Chamber pressure

About: Chamber pressure is a research topic. Over the lifetime, 2988 publications have been published within this topic receiving 30725 citations.

Thermal gradient enhanced CVD deposition at low pressure

Abstract: A method wherein a thermal gradient over a substrate enhances Chemical Vapor Deposition (CVD) at low pressures. An upper heat source is positioned above the substrate and a lower heat source is positioned below the substrate. The upper and lower heat sources are operated to raise the substrate temperature to 400-700° and cause a heat gradient of 100-200° C. between the upper and lower heat sources. This heat gradient causes an increase in the deposition rate for a given reactant gas flow rate and chamber pressure. The preferred parameters for implementation of the present invention for poly crystalline silicon deposition include the temperature of the upper heat source 100-200° C. above the lower heat source, a substrate temperature in the range of 400-700° C., a reactant gas pressure between 250 and 1000 mTorr, and a gas flow rate of 200-800 sccm. The substrate is rotated, with 5 RPM being a typical rate. A deposition rate of 2000 angstroms per minute deposition of poly crystalline silicon is achieved with a 200° C. temperature differential, substrate temperature of 650° C., pressure of 250 mTorr and silane flow of 500 sccm.

Electrode plate and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To provide an electrode plate having a large surface area and high reliability, in which peeling is not generated with temperature change, by forming a carbon thin film in a surface of a substrate, which is formed with projecting parts and recessed parts at a specified depth, by a chemical vapor deposition method. SOLUTION: A surface of an electrode plate, which is formed of a copper foil 10 at about 20μm of thickness, is formed with recessed parts and projecting parts at 1-100nm of depth by using a roller (b), and thereafter, in the condition at about 700 deg.C of substrate temperature and at about 0.1Torr of chamber pressure, a predetermined quantity of methane, argon and hydrogen are made to flow into a chamber, and a carbon thin film 11 at about 100μm of thickness is formed by using CVD method (c). With this structure, a film adhesive property is remarkably improved. The adhesive property is more improved by interposing a single layer or multi-layer structural film of the alloy of Fe, Co. Ni or carbide thereof as an intermediate layer between the substrate and the carbon thin film. At the time of vapor phase epitaxy, in the case where gas is used for plasma jetting method, a film having multiple standing pieces can be obtained, and a film having a remarkably large surface are can be obtained.

Pressure test for the diagnosis of Meniere's disease

Abstract: In the last 15 years, a pressure chamber able to generate negative air pressure has been used to treat patients with Meniere's disease. In this study we sought to clarify whether the underpressure chamber can be used to diagnose Meniere's disease. We studied 45 ears from patients with neurotological diseases. The subjects were placed supine in a soundproof pressure chamber. The pressure was first decreased to -500 mmH2O, and after 5 min to -700 mmH2O. The pressure was kept at this level for another 5 min and then increased to 0 mmH2O. This procedure was done three times in succession. While the chamber pressure was below 0 mmH2O, the subjects were instructed to abstain from actively equilibrating middle ear pressure. When the chamber pressure was raised to 0 mmH2O, they were instructed to equilibrate middle ear pressure, and if necessary Politzerization or catheterization of the Eustachian tube was done. As a result, hearing was improved after this procedure only in patients with Meniere's disease (50%) a...