Browsing by Author "Chen, CN"

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A highly sensitive CMOS compatible thermal-type microsensor
(1999)
Sheen, CS
;
Chen, CN
;
光電工程學系
;
Department of Photonics
A CMOS compatible thermal-type microsensor was fabricated with large sensitive area and ultra-low solid thermal-conductance. To reach high performance, a floating circular membrane with diameter, 460 mu m and lead length, 393 mu m, was formed after anisotropic etching the silicon substrate. The large membrane is well supported with four curved leads, which greatly release the residual stress. The highly sensitivity is reached by the extremely low solid conductance (10(-6) W/C), which is lower than the published data; the large active area give better response than other works. Output voltage versus frequency was measured and thermal conductance was characterized by DC method.
Fabrication and study of a shallow-gap Pirani vacuum sensor with a linearly measurable atmospheric pressure range
(1999-01-01)
Chou, BCS
;
Chen, CN
;
Shie, JS
;
光電工程研究所
;
Institute of EO Enginerring
A Pirani vacuum sensor with a shallow gap between its heated element and its surrounding substrate heat-sink was fabricated using polysilicon as a sacrificial layer. The polysilicon was post-etched by TMAH solution, and an anti-stiction method was used in several steps of the process including a crucial freeze-drying one. The smallest spacing in this device is 0.3 mu m, and via this narrow gap, the heat conductance from the gas-molecule-collisions from the hot element to the heat sink is greatly enhanced in the atmospheric pressure regime. Therefore, this Pirani vacuum sensor is capable of detecting gas pressure linearly up to around 7 bars. As for the low-pressure regime, a partial dummy compensation method reduces the ambient temperature drift effectively and pressure lower than 10(-3) Torr was measurable. Moreover, device packaging was also studied to protect the tiny sensor from any contamination including dust and particles.
Fabrication and study of a shallow-gap Pirani vacuum sensor with a linearly measurable atmospheric pressure range
(1999-01-01)
Chou, BCS
;
Chen, CN
;
Shie, JS
;
光電工程學系
;
Department of Photonics
A Pirani vacuum sensor with a shallow gap between its heated element and its surrounding substrate heat-sink was fabricated using polysilicon as a sacrificial layer. The polysilicon was post-etched by TMAH solution, and an anti-stiction method was used in several steps of the process including a crucial freeze-drying one. The smallest spacing in this device is 0.3 mu m, and via this narrow gap, the heat conductance from the gas-molecule-collisions from the hot element to the heat sink is greatly enhanced in the atmospheric pressure regime. Therefore, this Pirani vacuum sensor is capable of detecting gas pressure linearly up to around 7 bars. As for the low-pressure regime, a partial dummy compensation method reduces the ambient temperature drift effectively and pressure lower than 10(-3) Torr was measurable. Moreover, device packaging was also studied to protect the tiny sensor from any contamination including dust and particles.
Fabrication of a sensitive germanium microbolometer for tympanic thermometry
(1999-01-01)
Chen, CN
;
Shie, JS
;
光電工程研究所
;
Institute of EO Enginerring
Fabrication of a complementary-metal-oxide-semiconductor (CMOS)-process-compatible microbolometer for tympanic thermometry using an amorphous germanium thin film as the temperature-sensitive element has been studied. Heat treatment of the deposited films, with or without passivation, at different annealing temperatures was investigated for optimizing the sensitivity of the material and for considering the compatibility of the CMOS process. Microbolometers structured with a thermally isolated membrane to enhance the thermal responsivity were fabricated by micromachining. The fabricated devices were characterized by conducting appropriate experiments and evaluated for the necessary thermal and electrical parameters useful in applications. It has been found that, for an annealing condition around 370 degrees C for two hours, the passivated floating Ge thermistor has a 3%/degrees C temperature coefficient of resistance (TCR) and a comparably low flicker noise relative to other conditions. In a vacuum, the passivated device with an area of 250x250 mu m(2) shows a responsivity up to 400 kV/W at 1 Hz, and a normalized detectivity D* of 1.2x10(8) and 5.2x10(7) cmHz(1/2)/W at 3 Hz and 30 Hz, respectively. These measured values also prove that the device, in its current structure, can be used as a sensitive radiation detector for tympanic thermometers.
Fabrication of a sensitive germanium microbolometer for tympanic thermometry
(1999-01-01)
Chen, CN
;
Shie, JS
;
光電工程學系
;
Department of Photonics
Fabrication of a complementary-metal-oxide-semiconductor (CMOS)-process-compatible microbolometer for tympanic thermometry using an amorphous germanium thin film as the temperature-sensitive element has been studied. Heat treatment of the deposited films, with or without passivation, at different annealing temperatures was investigated for optimizing the sensitivity of the material and for considering the compatibility of the CMOS process. Microbolometers structured with a thermally isolated membrane to enhance the thermal responsivity were fabricated by micromachining. The fabricated devices were characterized by conducting appropriate experiments and evaluated for the necessary thermal and electrical parameters useful in applications. It has been found that, for an annealing condition around 370 degrees C for two hours, the passivated floating Ge thermistor has a 3%/degrees C temperature coefficient of resistance (TCR) and a comparably low flicker noise relative to other conditions. In a vacuum, the passivated device with an area of 250x250 mu m(2) shows a responsivity up to 400 kV/W at 1 Hz, and a normalized detectivity D* of 1.2x10(8) and 5.2x10(7) cmHz(1/2)/W at 3 Hz and 30 Hz, respectively. These measured values also prove that the device, in its current structure, can be used as a sensitive radiation detector for tympanic thermometers.
Fabrication of low-stress dielectric thin-film for microsensor applications
(1997-12-01)
Chou, BCS
;
Shie, JS
;
Chen, CN
;
光電工程研究所
;
Institute of EO Enginerring
A method of fabricating low-stress dielectric thin film as the supporting material of micromachined devices is reported. The film is processed by post thermal oxidation of silicon-rich nitride (SN) deposited on silicon substrate by LPCVD. Due to the compensation on the nitride by its top oxide, an ultra-low residual less than 10 MPa can be obtained with proper oxidation scheme. Characteristics of the oxidized nitride were analyzed by Auger electron spectroscopy (AES) and ellipsometry. Large floating membranes of 4 x 4 cm(2) and 400-nm thick can be made by this method with TMAH etching.
Fabrication of low-stress dielectric thin-film for microsensor applications
(1997-12-01)
Chou, BCS
;
Shie, JS
;
Chen, CN
;
交大名義發表
;
光電工程學系
A method of fabricating low-stress dielectric thin film as the supporting material of micromachined devices is reported. The film is processed by post thermal oxidation of silicon-rich nitride (SN) deposited on silicon substrate by LPCVD. Due to the compensation on the nitride by its top oxide, an ultra-low residual less than 10 MPa can be obtained with proper oxidation scheme. Characteristics of the oxidized nitride were analyzed by Auger electron spectroscopy (AES) and ellipsometry. Large floating membranes of 4 x 4 cm(2) and 400-nm thick can be made by this method with TMAH etching.
Micromachining on (111)-oriented silicon
(1999-06-08)
Chou, BCS
;
Chen, CN
;
Shie, JS
;
光電工程學系
;
Department of Photonics
Micromachining on (111)-oriented silicon in various alkaline solutions was studied. By means of spoke and donut-like etching patterns, the experiment shows that [110] directions have the highest etch rate and the final emergent periphery is hexagon bounded on the bottom surface plane. The six sidewalls are defined by {111} planes, which can be derived from its crystal geometry, having three facets with inclining angles of 70.5 degrees and another three with declining angles of 109.5 degrees respect to the (111) surface plane. SEM pictures show that aqueous KOH solution results in smooth surface morphology due to its higher etch rate of residual oxide existed in the silicon, while the other etchants such as hydrazine (N2H4) and tetramethyl ammonium hydroxide (TMAH) induce seriously wavy roughness. Moreover, various concentrations of KOH solution have been studied to determine the (110)/(111) etch ratio, and the ratio more than 100 were demonstrated. Using this method, suspended single-crystal silicon (c-Si) microstructures were fabricated for some potential uses such as thermopile, silicon bolometer, mass flow transducer and other force microsensors. As an application example, shallow-gap mu-Pirani vacuum sensor demonstrated its high pressure measuring capability as high as 10(3) Torr. (C) 1999 Elsevier Science S.A. All rights reserved.
Multi-gigabit pre-emphasis design and analysis for serial link
(2005-10-01)
Lin, CH
;
Tsai, CH
;
Chen, CN
;
Jou, SJ
;
電子工程學系及電子研究所
In this paper, a multi-Gbps pre-emphasis design methodology and circuits for a 4/2 Pulse Amplitude Modulation (PAM) transmitter of high-speed data serial link over cable are proposed. Theoretically analysis of the total frequency response including pre-emphasis, package, cable loss and termination are first carried out. In order to gain higher data rates without increasing of symbol rate, we use 4 PAM in our system. Then, we propose a pre-emphasis architecture and algorithm that can enlarge the high frequency response so the overall frequency response in the receiver side is uniform within the desired frequency range. The overall circuit is implemented in TSMC 0.18 mu m 1P6M 1.8 V CMOS process. A test chip of this transmitter with pre-emphasis, PLL circuit and on-chip termination resistors is implemented by full custom flow to verify the design methodology. The measurement results of 10/5 Gbps (4/2 PAM) are carried out over 5 meter (m) long cable and is in agreement with our analysis and Simulation results.
Multi-gigabit serial link transmitter- off-chip and on-chip
(2005)
Jou, SJ
;
Lin, CH
;
Chen, CN
;
Wang, YJ
;
Hsiao, JY
Multi-Gbps serial link transmitter for both off-chip and on-chip transmission are presented. For off-chip transmission, a new pre-emphasis design methodology and circuits for a 4/2 PAM transmitter over cable are proposed. A test chip of transmitter with pre-emphasis, PLL circuit and on-chip termination resistors is implemented using tsmc 0.18 urn CMOS process. The measurement results of 1015 Gbps (4/2 PAM) are carried out over 5 meter (m) long cable and is in agreement with our analysis and simulation results. For on-chip transmission, SerDes based serial link architecture is used in on-chip application. Using tsmc 0.13 um CMOS process, the operation speed and power consumption are 5 Gbps and 3.2 mW respectively with the interconnect area is half of parallel architecture.