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.

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-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.

Mass Spectrometric Study of Laser-Induced Chemical Vapor Deposition of Gold

1987 ◽  
Vol 101 ◽  
Author(s):  
Toivo T. Kodas ◽  
Paul B. Comita
Keyword(s):  
Surface Temperature ◽  
Reaction Rate ◽  
Chemical Vapor ◽  
Mass Spectrometric Study ◽  
Reaction Products ◽  
Quadrupole Mass ◽  
Product Concentration ◽  
Ion Laser ◽  
Phase Sensitive ◽  
Argon Ion

ABSTRACTA modulated surface temperature technique was used to study the surface chemical reactions occurring during the laser-assisted deposition of gold from dimethyl gold hexafluoroacetylacetonate. An argon ion laser was chopped and used to modulate the surface temperature on an area roughly 1 mm in diameter on an alumina substrate. Reactant and products of the photothermal reaction were sampled through an orifice located at the center of the deposit and were then introduced directly into a quadrupole mass filter. Since the reactant concentration at the surface decreased when the laser turned on while the product concentration at the surface increased when the laser turned on, modulating the surface reaction rate and employing phase-sensitive detection allowed the identification of reaction products.

Intensification of Spontaneous Raman Spectra by Use of Liquid Core Optical Fibers

1972 ◽  
Vol 26 (6) ◽  
pp. 585-589 ◽  
Author(s):  
G. E. Walrafen ◽  
J. Stone
Keyword(s):  
Fiber Optics ◽  
Raman Spectra ◽  
Optical Fibers ◽  
Laser Power ◽  
Liquid Core ◽  
Fused Quartz ◽  
Ion Laser ◽  
Argon Ion ◽  
Focused Beam ◽  
Good Agreement

Intense spontaneous Raman radiation has been obtained from C6H6 and C2CI4 by passing the focused beam from an argon ion laser (4880 Å, 5 to 250 mW) through filled hollow fused quartz optical fibers having core diameters of ∼75 µm and lengths from 10 to 25 meters. Spectral intensifications by factors of ∼102 to 103 compared to conventional sample techniques have been obtained with the fiber optics method. Raman spectra were recorded with a Cary model 81 spectrophotometer by collecting the divergent radiation emitted from the end of the optical fiber at the focus of the “image slicer.” However, the intensification method is general and may be employed with any double or triple monochromator by placing the fiber end near the entrance slit. For C6H6 at least 33 Raman components were observed in the 3300 > A Δ ν̄ > 1650 cm−1 region including shifts due to overtones and combinations, by using a slit-width of 2 cm−1 with a 15 m fiber length and a laser power of ∼130 mW. The Raman spectra from C6H6 were found to be in good agreement with those recently reported by Schrötter and Bofilias. For C2CI4 intense spectra were also obtained using 2 cm−1 slit-widths with fiber lengths of 25 m and power levels to 250 mW. These spectra augment those obtained earlier by Wittek and indicate five newly observed Raman and infrared coincidences that in several cases may result from the breakdown of D2h selection rules. Details of the fiber optics Raman technique are described.

scholarly journals Investigation of Thick-Film-Paste Rheology and Film Material for Pattern Transfer Printing (PTP) Technology

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Adrian Adrian ◽  
Dominik Rudolph ◽  
Jan Lossen ◽  
Norbert Willenbacher
Keyword(s):  
Solar Cell ◽  
Aspect Ratio ◽  
Yield Stress ◽  
Laser Power ◽  
Light Transmission ◽  
Pattern Transfer ◽  
Volatile Components ◽  
Film Material ◽  
Transfer Printing ◽  
Power Threshold

Steady cost pressure in silicon solar cell production leads to a continuous reduction of silver consumption per cell. Pattern Transfer Printing (PTP) technology enables to reduce silver consumption by depositing smaller front electrodes on solar cells. Here, we aim at a better understanding of the laser deposition process. The aspect ratio of printed lines improved with increasing paste yield stress but was lower than the theoretical aspect ratio for a given trench geometry, suggesting that line spreading was caused by the pressure that was due to the vaporization of volatile paste components and a yield stress reduction that was due to local paste heating. A low laser power threshold, mandatory to fabricate narrow electrodes with a high aspect ratio and low amount of debris, could be achieved using pastes with low boiling temperature of volatile components and poor wetting between paste and film. The material with the lowest light transmission exhibited the lowest laser power threshold. We attribute this to the weaker adhesion to the paste and a better alignment with the laser focal plane. Our results provide valuable guidelines for paste and film material design aimed at narrower electrodes, with a higher aspect ratio to be obtained at an even lower laser power threshold in PTP-based solar cell metallization.

Laser Induced Etching for Generation of Si Nanocrystals and Spectroscopic Investigation of Morphology

2005 ◽  
Vol 23 ◽  
pp. 43-46
Author(s):  
H.S. Mavi ◽  
S. Rath ◽  
Arun Shukla
Keyword(s):  
Quantum Confinement ◽  
Silicon Nanocrystals ◽  
Laser Wavelength ◽  
Interconnected Network ◽  
Substrate Type ◽  
Argon Ion Laser ◽  
Si Nanocrystals ◽  
Ion Laser ◽  
Laser Induced Etching ◽  
Argon Ion

Laser-induced etching of silicon is used to generate silicon nanocrystals. The pore structure depends on the substrate type and etching laser wavelength. Porous silicon (PS) samples prepared by Nd:YAG laser (1.16 eV) etching of n-type substrate showed a fairly uniform and highly interconnected network of nearly circular pores separated by thin columnar boundaries, while no circular pits were produced by argon- ion laser (2.41 eV) etching under similar conditions. The size and size distribution of the nanocrystals are investigated by Raman and photoluminescence spectroscopies and analyzed within the framework of quantum confinement models.

A Current Conduction Mechanism in Laser Recrystallized Silicon Metal-Oxide-Semiconductor Transistors

1983 ◽  
Vol 23 ◽  
Author(s):  
Han-Sheng Lee
Keyword(s):  
Conduction Mechanism ◽  
Single Crystal Silicon ◽  
Silicon Films ◽  
Oxide Semiconductor ◽  
Silicon Substrates ◽  
Mos Transistors ◽  
Crystal Silicon ◽  
Ion Laser ◽  
Argon Ion ◽  
A Current

ABSTRACTN-channel MOS transistors were fabricated on silicon films that had been recrystallized by an argon ion laser at different power levels. These transistors showed electrical characteristics similar, but somewhat inferior to those devices fabricated on single crystal silicon substrates. These differences are attributed to the presence of trapping states at the grain boundaries of the crystallites in the recrystallized silicon. A coulombic scattering model is presented to explain these differences. In the case of films annealed at low laser power, an additional factor of nonuniform trap state distribution is invoked to explain device characteristics. This model provides an adequate explanation for the observed transport properties of transistors fabricated from recrystallized silicon films.

Electron temperatures in a segmented-metal argon-ion laser

1972 ◽  
Vol 5 (10) ◽  
pp. 1807-1814 ◽  
Author(s):  
A Maitland ◽  
J C L Cornish
Keyword(s):  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion
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