Photothermally Assisted Dry Etching Of GaN

1996 ◽  
Vol 423 ◽  
Author(s):  
R. T. Leonard ◽  
S. M. Bedair
Keyword(s):  
Activation Energy ◽  
Laser Fluence ◽  
Etch Rate ◽  
Ion Beam ◽  
Sample Surface ◽  
Dry Etching ◽  
Process Conditions ◽  
Ion Damage ◽  
Arf Excimer Laser ◽  
193 Nm

AbstractPhotoassisted dry etching of GaN in HC1 by 193 nm ArF excimer laser is developed as apotential alternative process to eliminate the ion damage and surface roughness which occur inetching techniques that involve an energetic ion beam impinging the surface. A directed stream ofHC1 etchant with background pressure of ∼ 5 × 10−4 Torr, sample surface temperature between 200 to 400°C, and laser fluence of 10 to 20 mJ/ pulse combine to produce etching. The photoassistedetching reaction under these process conditions is thermal in nature, with activation energy near 1.2kcal/ mol. Increases in laser fluence results in increase of etch rate, but the surface also becomesrougher. Distinct etch features can be produced with smooth surfaces at expense of etch rate.

Reduced Time for Uniform Etching of Cu Power Planes during FIB Editing

2003 ◽  
Vol 766 ◽  
Author(s):  
V.V. Makarov ◽  
W.B. Thompson ◽  
T.R. Lundquist
Keyword(s):  
Etch Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Ion Bombardment ◽  
Dry Etching ◽  
Reduced Time

AbstractDry etching of Cu challenges the Focused Ion Beam (FIB) removal of metallizations. Cu metallizations are comprised of numerous, randomly orientated crystallites. Each orientation shows a different etch rate under ion bombardment, leading to unacceptable damage to underlying dielectric. An improved methodology for uniform Cu etching over dielectric consists of three steps: 1) Exposure, 2) Initial off-normal bombardment and 3) Chemistry assisted ion bombardment. Comparison is made with and without preliminary off-normal bombardment. It is shown that Cu etching preceded by off-normal bombardment was completed ∼50% sooner with decreased dielectric over-etch.

Laser-Assisted Dry Etching Ablation for Microstructuring of III-V Semiconductors

1995 ◽  
Vol 397 ◽  
Author(s):  
J.J. Dubowski ◽  
M. Julier ◽  
G.I. Sproule ◽  
B. Mason
Keyword(s):  
Laser Fluence ◽  
Structural Damage ◽  
Etch Rate ◽  
Matrix Material ◽  
Atomic Layer ◽  
Dry Etching ◽  
Microscopy Study ◽  
Characteristic Energy ◽  
Semiconductor Compounds

ABSTRACTLaser-assisted dry etching ablation (LADEA) has been reviewed with an emphasis on its applicability for the microstructuring of III-V semiconductor compounds. The method is based on the application of an excimer laser ( λ= 308 nm) for pulsed heating of a wafer which is placed in a stream of Cl2/He gas. Both the products of chemical reaction and the depth to which a laser-induced reaction takes place depend on laser fluence. This makes possible the ablation of a well defined volume of the material. Little or no structural damage to the surface is observed because ablation is carried out with laser fluences below those required to melt the matrix material. The laser fluence dependence of the etch rate indicates that the process is primarily temperature driven with a characteristic energy for desorption. We have investigated LADEA as a method for in-situ processing of III-V semiconductors and the fabrication of nanostructures. An atomic force microscopy study has shown that atomically smooth surfaces can be obtained if the etch rate is near 1/2 atomic layer per laser pulse. The lateral resolution of LADEA has been found to be at least 20 nm. This, as well as the results of in-situ photoluminescence and Auger electron spectroscopy measurements, indicate that LADEA can be used for the direct (photoresist-free) fabrication of high quality microstructures and, ultimately, for the nanostructuring of III-V semiconductor compounds.

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

High Resolution Displacement of Functional Groups onto Fluorocarbon Resin Surface by Using ArF Excimer Laser

1996 ◽  
Vol 451 ◽  
Author(s):  
T. Shimizu ◽  
M. Murahara
Keyword(s):  
Contact Angle ◽  
High Resolution ◽  
Laser Beam ◽  
Thin Layer ◽  
Functional Groups ◽  
Excimer Laser ◽  
Laser Fluence ◽  
Large Area ◽  
Three Solutions ◽  
Arf Excimer Laser

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.

Analysis of Voltage Contrast in Secondary Electron Images Using a High-Energy Electron Spectrometer

2019 ◽  
Author(s):  
Natsuko Asano ◽  
Shunsuke Asahina ◽  
Natasha Erdman
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Sample Surface ◽  
High Energy ◽  
Secondary Electrons ◽  
Analysis Technique ◽  
Quantitative Understanding ◽  
Voltage Contrast ◽  
Acceleration Voltage ◽  
Failure Localization

Abstract Voltage contrast (VC) observation using a scanning electron microscope (SEM) or a focused ion beam (FIB) is a common failure analysis technique for semiconductor devices.[1] The VC information allows understanding of failure localization issues. In general, VC images are acquired using secondary electrons (SEs) from a sample surface at an acceleration voltage of 0.8–2.0 kV in SEM. In this study, we aimed to find an optimized electron energy range for VC acquisition using Auger electron spectroscopy (AES) for quantitative understanding.

scholarly journals Crystallization behavior of ion beam sputtered HfO2 thin films and its effect on the laser-induced damage threshold

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Zoltán Balogh-Michels ◽  
Igor Stevanovic ◽  
Aurelio Borzi ◽  
Andreas Bächli ◽  
Daniel Schachtler ◽  
...  
Keyword(s):  
Activation Energy ◽  
Crystallization Process ◽  
Ion Beam ◽  
Damage Threshold ◽  
High Activation ◽  
Quarter Wave ◽  
Dimensional Growth ◽  
Laser Induced Damage ◽  
Significant Increment

AbstractIn this work, we present our results about the thermal crystallization of ion beam sputtered hafnia on 0001 SiO2 substrates and its effect on the laser-induced damage threshold (LIDT). The crystallization process was studied using in-situ X-ray diffractometry. We determined an activation energy for crystallization of 2.6 ± 0.5 eV. It was found that the growth of the crystallites follows a two-dimensional growth mode. This, in combination with the high activation energy, leads to an apparent layer thickness-dependent crystallization temperature. LIDT measurements @355 nm on thermally treated 3 quarter-wave thick hafnia layers show a decrement of the 0% LIDT for 1 h @773 K treatment. Thermal treatment for 5 h leads to a significant increment of the LIDT values.

scholarly journals Dry Etching of Germanium with Laser Induced Reactive Micro Plasma

2021 ◽  
Author(s):  
Martin Ehrhardt ◽  
Pierre Lorenz ◽  
Jens Bauer ◽  
Robert Heinke ◽  
Mohammad Afaque Hossain ◽  
...  
Keyword(s):  
Ion Beam ◽  
Etching Rate ◽  
Dry Etching ◽  
Etching Process ◽  
High Tech ◽  
Etching Time ◽  
High Quality ◽  
Machined Surface ◽  
Reactive Plasma ◽  
New Processing

AbstractHigh-quality, ultra-precise processing of surfaces is of high importance for high-tech industry and requires a good depth control of processing, a low roughness of the machined surface and as little as possible surface and subsurface damage but cannot be realized by laser ablation processes. Contrary, electron/ion beam, plasma processes and dry etching are utilized in microelectronics, optics and photonics. Here, we have demonstrated a laser-induced plasma (LIP) etching of single crystalline germanium by an optically pumped reactive plasma, resulting in high quality etching. A Ti:Sapphire laser (λ = 775 nm, EPulse/max. = 1 mJ, t = 150 fs, frep. = 1 kHz) has been used, after focusing with a 60 mm lens, for igniting a temporary plasma in a CF4/O2 gas at near atmospheric pressure. Typical etching rate of approximately ~ 100 nm / min and a surface roughness of less than 11 nm rms were found. The etching results were studied in dependence on laser pulse energy, etching time, and plasma – surface distance. The mechanism of the etching process is expected to be of chemical nature by the formation of volatile products from the chemical reaction of laser plasma activated species with the germanium surface. This proposed laser etching process can provide new processing capabilities of materials for ultra—high precision laser machining of semiconducting materials as can applied for infrared optics machining.

Reduction of EUV resist damage by neutral beam etching

2021 ◽  
Author(s):  
Gyo Wun Kim ◽  
Won Jun Chang ◽  
Ji Eun Kang ◽  
Hee Ju Kim ◽  
Geun Young Yeom
Keyword(s):  
Radiation Damage ◽  
Light Source ◽  
Ion Beam ◽  
Critical Dimension ◽  
Neutral Beam ◽  
Etch Depth ◽  
Etching Selectivity ◽  
193 Nm ◽  
20 Nm ◽  
Neutral Beam Etching

Abstract Even though EUV lithography has the advantage of implenting a finer pattern compared to ArF immersion lithography due to the use of 13.5 nm instead of 193 nm as the wavelengh of the light source, due to the low energy of EUV light source, EUV resist has a thinner thickness than conventional ArF resist. EUV resist having such a thin thickness is more vulnerable to radiation damage received during the etching because of its low etch resistance and also tends to have a problem of low etch selectivity. In this study, the radiation damage to EUV resist during etching of hardmask materials such as Si3N4, SiO2, etc. using CF4 gas was compared between neutral beam etching (NBE) and ion beam etching (IBE). When NBE was used, after the etching of 20 nm thick EUV resist, the line edge roughness (LER) increase and the critical dimension (CD) change of EUV resist were reduced by ~ 1/3 and ~ 1/2, respectively, compared to those by IBE. Also, at that EUV etch depth, the RMS(root mean square) surface roughness value of EUV resist etched by NBE was ~2/3 compared to that by IBE on the average. It was also confirmed that the etching selectivity between SiO2, Si3N4, etc. and EUV resist was higher for NBE compared to IBE. The less damage to the EUV resist and the higher etch selectivity of materials such as Si3N4 and SiO2 over EUV resist for NBE compared to IBE are believed to be related to the no potential energy released by the neutralization of the ions during the etching for NBE.

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