Papers by Keyword: Diamond Film

Abstract: The diamond films deposition experiment is carried out with MPCVD system. Some technology problems are discussed respectively, such as the substrate pretreatment, gases source compositions and deposition temperature. XRD pictures with different peaks illustrated that diamond film has good crystal orientation. A density of film crystal is observed and a thickness uniformity in detected by Scanning Electron Microscopy (SEM). The pureness of the diamond film was measured by Raman spectroscopy. The parameter coincidence rate is 90% based on the 10 prepared samples

Abstract: This paper presents a post-Si CMP cleaning using the boron-doped diamond (BDD) film electrode as anode in the electrochemical cleaning method. The BDD film electrode has wide potential window and high oxygen evolution potential, so it is able to electrochemically generate super-advanced oxidation free radicals, such as hydroxyl radicals, oxygen free radicals and so on. And the sub-product of the radicals are ozone and hydrogen peroxide. And the BDD film electrode electrochemically oxidation is an advanced oxidation technology. First using the surfactant to remove particles contaminants, then following this post-Si CMP cleaning, it can effectively remove organic as well as the adsorbed surfactant on the surface. The experiments of cleaning post-Si CMP wafer are introduced in this paper, and the results indicated that the effective cleaning process can meet the continuous development of microelectronic industry cleaning needs.

Abstract: Diamond film and diamond /Ti film were synthesized by microwave plasma chemical vapor deposition (MWPCVD) method on Si (100). Comparative studies on field emission properties of diamond and diamond /Ti films.The results show that diamond /Ti film has demonstrated large emission currents at much lower threshold voltages. Field emission current density increases rapidly with the increase of electric field and reaches to 1400μA/cm2 at 25 V/μm.

Abstract: According to the special case of high strain rate for diamond film produced by DC plasma jet method, a transient thermo-mechanical coupled model for the cooling process of diamond film and Mo substrate was developed. The direct coupled finite element method was used to simulate the transient thermal stresses in diamond film during the cooling period after the film deposition. The residual thermal stresses of diamond film were calculated and compared respectively under two conditions of real uneven temperature fields and unreal even temperature fields. Based on the simulated results of stresses, the moment and cause of diamond film cracking were analyzed. The conclusions are as the follows: (1) the thermal stresses in diamond film increase with the increase of cooling time, but the maximum first principal tensile stress may reach the fracture strength of common diamond film before the film cools to room temperature; (2) the excessive tensile stress at the film edge causes the film cracking; (3) in order to reduce the thermal (residual ) stresses and increase the finished product ratio of diamond film, it is essential to further improve the temperature uniformity.

Abstract: The DC plasma chemical vapor deposition (DC-PCVD) method was a promising technique to fabricate CVD diamond coatings in industry, because it has many good properties, such as high grown rate of diamond films, big grown area, high qualities, and cost effective. In the present work, we synthesized diamond films on cemented carbide (YG6) substrates, and studied the different nitric acid aqueous solution treatment durations influence on diamond nucleation stage. The results indicated that well-chosen nitric acid aqueous solution treatment durations should be selected. For too short treatment times, the residual Co will promote the carbon transform from diamond metastable phase into graphite stable phase. On the other side, too long treatment times will consume too much Co, which will lead to the shortage of cohesive body, and finally the crackers in the bulk propagated and peeled off with the diamond films well grown on WC grains.

Abstract: CVD diamond films were synthesized by the chemical vapor deposition method. With increasing the oxygen content in the deposition atmosphere, the density of diamond nuclei decreases. No diamond is formed when the oxygen content is more than one percent. The density of diamond nuclei is improved with increasing the methane content. Adding oxygen to the deposition atmosphere can enhance the purity of diamond.

Abstract: Nanocrystalline diamond (NCD) films were synthesized by hot-filament chemical vapor deposition (HFCVD) method at different temperatures (600 °C, 620°C, 640°C and 660°C). The AFM and Raman analyses demonstrated that deposition temperature has a great effect on the surface roughness and quality of NCD films and 620°C is the temperature to grow NCD films with smooth surfaces.

Abstract: Tool material has been one of the focuses in tool research. Diamond and cubic boron nitride (c-BN) are materials of exceptional and very similar properties that make them extremely valuable not only for the aesthetics of diamond. C-BN is a material synthesized rather recently that has rapidly spurred technological and scientific interest. Presently, both materials have found commercial applications. There is still a long way for the practical application of cBN film. The main problems are such as adhesion, thickness, purity, nucleating, and growth mechanism. We will develop a new way of DC plasma jet CVD way to synthesis the cBN film. The deposition of cBN films can be performed in a DC jet plasma CVD reactor by using an Ar-N2-BF3-H2 gas mixture, on the basis of deposition of diamond has been achieved.

Abstract: The relationship between textures and Young’s modulus in CVD diamond films was simulated based on the phenomenological theory, which indicates the textures induce the Young’s modulus anisotropy. The increase of methane concentration changes the density of different fiber textures in diamond films, which induces the increase of Young’s modulus in the directions that parallel to the film surface. Among the textures, {111} texture is of no influence whereas {011} texture has the maximum influence on the Young’s modulus anisotropy of diamond film.

Abstract: The boron-doped diamond film electrode grown on tantalum substrate (BDD/Ta) was prepared by hot filament chemical vapor deposition (HFCVD) technique. The morphology and quality of BDD/Ta film electrode were investigated by SEM and Raman spectroscopy respectively. The electrochemical behavior of the BDD/Ta film electrodes in Na₂SO₄ solution was also investigated by cyclic voltammetry and the window potential of BDD/Ta film electrode in Na₂SO₄ solution is of 4.1V, the hydrogen and oxygen evolution potentials are of-1.8V and +2.3V respectively. The characteristic measurements of BDD/Ta film electrode and its application to degradation of high concentration organic wastewater indicated that BDD/Ta film electrode have a series of advantages, including high overpotential for oxygen revolution, high current efficiency, good removal of chemical oxygen demand (COD).