An IT-cut quartz crystal unit has a discoidal or a rectangular quartz crystal blank which is cut from a crystal of quartz along a plane perpendicular to the Y-axis of the crystal of the quartz which is rotated over approximately 34.degree. about the X-axis, and further rotated from this rotated position over approximately 19.degree. about the Z-axis. Excitation electrodes are formed on both main surface of the crystal blank, respectively. The crystal blank is held at positions in at least one se...

A quartz crystal sensor cell in which the sensor is secured to the base of a well defining a test sample space by a layer of adhesive between the respective peripheral surfaces. Also a quartz crystal sensor cell is provided in which the quartz sensor crystal is inclined relative to the opposite surface of the test sample space. These constructions respectively improve distinctness of the "Q" peak and problems from reflected waves in the space.

A quartz sensor method and system are disclosed in which a plurality of SAW sensing resonators can be mechanically simulated for implementation upon a quartz wafer substrate. The quartz wafer substrate can thereafter be appropriately etched to produce a quartz diaphragm from the quartz wafer substrate. A plurality of SAW sensing resonators (e.g., pressure, reference and/or temperature SAW resonators) can then be located upon the quartz wafer substrate, which is based upon the previously mechanic...

A method of making quartz oscillators wherein, round-sectioned bar-shaped leads are inserted through a base and are glass-sealed to be secured to the base, the parts above the base are pressed to form flat plate-shaped inner parallel spaced leads, so that the leads annealed in the glass-sealing step will be compressed and hardened, and the inner leads will be resilient to enable a quartz piece to be resiliently held by its sides when it is inserted between the inner leads. The steps can be autom...

Described herein is a process chamber with a substantially all-quartz interior surface. The preferred embodiments have upper and lower walls being curved in both the x-z and y-z planes. In one embodiment, the chamber has thin upper and lower dome walls made from a generally transparent material such as quartz, each with a convex exterior surface and a concave interior surface. These walls are joined at their side edges to a cylindrical side wall, preferably formed from a generally translucent ma...

An apparatus for fixing the position of a quartz furnace tube in a semiconductor processing furnace is described. The furnace is of the type that has a cylindrical body possessing an open end through which the tube may be withdrawn, and a base postioned on the open end, wherein the tube includes a flange portion secured to the base through which gas may be withdrawn from or introduced into the furnace tube. The tube is coaxially disposed within the furnace body. The apparatus may include two cla...

Refractory materials, such as fused quartz plates and rods are welded using a heat source, such as a high power continuous wave carbon dioxide laser. The radiation is optimized through a process of varying the power, the focus, and the feed rates of the laser such that full penetration welds may be accomplished. The process of optimization varies the characteristic wavelengths of the laser until the radiation is almost completely absorbed by the refractory material, thereby leading to a very rap...

A flat-bottomed quartz glass crucible for the manufacture of monocrystalline silicon is made by disposing granular quartz particles on a flat base in a cylindrical mold. A vacuum is drawn on the particles through vacuum holes in the base to retain the particles thereon while the base and mold are rotated, and while the particles are heated to fuse them into a quartz glass crucible shape.

A crystal unit for high frequency use includes: a crystal blank having a central portion that is used as a vibration region and a peripheral portion that surrounds the central portion and that is provided with a greater thickness than the central portion; a pair of excitation electrodes provided respectively on both major surface of the crystal blank in said vibration region; a pair of extending electrodes led out from the pair of excitation electrodes toward ends of the crystal blank, respectiv...

A method for manufacturing quartz oscillators is provided which permits quartz oscillators having an oscillation frequency, as designed, to be obtained with small variation of individual oscillation frequency and with high reliability. The method for manufacturing quartz oscillators according to the present invention comprises the steps of forming a first resist layer (300) on one surface of a quartz substrate (100), exposing said first resist layer to light of a first amount of exposure to form...