• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.4
• /
• pp.25-29
• /
• 2002

We have fabricated a vertical trench Hall device which is sensitive to the magnetic field parallel to the sensor surface. The vertical trench Hall device has been built on SOI wafer which is produced by silicon direct bonding technology using bulk micromachining, where buried $SiO_2$ layer and surround trench define active device volume. Sensitivity up to 150 V/AT has been measured.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.49 no.9
• /
• pp.495-501
• /
• 2000

This paper presents a method to minimize the initial deflection of a multi-layer piezoelectric microactuator without loosing its piezoelectric deflection performance required for light modulating micromirror devices. The multi-layer piezoelectric actuator composed of PZT silicon nitride and platinum layers deflects or buckles due to the gradient of residual stress. Based on the structural analysis results and relationship between process conditions and mechanical properties we have modified the fabrication process and the thickness of thin film layers to reduce the initial residual stress deflection without decreasing its piezoelectric deflection performance. The modified designs fabricated by surface-micromachining process achieved the 77% reduction of the initial deflection compared with that of the conventional method based on the measured micromechanical material properties is applicable to the design refinement of multi-layer MEMS devices and micromechanical structures.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.49 no.10
• /
• pp.583-588
• /
• 2000

This paper presents the design and fabrication of micro electromagnetic vibration silicon elastic body characterized with small size, high efficiency and selective frequency bandwidth for Bio-MENS applications, such as implantable middle ear hearing aid. The presented electromagnetic vibration transducer that composed of wounded coil, permanent magnet and 4-beam cross type elastic body is fabricated by using of micromachining technology. The fabricated transducer has experimental characteristics, that is 5 nm/mA of an energy trasfer rate at the frequency range of 100∼2800 Hz. It has a size of $2{\times}2{\times}2.5\;mm^3$.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.6
• /
• pp.271-277
• /
• 2002

In this paper, a MEMS silicon package is newly designed, fabricated for HMIC, and characterized for microwave and millimeter-wave device applications. The proposed package is fabricated by using two high resistivity silicon substrates and surface/bulk micromachining technology. It has a good performance characteristic such as -20㏈ of $S_11$/ and -0.3㏈ of $S_21$ up to 20㎓, which is useful in microwave region. It has also better heat transfer characteristics than the commonly used ceramic package. Since the proposed silicon MEMS package is easy to fabricate and wafer level chip scale packaging is also possible, the production cost can be much lower than the ceramic package. Since it will be a promising low-cost package for mobile/wireless applications.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3286-3288
• /
• 1999

The electrostatically actuated test structure was presented to measure the micro mechanical characteristics of micromaterials as thin films forming the microactuators. The test structure was fabricated by the surface micromachining processes and driven by the electrostatic force, In order to measure the fracture toughness, the sharp notch in the test structure was introduced by the etching process. On the basis of the beam bending theory, the elastic modulus was measured by using the microcantilevr beam and the mechanical displacement, curvature and deflection curve under the electrostatic force was evaluated by using the electrostatic structure.

• Journal of Sensor Science and Technology
• /
• v.17 no.6
• /
• pp.425-428
• /
• 2008

This paper describes the resonant characteristics of polycrystalline SiC micro resonators. The $1{\mu}m$ thick polycrystalline 3C-SiC cantilevers with different lengths were fabricated using a surface micromachining technique. Polycrystalline 3C-SiC micro resonators were actuated by piezoelectric element and their fundamental resonance was measured by a laser vibrometer in vacuum at room temperature. For the $100{\sim}40{\mu}m$ long cantilevers, the fundamental frequency appeared at $147.2kHz{\sim}856.3kHz$. The $100{\mu}m$ and $80{\mu}m$ long cantilevers have second mode resonant frequency at 857.5.kHz and 1.14.MHz, respectively. Therefore, polycrystalline 3C-SiC resonators are suitable for RF MEMS devices and bio/chemical sensor applications.

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.251-253
• /
• 2002

We have fabricated a novel Vertical Trench Hall-Effect Device sensitive to the magnetic field parallel to the sensor chip surface for non-contact angular position sensing applications. The Vertical Trench Hall-Effect Device is built on SOI wafer which is produced by silicon direct bonding technology using bulk micromachining, where buried $SiO_2$ layer and surround trench define active device volume. Sensitivity up to 150 V/AT is measured.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.194-195
• /
• 2003

가속도 센서는 물체의 움직임, 속도의 변화, 충격, 진동 등의 동적힘을 순시적으로 감지하여 유용한 정보로 변환시키는 장치이다. 본 논문에서는 실리콘 기계 구조물과 광섬유형 Fabry - Perot 센서(FFPI)를 사용하여 광섬유 간섭계형 가속도 센서를 제작하였으며 실리콘 구조물의 구조를 변경하여 용도에 적합한 다양한 센서를 제작할 수 있음을 보였다. 광 간섭계는 그 구조에 따라 Fabry - Perot$^{[2]}$ , Mach-Zender$^{[3]}$ , Michelson$^{[4]}$ , Sagnac$^{[5]}$ 등으로 구분되면 이러한 간섭계 중에서 Fabry - Perot 간섭계는 측정영역이 두 반사막의 거리로 정확하게 정의되며 반사막의 거리를 조절하여 좁은 영역에서의 측정이 가능하고 고감도를 갖는다. (중략)

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.2
• /
• pp.481-487
• /
• 1996

A snapping-beam microswitch has been designed, fabricated and tested. From a design analysis, necessary and sufficient conditions for a snap-through switching fouction have been derived for a clamped shallow beam. The necessary condition has resulted in a geometric relation, in which the ratio of beam thickness to initial beam deflection plays a key role in the snapping ability. The sufficient condition for the snapping action has been obtained as a function of the inertia force due to applied acceleration, and the electrostatic force, adjustable by an inter-electrode voltage. For experimental investigations, a set of microbeams of silicon dioxide/$P^+$silicon bimorphs have been fabricated. Geometric size and mechanical behavior of each material film have been measured from on-chip test structures. Estimated and measured characteristics of the fabricated devices are compared.

• Journal of IKEEE
• /
• v.1 no.1 s.1
• /
• pp.1-10
• /
• 1997

It is well-known that rectangular bulk-Si sensors prepared by etch or epi etch-stop micromachining technology are already in practical use today, but the conventional bulk-Si sensor shows some drawbacks such as large chip size and limited applications as silicon sensor device is to be miniaturized. We consider a circular-shape SOI(Silicon-On-Insulator) micro-cavity technology to facilitate multiple sensors on very small chip, to make device easier to package than conventional sensor like pressure sensor and to provide very high over-pressure capability. This paper demonstrates the cross-functional results for stress analyses(targeting $5{\mu}m$ deflection and 100MPa stress as maximum at various applicable pressure ranges), for finding permissible diaphragm dimension by output sensitivity, and piezoresistive sensor theory from two-type SOI structures where the double SOI structure shows the most feasible deflection and small stress at various ambient pressures. Those results can be compared with the ones of circular-shape bulk-Si based sensor$^{[17]}. The SOI micro-cavity formed the sensors is promising to integrate with calibration, gain stage and controller unit plus high current/high voltage CMOS drivers onto monolithic chip.