Wet Etching Properties Research Articles

Anisotropic wet etching on the β‐phase poly(vinylidene fluoride) film

The ability to fabricate micro patterns or micro structures directly on a flexible and piezoelectric β-phase poly(vinylidene fluoride) (PVDF) film, has potential applications in the field of micro-electro-mechanical systems. The authors realised several tens to several hundred of micro patterns directly on a 110-μm thick flexible β-phase PVDF film by wet-etching technology. Through experiments, the authors also found that the β-phase PVDF film shows anisotropic etching characteristic in the proposed wet-etching process. In this Letter, the authors reported β-phase PVDF film micropattern fabrication process and its anisotropic wet-etching properties for the first time.

Oxidation and wet-etching behavior of MoAlTi thin films deposited by sputtering from a rotatable MoAlTi compound target

Within the current work, MoAlTi thin films have been developed and deposited by d.c. magnetron sputtering from a cold gas sprayed MoAlTi cylindrical rotatable target, to act as a novel molybdenum-based thin film system with improved oxidation and good wet-etching behavior. Chemical composition, microstructure, oxidation behavior, wet-etching properties, and electrical resistivity of the films are compared to those of a pure Mo reference film. Deviations in the chemical composition of the films with respect to the target are attributed to differences in gas phase scattering of the individual sputtered species. The films deposited are characterized by the formation of an Mo-based body-centered cubic solid solution, resulting in an increased electrical resistivity compared to the pure Mo film. While alloying Mo films with Al and Ti decreases the wet-etching rate in a phosphoric acid-based etching solution, the oxidation behavior could be significantly improved and the metallic-reflecting surface was maintained after annealing for 1 h at 330 °C in air.

스퍼터링 증착 조건에 따른 금속 박막의 습식 식각율

The wet etching is a process using chemical solution and occurring chemical reaction on substrate surface. when we do wet etching process, we have to consider stoichiometry, etching time and temperature of etchant for good resolution. In this experiment, we used Cr, Al andIndium-tin-oxide (ITO) metal and we deposited them with DC sputtering machine. The Cr thin film metal thickness is about , ITO films show a low electrical resistance and high transmittance in the visible range of an optical spectrum and Ai film is used for signal line. We measured and analysed wet etching properties on the metal thin films.

Wet etching characteristics of a HfSiON high-k dielectric in HF-based solutions

The wet etching properties of a HfSiON high-k dielectric in HF-based solutions are investigated. HF-based solutions are the most promising wet chemistries for the removal of HfSiON, and etch selectivity of HF-based solutions can be improved by the addition of an acid and/or an alcohol to the HF solution. Due to densification during annealing, the etch rate of HfSiON annealed at 900 °C for 30 s is significantly reduced compared with as-deposited HfSiON in HF-based solutions. After the HfSiON film has been completely removed by HF-based solutions, it is not possible to etch the interfacial layer and the etched surface does not have a hydrophobic nature, since N diffuses to the interface layer or Si substrate formation of Si–N bonds that dissolves very slowly in HF-based solutions. Existing Si–N bonds at the interface between the new high-k dielectric deposit and the Si substrate may degrade the carrier mobility due to Coulomb scattering. In addition, we show that N2 plasma treatment before wet etching is not very effective in increasing the wet etch rate for a thin HfSiON film in our case.

Investigating the Role of Stress in SOG-filled Shallow-Trench-Isolation Structures of sub-70 nm Device

In this work, the role of stress and shrinkage during the processing of the sub-70nm shallow-trench isolation (STI) structures filled with a spin-on glass (SOG) material containing perhydro-polysilazane is discussed. The stress behavior of this material on blanket and patterned structures are compared. The different parameters for adjusting the stress and their influences on wet-etching properties and uniformity over the wafer are discussed. Finally, the effect of stress on electrical parameters is presented.

Investigation of Wet Etching Properties and Annealing Effects of Hf-Based High-k Materials

Wet etching properties of Hf based high- dielectrics of , , Hf oxynitride and Hf silicate were investigated, using various chemicals employed for the current CMOS device fabrication. Experimental results show that fluorides species such as , and are very effective for dissolving Hf and in acids. is highly soluble in with a solubility of , which is much higher than the calculated result, and its solubility increases with reduced pH value. Etching properties of those high- dielectrics in and annealing effects on their microstructure were explored. It is observed that the etch rates of Hf and increase with increasing concentration and after etch, Hf and surfaces become F terminated. Although the mechanisms responsible for the change in etch rates after the Hf based high- films have undergone annealing are dependent on their chemical property, it is universally observed that the formation of the crystalline phase of is the primary attributor to the reduced etch rates. The etching of Hf based high- films occurs via weak points in the films, e.g., , and bonds, as well as amorphous areas of .

Characterization of anisotropic wet etching properties of single crystal silicon: Effects of ppb-level of Cu and Pb in KOH solution

We investigated the effect of ppb impurity level of Pb and Cu in KOH solution on the etching characteristics of Si for a number of crystallographic orientations using a hemispherical specimen. With the ppb-level of Cu, the location of the maximum etch rate shifted from the vicinity of {2 1 1} to {1 1 0}, i.e. the anisotropy changed, while the etched surface became rough showing fine textures regardless of the orientations. With the addition of the ppb-level of Pb, the etch rate decreased at almost all orientations, while the morphology of all etched surfaces did not show any substantial change. Because the ppb-level of Pb in KOH solution reduced the etching reaction uniformly for all orientations, the anisotropy in the etch rate did not change. These results support our hypothesis that: (i) Cu in the solution deposited onto the Si surface as fine particles and acted as etching masks, and (ii) the reduction–ionization of Pb is in competition with the etching reaction of Si and leads to a change in the etch rate.

A Novel Micromachining Technique to Fabricate Released GaAs Microstructures with a Rectangular Cross Section

The wet etching properties of GaAs in NH4OH–H2O2–H2O mixed solutions were investigated, and a fabrication method for producing released GaAs microstructures with a rectangular cross section using a (001) GaAs substrate was developed. To obtain the wet etching properties with respect to the crystallographic orientations, the etch rates and cross sectional etch profiles of (001) GaAs with 16 different compositions were measured. Based on the experimental data, a novel GaAs micromachining method in bulk (001) GaAs is proposed. In this proposed method, anisotropic wet etch, sidewall passivation, and wet undercut etch steps are performed, in order to release the <100> beams with a rectangular cross section. This proposed micromachining method is used to fabricate a released microbridge with a rectangular cross section. The developed GaAs micromachining method will be very useful for low loss, highly-tunable capacitors for RF components.

Ｈ２Ｏ２添加高周波マグネトロンスパッタにより作製した非晶質透明導電膜の物性評価

Amorphous transparent conductive electrode films prepared by RF magnetron sputterng using H2O2 addition gas which introduced to the chamber as a vapour. The films were deposited for changing addition partial gas pressure of H2O2. As a result, These films had fine electrical properties similar to the films prepared with H2O, and more, stable for time passage. We also investigated wet etching properties. In spite of changing addition partial gas pressure, it has constant wet etching rate. We observed not only films surface with AFM (JSPM-4200, JEOL), but also structure with XRD (RINT1400, Rigaku). The flatness was so improved, the average of roughness Ra was 0.378 nm at 11 × 10-3 Pa of H2O2 addition partial gas pressure. Still more, there were no change of electrical and optical properties for anneal (200 °C-1 h hold in vaccum).

Dry and wet etching properties of thermally grown silicon dioxide layer after N + ion implantation and annealing

We have investigated thermal oxidation of silicon, and dry and wet etching characteristics of the oxide layer after N + (Ar −) ion implantation and subsequent annealing. An oxidation resistance is observed in the N + implanted silicon with doses more than 1 × 10 15 N + /cm 2. The etch rate of the oxide layer in a diluted HF solution is enhanced with a dose of 1 × 10 15 N + / cm 2, whereas an etching resistance is observed for the samples with doses more than 2 × 10 15 N + /cm 2. However, only the etching resistance appears in the dry etching. These resistances are also observed by argon implantation and easily removed by subsequent annealing. These results indicate that the oxidation and etching resistances are related to a thin oxynitride formation and the surface modification by ion implantation.