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1.
Reactive ion etching (RIE) was performed on gallium nitride (GaN) films grown by electron cyclotron resonance (ECR) plasma
assisted molecular beam epitaxy (MBE). Etching was carried out using trifluoromethane (CHF3) and chloropentafluoroethane (C2ClF5) plasmas with Ar gas. A conventional rf plasma discharge RIE system without ECR or Ar ion gun was used. The effects of chamber
pressure, plasma power, and gas flow rate on the etch rates were investigated. The etch rate increased linearly with the ratio
of plasma power to chamber pressure. The etching rate varied between 60 and 500Å/min, with plasma power of 100 to 500W, chamber
pressure of 60 to 300 mTorr, and gas flow rate of 20 to 50 seem. Single crystalline GaN films on sapphire showed a slightly
lower etch rate than domain-structured GaN films on GaAs. The surface morphology quality after etching was examined by atomic
force microscopy and scanning electron microscopy. 相似文献
2.
N. Medelci A. Tempez D. Starikov N. Badi I. Berishev A. Bensaoula 《Journal of Electronic Materials》2000,29(9):1079-1083
Reactive ion etching (RIE) was performed on GaN and BN thin films using chlorine-based plasmas. The optimum chemistry was
found to be BCl3/Cl2/N2/Ar and Cl2/Ar at 30 and 40 mtorr for GaN and BN etching, respectively. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy
(AES) analysis of the GaN and BN etched surfaces show a decrease in the surface nitrogen atomic composition and an increase
in chlorine impurity incorporation with increasing self-dc bias. A photo-assisted RIE (PA-PIE) process using an IR filtered
Xe lamp beam was then used and resulted in improved etch rates and surface composition. Optical emission spectroscopy (OES)
measurements have also shown photoenhancement of the etch process. 相似文献
3.
One of the major GaN processing challenges is useful pattern transfer. Serious photoresist mask erosion and hardening are
often observed in reactive ion etching of GaN. Fine pattern transfer to GaN films using photoresist masks and complete removal
of remaining photoresist after etching are very difficult. By replacing the etch mask from conventional photoresist to a sputtered
iron nitride (Fe-8% N) film, which is easily patterned by wet chemical etching and is very resistive to Cl based plasmas,
GaN films can be finely patterned with vertical etched sidewalls. Successful pattern transfer is realized by reactive ion
etching using Cl (H) containing plasmas. CHF3/Ar, C2ClF5/Ar, C2ClF5/Ar/O2, SiCl4, and CHCl3 plasmas were used to etch GaN. The GaN etch rate is dependent on the crystalline quality of GaN. Higher crystalline quality
GaN films exhibit slower etch rates than GaN films with higher dislocation and stacking fault density. 相似文献
4.
M. Hlad L. Voss B. P. Gila C. R. Abernathy S. J. Pearton F. Ren 《Journal of Electronic Materials》2006,35(4):680-684
(Sc2O3)x(Ga2O3)1?x films grown by molecular beam epitaxy show promise for use as surface passivation layers and gate dielectrics on GaN-based high electron mobility transistors. Completely selective, low-damage, dry etching of (Sc2O3)x(Ga2O3)1?x films with respect to GaN can be achieved with low-power inductively coupled plasmas of CH4/H2/Ar with etch rates in the range 200–300 Å/min. The incident ion energies are of order 100 eV, and no roughening of the underlying GaN was observed under these conditions. Similar etch rates were obtained with Cl2/Ar discharges under the same conditions, but GaN showed rates almost an order of magnitude higher. 相似文献
5.
K. B. Jung J. W. Lee Y. D. Park J. R. Childress S. J. Pearton M. Jenson A. T. Hurst Jr. 《Journal of Electronic Materials》1997,26(11):1310-1313
Dry etching of multilayer magnetic thin film materials is necessary for the development of sensitive magnetic field sensors and memory devices. The use of high ion density electron cyclotron resonance (ECR) plasma etching for NiFe, NiFeCo, TaN, and CrSi in SF6/Ar, CH4/H2/Ar, and Cl2/Ar plasmas was investigated as a function of microwave source power, rf chuck power, and process pressure. All of the plasma chemistries are found to provide some enhancement in etch rates relative to pure Ar ion milling, while Cl2/Ar provided the fastest etch rate for all four materials. Typical etch rates of 3000Å/min were found at high microwave source power. Etch rates of these metals were found to increase with rf chuck power and microwave source power, but to decrease with increasing pressure in SF6/Ar, CH4/H2/Ar, and Cl2/Ar. A significant issue with Cl2/Ar is that it produces significant metal-chlorine surface residues that lead to post-etch corrosion problems in NiFe and NiFeCo. However, the concentration of these residues may be significantly reduced by in-situ H2 or O2 plasma cleaning prior to removal of the samples from the etch reactor. 相似文献
6.
Hyung-Ho Park Kwang-Ho Kwon Sang-Hwan Lee Byung-Hwa Koak Sahn Nahm Hee-Tae Lee Kyoung-Ik Cho Oh-Joon Kwon Young-II Kang 《ETRI Journal》1994,16(1):45-57
The effects of reactive ion etching (RIE) of SiO2 layer in CHF3 / C2F6 on the underlying Si surface have been studied by X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometer, Rutherford backscattering spectroscopy, and high resolution transmission electron microscopy. We found that two distinguishable modified layers are formed by RIE : (i) a uniform residue surface layer of 4 nm thickness composed entirely of carbon, fluorine, oxygen, and hydrogen with 9 different kinds of chemical bonds and (ii) a contaminated silicon layer of about 50 nm thickness with carbon and fluorine atoms without any observable crystalline defects. To search the removal condition of the silicon surface residue, we monitored the changes of surface compositions for the etched silicon after various post treatments as rapid thermal anneal, O2, NF3, SF6, and Cl2 plasma treatments. XPS analysis revealed that NF3 treatment is most effective. With 10 seconds exposure to NF3 plasma, the fluorocarbon residue film decomposes. The remained fluorine completely disappears after the following wet cleaning. 相似文献
7.
A. T. Ping A. C. Schmitz I. Adesida M. Asif Khan Q. Chen J. W. Yang 《Journal of Electronic Materials》1997,26(3):266-271
Dry etch-induced damage has been investigated using Pd Schottky diodes fabricated on n-type GaN surfaces that were etched
by reactive ion etching in SiCl4 and Ar plasmas. Damage was evaluated by measuring the current-voltage, current-voltage-temperature, and capacitance-voltage
characteristics of the diodes. A plasma chemistry that includes a chemical etching component (SiCl4) was found to significantly reduce the degree of induced damage in comparison to a chemistry that uses only a physical component
(Ar). The effective barrier height, ideality factor, reverse breakdown voltage, reverse leakage current, and the effective
Richardson coefficient of diodes etched under various plasma conditions are presented. The degree of etch-induced damage was
found to depend strongly on the plasma self-bias voltage but saturates with etch time after an initial two-minute etch period.
Rapid thermal annealing was found to be effective in improving the diode characteristics of the etched GaN samples. 相似文献
8.
D. C. Hays K. P. Lee B. P. Gila F. Ren C. R. Abernathy S. J. Pearton 《Journal of Electronic Materials》2000,29(3):285-290
Gd2O3 is a promising gate dielectric for GaN, but little is known of its dry etching characteristics. We achieved Gd2O3 etch rates up to ~600 Å · min?1 in high density Cl2-based discharges, with maximum selectivities of ~15 over GaN and ~4 over AlN. Pure Cl2 discharges produced reverse selectivities for both Gd2O3/GaN and Gd2O3/AlN, with typical values between 0.1–0.4. When a rare gas additive such as Ar or Xe was added to the plasma chemistry, the nitrides etched faster than the oxide. This indicates that volatile etch products (GaCl3, AlCl3, N2) form in Cl2-based plasmas once the GaN or AlN bonds are broken by ion bombardment, but that GdClx species are not volatile. In conjunction with the low efficiency for Gd2O3 bond-breaking at low ion energies, this leads to low selectivity. 相似文献
9.
An etching of a SiO2 contact hole with a diameter of 0.19 μm and an aspect ratio of 13, using C4F6/Ar/O2/CH2F2 and c-C4F8/Ar/O2/CH2F2 plasmas, was performed for a feasibility test of the use of unsaturated fluorocarbons (UFCs) as an alternative to perfluorocarbon (PFC) gases for a high aspect ratio contact hole etching. The etch profile of the contact hole obtained in the C4F6/Ar/O2/CH2F2 plasma was shown to have 23% lower degree of bowing than that in the c-C4F8/Ar/O2/CH2F2 plasma. The Kelvin and chain contact resistances of the contact holes etched in the C4F6/Ar/O2/CH2F2 plasma were 10-12% higher than those in the c-C4F8/Ar/O2/CH2F2 plasma, but they were within the device spec. The integration of device with 0.1 μm design rule using C4F6/Ar/O2/CH2F2 and c-C4F8/Ar/O2/CH2F2 plasmas during the contact hole etching was also conducted, and it was found that etch profiles, metal coverage, and bottom critical dimensions of the contact in the C4F6/Ar/O2/CH2F2 plasma were nearly identical to those in the c-C4F8/Ar/O2/CH2F2 plasma, suggesting that the use of C4F6 gas as an etchant gas for a high aspect ratio contact hole etching can be a good alternative to PFC gases. 相似文献
10.
Jong-Gyu Kim Gwan-Ha Kim Kyoung-Tae Kim Chang-Il Kim 《Materials Science in Semiconductor Processing》2006,9(6):1108
The etching mechanism of (Bi4−xLax)Ti3O12 (BLT) thin films in Ar/Cl2 inductively coupled plasma (ICP) and plasma-induced damages at the etched surfaces were investigated as a function of gas-mixing ratios. The maximum etch rate of BLT thin films was 50.8 nm/min of 80% Ar/20% Cl2. From various experimental data, amorphous phases on the etched surface existed on both chemically and physically etched films, but the amorphous phase was thicker after the 80% Ar/20% Cl2 process. Moreover, crystalline “breaking” appeared during the etching in Cl2-containing plasma. Also the remnant polarization and fatigue resistances decreased more for the 80% Ar/20% Cl2 etch than for pure Ar plasma etch. 相似文献
11.
Inductively coupled plasma reactive ion etching of SiC single crystals using NF3-based gas mixtures was investigated. Mesas with smooth surfaces and vertical sidewalls were obtained, with a maximum etch
rate of about 400 nm/min. Effects of CH4 and O2 addition to the NF3 gas and the crystalline quality of substrates were studied during the SiC dry etching using various masks. Selectivity of
the photoresist (PR) mask improved from about 0.2 to about 0.4 by the addition of 30% CH4 during the RIE, although the etch rate decreased by 50–70%. Results also indicated that the substrate quality does not significantly
affect the etch results. 相似文献
12.
Prakash N. K. Deenapanray C. S. Athukorala Daniel Macdonald W. E. Jellett E. Franklin V. E. Everett K. J. Weber A. W. Blakers 《Progress in Photovoltaics: Research and Applications》2006,14(7):603-614
This paper investigates the reactive ion etching of SiO2, Si3N4, and Si using CHF3/O2 plasma. In particular, we have characterized the time and rf power dependence of the carrier lifetimes in n‐ and p‐type FZ Si. The time dependence of reactive ion etching (RIE) at different rf powers provide insight into the two competing processes of damage accumulation and damage removal in the near‐surface region of the Si during plasma etching. The carrier lifetime, measured using the quasi‐steady‐state photoconductance (QSSPC) technique, has a quadratic dependence on the rf power, which can be related to changes in the dc self‐bias generated by the plasma at different rf powers. The change in carrier lifetime is similar in both n‐ and p‐type Si of the same doping concentration. Using this fact, together with the electronic properties of defects obtained by deep level transient spectroscopy (DLTS), we have modeled the injection‐dependence of the measured carrier lifetimes using the Shockley–Read–Hall model. The isochronal annealing behavior of plasma etched Si has also been studied. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
13.
The etching damage on nano-clustering silica (NCS) film due to etching radicals was investigated using a method of radical treatments in RIE plasma. NCS coated-side of the wafer was turned downward and put at 0.65 mm above the wafer stage to investigate only the influence of radicals. Etching radicals, which comes from CF4, diffuse into NCS film and reduce Si-CH3 bonds and Si-CH3 loss is proportional to the amount of diffused fluorine in NCS film. Several Si-CH3 bonds are converted to Si-F bonds then. As a result, the low-k performance is degraded and especially the leakage current heavily increases. We proposed a method for estimating the degree of the sidewall damage due to etching radicals using blanket wafers. The degree of sidewall damage is proportional to the value of CR−0.5, where C is the damage diffusion coefficient, which is derived from Si-CH3 decrement ratio from a radical treatment result and R is the etching rate, which is derived from a RIE treatment result under the same plasma condition. The value of CR−0.5 depends on the etching condition and must be decreased as much as possible in order to reduce the sidewall damage during RIE. For example, lower gas pressure, higher RF power, and higher CF4/Ar gas flow ratio were desirable for the sidewall damage reduction. 相似文献
14.
C. R. Eddy Jr. D. Leonhardt V. A. Shamamian J. R. Meyer C. A. Hoffman J. E. Butler 《Journal of Electronic Materials》1999,28(4):347-354
High density plasma etching of mercury cadmium telluride using CH4/H2/Ar plasma chemistries is investigated. Mass spectrometry is used to identify and monitor etch products evolving from the
surface during plasma etching. The identifiable primary etch products are elemental Hg, TeH2, and Cd(CH3)2. Their relative concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy and
substrate temperature are varied. General insights are made into surface chemistry mechanisms of the etch process. These insights
are evaluated by examining etch anisotropy and damage to the remaining semiconductor material. Regions of process parameter
space best suited to moderate rate, anisotropic, low damage etching of HgCdTe are identified. 相似文献
15.
R. Dylewicz S. Patela R. A. Hogg P. W. Fry P. J. Parbrook R. Airey A. Tahraoui 《Journal of Electronic Materials》2009,38(5):635-639
Optimized fabrication of submicron-sized features in gallium nitride (GaN) with the use of inductively coupled plasma (ICP)
dry etching, based on SiCl4/Cl2/Ar gas mixture, is presented. Dense periodic patterns, i.e., 400-nm-period gratings, were transferred into a gallium nitride
waveguide under different etching conditions. ICP power, radiofrequency (RF) power, chamber pressure, and Ar/Cl2 gas mixing ratio were altered during the experiment. Depths of fabricated grating couplers up to 670 nm were achieved. The
most suitable etching conditions are discussed with the assessment based on etching selectivity, scanning electron microscopy
(SEM) observation of grating tooth slope, hard-mask erosion process, and etched surface morphology. 相似文献
16.
Y. Naoi Y. Kawakami T. Nakanishi Y. Lacroix Y. Shintani S. Sakai 《Materials Science in Semiconductor Processing》2001,4(6)
We investigated GaN films etched by using reactive ion etching (RIE) technique to fabricate the GaN-based devices. The samples were grown on sapphire substrate by metal organic chemical vapor deposition (MOCVD), and Ti/Al contacts were formed on n-GaN surfaces after etching processes. The effects of the kinds of reactive gases were evaluated by secondary ion mass spectrometry (SIMS). The results showed that in the sample etched using BCl3 gas, the signal from boron contaminations was strongly detected at the interface between the contact metal and n-GaN, and we found that additional etching in Cl2 plasma after etching with BCl3 gas was essential to make a good contact. 相似文献
17.
A. T. Ping C. Youtsey I. Adesida M. Asif Khan J. N. Kuznia 《Journal of Electronic Materials》1995,24(4):229-234
Chemically assisted ion beam etching of gallium nitride (GaN) grown by metalorganic chemical vapor deposition has been characterized
using an Ar ion beam and Cl2gas. The etch rate of GaN was found to increase linearly with Ar ion beam current density, increase linearly then saturate
with Ar ion beam energy, vary slightly with Cl2 flow rate, and lastly, increase moderately with substrate temperature. Etch rates as high as 330 nm/min were obtained at
high beam energies and 210 nm/min at a more nominal level of 500 eV. The anisotropy of etched profiles improved in the presence
of Cl2 in comparison to those etched by Ar ion milling only. Elevated substrate temperatures further enhanced the anisotropy to
obtain near-vertical profiles for fairly deep-etched structures. Auger electron spectroscopy was used to investigate etch-induced
surface changes. Oxygen contamination was observed on the as-etched surface but a dilute HC1 treatment restored the stoichiometry
of the material to its unetched state. 相似文献
18.
Robert C. Keller M. Seelmann-Eggebert H. J. Richter 《Journal of Electronic Materials》1995,24(9):1155-1160
We report on several new aspects of etching of Hg1−xCdxTe (x = 0.22), HgTe, and CdTe in CH4/H2/Ar plasmas generated by an electron cyclotron resonance plasma source. Using a residual gas analyzer, we have identified
elemental Hg, TeH2, Te(CH3)2, and Cd(CH3)2 as the primary reaction products escaping from a HgCdTe surface during the plasma exposure. We have also demonstrated that
a bias is not needed to etch HgCdTe at moderate temperatures (30-40°C), as previously suggested by other researchers. We have
also developed a technique that avoids the formation of hydrocarbon polymer films on a HgCdTe sample during etching. Moreover,
we have examined by x-ray photoelectron spectroscopy analysis and ellipsometry the surface condition of HgCdTe resulting from
etching with this technique at zero bias. After exposure to the CH4/H2Ar plasma (or to a H2/Ar plasma only), the HgCdTe samples exhibited a depletion of the HgTe component in the near surface region (increase of the
x-value). The depletion covered a range from virtually x = 1 after H2/Ar (10:2 in sccm) etching to values 0.4 < x < 0.5 after CH4/H2Ar (7:7:2 in seem) etching. Exposures to the plasmas were found to result in surface roughening of HgCdTe, however, plasmas
rich in H2 were observed to cause significantly rougher surfaces than plasmas with small H2/CH4 ratios. This difference in the resulting surface condition is attributed solely to chemical effects since the respective
ion energies are considered to be below the damage threshold for HgCdTe in both cases. We also investigated the etching of
HgTe and CdTe single crystals. The etch rate of HgTe was found to be over one order of magnitude higher than that of CdTe
under similar conditions. This large difference in etch rates is assumed to be responsible for the observed preferential etching
of the HgTe component indicated by the HgTe depletion of the HgCdTe surface region. 相似文献
19.
E. P. G. Smith C. A. Musca D. A. Redfern J. M. Dell L. Faraone 《Journal of Electronic Materials》2000,29(6):853-858
An experimental study has been carried out on the performance of n-type x = 0.31 HgCdTe photoconductive detectors in order
to evaluate two different etching techniques; dry plasma etching, in the form of H2/CH4 reactive ion etching (RIE), and wet chemical etching using bromine in hydrobromic acid. Two-dimensional laser beam-induced
current (LBIC) imaging was employed as an in-line process monitoring tool to evaluate the lateral extent of reactive ion etching
(RIE) induced doping changes in the HgCdTe epilayer following mesa delineation. Responsivity and noise measurements were performed
on fabricated mid-wavelength infrared (MWIR) photoconductive devices to evaluate the influence dry plasma etching has on material
properties. For a signal wavelength of 3 μm, 60° field of view, and a temperature of 80 K, background limited D
λ
*
performance was recorded for wet chemical processed devices but not for the dry plasma processed devices. The D
λ
*
values obtained for wet chemical and dry plasma etched photoconductive detectors were 2.5×1011 cmHz1/2W−1 and 1.0×1010 cmHz1/2W−1, respectively. Mercury annealing, which has been shown to restore the electrical properties of dry plasma processed HgCdTe,
could be used to lessen the influence that RIE dry plasma etching has on photoconductor detector performance. 相似文献
20.
F. Karouta J. L. Weyher B. Jacobs G. Nowak A. Presz I. Grzegory L. M. F. Kaufmann 《Journal of Electronic Materials》1999,28(12):1448-1451
Reactive ion etching of {0001} oriented plate-like GaN single crystals has been investigated using SiCl4:Ar:SF6 chemistry. The reactive ion etching process is highly chemical. Large anisotropy of the etching rate and of the morphology
has been established on (000
) N-polar and (0001) Ga-polar sides of the GaN crystals, with remarkably higher rate on the N-polar side. Atomic force microscopy
measurements have shown smooth surface and good polishing effect obtained on Ga-polar side, while N-polar surface exhibits
an increased roughness of a factor of 10 after RIE. 相似文献