Prometrix Corporation

Wayne K Borglum

Chester L Mallory

Walter H Johnson

Edric H Tong

Hung Van Pham

The resistivity of the surface of a semiconductor wafer is measured at different temperatures to determine the resistivity as a function of temperature. The temperature of the semiconductor wafer is varied by a heater in thermal contact with the semiconductor wafer, and the temperature is measured by a temperature sensor in thermal contact with the semiconductor. The heater is controlled by a control unit which adjusts the amount of heat provided by the heater, thereby controlling the temperature at which a measurement from a four-point resistivity probe is taken.

Semiconductor surface resistivity probe with semiconductor temperature

A semiconductor wafer handling apparatus for automated movement of semiconductor wafers between wafer cassette trays and wafer test systems is provided. The apparatus includes a platform for carrying at least one semiconductor wafer cassette tray, a wafer alignment device carried by the platform for aligning a semiconductor wafer in a predetermined test position and a wafer transfer device associated with the platform and the wafer alignment device for transferring the wafer between the cassette tray, the alignment device and the test system. The wafer transfer device is operational in the same plane relative to the platform and capable of extending, retracting and rotating in the plane. In includes a shuttle arm assembly mounted for translational and rotational movement so that it may be selectively aligned with the cassette tray, the alignment device and the test system and further includes a device for controlling the translational and rotational movement of the shuttle arm assembly for selectively extending, retracting the rotating the shuttle arm assembly relative to each of the cassette tray, the alignment device and the test system so that in response to signals from the control device, the shuttle arm assembly can be selectively actuated to translate to a cassette tray position and secure and remove a semiconductor wafer from the cassette tray, translate to a wafer alignment position and insert, release, secure and remove the wafer from the alignment device, and translate and rotate to a wafer test position and place the wafer on, release, secure, and lift the wafer off the test system.

Apparatus for handling semiconductor wafers

A system for ascertaining the thickness of thin films, especially on semiconductor substrates, comprising a light source, a randomized bifurcated fiber optic bundle, a pentamirror, a rapid scanning monochromator with a rotating grating, a photodetector, and A/D converter, an interface and a data reduction computer. The randomized bifurcated fiber optic bundle via the pentamirror directs light to and receives reflected light from a surface of the thin film, the reflected light passes through the bifurcated bundle to the monochromator and to the photodetector whose output is read by the A/D converter. A timing control circuit is provided which has an input from an encoder coupled to the motor rotating the grating and clock and trigger outputs coupled to the A/D converter so that the A/D converter consistently samples the analog signal representative of the same portions of the reflected visible spectra returned from the thin film under test.

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San Jose, CA, United States of America

Wayne K Borglum