共查询到20条相似文献,搜索用时 15 毫秒
1.
Dry etching of GaAs was investigated in BCl3, BCl3/N2 and BCl3/Ar discharges with a mechanical pump-based capacitively coupled plasma system. Etched GaAs samples were characterized using scanning electron microscopy and surface profilometry. Optical emission spectroscopy was used to monitor the BCl3-based plasma during etching. Pure BCl3 plasma was found to be suitable for GaAs etching at > 100 mTorr while producing a clean and smooth surface and vertical sidewall. Adding N2 or Ar to the BCl3 helped increase the etch rates of GaAs. For example, the GaAs etch rate was doubled with 20% N2 composition in the BCl3/N2 plasma compared to the pure BCl3 discharge at 150 W CCP power and 150 mTorr chamber pressure. The GaAs etch rate was ∼ 0.21 µm/min in the 20 sccm BCl3 plasma. The BCl3/Ar plasma also increased etch rates of GaAs with 20% of Ar in the discharge. However, the surface morphology of GaAs was strongly roughened with high percentage (> 30%) of N2 and Ar in the BCl3/N2 and BCl3/Ar plasma, respectively. Optical emission spectra showed that there was a broad BCl3-related molecular peak at 450-700 nm wavelength in the pure BCl3 plasma. When more than 50% N2 was added to the BCl3 plasma, an atomic N peak (367.05 nm) and molecular N2 peaks (550-800 nm) were detected. Etch selectivity of GaAs to photoresist decreased with the increase of % N2 and Ar in the BCl3-based plasma. 相似文献
2.
The investigation of Al2O3 etch characteristics in the BCl3/Ar inductively coupled plasma was carried out in terms of effects of input process parameters (gas pressure, input power, bias power) on etch rate and etch selectivity over poly-Si and photoresist. It was found that, with the changes in gas pressure and input power, the Al2O3 etch rate follows the behavior of ion current density while the process rate is noticeably contributed by the chemical etch pathway. The influence of input power on the etch threshold may be connected with the concurrence of chemical and physical etch pathways in ion-assisted chemical reaction. 相似文献
3.
In this study, we monitored the HfAlO3 etch rate and selectivity to SiO2 as a function of the etch parameters (gas mixing ratio, RF power, DC-bias voltage, and process pressure). A maximum etch rate of 52.6 nm/min was achieved in the 30% BCl3/(BCl3 + Ar) plasma. The etch selectivity of HfAlO3 to SiO2 reached 1.4. As the RF power and the DC-bias voltage increased, the etch rate of the HfAlO3 thin film increased. As the process pressure decreased, the etch rate of the HfAlO3 thin films increased. The chemical state of the etched surfaces was investigated by X-ray Photoelectron Spectroscopy (XPS). According to the results, the etching of HfAlO3 thin films follows the ion-assisted chemical etching mechanism. 相似文献
4.
In this work, we investigated the etching characteristics of TiO2 thin films and the selectivity of TiO2 to SiO2 in a BCl3/Ar inductively coupled plasma (ICP) system. The maximum etch rate of 84.68 nm/min was obtained for TiO2 thin films at a gas mixture ratio of BCl3/Ar (25:75%). In addition, etch rates were measured as a function of etching parameters, such as the RF power, DC-bias voltage and process pressure. Using the X-ray photoelectron spectroscopy analysis the accumulation of chemical reaction on the etched surface was investigated. Based on these data, the ion-assisted physical sputtering was proposed as the main etch mechanism for the BCl3-containing plasmas. 相似文献
5.
Dong-Pyo Kim Jong-Chang Woo Kyu-Ha Baek Kun-Sik Park Kijun Lee Kwang-Soo Kim Lee-Mi Do 《Vacuum》2011,86(4):380
We investigated the N2 additive effect on the etch rates of TiN and SiO2 and etch profile of TiN in N2/Cl2/Ar adaptively coupled plasma (ACP). The mixing ratio of Cl2 and Ar was fixed at 75 and 25 sccm, respectively. The N2 flow rate was increased from 0 to 9 sccm under the constant pressure of 10 mTorr. As N2 flow rate was increased in N2/Cl2/Ar plasma, the etch rate of TiN was linearly increased, but that of SiO2 was increased non-monotonically. The etch profile and the compositional changes of TiN was investigated with field emission-scanning electron microscope (FE-SEM), FE-Auger electron spectroscopy (FE-AES) and x-ray photoelectron spectroscopy (XPS). When 9 sccm N2 was added into Cl2/Ar, a steep etch profile and clean surface of TiN was obtained. In addition, the signals of TiN and Ti were disappeared in FE-AES and XPS when N2 additive flow into Cl2/Ar was above 6 sccm. From the experimental data, the increase in TiN etch rate was mainly caused by the increase of desorption and evacuation rate of etch by products because of the increased effective pumping speed. The etch mechanism of TiN in N2/Cl2/Ar ACP plasma can be concluded as the ion enhanced chemical etch. 相似文献
6.
Jong-Chang Woo 《Thin solid films》2010,518(10):2905-2909
The etching characteristics of zinc oxide (ZnO) including the etch rate and the selectivity of ZnO in a BCl3/Ar plasma were investigated. It was found that the ZnO etch rate showed a non-monotonic behavior with an increasing BCl3 fraction in the BCl3/Ar plasma, along with the RF power, and gas pressure. At a BCl3 (80%)/Ar (20%) gas mixture, the maximum ZnO etch rate of 50.3 nm/min and the maximum etch selectivity of 0.75 for ZnO/Si were obtained. Plasma diagnostics done with a quadrupole mass spectrometer delivered the data on the ionic species composition in plasma. Due to the relatively high volatility of the by-products formed during the etching by the BCl3/Ar plasma, ion bombardment in addition to physical sputtering was required to obtain the high ZnO etch rates. The chemical state of the etched surfaces was investigated with X-ray Photoelectron Spectroscopy (XPS). Inferred from this data, it was suggested that the ZnO etch mechanism was due to ion enhanced chemical etching. 相似文献
7.
Mei-Hui Tsai Hong-Yi WangHsu-Tung Lu I-Hsiang TsengHung-Hua Lu Shih-Liang HuangJui-Ming Yeh 《Thin solid films》2011,519(15):4969-4973
Polyimide (PI) nanocomposites with different proportions of Al2O3 were prepared via two-step reaction. Silicon nitride (Si3N4) was deposited on PI composite films by a RF magnetron sputtering system and used as a gas barrier to investigate the water vapor transmission rate (WVTR). The thermal stability and mechanical properties of a pure PI film can be improved obviously by adding adequate content of Al2O3. At lower sputtering pressure (4 mTorr), the PI/Al2O3 hybrid film deposited with Si3N4 barrier film exhibits denser structure and lower root mean square (RMS) surface roughness (0.494 nm) as well as performs better in preventing the transmission of water vapor. The lowest WVTR value was obtained from the sample, 4 wt.%Al2O3-PI hybrid film deposited with Si3N4 barrier film with the thickness of 100 nm, before and after bending test. The interface bonding, Al-N and Al-O-Si, was confirmed with the XPS composition-depth profile. 相似文献
8.
The etching characteristics of ITO in a BCl3/Ar plasma, including the etch rate and selectivity of ITO, were investigated. The maximum etch rate of 62.8 nm/min for the ITO thin films was obtained at a BCl3/Ar gas mixing ratio of 25%/75%. Ion bombardment by physical sputtering was required to obtain such high etch rates, due to the relatively low volatility of the by-products formed during the etching. The chemical reactions on the etched surfaces were investigated using X-ray Photoelectron Spectroscopy (XPS) and the preferential losses on the etched surfaces were investigated using Atomic Force Microscopy (AFM). 相似文献
9.
We report a comparison of dry etching of polymethyl methacrylate (PMMA) and polycarbonate (PC) in O2 capacitively coupled plasma (CCP) and inductively coupled plasma (ICP). A diffusion pump was used as high vacuum pump in both cases. Experimental variables were process pressure (30-180 mTorr), CCP power (25-150 W) and ICP power (0-350 W). Gas flow rate was fixed at 5 sccm. An optimized process pressure range of 40-60 mTorr was found for the maximum etch rate of PMMA and PC in both CCP and ICP etch modes. ICP etching produced the highest etch rate of 0.9 μm/min for PMMA at 40 mTorr, 100 W CCP and 300 W ICP power, while 100 W CCP only plasma produced 0.46 μm/min for PMMA at the same condition. For polycarbonate, the highest etch rates were 0.45 and 0.27 μm/min, respectively. RMS surface roughnesses of PMMA and PC were about 2-3 nm after etching. Etch selectivity of PMMA over photoresist was 1-2 and that of PC was less than 1. When ICP power increased from 0 to 350 W, etch rates of PMMA and PC increased linearly from 0.47 to 1.18 μm/min and from 0.18 to 0.6 μm/min, while the negative self bias slightly reduced from 364 to 352 V. Increase of CCP power raised both self bias and PMMA etch rate. PMMA etch rates were about 3 times higher than those of PC at the same CCP conditions. SEM data showed that there was some undercutting of PMMA and PC after etching at 300 W ICP, 100 W CCP and 40 mTorr. The results also showed that the etched surface of PMMA was rough and that of PC was relatively smooth. 相似文献
10.
Etching characteristics of high-k dielectric materials (HfO2) and metal electrode materials (Pt, TaN) have been studied in high-density chlorine-containing plasmas at pressures around 10 mTorr. The etching of HfO2 was performed in BCl3 without rf biasing, giving an etch rate of about 5 nm/min with a high selectivity of >10 over Si and SiO2. The etching of Pt and TaN was performed in Ar/O2 with high rf biasing and in Ar/Cl2 with low rf biasing, respectively, giving a Pt etch rate of about several tens nm/min and a TaN etch rate of about 200 nm/min with a high selectivity of >8 over HfO2 and SiO2. The etched profiles were outwardly tapered for Pt, owing to the redeposition of etch or sputter products on feature sidewalls, while the TaN profiles were almost anisotropic, probably owing to the ion-enhanced etching that occurred. 相似文献
11.
The microstructure of thin HfO2-Al2O3 nanolaminate high κ dielectric stacks grown by atomic vapor deposition has been studied by attenuated total reflection spectroscopy (ATR) and 8 eV spectroscopic ellipsometry (SE). The presence of Al2O3 below HfO2 prevents the crystallisation of HfO2 if an appropriate thickness is used, which depends on the HfO2 thickness. A thicker Al2O3 is required for thicker HfO2 layers. If crystallisation does occur, we show that the HfO2 signature in both ATR and 8 eV SE spectra allows the detection of monoclinic crystallites embedded in an amorphous phase. 相似文献
12.
Moonkeun KimAlexander Efremov Hyun Woo LeeHyung-Ho Park MunPyo HongNam Ki Min Kwang-Ho Kwon 《Thin solid films》2011,519(20):6708-6711
Etching characteristics and the mechanism of HfO2 thin films in Cl2/Ar inductively-coupled plasma were investigated. The etch rate of HfO2 was measured as a function of the Cl2/Ar mixing ratio in the range of 0 to 100% Ar at a fixed gas pressure (6 mTorr), input power (700 W), and bias power (300 W). We found that an increase in the Ar mixing ratio resulted in a monotonic decrease in the HfO2 etch rate in the range of 10.3 to 0.7 nm/min while the etch rate of the photoresist increased from 152.1 to 375.0 nm/min for 0 to 100% Ar. To examine the etching mechanism of HfO2 films, we combined plasma diagnostics using Langmuir probes and quadrupole mass spectrometry with global (zero-dimensional) plasma modeling. We found that the HfO2 etching process was not controlled by ion-surface interaction kinetics and formally corresponds to the reaction rate-limited etch regime. 相似文献
13.
D.S. Rawal Henika AroraV.R. Agarwal Seema VinayakAshok Kapoor B.K. SehgalR. Muralidharan Dipankar SahaH.K. Malik 《Thin solid films》2012,520(24):7212-7218
Cl2/Ar based inductively coupled plasma (ICP) etching of GaN is investigated using photoresist mask in a consequential restricted domain of pressure < 1.2 Pa and radio frequency (RF) sample power < 100 W, for selective mesa etching. The etch characteristics and root-mean-square (rms) surface roughness are studied as a function of process parameters viz. process pressure, Cl2 percentage in total flow rate ratio, and RF sample power at a constant ICP power, to achieve moderate GaN etch rate with anisotropic profiles and smooth surface morphology. The etch rate and resultant surface roughness of etched surface increased with pressure mainly due to dominant reactant limited etch regime. The etch rate and surface roughness show strong dependence on RF sample power with the former increasing and the later decreasing with the applied RF sample power up to 80 W. The process etch yield variation with applied RF sample power is also reported. The studied etch parameters result in highly anisotropic mesa structures with Ga rich etched surface. 相似文献
14.
K. Pimraksa P. ChindaprasirtA. Rungchet K. Sagoe-CrentsilT. Sato 《Materials Science and Engineering: A》2011,528(21):6616-6623
The syntheses of lightweight geopolymeric materials from highly porous siliceous materials viz. diatomaceous earth (DE) and rice husk ash (RHA) with high starting SiO2/Al2O3 ratios of 13.0-33.5 and Na2O/Al2O3 ratios of 0.66-3.0 were studied. The effects of fineness and calcination temperature of DE, concentrations of NaOH and KOH, DE to RHA ratio; curing temperature and time on the mechanical properties and microstructures of the geopolymer pastes were investigated. The results indicated that the optimum calcination temperature of DE was 800 °C. Increasing fineness of DE and starting Na2O/Al2O3 ratio resulted in an increase in compressive strength of geopolymer paste. Geopolymer pastes activated with NaOH gave higher compressive strengths than those with KOH. The optimum curing temperature and time were 75 °C and 5 days. The lightweight geopolymer material with mean bulk density of 0.88 g/cm3 and compressive strength of 15 kg/cm2 was obtained. Incorporation of 40% RHA to increase starting SiO2/Al2O3 and Na2O/Al2O3 ratios to 22.5 and 1.7 and enhanced the compressive strength of geopolymer paste to 24 kg/cm2 with only a marginal increase of bulk density to 1.01 g/cm3. However, the geopolymer materials with high Na2O/Al2O3 (>1.5) were not stable in water submersion. 相似文献
15.
Y.-H. Ham A. EfremovH.W. Lee S.J. YunN.K. Min K.-H. BaekL.-M. Do K.-H. Kwon 《Vacuum》2011,85(11):1021-1025
We investigated the etch characteristics and mechanisms of Ga-doped ZnO (Ga-ZnO) thin films in HBr/X (X = Ar, He, N2, O2) inductively-coupled plasmas. The etch rates of Ga-ZnO thin films were measured as a function of the additive gas fraction in the range of 0-100% for Ar, He, N2, and O2 at a fixed gas pressure (6 mTorr), input power (700 W), bias power (200 W), and total gas flow rate (40 sccm). The plasma chemistry was analyzed using a combination of the global (zero-dimensional) plasma model and Langmuir probe diagnostics. By comparing the behavior of the etch rate and fluxes of plasma active species, we found that the Ga-ZnO etch process was not limited by ion-surface interaction kinetics and appeared in the reaction rate-limited etch regime. In the HBr/O2 plasma, the etch kinetics were probably influenced by oxidation of the etched surface. 相似文献
16.
Cobalt oxide (Co3O4) nanoparticles were successfully synthesized by the cetyltrimethylammonium bromide (CTAB)-assisted method at normal pressure for the first time. The structure and morphology of the as-prepared Co3O4 nanoparticles were characterized by powder X-ray diffracton (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2-sorption analysis. XRD studies indicated that the as-prepared product was well-crystallized cubic phase of Co3O4 with a cell constant of α = 8.0722 Å. The EM images showed that the obtained Co3O4 sample consisted of dispersive quasi-spherical particles with the size ranged from 15 to 25 nm. 相似文献
17.
The grain size and density of the sintered (Zn1 − xAlxO)mIn2O3 bodies decreased with the small Al2O3 content (≤ 0.012), and then increased gradually by further increasing the Al2O3 content. The addition of Al for Zn in the (ZnO)mIn2O3 led to an increase in both the electrical conductivity and the absolute value of the Seebeck coefficient. This indicates that the power factor was significantly enhanced by adding Al for Zn. The thermoelectric power factor was maximized to 1.67 × 10− 3 W m− 1 K− 2 at 1073 K for the (Zn0.992Al0.008O)mIn2O3 sample. 相似文献
18.
《Vacuum》2013
In this work, the etching properties of titanium dioxide (TiO2) thin film in additions of O2 at CF4/Ar plasma were investigated. The maximum etch rate of 179.4 nm/min and selectivity of TiO2 of 0.6 were obtained at an O2/CF4/Ar (=3:16:4 sccm) gas mixing ratio. In addition, the etch rate and selectivity were measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. The efficient destruction of the oxide bonds by ion bombardment, which was produced from the chemical reaction of the etched TiO2 thin film, was investigated by X-ray photoelectron spectroscopy. To determine the re-deposition of sputter products and reorganization of such residues on the surface, the surface roughness of TiO2 thin film were examined using atomic force microscopy. 相似文献
19.
A novel method for preparing Al2O3/ZrO2 (Y2O3) eutectic was developed by combining combustion synthesis with melt-casting under ultra-high gravity (CSMC-UHG). The application of UHG = 800 g resulted in a high relative density of 99.8%, and an orientation-growth along the UHG direction. The microstructure was composed of aligned growth regimes containing a triangular dispersion of orderly ZrO2 rods in Al2O3 matrix with a spacing of 300 nm. The eutectic had a high fracture toughness up to 17.9 MPa·m1/2, which was mainly attributed to the nanostructure and the elastic bridge effects of the aligned ZrO2 rods. 相似文献
20.
Aluminum rich oxynitride thin films were prepared using pulsed direct current (DC) magnetron sputtering from an Al95.5Cr2.5Si2 (at.%) target. Two series of films were deposited at 400 °C and 650 °C by changing the O2/(O2 + N2) ratio in the reactive gas from 0% (pure nitrides) to 100% (pure oxides). The films were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and nanoindentation. The results showed the existence of three different regions of microstructure and properties with respect to the oxygen concentration. For the samples deposited at 650 °C in the nitrogen rich region (O2/(O2 + N2) ≤ 0.08), the formation of the h-AlN (002) and Al-N bond were confirmed by XRD and XPS measurements. The hardness of the films was around 30 GPa. In the intermediate region (0.08 ≤ O2/(O2 + N2) ≤ 0.24), the presence of an amorphous structure and the shifting of the binding energies to lower values corresponding to non-stoichiometric compounds were observed and the hardness decreased to 12 GPa. The lowering of mechanical properties was attributed to the transition of the clean target to the reacted target under non-steady state deposition conditions. In the oxygen rich region (0.24 ≤ (O2/(O2 + N2) ≤ 1), the existence of α-Al2O3-(113), α-Al2O3-(116) and Al-O bonds confirmed the domination of this phase in this region of deposition and the hardness increased again to 30-35 GPa. Films deposited at 400 °C showed the same behavior except in the oxygen rich region, where hardness remains low at about 12-14 GPa. 相似文献