Laser-Controlled Etching of (Al,Ga)As Epitaxial Layers

1995 ◽  
Vol 397 ◽  
Author(s):  
T.C. Chong ◽  
Y.F. Lu ◽  
A. Lee
Keyword(s):  
Laser Power ◽  
Etch Rate ◽  
Scanning Speed ◽  
Laser Source ◽  
Epitaxial Layers ◽  
Exponential Rate ◽  
Cycle Number ◽  
Ion Laser ◽  
Etch Rates ◽  
Argon Ion

ABSTRACTWe report a systematic study of laser-controlled etching behaviors of AlxGa1−xAs epitaxial layers (x from 0 to 0.5) by varying parameters such as laser power, beam scanning speed, beam duty cycle, number of scans and different doping types and concentrations. The laser source was an argon ion laser emitting at 514.5 n-type layers were found to be significantly higher than those for p-type layers. Generally, higher etch rates were observed for layers with higher aluminium mole fraction. The etch rate was found to increase at an exponential rate with the laser power for CW beam, but this increase became linear when a chopped laser beam was used. The dependence of etch rates on different conditions can be largely accounted for by the differences in the built-in electric field at the surface as well as differences in the laser-induced local temperature rise in the layers.

Laser-Induced Dry Etching of GaAs with High Aspect Ratio

1991 ◽  
Vol 236 ◽  
Author(s):  
Cheon Lee ◽  
Hirokazu Sayama ◽  
Susumu Namba ◽  
Mikio Takai
Keyword(s):  
Aspect Ratio ◽  
Electron Spectroscopy ◽  
Laser Power ◽  
Chemical Compositions ◽  
Reaction Products ◽  
Scan Speed ◽  
Ion Laser ◽  
Etched Surface ◽  
Argon Ion ◽  
Scattering Measurement

AbstractLaser-induced thermochemical reactions have been investigated for GaAs in a CCl2F2 gas ambient using an argon-ion laser. The chemical compositions of the reaction products deposited on the etched groove were measured by Auger electron spectroscopy (AES). The conditions of laser power, scan speed, and CC12F2 gas pressure under which the etching reaction occurs without deposition of the residue were clarified. High etching rates up to 267 μm/s and an aspect ratio of 4.5 have been achieved by a single scan of a laser beam. Microprobe photoluminescence and Raman scattering measurement were carried out on the etched surface to characterize damage induced by this processing.

Cw Argon Ion Laser Annealed B and as Implanted Diodes in Oxide Defined Silicon Devices

1980 ◽  
Vol 1 ◽  
Author(s):  
T. O. Sedgwick ◽  
P. M. Solomon ◽  
H. J. Vollmer
Keyword(s):  
Sheet Resistance ◽  
Laser Power ◽  
Reverse Bias ◽  
Leakage Currents ◽  
Silicon Devices ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion ◽  
High Reverse Bias

ABSTRACTIn this paper, we present detailed reverse leakage data on laser annealed diodes which were formed by implanting 1 × 1013 and 1 × 1014 /cm2 B atoms at 20 keV and by implanting 1× 1014 and 1× 1015/cm2 As atoms at 50 keV into Si. The implant is made into bare Si through oxide windows where 1700Å thermal SiO2 is both the implant mask and the diode edge passivation. The thermal controls were annealed at 900°C for the B and 950°C for the As for 30 minutes. Diode reverse leakage curves versus voltage are reported for devices with variable perimeter to area ratios. The results indicate that B diodes can easily be made with characteristics similar to thermally annealed devices with leakage at 1V in the 10−9 A/cm2 range. For As implanted diodes, the results are mixed. For As implants of 1 × 1014 /cm2 the diodes had leakage currents at 3V in the high 10−9 A/cm2 range. At the 1 × 1015/cm 2 level devices with significantly higher leakage values at high reverse bias were obtained. The leakage and sheet resistance are determined in both cases and an optimum is shown as a function of laser power.

Dry Etching of Sol-Gel Pzt

1998 ◽  
Vol 546 ◽  
Author(s):  
R. Zeto ◽  
B. Rod ◽  
M. Dubey ◽  
M. Ervin ◽  
J. Conrad ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Etch Rate ◽  
Sol Gel ◽  
Reactive Ion Etching ◽  
Dry Etching ◽  
Ion Milling ◽  
Ion Etching ◽  
Wide Range ◽  
Etch Rates ◽  
Argon Ion

AbstractTwo techniques for dry etching of sol-gel lead zirconate titanate (PZT 52/48) thin films were investigated: reactive ion etching and argon ion milling. Etched profiles were characterized by scanning electron microscopy. For reactive ion etching, a parallel plate etcher was used with HC2ClF4, an environmentally safe etch gas, in a process described by other researchers. Etch rates were measured and compared as a function of electrode shield material (ardel, graphite, alumina) and RF input power (100 to 500 W). These etch rates varied from 10 to 100 nm/min. Reactive ion etched sidewall angles 12° off normal were consistently produced over a wide range of RF powers and etch times, but overetching was required to produce a clean sidewall. For argon ion milling, a 300 mA/500 V beam 40° off normal to the substrate operating in a 72 mPa argon pressure was used. These ion milling conditions produced an etch rate of 250 nm/min with a sidewall slope angle of about 70°. The ion milling etch rate for sol-gel PZT was significantly faster than rates reported for bulk PZT. The 500 nm thick PZT films used in this study were prepared by the sol-gel process that used methoxyethanol solvent, spin coating on t/Ti/SiO2 silicon substrates, and rapid thermal annealing for 30 s at 650 °C for crystallization of the perovskite phase.

Whole-Wafer Mapping of Dislocations in 4H-SiC Epitaxy

2007 ◽  
Vol 556-557 ◽  
pp. 295-298 ◽  
Author(s):  
Robert E. Stahlbush ◽  
Kendrick X. Liu ◽  
Q. Zhang ◽  
Joseph J. Sumakeris
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Epitaxial Layers ◽  
Local Concentration ◽  
Extended Defects ◽  
Order Of Magnitude ◽  
Ion Laser ◽  
Computer Controlled ◽  
Non Destructive ◽  
Argon Ion

A non-destructive technique to image the dislocations and other extended defects in SiC epitaxial layers has been developed. Basal plane dislocations (BPDs) and threading dislocations (TDs) are imaged. Photoluminescence from the dislocations is excited with the 364 and/or 351 nm lines of an argon ion laser and near-infrared light is collected. A computer controlled probe station takes multiple images and the mm-sized images are stitched together to form whole-wafer maps. The technique is applied to a set of four n+ wafers from the same boule with 50 um n- epitaxial layers. The epitaxy was grown with Cree’s low-BPD process. BPDs form as either single, isolated dislocations or as clusters encircling micropipes. The concentration of TDs is on the order 104/cm2 and the local concentration varies more than an order of magnitude. The advantages of mapping dislocations by UV-PL imaging compared to other techniques are discussed.

Laser-Controlled Etching Of Chromium-Doped and N-Doped Gaas

1982 ◽  
Vol 17 ◽  
Author(s):  
Gary C. Tisone ◽  
A. Wayne Johnson
Keyword(s):  
Wavelength Region ◽  
Etching Process ◽  
Photochemical Etching ◽  
Argon Ion Laser ◽  
Diffusion Controlled ◽  
Ion Laser ◽  
Etch Rates ◽  
Argon Ion

ABSTRACTThe photochemical etching of chromium-doped and n-doped <100> GaAs in HNO3 and KOH is examined in the wavelength region of 334 to 514 nm from an argon-ion laser. The etching process is found to be not thermally controlled. The etch rates of chromium-doped GaAs agree with a diffusion-controlled model of the photochemically produced holes. For both types of GaAs, HNO3 is found to produce morphologically superior results.

Application of Laser Microetching in Formation of Air-Bearing Surface for Magnetic Head Sliders

1995 ◽  
Vol 397 ◽  
Author(s):  
Y.F. LU ◽  
K.D. YE
Keyword(s):  
Laser Power ◽  
Etching Rate ◽  
Scanning Speed ◽  
Air Bearing ◽  
Magnetic Head ◽  
Bearing Surface ◽  
Ion Laser ◽  
Side Walls ◽  
Etching Parameters ◽  
Laser Induced Etching

ABSTRACTLaser-induced etching of polycrystalline Al2O3TiC material by a tightly-focused CW Ar ion laser has been investigated in a KOH solution with different concentrations. It is found that the KOH concentration can strongly affect the etching quality where low KOH concentration can result in rough and irregular patterns. The etching effect is also related to laser power and scanning speed. Laser-induced etching of polycrystalline AI2O3TiC in a KOH solution is found to be a photothermal reaction in which a threshold laser power exists. With an appropriate set of etching parameters, well defined grooves can be obtained with clean side walls and with an etching rate up to several hundred micrometers per second. It is also found that the grains in the polycrystalline Al2O3TiC material play an important role in the etching dynamics and etching quality. This etching process is believed to be applicable to the formation of a slider surface of magnetic heads in the future.

An Efficient Intracavity Laser Raman Spectrometer

1978 ◽  
Vol 32 (3) ◽  
pp. 298-302 ◽  
Author(s):  
Michael Hercher ◽  
William Mueller ◽  
Stanley Klainer ◽  
Robert F. Adamowicz ◽  
Ronald E. Meyers ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Output Power ◽  
Laser Power ◽  
Scattering Data ◽  
Raman Spectrometer ◽  
Laser Raman ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Intracavity Laser ◽  
Argon Ion

The design of an optimized intracavity laser Raman spectrometer is described, and representative Raman scattering data are presented. An intracavity laser power of 160 W was attained with an argon ion laser whose normal output power was 1 W.

Design a System of Ar-Ion Laser Enhanced Anisotropic Etching

2007 ◽  
Author(s):  
Dianzhong Wen
Keyword(s):  
Laser Power ◽  
Etching Rate ◽  
Silicon Crystal ◽  
Anisotropic Etching ◽  
Structure Design ◽  
System Structure ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion ◽  
Considerable Complexity

This paper a System of argon-ion laser enhanced anisotropic etching is designed. A basic description of the structure and principle of the system will first be presented. This system can be described as enhanced etching rate of silicon. It also has the important advantage of not requiring the silicon is covered with a thick of oxide or other masked for any plane of silicon crystal that adds considerable complexity to the manufacture. When experiment temperature is 90 °C and KOH density is 34mol, an averaged instantaneous etching rate as high 25μm/min has been observed in silicon for a 4.6W input laser power, this etching rate register a 500% increase model on conventional anisotropic etching of silicon. Discussing the anisotropic etching rate of silicon dependence on the laser power and on the temperature are further. The experiment results show that the system structure design is reasonable and it can meet the requirement of every planes of silicon crystal etching, it can be used widely in variety of application aspects.

Laser-Assisted Liquid-Phase Etching of Copper Conductors and its Application to Advanced Integrated Circuit Interconnect

1987 ◽  
Vol 101 ◽  
Author(s):  
Robert F. Miracky ◽  
Kantesh Doss
Keyword(s):  
Liquid Phase ◽  
Integrated Circuit ◽  
Elevated Temperatures ◽  
Dilute Solution ◽  
Practical Applications ◽  
Selective Area ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Etch Rates ◽  
Argon Ion

ABSTRACTWe have demonstrated a method f or the selective-area, laser-assisted liquid-phase etching of 6-μm thick copper conductors, by focusing the 488-μm line of an argon ion laser onto the surface of samples immersed in a dilute solution containing sulfuric acid and hydrogen peroxide. Average etch rates of up to 5.0 μm/s have been achieved, in the process of completely severing 14-μm wide copper lines, with little attendant damage to the underlying layer of polyimide. Two etchant formulations were identified which exhibited large etch rates at elevated temperatures and low enough background etch rates (approximately 1 μm/hr at 0 °C) to be useful in practical applications.

scholarly journals Fabrication of Microchannels by Using the CO2 Galvo Laser Marking Machine and Thermo-mechanical Sealing Method

2019 ◽  
Vol 35 (2) ◽  
Author(s):  
Ho Anh Tam ◽  
Nguyen Viet Hung ◽  
Nguyen Huu Duc ◽  
Do Thi Huong Giang
Keyword(s):  
Laser Power ◽  
Soft Lithography ◽  
High Performance ◽  
Lab On A Chip ◽  
Scanning Speed ◽  
Heat Sinks ◽  
Laser Source ◽  
Laser Marking ◽  
Constructal Design ◽  
Scanning Time

Abstract: Microchannel in microtechnology is a channel with a hydraulic diameter below 1 mm. Microchannels are primarily used in biomedical devices and microfluidic applications. Fabrication of microchannels has always been a complex task even at the world centres of excellence. This article addresses the fabrication techniques for creating microchannels using a 40W CO2 Galvo laser marking machine. It was able to control the channel dimensions by changing the power, scanning speed, and scanning time of the laser source. The results show that the created channel width increased as the laser power increased and the scanning speed decreased. Similarly, the channel depth increased as the laser power increased. Successfully tested in the laminar flow and droplet modes, the created microchannels were sealed using the thermo-mechanical method at 220oC. This is a new method for faster and cheaper production of microdevices that could be explored for sustainable development in the industry. The article concludes that with an appropriate solution, microchannels with minimal width and depth dimensions of 50 µm × 50 µm can be developed with channel roughness of 2-3µm. Keywords: Microfluidics, microchannels, CO2 marking machine, Galvo, mechanical sealing method. References: [1] G. Satish Kandlikar, Heat transfer and fluid flow in minichannels and microchannels. Amsterdam, The Netherlands: Elsevier B.V. (2006) p. 450. ISBN 978-0-08-044527-4. [2] D.B. Tuckerman and R.F.W. Pease, (1981). High-performance heat sinking for VLSI. IEEE Electron device letters, 2(5) (1981) 126-129. https://dx.doi. org/10.1109/EDL.1981.25367 [3] M.R. Salimpour, A.T. Al-Sammarraie, A. Forouzandeh and M. Farzaneh, Constructal design of circular multilayer microchannel heat sinks. Journal of Thermal Science and Engineering Applications, 11(1) (2019)011001. https://dx.doi. org/10.1115/1.4041196[4] Petra S. Dittrich, Lab-on-a-chip: microfluidics in drug discovery Nature, 442 (2016) 210-224.[5] D. Mark, Microfluidic Lab-on-a-Chip Plastforms: Requirements, Characteristics and Applications, NAPSA, 24 (2010) 305.[6] Shashi Prakash and Subrata Kumar, Fabrication of microchannels: A review, Proc IMechE Part B: J Engineering Manufacture, Vol. 229(8) (2015) 1273–1288[7] George M. Whitesides, The origins and the future of microfluidics, Nature, 442 (2006) 368-384.[8] Chee M.B. Ho, 3D printed microfluidics for biological applications, LabChip1, 5 (2015) 3627.[9] B. Ekstrom, G. Jacobsson, O. Ohman, et al. Microfluidic structure and process for its manufacturing. Patent WO 91/16966, 1990[10] Dong Qin, Soft lithography for micro and nano patterning, NatureProtocals, 5 (2010) 491-510.[11] Shashi Prakash, Experimental and theoretical analysis of defocused CO2 laze microchanneling on PMMA for enhanced surface finish, JMM, 27 (2016) 250.[12] Beat Jaeggi, Time-optimized laze micro machining by using a new high dynamic and high precision galvo scanner, Proceedings, (2016) 9735.

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