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Recently, silicon etching have received much attention for display industry, nano imprint technology, silicon photonics, and MEMS application. After the etching process, removing of etch mask and residue of sidewall is very important. The investigation of the etched mask removing was carried out by using the ashing, HF dipping and acid cleaning process. Experiment shows that oxygen component of reactive gas and photoresist react with silicon and converting them into the mask fence. It is very difficult to remove by using ashing or acid cleaning process because mask fence consisted of Si and O compounds. However, dilute HF dipping is very effective process for SiOx layer removing. Finally, we found optimized condition for etched mask removing.

During the etching process, the wafer surface temperature is an important parameter which influences the reaction probabilities of incident species, the vapor pressure of etch products, and the redeposition of reaction products on feature surfaces. In this study, the authors investigated that the effect of substrate temperature on the etch rate of Al2O3 thin film and selectivity of Al2O3 thin film over hard mask material (such as SiO2) thin film in inductively coupled plasma as functions of Cl2 addition in BCl3/Ar plasma, rf power, and dc-bias voltage based on the substrate temperature in range of 10–80 °C. The elements existed on the surface were analyzed by energy dispersive x-ray and x-ray photoelectron spectroscopy.

In this study, the etch mechanism of ALD deposited Al2O3 thin film was investigated in BCl3/Cl2/Ar plasma. The experiments were performed by comparing etch rates and selectivity of Al2O3 over hard mask materials (such as SiO2, and Si3N4) as function of the input plasma parameters such as gas mixing ratio, DC-bias voltage and RF power under fixed process pressure. The maximum etch rate was obtained at 115.75 nm/min under 5 mTorr, RF power 600 W, Cl2 10% was added to BCl3/Ar plasma, and the highest etch selectivity was 1.17 over Si3N4 under the 10 mTorr process pressure, −50 V DC-bias voltage. We used the X-ray photoelectron spectroscopy (XPS) to investigate the chemical reactions on the etched surface.

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to Si) of ZrO 2 thin films in the HBr/CF 4 high density plasma (HDP) system. The maximum etch rate of 70.8 nm/min for ZrO2 thin films was obtained at HBr(75%)/ CF 4 (25%) gas mixing ratio. At the same time, the etch rate was measured as a function of the etching parameter such as HDP chamber pressure. The X-ray photoelectron spectroscopy (XPS) analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the CF 4 -containing plasmas.

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to Si) of ZrO2 thin films in the HBr/SF6 high density plasma (HDP) system. The maximum etch rate of 54.8 nm/min for ZrO2 thin films was obtained at HBr(25%)/SF6(75%) gas mixing ratio. At the same time, the etch rate was measured as function of the etching parameters such as HDP source power, bias power, and chamber pressure. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the SF6-containing plasmas.

The etch of (NKN) thin film was performed in inductively coupled plasma. It was found that the 1sccm addition (5%) into plasma caused a non-monotonic behavior of the NKN etch rate. The maximum etch rate of NKN was 95.3 nm/min at (1 sccm)/ (16 sccm)/Ar (4 sccm), 800 W ICP power, 1 Pa pressure and 400 W bias power. The NKN etch rate shows a monotonic behavior a s the bias power increases. The analysis of the narrow scan spectra of XPS for both a s-deposited and etched NKN films allowed one to assume ion assisted etch mechanism. The most probable reason for the maximum etch rate can be defined as a concurrence of chemical and physical etch pathways.

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to and ) of TiN thin films in the /Ar inductively coupled plasma. The maximum etch rate of for TiN thin films was obtained at (80%)/Ar(20%) gas mixing ratio. At the same time, the etch rate was measured as function of the etching parameters such as RF power, Bias power, and process pressure. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the containing plasmas.

Transparent and conductive high preferential c -axis oriented Ni-doped ZnO (NZO) thin films as a function of Ni content have been prepared by sol–gel method using zinc acetate and nickel acetate as starting material, anhydrous ethanol and 2-methodxyethanol as solvent. The NZO thin films with a dopant ratio (0.2, and 0.4 mol%) have a preferred orientation in the (002) direction. However, when the Ni doping ratio exceeds 0.6 mol%, films possessed a non-textured polycrystalline structure. The electric and optical properties of the Ni doped ZnO films were found to be strongly dependent on the Ni contents. The lowest resistivity value was 4.8 × 10 − 4 Ω cm, which was obtained in the 0.2 mol% Ni-doped ZnO thin film. The improvement of the electrical and optical properties of NZO films may be related to the both increase in the concentration of oxygen vacancies and free carries of Ni ions. The average optical transmittance values of the 0.2 mol% Ni-doped NZO thin films were more than 91.2% in the visible range.

ZnS is an attractive material for future optical and electrical devices since it has a direct and wide band gap to provide blue emission at room temperature. In this study, inductively coupled plasma was used to etch ZnS:Mn thin films. The maximum etch rate of 164.2 nm/min for ZnS:Mn was obtained at a gas mixing ratio, an rf power of 700 W, a dc bias voltage of -200V, a total gas flow of 20 sccm, and a chamber pressure of 1Pa. The etch behaviors of ZnS:Mn thin films under various plasma parameters showed that the ZnS:Mn were effectively removed by the chemically assisted physical etching mechanism. The surface reaction of the ZnS:Mn thin films was investigated by X-ray photoelectron spectroscopy. The XPS analysis revealed that Mn had detected on the surface ZnS:Mn etched in plasma.

In this study, we carried out an investigation of the etching characteristics(etch rate, selectivity) of thin films in the inductively coupled plasma. It was found that variations of input power and negative dc-bias voltage are investigated by the monotonic changes of the etch rate as it generally expected from the corresponding variations of plasma parameters. At the same time, a change in either gas pressure or in gas mixing ratio result in non-monotonic etch rate that reaches a maximum at 2 Pa and for gas mixture, respectively. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas.

In this work, we investigated etching characteristics of HfO 2 thin film and Si using inductive coupled plasma (ICP) system. The maximum etch rate of HfO 2 is 85.5 nm/min at a BCl 3 /(Ar+BCl 3 ) of 20% and decreased with further addition of BCl 3 gas. From the QMS measurements, the most dominant positive ion energy distributions (IEDs) showed a maximum at 20% of BCl 3 . These tendency was very similar to the etch characteristics. This result agreed with the universal energy dependency of ion enhanced chemical etching yields. From the mass spectra, the Hf chloride and bromine oxide must be included in the etching by-products as volatile species.

The investigations of the influence of gas pressure and input power on the Cl2 plasma parameters in the inductively coupled plasma system were carried out. The investigations combined plasma diagnostics by Langmuir probe and plasma modeling using the self-consistent global model with Maxwellian approximation for electron energy distribution function. From the experiments, it was found that an increase of gas pressure in the range of 0.27–3.33 Pa at 400–700 W input power results in decreasing both electron temperature (3.3–2.0 eV) and density (6.6 × 1010 − 3.0 × 1010 cm− 3 for 400 W and 1.2 × 1011 − 6.4 × 1010 cm− 3 for 700 W). The model showed an outstanding agreement with the experiments and provided the data on densities and fluxes of active species. These data combined with the model of etch kinetics demonstrated the possibility of different etch rate behaviors depending on the input process parameters as well as on the properties of the etched surface.

The effect of Eu contents on the ferroelectric properties of (BET) thin films has been investigated. Bismuth Europium titanate thin films with a Eu contents were prepared on the substrate by metal-organic decomposition technique. The structure and the morphology of the films were analyzed using X-ray diffraction (XRD) and field emission scanning microscopy (FE-SEM), respectively. From the XRD analysis, it was found that BET thin films have polycrystalline structure, and the layered-perovskite phase is obtained when the Eu contents exceeds 0.2 (x > 0.2). Also, the ferroelectric characteristics of the BET thin films were found to be dependent on the Eu content. Particularly, the BET films doped with x

This work reports the results on the influence of gas mixing ratio, gas pressure (0.26-3.3Pa) and input power (400-900W) on the Cl"2/Ar plasma parameters in the planar inductively-coupled plasma reactor. The investigation combined plasma diagnostics by Langmuir probe and quadrupole mass-spectroscopy with plasma modelling given by the self-consistent global (0-dimensional) model with Maxwellian approximation for the electron energy distribution function. It was shown that, for the given range of experimental conditions, the model showed an outstanding agreement with the experiments and provided the near-to-adequate data on kinetics of plasma active species, their densities and fluxes.

In this work, we investigated etching characteristics of BST thin films and higher selectivity of BST over Si using inductive coupled O"2/Cl"2/Ar plasma (ICP) system. The maximum etch rate of BST thin films and selectivity of BST over Si were 61.5nm/min at a O"2 addition of 1sccm, 9.52 at a O"2 addition of 4sccm into the Cl"2(30%)/Ar(70%) plasma, respectively. Plasma diagnostics was performed by Langmuir probe (LP), optical emission spectroscopy (OES) and quadrupole mass spectrometry (QMS). These results confirm that the increased etch rates at O"2 addition of 1sccm is the result of the enhanced chemical reaction between BST and Cl radicals and an ion bombardment effect.

Investigations of the influence of gas pressure and input power on the Cl 2 plasma parameters in the inductively coupled plasma system were carried out. The investigations combined plasma diagnostics by Langmuir probe with plasma modeling represented by the self-consistent global model with Maxwellian approximation for the electron energy distribution function. From the experiments, it was found that the increase of gas pressure in the range of 0.27–3.33 Pa for 400–700 W of input power results in a decrease in both electron temperature (3.3–2.0 eV) and density (6.5×10 16 −3.0×10 16 m −3 for 400 W and 1.2×10 17 –6.7×10 16 m −3 for 700 W). For the given range of experimental conditions, the model showed an outstanding agreement with the experiments and provided the data on kinetics of plasma active species, their densities and fluxes.

The self-aligned contact (SAC) oxide etching is a key process in developing the next generation ultra large scale integrated (ULSI) device because transistor gate feature size is scaling down, and aspect ratio is becoming higher and higher. In this study, the SAC etching will be characterized by C"5F"8/O"2/Ar plasmas as a function of C"5F"8/O"2 gas mixing ratio, Ar flow rate, process pressure, and RF power. The oxide etch rate increases when C"5F"8 fractional flow rate increases from 38% to 62% and then abruptly drops at the C"5F"8 percentage above 62%. The selectivity of nitride to oxide and fluorocarbon polymer increased under the following conditions: high C"5F"8 flow rate, low Ar flow rate, high process pressure, and low RF power. However, when the ratio of O"2 increases in the C"5F"8/O"2 mixture, the amount of polymer decreases and the ability of contact etching increases. SAC patterned samples were characterized by top-down critical dimension scanning electron microscopy (CD-SEM) and transmission electron microscopy (TEM). To analyze the effect of C"5F"8/O"2 gas mixing ratio, we investigated the chemical species in the gas phase with optical emission spectroscopy (OES). The components and thickness of fluorocarbon polymer on contact surface, bottom and sidewall were investigated with transmission electron microscopy-element mapping system (TEM-EELS) and X-ray photoelectron spectroscopy (XPS).

The investigations of plasma parameters and active particles kinetics in an HCl DC glow discharge system were carried out. The investigation combines plasma diagnostics by electric probes and plasma modeling based on the self-consistent solution of Boltzmann kinetic equation and the balance equation of chemical kinetic for neutral and charged particles. It was shown that the direct electron impact dissociation of the HCl molecules represents the main mechanism for the formation of the Cl and H atoms while the total balances for all kinds of neutral particles are noticeably influenced by the volume atom–molecular reactions. The analysis of the vibrational kinetics shows low population of the vibrational energy levels for HCl molecules, but the role of the HCl V >0 in the negative ions formation process cannot be neglected. The assumption of the Eley-Rideal recombination kinetics for both chlorine and hydrogen atoms provides a good agreement between the calculated and experimental values of reduced electric field ( E / N ) and the total flux of positive ions.

This article describes the synthesis and the purification of carbon nanotubes. Large quantities of single-walled carbon nanotubes (SWNTs) with few defects and very small amount of amorphous carbon coating have been synthesized by catalytic decomposition of methane over well-dispersed iron particles supported on MgO at the temperature range from 800to1000°C. It was found that the quality of carbon nanotubes was slightly increased as increasing growth temperature while the yield was decreased to some degree. It was also found that the as-grown SWNTs can be separated easily from the support by a simple acidic treatment rather than thermal oxidation to obtain a product with high yields of SWNTs. Above 94wt% high purity SWNTs were obtained by combining two-step processes of thermal oxidation in air and acid treatment without multistep filtration. The as-grown and purified SWNTs were also characterized by field emission scanning electron microscopy, x-ray diffraction, and Raman spectroscopy.

The etching mechanism of (Bi4−xLax)Ti3O12 (BLT) thin films in Ar∕Cl2 inductively coupled plasma (ICP) was investigated as a function of gas mixing ratios, process pressure, and ICP powers at fixed other conditions. Etch rates were measured by using an α-step surface profiler. The maximum etch rate of BLT thin films was 117nm at 0.8 Ar∕(Ar+Cl2) gas mixing ratios with following conditions: process pressure of 15mTorr, gas flow rate of 20sccm, ICP power of 700W, and dc bias of −150V. The etch rate was increased as decreasing the process pressure. For a detailed investigation of etching mechanisms of BLT thin films, the ion energy distributions of each positive species were measured using quadrupole mass spectrometer and analyzed those data. Also the electron energy distribution was measured as a function of Ar∕Cl2 gas mixing ratios.

The etching characteristics of LaNiO3 (LNO) thin films and SiO2 in Cl2/Ar plasma were investigated. LNO etch rates decreased with increasing Cl2 fraction in Ar plasma and the working pressure. Langmuir probe measurement showed a noticeable influence of Cl2/Ar mixing ratio on electron temperature, electron density, and ion current density. The modeling of volume kinetics for charged particles and OES measurements for neutral atoms indicated monotonous changes of both densities and fluxes of active species such as chlorine atoms and positive ions. The LNO etch rate behavior may be explained by physical mechanisms.

The etching behaviour of MgO thin films in BCl3/Ar plasma was investigated. It was found that the increasing Ar mixing ratio under the constant total pressure conditions causes the monotonic decrease of MgO etch rate, which falls from 93 to 17 nm/min. Plasma diagnostics combined with a 0-dimensional plasma model showed the noticeable sensitivity of both electron temperature and electron density to the process parameters as well as monotonic changes of both densities and fluxes of active species. The analysis of etching kinetics and mechanisms was performed. The results showed in the BCl3-rich plasma the etching process is dominantly supplied by the chemical pathway through the ion-assisted chemical reaction.

In this work, we investigated the effect of the Cl"2/N"2 mixing ratio on both the plasma parameters and the volume densities of the neutral and the charged particles in inductively coupled plasma system. It was found that the addition of nitrogen to chlorine causes an increase in the electron temperature while the electron density and the total density of positive ions decrease. The analysis of Cl"2 dissociation kinetics showed the weak possibility of stepwise dissociation involving electronically excited metastable molecules N"2^*(A^3@S"u^+) as well as vibrationally excited nitrogen. Both plasma diagnostics and modeling gave a monotonic change of Cl atom density as a function of Cl"2/N"2 mixing ratio.

In this study (Pb,Sr)TiO3 (PST) thin films were etched with inductively coupled Cl2∕(Cl2+Ar) plasmas. The etch characteristics of PST thin films as a function of Cl2∕(Cl2+Ar) gas mixtures were analyzed by using a quadrupole mass spectrometer. Systematic studies were carried out as a function of the etching parameters, including the radio frequency power and the working pressure. The maximum PST film etch rate is 56.2nm∕min, because a small addition of Cl2 to the Cl2∕Ar mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of a chemical reaction is relatively low due to low volatility of the etching products.

BST thin films were etched with inductively coupled plasmas. A chemically assisted physical etch of BST was experimentally confirmed by ICP under various gas mixtures. After a 20% addition of BCl 3 to the Cl 2 /Ar mixture, resulting in an increased the chemical effect. As increases of RF power and substrate power, and decrease of working pressure, the ion energy flux and chlorine atoms density increased. The maximum etch rate of the BST thin films was 90.1 nm/min, and at the RF power, substrate power, and working pressure were 700 W, 300 W, and 1.6 Pa, respectively. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

BST thin films were etched with inductively coupled CF 4 /(Cl 2 +Ar) plasmas. The maximum etch rate of the BST thin films was 53.6 nm/min for a 10% CF 4 to the Cl 2 /Ar gas mixture at RF power of 700 W, DC bias of -150 V, and chamber pressure of 2 Pa. Small addition of CF 4 to the Cl 2 /Ar mixture increased chemical effect. Consequently, the increased chemical effect caused the increase in the etch rate of the BST thin films. To clarify the etching mechanism, the surface reaction of the BST thin films was investigated by X-ray photoelectron spectroscopy.

Etching characteristics of (Pb,Sr)TiO 3 (PST) thin films were investigated using inductively coupled chlorine-based plasma system as functions of gas mixing ratio, radio frequency power and direct current bias voltage. It was found that the increasing of Ar content in gas mixture lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is 56.2 nm/min and the selectivity of PST to Pt is 0.8 at Cl 2 /(Cl 2 +Ar) of 0.2. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

Etching characteristics of (Pb,Sr)TiO 3 (PST) thin films were investigated using inductively coupled chlorine-based plasma system as functions of gas-mixing ratio, radio frequency power and direct current bias voltage. It was found that increasing of Ar content in gas mixture lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is 56.2 nm/min and the selectivity of PST film to Pt is 0.8 at Cl 2 /(Cl 2 +Ar) of 20%. It was proposed that sputter etching is the dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

We show that the temperature dependence of a silicon waveguide can be controlled well by using a slot waveguide structure filled with a polymer material. Without a slot, the amount of temperature-dependent wavelength shift for TE mode of a silicon waveguide ring resonator is very slightly reduced from 77 pm/ degrees C to 66 pm/ degrees C by using a polymer (WIR30-490) upper cladding instead of air upper cladding. With a slot filled with the same polymer, however, the reduction of the temperature dependence is improved by a pronounced amount and can be controlled down to -2 pm/ degrees C by adjusting several variables of the slot structure, such as the width of the slot between the pair of silicon wires, the width of the silicon wire pair, and the height of the silicon slab in our experiment. This measurement proves that a reduction in temperature dependence can be improved about 8 times more by using the slot structure.

In this work, we investigated the etching characteristics of ZrO2 thin film and the selectivity of ZrO2 thin film to Si in the HBr/CF4 high density plasma (HDP) system. The maximum etch rate of 70.8 nm/min for ZrO2 thin film was obtained at HBr (75%)/CF4 (25%) gas mixing ratio. At the same time, the etch rate was measured as functions of the etching parameters such as HDP source power, bias power and temperature. The angle-resolved X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism of ZrO2 for the CF4-containing plasmas.