Papers by Keyword: Selective Deposition

Abstract: Si doped CVD diamond films are prepared on Si substrate by means of hot filament chemical vapor deposition (HFCVD) through adding tetraethoxysilane (TEOS) into acetone as source of reactant gas during the growth process. The samples of diamond films are investigated by scanning electron micrograph (SEM), Raman spectrum, X-ray diffractometry (XRD) and surface profiler. The experimental results show that compared with pure diamond film, Si doped CVD diamond film exhibits grain refinement and smoother surface. Then selective area deposition (SAD) of B-doped diamond films are achieved on both Si doped CVD diamond film and pure CVD diamond film with silicon dioxide layer as sacrificial layer. SEM investigation demonstrates that the boundary of patterning on pure diamond film is rather fuzzy while on pure diamond film it is trim and distinct, which is mainly attributed to the relatively low surface roughness.

Abstract: Titanium dioxide (TiO2) thin film was fabricated on the surface of glass monolayers at room temperature, using KH-550 as self-assembled monolayers (SAMs). The TiO2 gel precursor was characterized with differential scanning calorimetry – thermogravimetry (DSC-TG), and the TiO2 powder was analyzed with X-ray diffraction (XRD). The TiO2 thin film was tested with X-ray fluorescence spectroscopy (XRF). With the application of atomic force microscope (AFM) the surface topography of siloxane layer and TiO2 film were studied. Their hydrophilicities were measured. The transmittance of TiO2 film was detected by using dual beam ultraviolet - visible spectrophotometer. The results show that the TiO2 thin film is in monolayer with nanometer level, the deposition is the anatase structure. TiO2 is deposited on the surface instead of channel or gap of siloxane, the hydrophilicities of TiO2 monolayer film are perfect, and TiO2 monolayer film has a good transmissivity in the visible light area.

Abstract: Simple process for the fabrication of Co/TiO2/Pt resistive random access memory, called ReRAM, has been developed by selective deposition of Co on micro-contact printed (μ-CP) self assembled monolayers (SAMs) patterns. Atomic Layer Deposition (ALD) was used to deposit TiO2 thin films, showing its ability of precise control over the thickness of TiO2, which is crucial to obtain proper resistive switching properties of TiO2 ReRAM. The fabrication process for Co/TiO2/Pt ReRAM involves the ALD of TiO2 on sputter-deposited Pt bottom electrode, followed by μ-CP with SAMs and then selective deposition of Co. This results in the Co/TiO2/Pt structure ReRAM. For comparison, Pt/TiO2/Pt ReRAM was produced and revealing the similar switching characteristics as that of Co/TiO2/Pt, thus indicating the feasibility of Co replacement with Pt top electrode. The ratios between the high-resistance state (Off state) and the low-resistance state (On state) were larger than 102. Consequently, the selective deposition of Co with μ-CP, newly developed in this study, can simplify the process and thus implemented into the fabrication of ReRAM.

Abstract: This paper proposes a electromagnetic interference (EMI) shielding effect of Cu mesh patterns which were formed by a novel, low-cost, photodefined metal pattern using a bilayer thin film of amorphous titanium dioxide (TiO2) and hole-scavenger-containing poly(vinyl alcohol) (PVA). Via UV-irradiation through a photomask on the bilayer film, the photodefined image of photoelectrons can be easily produced, resulting in selective palladium (Pd) catalyst deposition by reduction. In the bilayer thin film, the hole-scavenger-containing PVA layer scavenge the holes in the valence band of UV-irradiated TiO2 thin film, this retarding the recombination of the photoexcited electron-hole pairs for a few minutes. These long-surviving photoelectrons in the bilayer structure can reduce the Pd ions on only the photodefined region. Successive Ni electroless plating on Pd catalysts and Cu electroplating on an electroless plated pattern are possible. The electromagnetic interference shielding effects of selective nickel and copper mesh patterns were investigated.

Abstract: A selective atmospheric pressure chemical vapor deposition (APCVD) process has been developed to deposit porous polycrystalline silicon carbide (poly-SiC) thin films containing a high density of through-pores measuring 50 to 70 nm in diameter. The selective deposition process involves the formation of poly-SiC films on patterned SiO2/polysilicon thin film multilayers using a carbonization-based 3C-SiC growth process. This technique capitalizes on significant differences in the nucleation of poly-SiC on SiO2 and polysilicon surfaces in order to form mechanically-durable, chemically-stable, and well anchored porous structures, thus offering a simple and potentially more versatile alternative to direct electrochemical etching.