microelectronics devices, self-assembled silica nanoparticle thin film acted as the dielectric layer for field-effect transistors. Nanoparticle- and polymer-based field-effect transistors with embedded nano self-assembled films as dielectric and active layers were fabricated and characterized successfully as well.

Interferometric surface profiling, which combines high speed, accuracy, resolution and flexibility, has proven successful for measuring surface features of unpackaged MEMS (Micro-Electro-Mechanical Systems) and MOEMS (Micro-Opto-Electro-Mechanical Systems) devices. With the further productization of MEMS technology, however, devices also need to be tested in their final packaged state, typically beneath a protective, transparent cover. Objectives capable of imaging through transparent media at low magnifications have been available for several years. Increasingly, however, higher magnifications are required to resolve smaller critical features. At high magnifications, transmissive media can greatly degrade interferometric measurements due to dispersion and aberration effects. In this paper we describe an improved technique for measuring MEMS features through transmissive media, at magnifications as high as 40X. The technique enables improved dispersion compensation, reduced coherence effects, thickness variation insensitivity, and enhanced illumination. Measurement results are presented.

We propose a tunable micro-laser using a guided mode resonant grating (GMRG). The GMRG is used for both cavity and periodic gain medium. In order to realize the proposed device, first, the passive GMRG suitable for the wavelength filtering was investigated. Rigorous coupled wave analysis (RCWA) was used to design the grating. We found that the resonant reflection was obtained even in such structure that a single grating layer was suspended in the air. For tuning the wavelength of the GMRG, we propose the grating combined with a MEMS actuator. The GMRG combined with an electrostatic comb actuator was fabricated from SOI (silicon on insulator) wafer by Si micromachining. The period of the Si grating was varied form 600nm to 700nm. The peak of the reflectance shifted with the increase of the period in the visible and infrared region. In order to install the periodic gain structure in the Si MEMS, a monolithic fabrication of GaN device on Si substrate is studied. The GaN is a powerful material for the active optical devices in visible (especially blue) region. We studied the growth of GaN film on Si substrate using molecular beam epitaxy (MBE). Some basic characteristics of the GaN film grown on Si substrate were measured and analyzed. Furthermore, the self-suspended gratings with the periods around 500nm were fabricated form the GaN film grown on Si substrate.

This paper presents the fabrication and characterizations of a PZT actuated monolithic microstage with multi degrees of freedom (DOFs) used for high-precision positioning. The entire device is fabricated in a symmetrically arrangement from a PZT plate with a size of 15×15×0.8 mm³. Four actuation units with a displacement amplification mechanism are integrated in the structure. They can be driven individually which result in movements of a stage in different directions. The performances of the displacement and the resonant frequencies are simulated using a finite element method (FEM). Simulation results show the possibility of achieving a displacement of 8 μm in x- and y-axes and 10 μm in z-axis under the applied voltage of 100 V. A prototype has been fabricated and evaluated. Comparisons between FEM simulation and experimental results are carried out.

High-temperature and high-pressure connection between micro combustor and macro world for feeding of air/fuel gas is required in PowerMEMS development. A Kovar tubing-Glass-Si sealing process has been developed for an on-going PowerMEMS project to connect Kovar tubes with diameters of 2mm and 4mm, to top Si wafer of micro combustor fabricated by DRIE process. Due to the different CTEs (coefficients of thermal expansion) of the connected materials, thermal stress around the sealing area could probably influence the obturation and other properties of the sealed combustor. A numeric simulation on sealing of the structure was conducted on ANSYS software to investigate this kind of sealing process. The thermal stress and displacement from room temperature to combustion circumstance and to sealing condition as high as 1220K were simulated. The size affection of glass bonder and the metal tubes was investigated. A process of high temperature sealing Kovar-glass-silicon was developed and a prototype of the packaged micro combustor was manufactured.

We microfabricated a MEMS (Micro Electro Mechanical System) based thin palladium (Pd) membrane microreactor with oxidized porous silicon (PS) support. The membranes were characterized by permeation experiments with hydrogen, nitrogen, and helium at temperature ranging from 200°C to 250°C. The hydrogen flux through the Pd membrane with a thickness of 340 nm was 0.112 mol m^-2 s^-1 at 250°C and a partial pressure difference of 110 kPa. H₂/N₂ and H₂/He selectivity was about 46 and 10 at 250°C, respectively. The thermal isolation of the Pd membrane, which was heated by an integrated microheater, was realized by using the oxidized PS. We also carried out the hydrogenation of 1-butene at 250°C using the developed microreactor. The results of long term test of about three months suggest that Pd membrane microreactor has a potential to be used in practical applications.

An evanescent wave sensor made of few modes optical fiber was studied. The influence of the geometry of the sensing region, including absorbing medium refractive index n₂ and the core radius of the bare fiber a, on the modal fractional power in the cladding was analyzed. The percentage of the mode power in total guiding power was mainly calculated at different launching conditions, such as the incidence angle θ_i By analyzing the output power fraction from calculation and the experiment, the suitable parameters of the sensor could be chosen and the sensitivity was improved. The results will help the design in some way of this kind of sensor.

A novel nanopositioning stage was designed according to the scanning property of SPM with flexure hinge as kinematic structure and piezoelectric ceramic as actuator. Kinetic precision and X directional area of nanopositioner are 1.55nm and 26.4 micron, respectively, which is demonstrated by kinetic analysis and finite element method FEM simulation. Designed nanopositioner based on SPM moves at 3 dimensions with nanometer scale and its motion of X, Y, and Z directions is decoupled and isotropic. Furthermore, frame of nanopositioner is simple and manufacturing is convenient, which will have broad prospect in the field of nanopositioning and nanotracing.

A novel micro-mechanical temperature sensor is presented theoretically and experimentally. The working principle of this sensor is based on Optical interference theory of Fabry-Perot cavity that is formed between a polished optical fiber end and micro-mechanical Bi-layered membranes. When ambient temperature is changing, Bi-layered membranes will be deflected based on 'Bi-coating effect', and then the length of Fabry-Perot cavity will be changed correspondingly. By detecting the optical output of Fabry-Perot cavity resulted from the change of Fabry-Perot cavity length, the ambient temperature can be measured. First, using finite element software ANSYS, the structures of this sensor was designed and corresponding theoretical model was set up based on theoretical analysis; Second, the sensor structure was optimized based on Fabry-Perot optical Interference theory and Bi-layered membranes dimensions selection, and theoretical characteristics was given by simulation; Third, using optical fiber 2×2 coupler and photo-electrical detector, the fabricated sample sensor was tested successfully by experiment that demonstrating above theoretical analysis and simulation results. This sensor has some favorable features, such as: micro size owing to its micro-mechanical structure, high sensitivity owing to its working Fabry-Perot interference cavity structure, and optical integration character by using optical fiber techniques.

Vacuum packaging is very important for some micro-electro-mechanical systems (MEMS) devices to perform their basic functions properly and to enhance their reliability by keeping these devices away from harmful external environment. In order to maintain high vacuum in a cavity of MEMS devices, residual gases and leaking gases must be eliminated by getter materials embedded. This paper will report the fabrication and characterization of advanced getter, or micro/nano getters for MEMS applications.

High-temperature and high-pressure connection between micro combustor and macro world for feeding of air/fuel gas is required in PowerMEMS development. A Kovar tubing-Glass-Si sealing process has been developed for an on-going PowerMEMS project to connect Kovar tubes with diameters of 2mm and 4mm, to top Si wafer of micro combustor fabricated by DRIE process. Due to the different CTEs (coefficients of thermal expansion) of the connected materials, thermal stress around the sealing area could probably influence the obturation and other properties of the sealed combustor. A numeric simulation on sealing of the structure was conducted on ANSYS software to investigate this kind of sealing process. The thermal stress and displacement from room temperature to combustion circumstance, and to sealing condition as high as 1220K were simulated. The size affection of glass bonder and the metal tubes was investigated. A process of high temperature sealing Kovar-glass-silicon was developed and a prototype of the packaged micro combustor was manufactured.

The device of optical waveguide multilayer storage (WMS) consists of a stuck of slab optical waveguide. The guide waves are restricted within the addressed layer without leakage except for the defects where information is recorded. This phenomenon is employed in WMS for layer addressing and data reading to reduce the cross talk between layers. In this paper, we introduce the method of WMS device fabrication. The basic process includes writing data into monolayer waveguide and bonding the monolayers together as a multi-layers device. The method of data writing is based on the technique of conventional photolithography. To simplify the fabrication, an adhesive having refractive index lower than the core's is used as bonding material and functions as cladding medium as well. The bonding process by using RTV 615 silicone is described and the experimental observation of WMS device is demonstrated. The experimental results show that the described process is a feasible way to fabricate WMS device.

Light-induced waveguide arrays pave a way to implement massive parallel and adaptive interconnection, and provide a fertile ground for investigating self-localized states, better known as discrete solitons. In this paper, creating planar and channel waveguide arrays by illuminations of two- or four-beam interference fields are investigated both theoretically and experimentally in LiNbO₃:Fe, SBN:Cr, and KNSBN:Ce crystals. The distributions of refractive index changes induced by multi-beam interference fields with different orientations in various photorefractive crystals are numerically simulated. Employing illuminations of two-beam interference fields, planar waveguide arrays are experimentally demonstrated in an open circuit LiNbO₃:Fe crystal and biased SBN:Cr and KNSBN:Ce crystals. An approach for fabricating channel waveguide arrays by employing illuminations of two-beam interference fields is presented. By fabricating a square and a rectangular channel waveguide arrays in a LiNbO₃:Fe crystal this approach is experimentally demonstrated. Creating channel waveguide arrays using four-beam interference fields with different orientations are also performed in the three kinds of crystals. The index profiles of the light-induced waveguide arrays are measured employing the interferometric method or the digital holography. The near field patterns, diffraction patterns and the guiding test results show that the waveguide arrays are successfully fabricated.

The two-dimensional (2-D) dynamic cellular automata (CA) model for photoresist etching simulation has been originally extended to simulate the negative chemical amplification process to further investigate its possibility to simulate monolithic simulation of lithography processes. Simulation profiles of the 2-D dynamic CA model show a good agreement with experiment profiles, and the computation time of negative chemical amplification process using the 2-D dynamic CA model is greatly reduced compared with that of the 2-D static CA model. The results indicate that the 2-D dynamic CA model is accurate, fast, and capable of being integrated into monolithic lithography process simulation. This is identified to be greatly useful to increasingly needed monolithic simulation of various lithography processes for integrated circuits (IC), Microelectromechanical Systems (MEMS), and even future Nanoelectromechanical Systems (NEMS).

A novel ICP etch model based on time multiplexed deep etching is reported in this paper. 2-D and 3-D zonal simulations of surface evolvement can be performed using this model. The simulation is advanced with the simplex algorithm for surface evolvement and consequent higher efficiency than other reported hybrid algorithms. And the etching of different material types can also be simulated using this model. Simulations with different aspect ratios are performed in this paper and the results are quite perfect without aforehand experimental fitting.

A simplified numerical model for two-dimensional etched profile evolution is developed based on dynamics of plasma~surface interactions. The Lag effect, which is an important phenomenon in plasma etching, is detected in fixed-aspect-ratio structures by this model. So it may provide aid to theory and experiment research of plasma etching. The setting of time steps in numerical simulations is also discussed in this paper and the optimal time steps are proposed and verified.

This paper presents the development of system-level modeling and simulation of segmented deformable micromirror. We represent a system-level modeling methodology called Multi-Port-Element Network (MuPEN) method for micromirror design which is different from conventional finite-element analysis(FEA) and boundary-element analysis(BEA) method in the paper. Based on this method, the segmented deformable micromirror is decomposed into functional components such as rigid plate-mass, spring beam and electrostatic gap. MuPEN models of functional components have been generated and are coded in MAST language. Then a system-level model of segmented deformable micromirror is established using MuPEN models and both static and dynamic simulation is implemented in SABER. The resonance frequency, the pull-in voltage and the response time of the micromirror are ascertained through different simulations and the simulation results show that the micromirror we designed can satisfy the adaptive optical system requirements. Besides, the frequency analysis results are verified by comparison with ANSYS simulations, and the results prove that MuPEN method has near FEM accuracy. In addition, transient analysis results indicate that the computation cost is low enough and the simulation of complicated electro-mechanical coupled system which is hardly completed by FEM software can be accomplished quickly in this way.

A novel MEMS deformable mirror was proposed and characterized. Actuator deflection was simulated using one dimensional electromechanical model. The diaphragm was modeled as a double cantilever beam, with a gap-dependent electrostatic actuating force. The effect of the structural parameters and actuated voltages on the deflection of the actuator was closely studied. A lumped parameter model for predicting the reset transient motion of the actuator, taking into account tensile forces and viscous air damping via squeeze film theory, was used to determine the reset time. The results show that the elastic diaphragm thickness, the elastic diaphragm length and gap spacing have a strong effect on the deflection, the actuator displays typical nonlinear deflection versus voltage characteristics and electromechanical instability at elevated voltages. The reset transient motion of the actuator is an exponential decay oscillation line, the reset time is about 0.14μs.

A novel method for the fabrication of continuous micro-optical components is presented in this paper. It employs a computer controlled digital-micromirror-device(DMD^TM) as a switchable projection mask and silver-halide sensitized gelatin (SHSG) as recording material. By etching SHSG with enzyme solution, the micro-optical components with relief modulation can be generated through special processing procedures. The principles of etching SHSG with enzyme and theoretical analysis for deep etching are also discussed in detail, and the detailed quantitative experiments on the processing procedures are conducted to determine optimum technique parameters. A good linear relationship within a depth range of 4μm was experimentally obtained between exposure dose and relief depth. At last, the microlensarray with 256.8μm radius and 2.572μm depth was achieved. This method is simple, cheap and the aberration in processing procedures can be corrected in the step of designing mask, so it is a practical method to fabricate good continuous profile for low-volume production.

Wafer level thin film residual stress measurement is crucial for the structural reliability of many semiconductor and MEMS devices. The curvature measurement scheme is usually the most widely used method. Film stress is determined by converting the measured curvatures using Stoney formula. During the fabrication of the IC and MEMS devices, however, multilayered thin films are often generated on both sides of the wafer simultaneously. By extending the Stoney formula, this paper presents a method for measuring residual stress in the multilayered films on the wafer. In the method, only the back film layers of the wafer need to be etched in turn and corresponding curvature radii need to be measured by a full-field optical method. The residual stress of each film layer may then be obtained by the radii using the extended Stoney formula. The extended Stoney formula was verified by Coventorware. Experiments show that the proposed method is simple and accurate for process monitoring.

The micro-actuator with the torsion beam and the cantilever beam on silicon is designed and analyzed, which is actuated by electrostatic force. Based on the torsion dynamics theory, the technique and relative formula are presented for analyzing the actuating voltage and the switching time, on which the effect of the air squeeze film damping is already considered. The optimized results of the structural parameters are compared between this technique and the finite element modeling (FEM). The optimized result of parameters is as: length, width and thickness of the torsion beam are 700, 12, and 10μm, length and width of the cantilever beam are 1900 and 1000μm, length and width of the balance beam are 100 and 1000μm, and distance of the upper and lower electrodes is 55 μm, respectively. The actuating voltage is about 50 V, and the switching time T off and T on are about 5 and 12 ms, respectively. The computed results show that the air squeeze film damping is an important factor for the study of dynamic response on micro-actuator. Finally, an optical technique is described for the measurement of the actuating voltage and switching time of the device, and the difference between the experimental results and theoretical datum is discussed.

Microscopic interferometry is up to now the most widely used technique for microstructure surface profiling, and is also capable of measuring out-of-plane motion and deflection of microstructures with stroboscopic illumination. In this paper we put forward a stroboscopic Mirau microscopic interferometer system, which is built of commercially available components and instruments based on virtual instrument technology. An improved Fourier transform method (FTM) is described, and two interferograms with different phase shifting are processed for achieving reliable phase demodulation. The system is applied to the measurement of microcantilever surface profile and out-of-plane deflection and motion. Finally, experiment results are compared with that of temporal phase-shifting method for validating the process method.

Optical switch is one of key supporting technologies in all-optical-network (AON). And electrostatic MOEMS (Micro-Optical-Electro-Mechanical Systems) switch plays a very important role in all the researched switches, because of their excellent features, including low insertion, low crosstalk and scalability. But the packaging technology has been limiting the development of optical switch. In this paper, the authors study the laser beam propagating during the free space and select collimator, design the pedestal to packaging and address aspects of the insertion loss that are most important loss mechanisms for the 2D cross-connect switch.

The deflection analysis of a micro silicon cantilever beam actuated by electrostatic force is presented in this paper, from analysis, it has been shown that the force applied on the cantilever varies according to the deflection of cantilever, so, it is difficult to solve the differential equation of the deflection, especially, and the load is changing. A new increment method to solve this problem is presented, the cantilever is divided into a number of small segments, it is assumption that every segment has a constant concentrated force, and the electrostatic force is loaded on step by step, when the segment and load step is small enough, the simulation result will be limited to accuracy. In the same time, the frequency of the cantilever is also obtained.

A new type of high isolation RF MEMS switch is studied in this paper. The structure of cantilever beam with electrodes Sandwiched between Si and SiO2 layers has been evaluated. The top and bottom dielectric materials separate two conducting electrodes when actuated. Therefore the reliability has been improved greatly. The curves of the cantilever beam and the voltage have been simulated.

Micro machine vision system is an important part of a micromanipulating system which has been used widely in many fields. As the research activities on the micromanipulating system go deeper, micro machine vision system catches more attention. In this paper, micro machine vision system is treated as a kind of machine vision system with constrains and characteristics introduced by specific application environment. Unlike the traditional machine vision system, a micro machine vision system usually does not aim at the reconstruction of the scene. It is introduced to obtain expected position information so that the manipulation can be accomplished accurately. The architecture of the micro machine vision system is proposed. The key issues related to a micro machine vision system such as system layout, optical imaging device and vision system calibration are discussed to explain the proposed architecture further. A task-oriented micro machine vision system for biological micromanipulating system is shown as an example, which is in compliance with the proposed architecture.

In this paper, a 27um×27um novel grating light modulator supported by cantilevers has been presented, and it can be fabricated using silicon surface-micromachining technology. The structure and basic operation principle of grating light modulator is introduced. The structure is composed of grating plate, address electrode and four cantilevers, the grating plate, which is supported by four cantilevers placed around, is overhung about one wavelength of incidence light from the underlying address electrode, it is actuated like a piston by electrostatic force, and piston-type motion of grating can be used to modulate phase of incident light, therefore, the grating light modulator array is a potential device for projection displays and relevant devices for its intrinsic characteristics. Mechanics model is developed for deducing the deformation equation, the relationship between the electromechanical characteristics of the device and the geometrical parameters and material performance is analyzed, such as pull-in voltage, resonance frequency and step response time. Electromechanical coupled simulation is done by Coventorware, then, more reasonable geometrical parameters are obtained for fabricated in the next step.

The mechanism of beam shearing splitting and principle of the interfering imaging of the self-developed onboard Polarization Interference Imaging Spectrometer (PIIS) were expounded in this paper. The throughput of PIIS is analyzed. The relation of the throughput with the angle of the polarized orientation of the polarizer to the ideal direction is derived. This Polarization Interference Imaging Spectrometer has the merit of simple structure, no moving parts, and high throughput. Because of its unique advantage of static, compact in size, wide field of view, it is applicable for the aviation, spaceflight, remote sensing, fieldwork or weak signal detection.

In this paper, the authors report their resent results of the study on the epoxy resin compound X-ray refractive lens. At the first, the theoretical results of the structure parameters for such a device are given. Then, the fabrication technologies are presented. They are deep soft X-ray lithography, mold-manufacturing and molding. The material of X-ray photoresist is PMMA, the mold is made of silicone rubber, and the material of the lens is epoxy resin. Some measured results by means of optical microscope and SEM are also shown. The structure height of the epoxy resin compound lens is measured to be 500 micrometers.