Browsing by Author "Huang, Chih-Yung"

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Characterization of Al2O3/ZnO Grown on Si Substrate by Plasma Enhanced Atomic Layer Deposition
(2013-01-01)
Chung, Chen-Chen
;
Tran, Binh-Tinh
;
Lin, Kung-Liang
;
Wang, Ching-Chiun
;
Chen, Chien-Chih
Characterization of nanolaminate Al2O3/ZnO oxide films grown on Si substrates was conducted by using plasma enhanced atomic layer deposition (PE-ALD) method. PE-ALD can minimize the structural imperfections in films and reduce substrate damage. The film deposition by using PE-ALD are dense, defect-free, highly uniform, conformal films and show excellent step coverage. Moreover, compared to other deposition techniques, it is possible to deposit high quality films at much lower temperatures. High resolution transmission electron microscope (TEM) images showed the existence of sharp interfacial layers among the Al2O3, ZnO layer, and the Si substrate for the growth rate of 1.56 angstrom/cycle, and the surface roughness of about 0.2 nm. The nanolaminate-stacking layer can be used in organic light emitting diode encapsulation application as the gas barrier.
Flow field investigation in a rotating disk chemical vapor deposition chamber with a perforated showerhead
(2017-11-01)
Liu, Yao-Hsien
;
Peng, Guan-Jhong
;
Lai, Wei-Chia
;
Huang, Chih-Yung
;
Liang, Jin-Hsing
A flow field in a simulated rotating disk chemical vapor deposition chamber in which the inflow gases entered through a showerhead inlet was experimentally investigated using particle image velocimetry. The deposition uniformity was highly related to the flow pattern, which was influenced by the buoyancy, centrifugal, and flow inertia forces. This study investigated flow patterns for different processing parameters, namely chamber heights (20 and 40 mm), jet-to-disk temperature differences (0-500 degrees C), and disk rotational speeds (0-500 rpm). The time-averaged axial and radial velocity profiles were determined for examining the effects of rotation and heating on flow uniformity above the rotating disk. The Reynolds stress and turbulence intensity was found to be influenced by the buoyancy and rotation induced flow. At a high jet-to-disk temperature difference, the upward buoyancy force lifted the flow and prevented the inlet flow from reaching the disk surface. The buoyancy-induced flow can be suppressed through disk rotation or chamber height reduction. Moreover, the nondimensional parameters (Grashof number and rotational Reynolds number) can be used to construct flow regime maps and quantify the effects of rotation and heating even with the contribution from different chamber heights, disk temperatures, and rotational speeds. (C) 2017 Elsevier Inc. All rights reserved.
Growth and Fabrication of GaN Light Emitting Diode on Patterned-Sapphire Substrate
(2013-01-01)
Binh-Tinh Tran
;
Ming, Chen-Hauw
;
Lin, Kung-Liang
;
Chen, Hao-Ming
;
Wang, Ching-Chian
In this study, the growth of GaN-films-based light emitting diodes (LEDs), have been clearly demonstrated on wet-etching patterned sapphire substrate (PSS) and conventional LEDs. The wet-etching PSS LED device showed a significantly higher performance than the conventional LED device. The wet-etching PSS LED device exhibited a leakage current of 9 mA under a bias of 8 V, an external quantum efficiency and output powers of 35.09 % and 19.23 mW under 20 mA injection current as compared to 12 mA, 27.23%, and 15.02 mW of the conventional LED device.
Nanoindentation characterization of GaN epilayers on A-plane sapphire substrates
(2010-03-15)
Lin, Meng-Hung
;
Wen, Hua-Chiang
;
Huang, Chih-Yung
;
Jeng, Yeau-Ren
;
Yau, Wei-Hung
Gallium nitride (GaN) epilayers was deposited on a-axis sapphire substrate by means of metal-organic chemical vapor deposition (MOCVD) method. The GaN epilayers has been investigated in their repetition pressure-induced impairment events from nanoindentation technique and, the relative deformation effect was observed from atomic force microscopy (AFM). From the morphological studies, it is revealed that none of crack and particle was found even after the indentation beyond the critical depth on the residual indentation impression. The 'pop-in' event was explained by the interaction of the deformed region, produced by the indenter tip, with the inner threading dislocations in the GaN films. Pop-in events indicate the generation and motion of individual dislocation, which is measured under critical depth and, no residual deformation of the GaN films is observed. (C) 2009 Elsevier B. V. All rights reserved.
Particle image velocimetry measurement of jet impingement in a cylindrical chamber with a heated rotating disk
(2013-10-01)
Liu, Yao-Hsien
;
Tseng, Li-Wei
;
Huang, Chih-Yung
;
Lin, Kung-Liang
;
Chen, Chien-Chih
We studied the flow field of a jet impingement on a rotating heated disk to simulate the flow field surrounding the rotating disk of a chemical vapor deposition (CVD) reactor, which is widely used for large-scale production of thin-films and semiconductor materials. The flow field influences the growth rate and deposition uniformity, and is subject to the combined effects of buoyancy, centrifugal, and flow inertia forces that occur during the deposition process. The study investigated various flow-cell sizes and locations, such as the inlet flow-rate (1-10 slpm), jet-to-disk temperature difference (40-80 degrees C), and disk rotational speeds (0-500 rpm). Particle image velocimetry (PIV) was used to measure the flow-velocity field and flow-streamlines in the test chamber. The time-averaged axial and radial velocity profiles near the disk were used to determine the variations in flow velocity resulting from rotation and heating. Upward buoyancy forces, caused by the heated disk, produce flow cells and break the flow uniformity above the disk. When the rotational Reynolds number increases, the rotational effect eventually dominates the flow field that increases the flow velocity and generates flow cells near the chamber wall. Flow regime maps of these flow patterns were constructed, based on the Grashof number and rotational Reynolds number. (c) 2013 Elsevier Ltd. All rights reserved.