Browsing by Author "Tsai, MY"

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10 Gbps InGaAs : Sb-G-aAs-GaAsP quantum well vertical cavity surface emitting lasers with 1.27 mu m emission wavelengths
(2005-04-01)
Chang, YH
;
Kuo, HC
;
Chang, YA
;
Chu, JT
;
Tsai, MY
InGaAs:Sb-GaAs-GaAsP vertical cavity surface emitting lasers (VCSELs) with 1.27 mu m emission wavelength were grown by metal-organic chemical vapor deposition (MOCVD) and exhibited excellent performance and temperature stability. The threshold current changes from 1.8 to 1.1 mA and the slope efficiency falls less than similar to 35% as the temperature is increased from room temperature to 70 degrees C. With a bias current of only 5 mA, the 3 dB modulation frequency response was measured to be 8.36GHz, which is appropriate for 10Gb/s operation. The maximal bandwidth is measured to be 10.7GHz With a modulation current efficiency factor (MCEF) of similar to 5.25 GHz/(mA) 1/2. Bit error rates of less than 10(-12) are demonstrated for 10 Gb/s data transmission from 25 degrees C to 70'C. We also accumulated life test data up to 1000 h at 70 degrees C/10 mA.
Advanced handoff controls in third generation CDMA wireless systems
(2004)
Huang, CY
;
Tsai, MY
;
Huang, J
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In a wireless communication system, there exits it non-linear relationship among the connection quality, the overall interference level, and the required resources. To meet the handoff design challenges in 3G systems, we will demonstrate the need of having a flexible handoff control algorithm. The proposed algorithms will be evaluated again other existing handoff algorithms based on the performance of the connection quality, the forward-link power budget, the channel element usage, and the handoff frequency.
Enhanced negative-bias-temperature instability of P-channel metal-oxide-semiconductor transistors due to plasma charging damage
(2002-04-01)
Lee, DY
;
Lin, HC
;
Wang, MF
;
Tsai, MY
;
Huang, TY
The effects of plasma charging on the negative-bias-temperature instability (NBTI) of p-channel metal-oxide-semiconductor (PMOS) transistors were explored in this work. It is clearly shown that the threshold voltage shift during bias-temperature stressing (BTS) could be enhanced by plasma charging damage. More importantly, we also found that electron trappings are aggravated by plasma charging, even on new devices with large antenna area ratios prior to BTS. Our charge pumping current measurements confirm that the interface-state density is increased for devices with large antennas, both before and after the BTS. This indicates, without ambiguity, that electron trapping is solely responsible for the observed low (in absolute value) threshold voltage in new devices with large antennas. Finally, it is proposed that the NBTI characterization can be used as a sensitive method for characterizing the antenna effects in devices with ultrathin gate oxide, which is particularly attractive in light of the fact that conventional indicators are becoming inadequate as oxide is scaled down.
High-speed modulation of InGaAs : Sb-GaAs-GaAsP quantum-well vertical-cavity surface-emitting lasers with 1.27-mu m emission wavelength
(2005-03-01)
Kuo, HC
;
Chang, YH
;
Yao, HH
;
Chang, YA
;
Lai, FI
1.27-mum InGaAs: Sb-GaAs-GaAsP vertical-cavity surface-emitting lasers (VCSELs) were grown by metal-organic chemical vapor deposition and exhibited excellent performance and temperature stability. The threshold current changes from 1.8 to 1.1 mA and the slope efficiency falls less than similar to35% as the temperature raised from room temperature to 70 degreesC. With a bias current of only 5 mA, the 3-dB modulation frequency response was measured to be 8.36 GHz, which is appropriate for 10-Gb/s operation. The maximal bandwidth is measured,to be 10.7 GHz with modulation current efficiency factor (MCEF) of similar to5.25 GHz/(mA)(1/2). These VCSELs also demonstrate high-speed modulation up to 10 Gb/s from 25 degreesC to 70 degreesC.
MOCVD growth of highly strained InGaAs : Sb-GaAs-GaAsP quantum well vertical cavity surface-emitting lasers with 1.27 mu m emission
(2004-12-10)
Kuo, HC
;
Yao, HH
;
Chang, YH
;
Chang, YA
;
Tsai, MY
1.27mum InGaAs:Sb-GaAs-GaAsP vertical cavity surface-emitting lasers (VCSELs) were grown by metalorganic chemical vapor deposition (MOCVD) with superior performance. The threshold current changes between 1.8 and 1.1 mA and the slope efficiency drops below similar to35% when the temperature is raised from room temperature to 70degreesC. With only 5 mA of bias current, the 3 dB modulation frequency response is measured to be 8.36 GHz which is suitable for 10Gb/s operation. The maximal bandwidth is estimated to 10.7GHz with modulation current efficiency factor MCEF) of similar to5.25GHz/(mA)(1/2). The results of InGaAs:Sb-GaAs-GaAsP VCSELs can reach a performance level comparable to GalnAsN VCSELs with better thermal stability and should be considered as a very promising candidate for 1.3 mum commercial applications. (C) 2004 Elsevier B.V. All rights reserved.
Post-soft-breakdown characteristics of deep submicron NMOSFETs with ultrathin gate oxide
(2001-07-01)
Tsai, MY
;
Lin, HC
;
Lee, DY
;
Huang, TY
;
電子工程學系及電子研究所
The impacts of soft-breakdown (SBD) on the characteristics of deep sub-micron NMOSFETs were investigated. It is shown that the ED location plays a crucial role in the post-ED switching function of the device, When ED occurs at the channel, the turn-on behavior of the drain current would not be significantly affected, which is in strong contrast to the case of ED at the drain. Nevertheless, significant increase in gate current is observed in the off-state when the gate voltage is more negative than -1 V, Its origin is identified to be due to the action of two parasitic bipolar transistors formed after SBD occurrence at the channel.
Quaternary AlInGaN multiple quantum well 368 nm light-emitting diode
(2006-01-25)
Wang, TC
;
Kuo, HC
;
Lee, ZH
;
Chuo, CC
;
Tsai, MY
We report high output power from AlInGaN multiple quantum well (MQW) ultraviolet light-emitting diodes. The high Al containing cladding layer, electron blocking layer and p-contact layer were chosen for transparency at 365 nm to reduce the internal absorption, reduce electron overflow and enhance output power. The UV output power was as high as 1.52 mW at 20 mA at 368 nm under room temperature CW operation. The maximum output power in CW operation is 11 mW at 170 mA. In this letter, we demonstrate a helpful and easy way to measure and calculate the junction temperature of AlInGaN UVLEDs. (c) 2005 Elsevier B.V. All rights reserved.
Single mode 1.27-mu m InGaAS : Sb-GaAs-GaAsP quantum well vertical cavity surface emitting lasers
(2005-01-01)
Kuo, HC
;
Chang, YA
;
Chang, YH
;
Chu, JT
;
Tsai, MY
1.27 mu m InGaAs:Sb-GaAs-GaAsP vertical cavity surface emitting lasers (VCSELs) were grown by metalorganic chemical vapor deposition (MOCVD) and exhibited excellent performance and temperature stability. The threshold current changes from 1.8 to 1.1 mA and the slope efficiency falls less than similar to 35% as the temperature raised from room temperature to 70 degrees C. With a bias current of only 5mA, the 3dB modulation frequency response was measured to be 8.36 GHz, which is appropriate for 10 Gb/s operation. The maximal bandwidth is measured to be 10.7 GHz with modulation current efficiency factor (MCEF) of similar to 5.25 GHz/(mA)(1/2). These VCSELs also demonstrate high-speed modulation up to 10 Gb/s from 25 degrees C to 70 degrees C.
Study of InGaN multiple quantum dots by metal organic chemical vapor deposition
(2006-04-01)
Wang, TC
;
Kuo, HC
;
Lu, TC
;
Tsai, CE
;
Tsai, MY
We reports a study of InGaN Multiple quantum dot layers. Using the in-situ SiNx treatment process, InGaN multiple quantum dot layers were successfully developed. The InGaN multiple quantum dot layers were constructed with SiNx dot mask layers, InGaN dot layers, and GaN cap layers on a 2-mu m-thick GaN underlying layer on a sapphire substrate. Optical properties including room temperature photoluminescence (PL), temperature dependent PL, and low power power-dependent PL were examined and discussed. The structure was also analyzed by transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) line scan.
Temperature-dependent photoluminescence of highly strained InGaAsN/GaAs quantum wells (lambda=1.28-1.45 mu m) with GaAsP strain-compensated layers
(2005-08-01)
Lai, FI
;
Kuo, HC
;
Chang, YH
;
Tsai, MY
;
Chu, CP
The effects of nitrogen incorporation into the In(0.4)Ga(0.6)As(1-x)N(x)/GaAs single quantum wells (SQWs), where x = 0.5 and 2%, grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD) were investigated using photoluminescence (PL) and high-resolution transmission electron microscopy (HRTEM). The evolution of the excitation-dependent PL and PL-peak position with temperature between 10 and 300 K shows that quantum-dot-like states occurred at that high nitrogen incorporation (x = 2%) and were confirmed by an HRTEM image which showed small dark regions about 2 - 3 nm in size was found in the interface of In(0.4)Ga(0.6)As(0.98)N(0.02) and GaAs. Our investigations indicate that high nitrogen incorporation into the In(0.4)Ga(0.6)As(1-x)N(x)/GaAs system influenced carrier localization and might cause the formation of the dot-like states.
The design of automatic-lock-automatic-retrieve single-chip IPM for converter systems
(2001)
Chang, LK
;
Tsai, MY
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper describes a single-chip intelligent power module (IPM) manufactured by utilizing a modified high voltage BCD process that integrates power devices, LIGBTs, and protection circuits on the SOI substrate. The smart integrated circuits provide automatic-lock-automatic-retrieve sensing and protection functions To give strong and fast protection ability against faults of over-on-state-voltage, over-current, and over-temperature, those are specially designed for power converter usage. When the gate voltage of LIGBT is high and the faulty event is sensed, the protection circuit pulls down the gate voltage to low and toggles LIGBT to off state immediately. However, each time the gate voltage returns to high, LIGBT is retrieved to the normal operating condition automatically. Therefore, the proposed IPM can operate superior in the converters with pulse-width-modulation (PWM) applications.