Abstract: A wafer chuck and a wafer loading and unloading system wherein a flat support surface of the chuck has a plurality of peaks and valleys, with the peaks minimizing contact with the wafer, yet having sufficient contact area for wafer support without deformation. The peaks are provided with a top edge serving to dislodge particles from a wafer surface when loading the wafer onto the chuck. The loading system includes wafer pushing members for bringing a wafer to a desired position on the support surface.

Abstract: A surface profile measuring instrument, which has a stylus supported on a linear elongated beam for linear scanning. The beam is supported by a mounting mechanism which compensates for tilt by means of a servo. The stylus is pushed and pulled along the beam for linear scans of desired length.

Abstract: A scanning laser contaminant and defect detector for reflective surfaces, having a light collector for increasing sensitivity to scattered light. The collector is preferably one quadrant of a spherical shell cradled between V-shaped reflective side walls. The collector has beam entrance and exit ports, as well as a detector port where a light detector resides. The collector is placed in proximity to a surface to be inspected. Light scattered from the test surface is directed to the reflective crown surface, then to the reflective side walls and ultimately to the detector.

Abstract: A wafer orienting apparatus having inwardly biased rollers, spaced about the circumferential edge of a wafer in contact with the edge. Two of the rollers are spaced apart a distance less than the dimension of a primary flat registration edge and are mounted to follow the wafer edge upon rotation of the wafer. When a flat registration edge passes these closely spaced rollers they move inwardly, activating switches associated with a coincidence circuit. When both switches are simultaneously activated, the coincidence circuit produces a signal which stops wafer rotation, thereby orienting the wafer. The rollers are mounted so that they can be moved from the path of wafer travel after wafer orientation, permitting a queue of wafers to be oriented, one after the other.

Abstract: An instrument for computing resistivity based upon measurements of thickness and conductance. A conductance transducer is a solenoid in an annular ferrite cup connected to a tank circuit for an eddy current measurement of conductance. Within the center of the annular ferrite cup concentric acoustic wave sending and receiving channels are disposed for making an acoustic pressure wave measurement which is used for a thickness measurement using two gauge heads, spaced on opposite sides of an article to be measured. Each gauge head contains identical conductance and thickness transducers. The thickness measurement is divided by the conductance measurement to derive resistivity.

Abstract: A gauge for measuring variations in distance of a surface relative to a reference by means of phase shifts in a zone of high acoustic impedance. A gauge head is provided with a first orifice for emitting acoustic waves, driven by a reference signal, toward a surface positioned very close to the gauge head, forming a high impedance zone. A second orifice in the gauge head picks up acoustic waves subjected to the zone and these waves are converted to electrical signals for comparison to the reference signal in a phase detector. The phase error between the two signals is indicative of surface distance variations.

Abstract: A probe for determining the p or n-type of semiconductor material wherein a conductive wire is positioned for point contact with the semiconductor, forming a diode. The wire is energized by r.f. current passing through a capacitor so that the current is rectified at the diode, charging the capacitor. A voltage comparator is connected to the capacitor for determining the polarity of charge on the capacitor and hence the p or n-type of the semiconductor wafer. The semiconductor is supported on a non-diffusing dielectric over a conductive carrier such that r.f. current passes through the dielectric to the carrier, thereby completing the circuit.

Abstract: A measurement system wherein an acoustic distance measuring transducer is moved over a flat reference surface, measuring the distance from the transducer to a calibration surface and then to a test surface. The transducer is moved along a path within a ring while the top edge of the ring is used to support the calibration surface and then the test surface. The ring is mounted for rotation so that the transducer can scan a supported surface at a locus of points. Scans across the calibration surface and then the test surface are compared to measure deviations of the test surface from calibration surface.

Abstract: Apparatus for measuring distance between a gauge head orifice, and the front planar surface of an object by sensing acoustic pressure near the gauge head orifice. The acoustic pressure is initially generated by an audio oscillator activating a speaker which emits acoustic waves through a first orifice. Acoustic pressure is sensed through a second orifice, proximate to the first, and the pressure is converted to an electrical signal which is processed to yield a distance signal for a display. Two similar distance gauges spaced apart on opposite sides of a planar member at a known distance are used to compute the thickness of the planar member.

Abstract: A surface profile measuring instrument, which has a stylus supported on a counterbalanced scanner arm, in turn supported in a gimbal mounting having two axes, one of which is adjustable by a servo. A connected electronics package provides axis compensation for levelling through the servo, as well as zero adjustment of a display device and discrimination against small, unwanted slops. Stylus motion is translated into an analog signal by a linear position differential transformer. To achieve slope discrimination, the analog signal is differentiated and compared in a comparator to a reference for rejection of signals corresponding to small slopes. The signal is then integrated and displayed, with reference to a selected zero of a display device.