Abstract: A TEOS trap for controlling TEOS polymerization from reaction furnace effluent in a vacuum pump line a SiO2 CVD process includes a molecular species-selective flow impeding medium that adsorbs and retains TEOS and water molecules from the effluent long enough to consume substantially all the water molecules in TEOS hydrolysis reactions while allowing non-hydrolyzed TEOS, ethylene, and other gaseous byproducts to pass through the trap and retaining solid and liquid phase SiO2-rich TEOS polymers formed by the hydrolysis reactions in the trap for subsequent removal and disposal. The molecular species-selective flow impeding medium has a plurality of adsorption surfaces to make a surface density that performs the TEOS and water flow impeding fuction and solid and liquid phase TEOS polymer trapping function.

Abstract: A gas delivery system comprises a common mounting block that supports the components in a predetermined arrangement and defines passageways between components so that a gas can flow through the passageways and components along a predetermined flow path. The mounting block is formed so that at least a portion of at least one mechanical part of at least one component is provided in the block, the passageways connect the components together and the remaining portion of each component not formed in the block is removably attached to the block. The electrical circuitry that is used to operate the components is separately provided remote from the components so that replacement of a component replaces those mechanical parts of the components not provided in the block, without requiring the replacement of the electrical components.

Abstract: A gas delivery system comprises a gate valve that can be connected between a turbo pump and a process chamber. The gate valve includes a valve body, a valve seat and a housing constructed to support the valve seat, wherein (a) the valve body is secured within the housing so as to move relative to the valve seat between an opened position and a closed position, and (b) the housing is provided with a gas passageway connected to each of the spaces on opposite sides of the valve body when the valve body is in the closed position. A plurality of valves are mounted to the housing of the gate valve and arranged so as to control the flow of gas through the passageway so that in operation the chamber and turbo pump each can be pumped down through the gas passageway with a second pump connected to one of the valves, and gas can be transferred and the flow controlled through the passageway bypassing the valve body when the valve body is in the closed position.

Abstract: The disclosed pressure transducer assembly includes a body, a diaphragm, an insulating member, a conductor, a compressed member, and a support member. The body defines an interior cavity. The diaphragm is mounted in the body and divides the interior cavity into a first chamber and a second chamber. A portion of the diaphragm moves in a first direction in response to a pressure in the first chamber being greater than a pressure in the second chamber, and that portion of the diaphragm moves in a second direction opposite the first direction in response to the pressure in the second chamber being greater than the pressure in the first chamber. The conductor is disposed on the insulating member. The insulating member is disposed within the first chamber so that the conductor and the diaphragm form plates of a capacitor. The compressed member is disposed in the first chamber and generates a force that biases the insulating member towards the diaphragm.

Abstract: A pendulum valve assembly comprises a housing including an interior space and a pair of openings through which fluid can enter and exit the interior space; a valve seat disposed in the interior space around the edge of a first of the openings; a disk mounted relative to the housing so that the disk is movable within the interior space between a completely opened position and a completely closed position, the disk being constructed so that when the disk is moved to the closed position the disk engages the valve seat and seals the first opening so that fluid can not pass therethrough; a longitudinal shaft defining a longitudinal axis, fixedly coupled to the disk through at least one pivot arm and at least partially mounted within the housing so that (a) the shaft and disk can rotate about the longitudinal axis between a first angular position where the disk is in the completely opened position and a second angular position where the disk is substantially axially aligned with the first opening but spaced therefr

Abstract: A logarithmic amplifier is provided with a calibration circuit to allow for current measurement over a wide-dynamic range that includes extremely low current levels in a manner which mitigates or eliminates sensitivity to temperature. Calibration currents are generated by application of a series of voltage ramps of selectable slope to a capacitor. This provides a set of known current levels, selectable over a range of decades, for periodic calibration of the logarithmic amplifier. The selectable calibration currents can also be advantageously used to provide a fixed, known bias current to the input of the logarithmic amplifier to improve the response time of the amplifier for measurement of small sensor currents on the order of 10-100 fA.

Abstract: The disclosed pressure transducer assembly includes a first body, a second body, a diaphragm, and an electrode. The first body induces a case, one or more spokes, and a hub. The case has an interior surface. Each of said spokes extends from a first end to a second end. The first end of each spoke contacts the interior surface and the second end of each spoke contacts the hub. The diaphragm is mounted between the first and second bodies. The first body and the diaphragm form a first chamber. The second body and the diaphragm form a second chamber. A portion of the diaphragm flexes in a first direction in response to pressure in the first chamber being greater than pressure in the second chamber. A portion of the diaphragm flexes in a second direction, opposite the first direction, in response to pressure in the second chamber being greater than pressure in the first chamber. The electrode is disposed in the first chamber and is fixed to the hub.

Abstract: A pressure sensor has a housing for receiving a fluid whose pressure is being sensed, and an electrode assembly and a diaphragm arranged to form a variable capacitor within the housing. In one embodiment, the electrode assembly includes a dielectric disk with a conductive electrode and a standoff being formed on a surface of the disk facing the diaphragm. A spacer ring is provided between the standoff and the diaphragm so that the thickness of the spacer ring sets the gap between the electrode of the electrode assembly and the diaphragm. In another embodiment, the electrode assembly is an integral unit that includes a housing and an electrode such that lower surfaces of the housing and the electrode are coplanar to each other. In this embodiment, the spacer is between the housing and the diaphragm such that the thickness of the ring sets the length of the gap.

Abstract: A vapor delivery system for delivering a vapor-phase reactant to a chemical process reactor at a substantially constant flow rate. The vapor delivery system includes a source of a reactant material, means for converting the reactant material to a vapor and for maintaining a predetermined volume of vapor in a vapor phase, a flow controller for providing a controlled flow of the vapor-phase reactant to the process reactor, means for detecting a parameter related to the availability of the vapor-phase reactant material to the process reactor from the flow controller, and means responsive to the detection signal for controlling the supply of reactant material to the vapor converter. In one embodiment the parameter is the pressure of the vapor within the predetermined volume. In another embodiment the parameter is the fluid conductance of a control valve within the flow controller. The vapor delivery system of the present invention can operate in either a substantially continuous or a noncontinuous delivery mode.

Abstract: A capacitive pressure sensor includes a chamber coupled to a region whose pressure is to be determined. The sensor includes a conductive flexible diaphragm and a pair of electrodes, each defining a capacitance with the diaphragm. Variations in pressure in the chamber cause deflection of the diaphragm which in turn causes variation in the capacitances. A processing circuit applies an excitation signal to the capacitances and couples the capacitances to inductive elements. A current through the inductive elements is detected to determine the difference in the sensor capacitances and, therefore, the deflection of the diaphragm and the pressure in the chamber.

Abstract: The disclosed pressure transducer assembly includes an external enclosure, a thermal shell disposed within the external enclosure, and a pressure sensor disposed within the thermal shell. The pressure sensor senses the gas or vapor pressure present in a tube coupling the sensor to a source of pressurized gas or vapor. The assembly includes a device for heating the thermal shell, and thermal insulation is disposed between the thermal shell and the external enclosure. The thermal insulation includes a plurality of metalized high temperature films stacked one on top of another and a plurality of spacer layers, each of the spacer layers being disposed between adjacent ones of the metalized high temperature films.

Abstract: The disclosed pressure transducer assembly includes metallic body, a diaphragm, a metallic plate, an insulator, and a conductor. The body defines an interior cavity. The diaphragm is mounted in the body and divides the interior cavity into a first chamber and a second chamber. A portion of the diaphragm flexes in a first direction in response to a pressure in the first chamber being greater than a pressure in the second chamber, and that portion of the diaphragm flexes in a second direction opposite the first direction in response to the pressure in the second chamber being greater than the pressure in the first chamber. The metallic plate is fixed to the metallic body in one of the first and second chambers. The insulator is also disposed in that chamber and is fixed to the metallic plate. The conductor is disposed on the insulator. The diaphragm and the conductor are characterized by a capacitance. The capacitance is representative of a difference between the pressures in the first and second chambers.

Abstract: A pressure-based mass flow controller suitable for accurately monitoring and controlling the flow of many types of precursors characterized by vapor pressures ranging from approximately 2 torr or lower to at least 760 torr or higher at delivery temperatures of up to at least 250 degrees C. or higher for flow rates ranging from molecular to sonic. A flow restrictive element is installed in the precursor flow path, and the pressures of the fluid upstream and downstream of the flow restrictive element are measured. The ratio of the upstream and downstream fluid pressures is computed and compared to a value stored in the memory of a CPU associated with the controller to determine whether the flow is choked or non-choked. The mass flow of the precursor fluid is then computed by the CPU in accordance with a linear function of the upstream pressure, for choked flow, and in accordance with a nonlinear function of both the upstream and downstream pressures, for non-choked flow.

Abstract: Ions in a chamber or space are detected using an electron multiplier operating at relatively low gain. The electron multiplier is placed in communication with the chamber, such as a chamber of a mass spectrometer, such that ions from the chamber enter the electron multiplier. A bias voltage applied to the multiplier sets the gain of the multiplier. By setting the gain at a relatively low value, the gain of the multiplier remains independent of chamber pressure, such that an accurate pressure measurement is obtained without calibration at a particular pressure or as a function of pressure.

Abstract: An apparatus for preventing the deposition and build-up of chains of polymerized TEOS molecules in the pipes downstream from a reaction furnace in a semiconductor manufacturing process includes an annular nozzle assembly positioned inside the pipes such that a plenum is formed between the annular nozzle assembly and the pipes and such that the annular nozzle forms a hollow tubular conduit for conducting effluent from the reaction furnace. The annular nozzle assembly preferably includes three hollow and generally cylindrical sections, an upstream collar, a downstream spacer ring, and a middle section(s) positioned between the upstream collar and the downstream spacer ring. The annular nozzle assembly is placed within the pipes downstream of the reaction furnace during operation and is modularly constructed so that the length of the annular nozzle assembly can be varied, depending on the length of the downstream pipes from the reaction furnace.

Abstract: The disclosed mass flowmeter includes a section defining a passageway and a laminar flow element disposed within the passageway so as to define a laminar flow channel within the passageway. The maximum cross sectional dimension of the laminar flow element is smaller than the maximum cross sectional dimension of the passageway. In one embodiment the flowmeter includes a device for mounting the laminar flow element within the passageway so that the laminar flow element contacts at least a portion of an inner surface of the passageway so that various sized laminar flow elements can easily and reliably be substituted for one another so as to select the mass flow rate through the channel. In a second embodiment the laminar flow element includes two support segments which are fitted within the passageway and support a central segment which defines within the passageway the laminar flow channel.

Abstract: The liquid cooled trap for effectively and efficiently collecting condensable vapor in a chemical vapor reaction system includes two stages. The first stage includes an entrance area to the trap that is purposely designed to be large in space and a very poor heat exchanger in order to avoid condensation and resulting solid deposits that could clog the entrance port to the trap. The second stage comprises a better heat exchanger to spread the condensation and deposits efficiently over a larger surface area and a longer flow path. The second stage is a very efficient heat exchanger to clean up and remove whatever small amount of the condensable vapor remains after the first stage of the trap. The second stage includes cooling coil tubes and cooling cones or fins to increase the overall efficiency of the trap be increasing the interior surfaces upon which the flowing condensable vapor can condense, while not significantly reducing the flow conductance of the trap.

Abstract: A variable capacitance fluid pressure sensor of the type which includes a deflectable member includes a contaminant exclusion system which protects the deflectable member from both solid and non-solid fluid-borne contaminants. A system of traps disposed between the fluid inlet to the sensor and the deflectable member prevents deposition of process vapors in the fluid on the deflectable member and collects a variety of sizes of fluid-borne solid contaminants remote from the deflectable member.

Abstract: The disclosed pressure transducer assembly includes an external enclosure, a thermal shell disposed within the external enclosure, and a pressure sensor disposed within the thermal shell. The pressure sensor senses the gas or vapor pressure present in a tube coupling the sensor to a source of pressurized gas or vapor. The assembly includes a device for heating the thermal shell, and thermal insulation is disposed between the thermal shell and the external enclosure. The thermal insulation includes a plurality of metalized high temperature films stacked one on top of another and a plurality of spacer layers, each of the spacer layers being disposed between adjacent ones of the metalized high temperature films.

Abstract: A multi-channel mass flow transducer has a single laminar flow element in a primary fluid flow path and multiple secondary flow paths in parallel with and in fluid communication with the primary flow path. Flow restriction elements are disposed in one or more of the secondary flow paths to establish different flow rate measurement "channels" having particular flow rate ranges. The multi-channel transducer of the present invention is capable of measuring fluid flow rates over an extended range and eliminates the need for multiple transducers to measure varying fluid flows.