Abstract: A system and a method provide a vacuum seal to be used when mounting an optical device onto a process chamber or a pump line removing exhaust gas from a process chamber. The system of the present invention includes: (a) a threaded nipple, having an internal mating surface and a threaded external surface, that is attached to the process chamber or to the pump line; (b) an internally threaded coupling, provided for accommodating the optical device, that is screwed onto the threaded external surface of the nipple, and having internally a first mating surface touching the internal mating surface of the nipple and a second mating surface; (c) a window placed on the second mating surface of the coupling; (d) means for creating a vacuum seal, e.g. an elastomer O-ring, between the first mating surface of the coupling and the mating surface of the nipple; and (e) means for creating a vacuum seal, e.g. an elastomer O-ring, between the second mating surface of the coupling and the mating surface of the window.

Abstract: A structure and a method provide a quasi bright field particle sensor for the detection of non-spherical particles, using a laser beam of predetermined polarization. A phase shift caused by non-spherical particles passing through the laser beam is utilized to detect the presence of such particles. In one embodiment, a single laser beam is used to detect the concentration of non-spherical particles in the pump line receiving the exhaust gas from a process chamber.

Abstract: A structure and a method provide a quasi bright field particle sensor, using a laser beam of predetermined polarization. A phase shift caused by a particle passing through a laser beam is utilized to detect the presence of a particle. In one embodiment, the laser beam is split into two components of laser beams of orthogonal polarization separated by a predetermined distance, so as to allow detection of both spherical and non-spherical particles. In another embodiment, where only non-spherical particles are detected, a single laser beam is used.

Abstract: A method for accomplishing particle monitoring above the throttle valve of a turbo pump provides a particle sensor which is built into the throttle valve in such a way that it is insensitive to local plasma glows. Furthermore, the particle sensor is placed such that a particle monitoring laser beam of the particle sensor is offset from the centerline of the pipe, so as to maximize exposure to process gas flow which is diverted to the periphery of the pipe by the position of a butterfly valve plate.

Abstract: An apparatus and a method provide a modular design for a particle monitor of external design used in a vacuum process equipment. In one embodiment, the key elements, i.e. laser assembly, the detection module, the beam stop and a darkened surface opposite the detection module, can be independently mounted on a pump line. The particle monitors of the present invention can be mounted on both straight sections and bends of the pump line. Each key element can be accessed independently of other key elements for repair and service.

Abstract: A method and an apparatus allow dynamic tuning of a particle sensor. The particle sensor provides output signals indicating particle detection to a controller, which includes an amplifier whose bandwidth and gain can be adjusted. The bandwidth and the gain of the amplifier are adjusted in accordance with predetermined optimal performance levels under the varying process conditions in which the particle sensor is placed. The optimal signal-to-noise ratio is maintained by adjusting the bandwidth and the gain according to both expected particle velocities and whether a plasma glow is present in the exhaust line for carrying gasses out of a process chamber.

Abstract: A real-time particle sensor is provided which can monitor particles near the surface of a disk in a computer disk drive system and in the region between disks in a multiple disk stack. A laser and lens are housed in a compact cartridge which is mounted on an actuator arm of a disk. Photocells which are also mounted on the actuator arm detect light scattered by particles passing through the laser beam, and so generate an electrical signal used to count the detected particles. The sensor's small size allows a separate sensor to fit in each of the regions between adjacent disks in a stack of disks, or near the surface of a single disk.

Abstract: A real-time particle counter apparatus for monitoring contaminant particles in liquids includes a nebulizer, a drying chamber and a counter. The nebulizer provides an aerosol of droplets containing particles to the drying chamber, and the droplets are evaporated leaving solid particles to be counted and sized by the counter. Liquid is recirculated in a closed loop by pumping means that moves the liquid between the liquid source and the nebulizer. A constant air flow containing particles is provided to the counter and the apparatus is self-regulating so that no operator is required to maintain the level of liquid in the nebulizer.