• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.225-225
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• 2010

In this study, the optimum structure of a magnetic thin film inductor was designed for application of DC-DC converters. The $Ni_{81}Fe_{19}$ (at%) alloy was selected as a high-frequency($\geq$ MHz) magnetic thin film core material and deposited on various substrates (bare Si, $SiO_2$ coated Si) using a high vacuum RF magnetron sputtering system. As-deposited NiFe thin films show similar magnetic properties compared to bulk NiFe alloys, indicating that they have a good film quality. The optimum design of solenoid-type magnetic thin film inductors was performed utilizing a Maxwell computer simulator (Ansoft HFSS V7.0 for PC) and parameters obtained from the magnetic properties of magnetic core materials selected. The high-frequency characteristics of the inductance(L) and quality factor(Q) obtained for the designed inductors through simulation agreed well with those obtained by theoretical calculations, confirming that the simulated result is realistic. The optimum structure of high-performance ($Q{\geq}60$, $L\;=\;1{\mu}H$, efficiency${\geq}90%$), high-frequency (${\geq}5MHz$), and solenoid-type magnetic thin film inductors was designed successfully.

• Journal of IKEEE
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• v.12 no.3
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• pp.138-143
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• 2008

In this study, we propose that the structures of spiral inductors have the environment advantage utilizing direct-write and LAM(Laser Ablation of Microparticles) processes without process step of lithography and etching etc. of existing semiconductor process. The structures of inductors have Si thickness of 540${\mu}m$, $SiO_2$ thickness of 3${\mu}m$. The width of Cu coils and the space between segments have 30${\mu}m$, respectively, using for direct-write and LAM processes. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The inductors without underpass and via have inductance of 1.11nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 38 at 5 GHz, SRF of 18 GHz. Otherwise, inductors with underpass and via have inductance of 1.12nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 35 at 5 GHz, SRF of 16 GHz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1284-1287
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• 2012

In this study, we propose the structures of octagonal spiral planar inductors without underpass and via, and confirm the frequency characteristics. The structures of inductors have Si thickness of $300{\mu}m$, $SiO_2$ thickness of $7{\mu}m$. The width of Cu coils and the space between segments have $20{\mu}m$, respectively. The number of turns of coils have 3. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The octagonal spiral planar inductors have inductance of 2.5nH over the frequency range of 0.8 to 1.8 GHz, quality-factor of maximum 18.9 at 5 GHz, SRF of 11.1 GHz. Otherwise, square spiral planar inductors have inductance of 2.8nH over the frequency range of 0.8 to 1.8 GHz, quality-factor of maximum 18.9 at 4.9 GHz, SRF of 10.3 GHz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4101-4106
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• 2011

In this study, we propose that the structures of 2-layer spiral planar inductors have a lower spiral coil and via increasing inductance in limited possession are and confirm the frequency characteristics. The structures of inductors have Si thickness of $300{\mu}m$, $SiO_2$ thickness of $7{\mu}m$. The width of Cu coils and the space between segments have $20{\mu}m$, respectively. The number of turns of coils have 3. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The 2-layer spiral planar inductors have inductance of 3.2nH over the frequency range of 0.8 to 1.8 GHz, quality-factor of maximum 8.2 at 2.5 GHz, SRF of 5.8 GHz. Otherwise, 1-layer spiral planar inductors have inductance of 1.5nH over the frequency range of 0.8 to 1.8 GHz, quality-factor of maximum 18 at 8 GHz, SRF of 19.2 GHz.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.149-167
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• 2004

Passive components are indispensable in the design and development of microchips for high-frequency applications. Inductors in particular are used frequently in radio frequency (RF) IC's such as low-noise amplifiers and oscillators. This paper gives a broad overview on the on-chip spiral inductors. The design concept and modeling approach of the typical square-shaped spiral inductor are first addressed. This is followed by the discussions of advanced structures for the enhancement of inductor performance. Research works reported in the literature are summarized to aid the understanding of the recent development of such devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.139-142
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• 2001

As microeletronics technology continues to progress, there is also a continuous demand on highly integration and miniaturization of systems. For example, it is desirable to package several integrated circuits together in multilayer structure, such as multichip modules, to achieve higher levels of compactness and higher performance. Passive components (i.e., capacitors, resistors, and inductors) are very important for many MCM applications. In addition, the low-temperature co-fired ceramic (LTCC) process has considerable potential for embedding passive components in a small area at a low cost. In this paper, we investigate a method of statistically modeling integrated passive devices from just a small number of test structures. A set of LTCC inductors is fabricated and their scattering parameters (5-parameters) are measured for a range of frequencies from 50MHz to 5GHz. An accurate model for each test structure is obtained by using a building block based modeling methodology and circuit parameter optimization using the HSPICE circuit simulator.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.295-301
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• 2002

In this paper, solenoid-type 3-D passives (inductors and transformers) have been designed, fabricated, and characterized by using electroplating techniques, wire bonding techniques, multi-layer thick photoresist, and low temperature processes which are compatible with semiconductor circuitry fabrication. Two different fabrication approaches are performed to develop the solenoid-type 3-D passives and relationship of performance characteristics and geometry is also deeply investigated such as windings, cross-sectional area of core, spacing between windings, and turn ratio. Fully integrated inductor has a quality factor of 31 at 6 GHz, an inductance of 2.7 nH, and a self resonant frequency of 15.8 GHz. Bonded wire inductor has a quality factor of 120, an inductance of 20 nH, and a self resonant frequency of 8 GHz. Integrated transformers with turn ratios of 1:1 and n:l have the minimum insertion loss of about 0.6 dB and the wide bandwidth of a few GHz.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1498-1499
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• 1998

Thin film inductors of 10 mm ${\times}$ 10 mm with spiral pattern of 14 turns were fabricated by sputtering, photo-masking, and etching processes. Their impedence characteristics and annealing after effects were investigated. After magnetic annealing, the impedence characteristics of the inductors were improved at comparatively low frequencies, but the tendencies of it for thr frequency changes were almost same. These improvement was caused by the annihilation of the internal stresses of films, Uniaxial field annealed thin film inductor had an inductance of 1000 nH, resistance of 6 $\Omega$, and quality factor of 1 at 2 MHz.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.233-236
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• 2002

This paper has been designed and fabricated C-type micro, high-performance solenoid RF chip inductors with the size of 1.58$\times$0.82r0.94m0. The high frequency characteristics of simulated results obtained by HFSS were compared to those of measured results obtained by RF Impedance/Material Analyzer (HP16193A). Although the simulated inductance values were two times larger than the measured values and there are discrepancies in SRFs between simulated and measured values, it was observed that tile Q-factor values for fabricated inductors could be predicted from the simulated values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.8
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• pp.780-784
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• 2006

We present high aspect ratio air-core solenoid inductors with $100{\mu}m\;and\;200{\mu}m$ tall via structures on Pyrex wafer. The effect of various parameters such as different number of turns, via heights, pitch distance between turns on inductor's radio frequency (RF) characteristics have been studied. The highest Q factor we obtained from various solenoid inductors is 72.8 at 9.7 GHz, which was produced by a 3-turn inductor.