Abstract: An improved method for minimizing interferences from random noise and correlated fluctuations which obscure electrical signals converted from optical emissions. In particular, an improved method for the removal of interferences from optical emission signals during endpoint determination in dry etching processes for the fabrication of microelectronic devices which derives information in the presence of random noise, correlated fluctuations and periodic modulations of the plasma by maximizing the signal to random noise ratio and minimizing the obscuring effects of correlated fluctuation.

Abstract: A method for the control of photoresist develop processes employing multiple spray-puddle steps in which process changes other than time, such as endpoint are used to determine the length of the spray and puddle steps.

Abstract: An improved method for minimizing interferences from random noise and correlated fluctuations which obscure electrical signals converted from optical emissions. In particular, an improved method for the removal of interferences from optical emission signals during endpoint determination in dry etching processes for the fabrication of microelectronic devices which derives information in the presence of random noise, correlated fluctuations and periodic modulations of the plasma by maximizing the signal to random noise ratio and minimizing the obscuring effects of correlated fluctuation.

Abstract: A method for the control of photoresist develop processes employing multiple spray-puddle steps in which process changes other than time, such as endpoint are used to determine the length of the spray and puddle steps.

Abstract: A device for the optical measurement of light transmitted through silicon wafers and other media during the manufacture of electronic components and particularly during processing within a spray environment. The device is characterized by being a stationary assembly designed to provide structurally inherent optical alignment and focus. In addition the device is provided with a geometry specifically designed to direct any condensate flow away from the surface of the wafer, and with surface characteristics which minimize droplet separation from the surface of the device within a spray environment. The device is designed to permit its location out of the main spray pattern. The light source of the device is made as small as possible to minimize intrusion into the process environment.

Abstract: A sensor board for use with an endpoint controller which monitors light intensity is provided. The sensor board can provide a dynamic range of up to five million because a constant current driver and phase sensitive detector help eliminate noise from the detected signal. The sensor board can also subtract a DC voltage offset from the detected signal and amplify the difference to provide increased resolution of small changes in the detected signal.

Abstract: The device of this invention employs a short focal length anamorphic lens to collect light from a source with asymmetric angular dispersion of the flux. Focal lengths are chosen to provide an approximate line fuzzy focus with a f/number equal to or smaller than one of the associated detector. Fiber optic cable systems are used to deliver the condensed light and the diameter of the optical fibers is chosen to give a numerical aperture greater than that of the detector. The number of optical fibers in the cable should be large enough to over-fill the limiting area of the etendue of the detector. In a preferrred embodiment the fiberoptic cable is bifurcated and fibers from the separate channels are interleaved.

Abstract: A method and apparatus for determining the amount and size of particles and bubbles in a liquid process medium. The invention comprises the steps of providing a collimated light source to generate a light beam of a known wavelength, and directing it to illuminate a liquid sampling volume within a cell positioned within a sensor housing constructed to collect the light scattered by particles and/or bubbles within the sample caused by the impingement of the light beam. The scattered light is then separated into forward, and/or right angle and back scattering portions, and converted into separate electrical signals for each scatter direction. Since the scattering coefficient is a direct function of the density of the sampling volume, the presence of bubbles reduces the density and the amount of radiation scattered in the backward direction.