The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Stella W. Pang - One of the best experts on this subject based on the ideXlab platform.
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Dry Etching Technology for Optical Devices
WDM Technologies, 2007Co-Authors: Stella W. PangAbstract:Publisher Summary This chapter reviews Dry Etching technology used for the fabrication of high-performance optical devices. Various plasma systems are used for Dry Etching. High-density plasma systems with an inductively coupled plasma source provide better control and more flexibility because ion density and ion energy can be adjusted using separate power supplies. The chapter presents a number of Dry etched optical devices, including high aspect ratio vertical mirrors in silicon (Si) as optical switching arrays, Dry etched mirrors in gallium arsenide/ aluminum gallium arsenide (GaAs/AlGaAs) for microcavities and triangular ring lasers, high reflectivity horizontal distributed Bragg reflector mirrors with air gaps between semiconductor layers, and photonic bandgap lasers. All these optical devices require precise control of etch depth, etch profile, and smooth morphology. The chapter further discusses the importance of developing low-damage Dry Etching technology, and reviews the techniques to minimize surface damage. With precisely controlled, low-damage Dry Etching technology, high-performance optical devices using Dry etched components can be achieved.
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Surface Damage Induced by Dry Etching
Handbook of Advanced Plasma Processing Techniques, 2000Co-Authors: Stella W. PangAbstract:As the size of electrical and optical devices is scaled to ever smaller dimensions, the surface condition of the devices affects the performance more dramatically. Dry Etching is often used for pattern transfer for high performance devices with submicrometer dimensions. Dry Etching is needed to control the directionality of the etch profile for small features. Besides vertical profile, low damage and high etch rate are also important to maintain high device performance and high throughput. Dry-Etching processes, with energetic particles bombarding the samples, can induce defects in the materials that degrade device properties [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]. The defects generated by Dry Etching often are much deeper than the ion penetration range and they make damage removal difficult [14,15].
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Fabrication of Si field emitters by Dry Etching and mask erosion
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1996Co-Authors: M. R. Rakhshandehroo, Stella W. PangAbstract:A Cl2 plasma generated by an electron cyclotron resonance source was used to etch field emitter arrays in Si. Compared to wet Etching, emitter arrays with sharper emitter tips and higher packing density can be formed by Dry Etching. Mask erosion was used to control the etch profile in Si. SiO2 masks with different profiles were patterned by wet and Dry Etching, and the effects of the initial SiO2 masks slope and etch conditions on the resultant Si profile were investigated. The lateral etch rate of SiO2 decreased from 363 to 150 nm/min as the SiO2 slope increased from 17° to 45°. As a result, the slope of the Si etch profile increased from 52° to 78° after Dry Etching to a depth of 1.8 μm. The ion flux and energy, controlled through coupled microwave and rf power, were used to obtain the desired etch rate and basewidth of the emitters. By increasing the pressure during Etching, the lateral etch rate of SiO2 was reduced and more vertical Si profiles were developed. As pressure was increased from 0.5 to 10 ...
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Surface damage in III-V devices by Dry Etching
1998 3rd International Symposium on Plasma Process-Induced Damage (Cat. No.98EX100), 1Co-Authors: Stella W. PangAbstract:In this paper, surface damage induced by Dry Etching in III-V devices is reviewed. Defects after Dry Etching are balanced by their generation and removal rates. The degree of damage depends strongly on the etch conditions, such as the ion energy, ion density, temperature, pressure, and gas used for Etching. In general, it is important to use low ion energy to prevent extensive damage. Therefore, high density plasma sources are desirable since they can generate low energy ions with high density to reduce damage while still maintaining fast etch rates. A plasma system consisting of an electron cyclotron resonance source was used to etch the devices reported here. Techniques to minimize or remove etch induced damage are discussed. Changes in device characteristics for Schottky diodes, transmission lines, conducting wires, in-plane gated (IPG) quantum wire transistors, and heterostructure bipolar transistors (HBTs) are reported.
C. D. W. Wilkinson - One of the best experts on this subject based on the ideXlab platform.
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Dry Etching and sputtering
Philosophical transactions. Series A Mathematical physical and engineering sciences, 2003Co-Authors: C. D. W. Wilkinson, M. RahmanAbstract:Dry Etching is an important process for micro- and nanofabrication. Sputtering effects can arise in two contexts within a Dry-etch process. Incoming ions cause removal of volatile products that arise from the interaction between the Dry-etch plasma and the surface to be etched. Also, the momentum transfer of an incoming ion can cause direct removal of the material to be etched, which is undesirable as it can cause electrical or optical damage to the underlying material. This is largely avoided in Dry-etch processes by use of reactive chemistries, although in some processes this component of the Etching can be significant. Etch processes, both machine type and possible etch chemistries, are reviewed. Methods of characterizing the electrical and optical damage related to ion impact at the substrate are described. The use of highly reactive chemistries and molecular constituents within the plasma is best for reducing the effects of damage.
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Dry Etching damage in III–V semiconductors
Journal of Vacuum Science & Technology B, 1996Co-Authors: S. K. Murad, M. Rahman, Nigel P. Johnson, Stephen Thoms, S. P. Beaumont, C. D. W. WilkinsonAbstract:Dry Etching using ions can cause damage to the underlying semiconductor. This paper discusses damage in III–V semiconductors and presents examples of Etching conditions under which it can be effectively eliminated. A distinction between surface and sidewall damage is made and methods of measuring both parameters are reviewed. It is noted that the noble gases cause relatively deep damage, while under the correct circumstances, etchants that have a marked chemical effect can cause much less damage. The present state of understanding of the mechanisms for the damage is discussed.
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Nanostructure Fabrication: Dry Etching Damage
MRS Proceedings, 1991Co-Authors: G. F. Doughty, Rebecca Cheung, M. A. Foad, M. Rahman, N.i. Cameron, Nigel P. Johnson, P. D. Wang, C. D. W. WilkinsonAbstract:AbstractAlthough the directed energy and chemical reactivity of Dry Etching permits the fabrication of nanostructures with precise geometries, it also causes unwanted electrical and optical changes to the surface, changes generally referred to as “damage”.This paper discusses the extent and the impact of Dry-Etching damage on rI-V and I[-VI compound semiconductors as assessed by a very wide range of techniques: the performance of devices such as MESFETs, and measurements of other properties - surface uniformly and precisely, Schottky junction characteristics, cut-off of epitaxial wire conductance, integrated photoluminescence, X-ray reflectivity, DLTS, TEM imaging and Raman scattering.We distinguish an important difference between the nature of damage on sidewalls and on surfaces normal to the directed ions, and report on progress towards establishing a model of the nature of Dry Etching damage. This model is applied to indicate what kinds of processes are likely to give Etching with low damage.
M. Rahman - One of the best experts on this subject based on the ideXlab platform.
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Dry Etching and sputtering
Philosophical transactions. Series A Mathematical physical and engineering sciences, 2003Co-Authors: C. D. W. Wilkinson, M. RahmanAbstract:Dry Etching is an important process for micro- and nanofabrication. Sputtering effects can arise in two contexts within a Dry-etch process. Incoming ions cause removal of volatile products that arise from the interaction between the Dry-etch plasma and the surface to be etched. Also, the momentum transfer of an incoming ion can cause direct removal of the material to be etched, which is undesirable as it can cause electrical or optical damage to the underlying material. This is largely avoided in Dry-etch processes by use of reactive chemistries, although in some processes this component of the Etching can be significant. Etch processes, both machine type and possible etch chemistries, are reviewed. Methods of characterizing the electrical and optical damage related to ion impact at the substrate are described. The use of highly reactive chemistries and molecular constituents within the plasma is best for reducing the effects of damage.
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Dry Etching damage in III–V semiconductors
Journal of Vacuum Science & Technology B, 1996Co-Authors: S. K. Murad, M. Rahman, Nigel P. Johnson, Stephen Thoms, S. P. Beaumont, C. D. W. WilkinsonAbstract:Dry Etching using ions can cause damage to the underlying semiconductor. This paper discusses damage in III–V semiconductors and presents examples of Etching conditions under which it can be effectively eliminated. A distinction between surface and sidewall damage is made and methods of measuring both parameters are reviewed. It is noted that the noble gases cause relatively deep damage, while under the correct circumstances, etchants that have a marked chemical effect can cause much less damage. The present state of understanding of the mechanisms for the damage is discussed.
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Nanostructure Fabrication: Dry Etching Damage
MRS Proceedings, 1991Co-Authors: G. F. Doughty, Rebecca Cheung, M. A. Foad, M. Rahman, N.i. Cameron, Nigel P. Johnson, P. D. Wang, C. D. W. WilkinsonAbstract:AbstractAlthough the directed energy and chemical reactivity of Dry Etching permits the fabrication of nanostructures with precise geometries, it also causes unwanted electrical and optical changes to the surface, changes generally referred to as “damage”.This paper discusses the extent and the impact of Dry-Etching damage on rI-V and I[-VI compound semiconductors as assessed by a very wide range of techniques: the performance of devices such as MESFETs, and measurements of other properties - surface uniformly and precisely, Schottky junction characteristics, cut-off of epitaxial wire conductance, integrated photoluminescence, X-ray reflectivity, DLTS, TEM imaging and Raman scattering.We distinguish an important difference between the nature of damage on sidewalls and on surfaces normal to the directed ions, and report on progress towards establishing a model of the nature of Dry Etching damage. This model is applied to indicate what kinds of processes are likely to give Etching with low damage.
Woo-sung Han - One of the best experts on this subject based on the ideXlab platform.
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The study of optical performance for quartz Dry Etching quality in ArF lithography
Photomask Technology 2006, 2006Co-Authors: Won-suk Ahn, Hye-kyung Lee, Young-ju Park, Hyuk-joo Kwon, Seong-woon Choi, Woo-sung HanAbstract:Dry Etching has become critical to manufacture the resolution enhancement technique (RET) mask in the ArF lithography. Among RET masks, alternating phase shift mask (PSM) and chrome-less phase lithography (CPL) mask require the formation of 180 degrees phase differences by quartz Dry Etching. There are many error factors, which can influence CD uniformities on mask and wafers, in Quartz Dry etch step such as sidewall angle, phase MTT and uniformity, micro-trench, and morphology. Furthermore, quartz depth is hard to control because there is no stopping layer for quartz Etching. Additionally, Pattern profile of Chrome layer is very important, because chrome profile affect sidewall angle for quartz. We have simulated and investigated to identify the influences of many error factors on RET. Consequently, we investigated characteristics of quartz Dry Etching process performance and the influences on resolution, which can be improved by Dry etch parameters.
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A study of Cr to Mosi in-situ Dry Etching process to reduce plasma induced defect
25th Annual BACUS Symposium on Photomask Technology, 2005Co-Authors: Il-yong Jang, Young-ju Park, Hyuk-joo Kwon, Seong-woon Choi, Seong-yong Moon, Woo-sung HanAbstract:Dry Etching process is widely used in semiconductor field and in photomask manufacturing. Even though Dry Etching technique can be much better in obtaining straight profile and better CD (Critical Dimension) uniformity than wet Etching technique, it has a severe problem in terms of defect issue. Especially, very tough controllability of defects is essential for the photomask Dry Etching process because defect can be printed on the wafer over. Therefore, we studied defect free photomask Etching techniques and found out the possibility of particle evasion. With In-situ Etching method, defect generation by MoSiON Etching could be reduced compared to when standard Etching process is used while the process result is almost same as that of the standard process. In this paper, we will present the experimental result of in-situ. Dry Etching process technique for Cr and MoSiON, which reduces the defect level significantly.
Kyoung Ik Cho - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of Oxide TFTs with Al2O3 / ZnO Gate Stacks Patterned Using a Dry Etching Method
Electrochemical and Solid-State Letters, 2008Co-Authors: Sung-min Yoon, Sang-hee Ko Park, Chi-sun Hwang, Hye Yong Chu, Kyoung Ik ChoAbstract:In this paper, we describe a newly developed Dry Etching process for the fabrication of ZnO-based oxide thin-film transistors (TFTs). The Dry Etching behavior of ZnO and Al 2 O 3 thin films was systematically investigated by varying the Etching gas mixtures and their mixing ratios in a Dry Etching system using high-density helicon plasma. We fabricated an oxide TFT using an Al 2 O 3 /ZnO gate stack patterned by Dry Etching and confirmed good device characteristics, in which the field effect mobility and the ratio of on/off drain currents were about 0.8 cm 2 /(V s) and 10 7 , respectively.
