Browsing by Author "Hsu, WC"

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Annealing effect on boron high-energy-ion-implantation-induced defects in
(2004-08-01)
Hsu, WC
;
Liang, MS
;
Chen, SC
;
Chen, MC
;
電子工程學系及電子研究所
In this work, we investigate the annealing effect on defects in Si induced by boron high-energy (1.5 MeV) ion implantation with respect to implantation dose (1.1 X 10(13) and 5 x 10(13) cm(-2)) as well as annealing scheme [rapid thermal annealing (RTA) and furnace annealing (FA)]. The higher dose implantation resulted in more serious degradation of the minority carrier generation lifetime in the implanted layers. Also, the degree of lifetime recovery by either RTA or FA was very limited with the higher dose implantation, presumably due to the presence of the implantation-induced dislocations. The degradation of the lifetime in the lower dose-implanted sample could be significantly recovered by the annealing process, particularly the RTA scheme; this is presumably because RTA has a better ability to reduce the implantation-induced interstitials.
Detection of the defects induced by boron high-energy ion implantation of silicon
(2000-08-01)
Hsu, WC
;
Chen, MC
;
Liang, MS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A preferential chemical etching method was used to investigate the secondary defects induced in silicon by high-energy boron ion implantation followed by a rapid thermal anneal at 1000 degrees C for 30 s in N-2 ambient. The dislocation defects in silicon can be clearly delineated by the etchant of CrO3/HF mixing solution. Moreover, a band of striation corresponding To the region of dislocation defects can be observed from the cross-sectional view micrographs of scanning electron microscopy. For the high-energy boron ion implantation at a dose of 3 x 10(14) cm(-2) and energies of 0.5 to 2 MeV studied in this worst, the defect density is estimated to be in the order of 6 x 10(6) cm(-2). Furthermore, we found a close correlation between the depth profiles of the observed etching pits and that of the implanration-induced damage. (C) 2000 The Electrochemical Society. S0013-4651(00)01-011-9. All rights reserved.
Effect of annealing on low-threshold-current large-wavelength InGaAs quantum well vertical-cavity laser
(2006-02-01)
Chen, IL
;
Hsu, WC
;
Kuo, HC
;
Sung, CP
;
Chiou, CH
An emission wavelength record emission wavelength of 1245 nm in double InGaAs/GaAs quantum wells without a strain-compensated barrier is obtained by metalorganic chemical vapor deposition (MOCVD). The effect of annealing on highly strained InGaAs quantum wells is analyzed using phtoluminanescence spectra. By comparing devices p-type distributed Bragg reflector (p-DBR) growth temperatures, the preliminary results indicate that a device with a low p-DBR growth temperature of 670 degrees C exhibits a low threshold current and a high light output power. A threshold current of 6.7 mA in an InGaAs vertical-cavity surface emitting laser (VCSEL) in CW operation is realized with an emission spectrum up to 1.26 mu m.
Growth of highly strained RnGaAs quantum wells by metalorganic chemical vapor deposition with application to vertical-cavity surface-emitting laser
(2006-01-01)
Chen, IL
;
Hsu, WC
;
Lee, TD
;
Kuo, HC
;
Su, KH
A series of highly strained InGaAs quantum wells (QWs) with GaAs barriers emitting at wavelength longer than 1.2 mu m are grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). The optimized windows of the V/III ratio of the InGaAs layer and the growth rate of the barrier are first investigated on thease highly strained QWs. By an appropriate choice of the growth conditions, we extend the room-temperature photoluminescence (PL) wavelength of InGaAs QWs to 1245 nm, which corresponds to an indium content of 42%. A GaAs-based InGaAs vertical-cavity surface-emitting laser (VCSEL) at an emission wavelength of 1.28 mu m with a large detuning of 90 nm has been realized by the use of highly strained InGaAs QWs.
Implantation induced defects in the retrograde well with a buried layer
(2002-03-01)
Hsu, WC
;
Liang, MS
;
Chen, MC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This work investigates the implantation induced extended defects in the retrograde p- and n-well with/without a buried layer after postimplantation thermal annealing at 950degreesC in N(2) ambient. A preferential etchant of CrO(3)/HF mixed solution was used to delineate the defects induced by high-energy ion implantation. It is found that the extended defects elongated to the top surface of the retrograde well with a buried layer, which was implanted with high-energy boron ion at 1500 keV to a dose of 3x10(13) cm(-2), resulting in the etching pits of extended defects at a density of about 10(5) cm(-2). (C) 2002 The Electrochemical Society.
Low-threshold-current-density, long-wavelength, highly strained InGaAs laser grown by metalorganic chemical vapor deposition
(2005-10-01)
Chen, IL
;
Hsu, WC
;
Kuo, HC
;
Yu, HC
;
Sung, CP
A long-emission-wavelength laser with multiple InGaAs/GaAs quantum wells without a strain-compensated barrier was grown by metalorganic chemical vapor deposition (MOCVD). InGaAs quantum well (QW) broad-area laser diodes with an emission wavelength of up to 1214 nm were realized. A measured room-temperature threshold current density of only 173 A/cm(2) for a 2-mm-cavity device and a transparency current density of 66 A/cm(2) were obtained. The internal quantum efficiency and laser cavity loss were 67% and 6 cm(-1), respectively.
Novel planar, square-shaped, dielectric-waveguide, single-, and dual-mode filters
(2002-11-01)
Chang, CY
;
Hsu, WC
;
電信工程研究所
;
Institute of Communications Engineering
This paper presents a novel concept of a square-shaped dielectric-waveguide resonator, which can easily realize a dielectric-waveguide cross-coupled filter or a dielectric-waveguide dual-mode filter, using the conventional printed circuit board (PCB) process. This planar dielectric-waveguide resonator has a higher Q value than a microstrip resonator. The physical mechanisms of both single- and dual-mode filters are elucidated. Some new coupling structures are developed for undergoing the PCB process. Filter design procedures are detailed. Design curves for the coupling coefficients of internaland external-coupling structures are determined by full-wave finite-element-method electromagnetic calculations. Measurement results are highly consistent with theory for all trial filters. This study offers an effective means of producing low-cost high-performance planar circuit filters.
Oxygen and nitrogen co-doped GeSbTe thin films for phase-change optical recording
(2002-03-01)
Dimitrov, DZ
;
Lu, YH
;
Tseng, MR
;
Hsu, WC
;
Shieh, HPD
Nitrogen and oxygen co-doped GeSbTe films for phase-change optical recording are investigated. It is found that optical properties of amorphous and crystalline state are similar to that of GeSbTe, crystallization temperature increases and crystalline microstructure is refined which indicate a nucleation rate increases by co-doping. The carrier-to-noise ratio (CNR) and erasability of phase-change optical disks are improved being up to 52 dB and 35 dB, respectively, by using an appropriate co-doping concentration in the recording layer.
Photonic bandgap dielectric waveguide filter
(2002-04-01)
Chang, CY
;
Hsu, WC
;
電信工程研究所
;
Institute of Communications Engineering
The application of photonic bandgap (PBG) structures as the sidewall of the printed circuit board (PCB) dielectric waveguide filter is investigated in this letter. The effect of different PBG parameter on the Q-value of PBG dielectric waveguide resonator is evaluated. A PBG dielectric waveguide three-pole Chebyshev bandpass filter is realized. The measured performance matched well with the calculated results. The newly proposed I/O coupling structure makes the filter much easier for mass production.
Post-implantation thermal annealing effect on the gate oxide of triple-well-structure
(2002-05-01)
Hsu, WC
;
Liang, MS
;
Lin, CT
;
Chen, MC
;
電子工程學系及電子研究所
In this work, we investigate the effect of post-implantation thermal annealing on the quality of thin gate oxides grown on MeV ion-implanted Si substrates for the triple-well structure. The thin gate oxide grown on the MeV ion-implanted Si substrates without post-implantation thermal annealing may contain pinholes, leading to oxide failure at a very low voltage; in addition, the gate oxide has a higher density of interface states, which may result in a low breakdown voltage. With appropriate post-implantation thermal annealing before the growth of the gate oxide, e.g., 1000degreesC for 30 min under the MeV implantation conditions employed in this work, the gate oxide is able to regain its integrity in terms of electrical breakdown voltage.
Spectrally resolved spontaneous emission patterns of oxide-confined vertical-cavity surface-emitting lasers
(2004-12-01)
Lu, TC
;
Hsu, WC
;
Chang, YS
;
Kuo, HC
;
Wang, SC
Spectrally resolved spontaneous emission patterns of oxide-confined vertical-cavity surface-emitting lasers under the subthreshold condition were investigated. The spontaneous emission mode patterns show clear and stable Hermite-Gaussian modes and high-order Laguerre-Gaussian modes associated with a distinct spectrum. The coexistence of two sets of identical low-order Hermite-Gaussian modes with different spot sizes reveals the presence of two cavity configurations. The data on mode evolution and spot size variation reveal that the modes with larger spots are supported by the cavity with the carrier-induced aperture, and become the dominant modes above the laser threshold; the modes associated with smaller spots are considered to have been formed by the cavity with the oxidized aperture and are suppressed above the threshold. (C) 2004 American Institute of Physics.