Browsing by Author "Shih, YC"

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A new CMOS pixel structure for low-dark-current and large-array-size still imager applications
(2004-11-01)
Shih, YC
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new pixel structure for still CMOS imager application called the psedoactive pixel sensor (PAPS) is proposed and analyzed in this paper. It has the advantages of a low dark current, high signal-to-noise ratio, and a high fill factor over the conventional passive pixel sensor imager or active pixel sensor imager. The readout circuit called the zero-bias column buffer-direct-injection structure is also proposed to suppress both the dark current of the photodiode and the leakage current of row switches by keeping both biases of photodiode and the parasitic p-n junction in the column bus at or near zero voltage. The improved double delta sampling circuits are also used to suppress fixed pattern noise, clock feedthrough noise, and channel charge injection. An experimental chip of the proposed PAPS. CMOS imager with the format of 352 x 288 (CIF) has been fabricated by using a 0.25-mum single-poly-five-level-metal (1P5M) n-well CMOS process. The pixel size is 5.8 mum x 5.8 mum. The pixel readout speed is from 100 kHz to 10 MHz, corresponding to the maximum frame rate above 30 frames/s. The proposed still CMOS imager has a fill factor of 58%, chip size of 3660 mum x 3500 mum, and power dissipation of 24 mW under the power supply of 3.3 V. The experimental chip has successfully demonstrated the function of the proposed new PAPS structure. It can be applied in the design of large-array-size still CMOS imager systems with a low dark current and high resolution.
Active feedback microstrip leaky wave antenna-synthesiser design with suppressed back lobe radiation
(1999-04-01)
Shih, YC
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Chen, SK
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Hu, CC
;
Jou, CF
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傳播研究所
The design of an active leaky-wave antenna which integrates the antenna with a feedback synthesiser is introduced. The measurement result shows that the antenna has very low back lobe radiation compared with that of traditional single-terminal feeding leaky-wave antennas. Single frequency measurement shows that the radiated power differmce between the main beam and back lobe is >15 dB at 8.2 GHz For the designed feedback synthesiser antenna, the measured radiated power difference between the main beam and back lobe is >15dB at 9.25 GHz, and the scanning angle is similar to 5 degrees as the synthesiser frequency sweeps from 9.25 to 9.37 GHz.
Beam-switchable scanning leaky-wave antenna
(2000-03-30)
Wang, CJ
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Shih, YC
;
Jou, CF
;
傳播研究所
;
Institute of Communication Studies
A beam-switchable scanning leaky-wave antenna (LWA) has been developed. This LWA with a two-terminal feeding microstrip, line structure is integrated with a single port double throw (SPDT) snitch as a control circuit. In dual-beam mode, the scanning angle is steered over a range of 36-64 degrees for the right-hand beam and 144 -116 degrees for the left-hand beam. In one-beam made, the scanning angle is measured over 20 degrees for the right-hand beam. The measured result shows that we can change from the, one-beam mode to the dual-beam mode electronically by controlling the on/off status of an SPDT switch, in contrast to the case For traditional leaky wave antennas.
CMOS chip as luminescent sensor for biochemical reactions
(2003-06-01)
Lu, U
;
Hu, BCP
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Shih, YC
;
Yang, YS
;
Wu, CY
We describe a novel biochemical sensing method and its potential new biosensing applications. A light-sensitive complementary metal oxide semiconductor (CMOS) chip prepared through a standard 0.5-mum CMOS process was developed for measuring biochemical reactions. A light producing enzymatic reaction catalyzed by horseradish peroxidase (HRP) was designed as a platform reaction to determine the concentration of hydrogen. peroxide (H2O2) by the CMOS chip with a standard semiconductor parameter analyzer (HP4145). The kinetics of enzymatic reaction were determined and compared with a standard and sophisticated fluorometer (Hitachi F-4500) in a biochemical laboratory. Similar results were obtained by both instruments. Using glucose oxidase as an example, we further demonstrated that the HRP platform can be used to determine other H2O2 producing reactions with the CMOS system. The result points to an important application of the CMOS chip in biological measurements and in diagnosis of various health factors.
Design, optimization, and performance analysis of new photodiode structures for CMOS active-pixel-sensor (APS) imager applications
(2004-02-01)
Wu, CY
;
Shih, YC
;
Lan, JF
;
Hsieh, CC
;
Huang, CC
The dark current in the active-pixel-sensor (APS) cell of a CMOS imager is known to be mainly generated in the regions of bird's beak after the local oxidation of silicon process as well as the surface damage caused by the implantation of high doping concentration. Furthermore, shallow and deep pn-junctions can improve the photo-sensitivity for light of short and long wavelengths, respectively. In this paper, two new photodiode structures using p-substrate and lightly-doped sensor implant SN- as pn-junction photodiode with the regions of bird's beak embraced by SN- and p-field implants, respectively, are proposed and analyzed to reduce dark current and enhance the overall spectral response. 5 mum x 5 pm APS cells fabricated in a 0.35-mum single-poly-triple-metal (1P3M) 3.3-V CMOS process are designed by using the proposed photodiode structures. As shown from the experimental results, the two proposed photodiode structures of 5 pin x 5 pm APS cells have lower dark currents of 30.6 mV/s and 35.2 mV/s at the reverse-biased voltage of 2 V and higher spectral response, as compared to the conventional structure and other photodiode structures. Thus, the two proposed new photodiode structures can be applied to CMOS imager systems with small pixel size, high resolution, and high quality.
Detection of serum uric acid using the optical polymeric enzyme biochip system
(2004-07-15)
Huang, SH
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Shih, YC
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Wu, CY
;
Yuan, CJ
;
Yang, YS
An optical polymeric biochip system based on the complementary metal oxide semiconductor (CMOS) photo array sensor and polymeric enzyme biochip for rapidly quantitating uric acid in a one-step procedure was developed. The CMOS sensor was designed with N+/P-well structure and manufactured using a standard 0.5 mum CMOS process. The polymeric enzyme biochip was immobilized with uricase-peroxidase and used to fill the reacting medium with the sample. This study encompasses the cloning of the Bacillus subtilis uricase gene and expression in Escherichia coli, as well as the purification of uricase and measurement of its activity. The cloned uricase gene included an open reading frame of 1491 nucleotides that encodes a protein of approximately 55 kDa. The expression of the putative MBP-fusion protein involved approximately 98 kDa of the protein. The CMOS sensor response was stronger at a higher temperature range of 20-40degreesC, with optimal pH at 8.5. The calibration curve of purified uric acid was linear in the concentration range from 2.5 to 12.5 mg/dL. The results obtained for serum uric acid correlated quite closely with those obtained using the Beckman Synchron method. (C) 2004 Elsevier B.V All rights reserved.
Optimal design of CMOS pseudoactive pixel sensor (PAPS) structure for low-dark-current and large-array-size imager applications
(2005-10-01)
Shih, YC
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a pixel structure called the optimal pseudoactive pixel sensor (OPAPS) is proposed and analyzed for the applications of CMOS imagers. The shared zero-biased-buffer in the pixel is used to suppress both dark current of photodiode and leakage current of pixel switches by keeping both biases of photodiode and parasitic pn junctions in the pixel bus at zero voltage or near zero voltage. The factor of photocurrent-to-dark-current ratio per pixel area (PDRPA) is defined to characterize the performance of the OPAPS structure. It is found that a zero-biased-buffer shared by four pixels can achieve the highest PDRPA. In addition, the column sampling circuits and output correlated double sampling circuits are also used to suppress fixed-pattern noise, clock feedthrough noise, and channel charge injection. An experimental chip of the proposed OPAPS CMOS imager with the format of 352 x 288 (CIF) has been designed and fabricated by using 0.25-mu m single-poly-five-level-metal (1P5M) N-well CMOS process. In the fabricated CMOS imager, one shared zero-biased-buffer is used for four pixels where the PDRPA is equal to 47.29 mu m(-2). The fabricated OPAPS CMOS imager has a pixel size of 8.2 x 8.2 mu m, fill factor of 42%, and chip size of 3630 x 3390 mu m. Moreover, the measured maximum frame rate is 30 frames/s and the dark current is 82 pA/cm(2). Additionally, the measured optical dynamic range is 65 dB. It is found that the proposed OPAPS structure has lower dark current and higher optical dynamic range as compared with the active pixel sensor (APS) and the conventional passive pixel sensor (PPS). Thus, the proposed OPAPS structure has high potential for the applications of high-quality and large-array-size CMOS imagers.
The design of a novel complementary metal oxide semiconductor detection system for biochemical luminescence
(2004-05-15)
Lu, U
;
Hu, BCP
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Shih, YC
;
Wu, CY
;
Yang, YS
We designed a complementary metal oxide semiconductor (CMOS) chip with accompanied accessories as a system for the detections and quantifications of biochemical luminescence. This is the first of such instruments that has been reported. The semiconductor chip was manufactured through a 0.25 mum CMOS standard process. A current mirror was designed in integrated circuit (IC) to amplify the signal current that was induced by chemiluminescence. Horseradish peroxidase (HRP)-luminol-H2O2 system was used as an example to constitute a useful platform for coupling to chemiluminescence reactions which produce H2O2. Glucose-glucose oxidase (GOD) reaction was coupled with HRP-luminol-H2O2 reaction to demonstrate the ability of the novel CMOS base instrument for quantifying the biological luminescence of a variety of valuable clinical assays. Our results illustrated that the combination of the specifically designed CMOS IC and commercially available electronic devices established a simple and useful bioanalytical tool. (C) 2003 Elsevier B.V. All rights reserved.
The design of high-performance 128Xi28 CMOS image sensors using new current-readout techniques
(1999)
Shih, YC
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An 128x128 high-performance CMOS image sensor is designed by using shared-buffer direct injection (SBDI) biasing technique and shared off-focal-plane-array (off-FPA) integration capacitor structure [1]-[2]. Each pixel contains only a photodiode and a MOS switch. The pixel size is 30x30 mu m(2) and can be further shrunk. Due to the new SBDI biasing technique, the linearity and the dynamic range of the CMOS image sensor are increased. The use of shared off-FPA integration capacitor leads to large charge capacity and dynamic range. The CMOS image sensor has charge capacity of 5x10(7) electrons, transimpedance of 5x10(8) ohms at 20nA background current, and power dissipation of 30mW under 5V power supply. Moreover, the current-mode background suppression and dynamic discharge source follower output stage are proposed to further increase the signal dynamic range and improve the speed performance of output stage. The designed CMOS image sensor is fabricated by 0.5 mu m double-poly double-metal (DPDM) n-well CMOS technology. The function and performance of the proposed CMOS image sensor have been verified by experimental results.