Abstract: A sensor, such as a mass spectrometer, capable of detecting the presence of materials in a sampled gas is interconnected with a processing chamber of a vacuum manufacturing tool. The sensor includes a timing circuit which is activated only if certain levels of specific materials are detected. Furthermore, the timer is set to run a predetermined time interval after activation so as to discriminate between known transient processing conditions and the presence of impurities which can greatly influence the manufacturing process. When the timer exceeds the predetermined time duration, an output signal can alert the process operator or automatically shutdown the manufacturing tool.

Abstract: A sensor, such as a mass spectrometer, capable of detecting the presence of materials in a sampled gas is interconnected with a processing chamber of a vacuum manufacturing tool. The sensor includes a timing circuit which is activated only if certain levels of specific materials are detected. Furthermore, the timer is set to run a predetermined time interval after activation so as to discriminate between known transient processing conditions and the presence of impurities which can greatly influence the manufacturing process. When the timer exceeds the predetermined time duration, an output signal can alert the process operator or automatically shutdown the manufacturing tool.

Abstract: A method of determining the reaction efficiency of a CVD process reactor by which a reactive gas combination entering the reactor deposits a solid reaction product as a thin film onto a substrate. The composition of the reactive gas combination is measured by an acoustic cell which is disposed downstream from the outlet port of the reactor to determine the reactor's efficiency. Determination of the reactor's efficiency allows the growth rate of the thin film to be determined as well as associated rates of the products which have been exhausted from the reactor.

Abstract: A sensor, such as a mass spectrometer, capable of detecting the presence of materials in a sampled gas is interconnected with a processing chamber of a vacuum manufacturing tool. The sensor includes a timing circuit which is activated only if certain levels of specific materials are detected. Furthermore, the timer is set to run a predetermined time interval after activation so as to discriminate between known transient processing conditions and the presence of impurities which can greatly influence the manufacturing process. When the timer exceeds the predetermined time duration, an output signal can alert the process operator or automatically shutdown the manufacturing tool.

Abstract: An ion collector includes a Faraday collector having a conductive surface disposed substantially parallel to and spaced from the axis of an entering particle beam containing charged and uncharged particles. A grounded plate disposed in the path of the particle beam allows incoming uncharged particles to impinge thereupon. Preferably, the application of a suitable potential to the conductive plate manipulates incoming charged ions to impinge upon either the electron multiplier or the Faraday collector. The ion collector can further include an electron multiplier used in conjunction with the Faraday collector to allow separate modes of operation. Application of a suitable first potential to the electron multiplier can cause charged particles to be deflected directly to the Faraday collector in one mode, and application of a second potential can cause deflection of charged particles to the electron multiplier, with the effects of the uncharged particles on the output of the detector being minimized.

Abstract: A wall deposit monitoring system for measuring variation in wall deposit thickness in an etch or deposition chamber having a contained reactive environment includes at least one quartz or other piezoelectric crystal sensor installed through a wall of the chamber using a feed-through member. A cover assembly retains the sensor at a projecting end of the feed-through member in a position in proximity with the interior of a chamber wall. The cover includes an opening providing access to the active portion of the sensor for exposure to the reactive environment. An attached oscillating device causes the active portion of the sensor to resonate. As processing is performed in the chamber, a solid reaction product accumulates on the exposed active portion, damping the vibration of the sensor. A detection device sensing the shift in frequency can then calculate the relative change in thickness for a given material.

Abstract: A method for linearizing the sensitivity of a quadrupole mass spectrometric system to allow the sensor to more accurately report partial pressures of a gas in high pressure areas in which the reported data is effected by a number of loss mechanisms. According to the invention, correction factors can be applied empirically or software in a quadrupole mass analyzer system can be equipped with correcting software to expand the useful range of the mass spectrometer.

Abstract: A method for manufacturing a miniature quadrupole from a single blank includes fastening four lengthwise insulating strips into parallel slots formed in the blank. A lengthwise axial hole is cut through the blank for the guide wire used in the EDM process. The blank is machined lengthwise into four electrodes using the EDM process so that the electrodes are spaced apart in a widthwise direction and each electrode is connected to an adjacent electrode by one of the insulating strips. During the cutting, the electrodes are held in place by the insulating strips.

Abstract: A miniaturized ion source for a mass spectrometer includes a anode and a focus plate whose interior surfaces form an ionization volume for a retained gas sample. Molecules of the gas sample are ionized by electrons, and the resulting ions are concentrated and converged through an exit aperture in the focus plate to the entrance of an ion analyzer, such as a quadrupole mass filter. Preferably, at least one of the anode and the focus plate includes a curved interior surface which converges the formed ions into a focused beam for directing into the ion analyzer. In addition, the thickness of the exit aperture of the focus plate and or the setback of the focus plate relative to the anode ensures that no line of sight exists between the interior surface of the anode from which ion-forming electrons can scatter into the adjacent ion analyzer.

Abstract: A mass spectrometer gas analyzer includes an ion source for producing ions of a sample gas in a defined ion volume. An ion analyzer collects and analyzes a first portion of the produced ions to determine a partial pressure for a selected gas species within the sample gas. An oppositely disposed ion collector collects a second portion of the ions to determine a total pressure of the contained gas sample. A collecting surface of the ion collector is positioned relative to the incoming ion beam to allow collection of ion current but the surface is configured such that a substantial portion of a plurality of secondary electrons produced by ion bombardment with the ion collector are deflected away from the ionization volume. The partial pressure is thus determined by the ion analyzer without secondary electrons entering the ion analyzer.

Abstract: A dual beam ion source comprises an ion volume in an ion chamber, an ion collector, and two identical ion accelerators. One ion accelerator accelerates a first, "test" ion stream from the ion volume in a first direction and directs it to the ion collector where it can be directly measured. The second ion accelerator accelerates a second, "utilizable" ion stream from the ion volume in a second direction. By directly measuring the ion current (caused by the first, "test" ion stream) at the ion collector, either or both the total ion pressure of the gas within the ion volume, and the magnitude of the second, "utilizable" ion stream, can be calculated.

Abstract: An acoustic cell includes multiple acoustic cavities fluidly coupled together. At least two of the acoustic cavities have unequal lengths and cross sections. End segments of the acoustic cell are uniformly cylindrically shaped or conically shaped. A driver transducer at one end of the acoustic cell and a receiver transducer at another end of the acoustic cell are acoustically isolated from the acoustic cell. A pair of preferably metallic isolation diaphragms transmit acoustic signals to and from the transducers without significantly altering the phase-frequency characteristics of the acoustic signals. The acoustic cell operates as an acoustic resonator operating at frequencies lower than any possible self-resonance frequencies of the isolation diaphragms or the driver and receiver transducers. When a binary gas is flowed through the cell, a processor detects a resonant frequency of the gas within the cell to determine a composition of the gas.

Abstract: For treating a fluid sample for introduction to a mass spectrometer or other appropriate use, a composite membrane and support assembly allows analytes from a sample flow to permeate through a membrane free from the undesired background matrix. The composite membrane and support assembly comprises a semipermeable membrane, a fiber member for supporting the membrane, and a rigid perforated member for supporting the membrane and the fiber support.

Abstract: An acoustic technique is employed to identify the species of a sample of refrigerant gas and whether it contains significant contaminants. The refrigerant is admitted into a Helmholtz resonator under controlled pressure, and a drive frequency is swept across a frequency band and applied to a first transducer. A second transducer picks up the vibrations in the resonator and the output signal is compared to the drive signal. The resonant peak or center frequencies are identified and the sharpness or quality factors are measured. These measured data are compared with stored data to identify the refrigerant.

Abstract: An acoustic technique is employed to identify the species of a refrigerant gas and whether it contains significant contaminants. Air in the refrigerant can be tolerated, but must be accounted for in determining the acoustic properties of the sample. The refrigerant is admitted into a Helmholtz resonator under a controlled pressure, and a drive frequency is applied to a transducer. Another transducer picks up the vibrations in the resonator and an output signal is compared to the drive signal to find resonant peaks and sharpness factors. The change in resonant frequency with pressure is measured, and is employed to quantify the presence of air in the sample. The amount of air present determines a frequency correction, which permits unambiguous identification of the species of refrigerant and of its purity.

Abstract: A gas analyzing system that includes a vacuum chamber containing a mass spectrometer and a sampling device for introducing a gas sample into the chamber. A sorption pump is operatively connected to the chamber which is capable of maintaining the chamber at a high vacuum. The pump includes a diffusion barrier that provides smooth pumping characteristics and repeatable short term system behavior when sample pulses are introduced into the system.

Abstract: A sorption pump for high vacuum applications that is suited for use in gas analyzers such as mass spectrometers. The pump includes a housing containing a quantity of getter material and a diffusion barrier in the gas inlet to the housing. A finite period of time is required for gas molecules in the vacuum analyzer system to cross the barrier, thus providing a window during which gas pulses can be accurately analyzed.

Abstract: A miniaturized, portable sensor is provided for selectively sensing the presence of halogenated gases, particularly HFC's, within an atmosphere. The apparatus includes a ceramic element containing either a mixture of potassium silicate and either aluminum oxide or silicon dioxide which react with ions of the halogenated gas when the two are brought together forming a depletion layer on and within the ceramic. The sensor is formed with two electrodes on opposite sides of the ceramic having terminals connected into a circuit for detecting a potential difference across the depletion layer. Means are provided for detecting the potential differences and for producing a discernable signal in response thereto.

Abstract: An AT-cut quartz crystal for a quartz crystal microbalance has a buffer layer sandwiched between an adhesion layer and an electrode layer on the front or deposition side of the crystal. The buffer layer can be a zinc layer of 6000 .ANG. sandwiched between a titanium or chromium adhesion layer of 100 to 160 .ANG. and a gold, silver, or aluminum outer electrode layer of about 2000 .ANG.. The zinc layer has a relatively low bulk modulus, and absorbs stress imposed by the deposited layer. The buffer layer prolongs useful crystal life, particularly when depositing dielectric materials. The crystal should have a modest surface roughness as keying-in structure.

Abstract: A method for linearizing the sensitivity of a quadrupole mass spectrometric system to allow the sensor to more accurately report partial pressures of a gas in high pressure areas in which the reported data is effected by a number of loss mechanisms. According to the invention, correction factors can be applied empirically or software in a quadrupole mass analyzer system can be equipped with correcting software to expand the useful range of the mass spectrometer.