Browsing by Author "Chiang, CD"

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A new CMOS readout circuit for uncooled bolometric infrared focal plane arrays
(2000)
Yu, TH
;
Wu, CY
;
Chin, YC
;
Chen, PY
;
Chi, FW
By incorporating the basic Constant Current (CC) configuration with the buffered direct injection (BDI) structure, a new readout circuit called the constant current buffered direct injection (CCBDI) is proposed for the uncooled bolometer detector FPAs. Due to the use of BDI structure, the offset is decreased and the linearity range is increase. Thus linearity, dynamic range, and uniformity are improved. An experimental chip of 64x64 CCBDI FPA readout circuit has be designed and fabricated by using 0.5 mu m double-poly double-metal n-well CMOS technology with the cell size of 50x50 mu m(2). The measured linearity is 94.36% whereas the measured uniformity is 81.3%. Both measurement and simulation results have verified the advantageous features of the proposed CCBDI readout circuit. It is believed that the new CCBDI structure has a great potential in the applications of large uncooled bolometer FPAs.
Optical recombination-emission characteristics and surface morphologies of InAs quantum dots grown on misoriented GaAs substrate by MOCVD
(2006-03-01)
Hsu, MY
;
Tang, SF
;
Chiang, CD
;
Su, CC
;
Wang, LC
The InAs quantum dot (QD) structures grown on (100) 2 degrees, 6 degrees, 10 degrees, 15 degrees off-angles to (111)A GaAs substrate have been investigated by atomic force microscopy (AFM) and cryogenic photoluminescence (PL). The exact-angle InAs/GaAs is used as the reference sample. The blue shift of PL peak spectra with increasing misoriented scales has also been observed experimentally. In this work, we demonstrated that different off-angle substrates would influence the distribution and uniformity of QD due to variant surface potential energies, which are responsible for the two-stage process (migration and nucleation) of InAs adatoms on the off-angle substrates. (c) 2005 Elsevier B.V All rights reserved.
Wet etching characterization of InSb for thermal imaging applications
(2006-03-01)
Chang, KM
;
Luo, JJ
;
Chiang, CD
;
Liu, KC
;
電子工程學系及電子研究所
A citric acid/hydrogen peroxide-based chemical system has been reported for the first time to meet the requirements of continuously scaling down the pixel area for InSb high-density infrared camera applications. This chemical system with a reaction-rate-limited mechanism was concluded to have superior etching performance compared with the nitric acid-based Solution. It is established that this etching mechanism has better control over device structure uniformity due to its linear proportionality to etching time and its nondependence oil agitation and exposed etched area. Two different chemical systems have been studied to form the high-density mesa structures ill this Study. The wet etching characteristics corresponding to these chemical Solutions were measured and analyzed. From atomic force microscopy (AFM), the results clearly indicate that the surface-reaction-rate-limited dominant-control mechanism for InSb mesa etching in citric acid/hydrogen peroxide produces a fairly smooth morphology near junction edges and well-controlled sidewall profiles. Good step coverage for dielectric deposition as shown by field-emission scanning electron microscopy and a highly uniformly distributed dark current of InSb pn junction arrays at 77 K have proven the feasibility of the citric acid/hydrogen pet-oxide wet etching process to bring superior etching performance compared with the nitric acid-based Solution.