Abstract: The height of protuberances present on the surface of a product, typically a bump wafer, can be measured with a high accuracy irrespective of the state of the upper surfaces of the protuberances. In the signal processor of a bump height measuring apparatus, a bump height measurement area setting section set a bump height measurement area by the bump layout information, a statistical application section averages the height data in an statistical calculation within the measurement area, a contour line calculating section calculates a contour line of a section of the bump, and a bump height determining section determines a peak value in the contour line as the height of the bump.

Abstract: An apparatus for inspecting a ball-bumped wafer is provided in which an wafer to be inspected, in which a plurality of chips having ball bumps are formed, is mounted on a wafer table; an inspection light is irradiated from a light projection optical system to the wafer mounted on the wafer table; an intensity of the reflected light from a surface, including a bump surface, of the wafer is detected by a detection optical system; and a shape, such as a height, a diameter and a position, of the ball bump is measured on the basis of the intensity of the inspection light.

Abstract: In a phase interference detecting system with use of an interferometer, a height from a reference surface on a measurement surface is detected by receiving interference components of reflection lights from the reference surface and a measurement surface, which lights are divided from a laser beam and are modulated with a frequency being different therefrom, i.e., by irradiating only one laser beam. A light detector is constructed with a line type sensor for receiving the interference components of the reflection lights, and has a plurality of pixel groups for common use of a measurement surface and a plurality of pixel groups for exclusive use of a reference surface, which are provided at both thereof.

Abstract: In a wafer thickness measuring apparatus and a method thereof, detection values are obtained from a sample piece (for example, a wafer chip) at a plurality of measurement points thereon by first and second detectors for absolute measurement of distances, and at the same time, measurement values of the fluctuations, for relative measurement of distances, are obtained by the optical heterodyne interferometer, and those measurement values are memorized as a plurality of measurement data being related with those measurement values. When measuring the thickness of a wafer, the measurements are performed at measurement points on the wafer which has a front surface and a reverse surface in height lying within the height of the sample piece, on which such a correspondence is obtained, thereby obtaining the detection values of the first and second detectors.

Abstract: Interference light occurring between a first laser light of a reference phase and a second laser light of a measuring phase is divided via a light divider into two interference light beams to be directed in two directions. One of the divided interference light beams is received by a polarizing light separator, which separates components of the first and second laser lights from the received interference light beam. First and second light detectors convert respective light energy of the separated components into corresponding electric signals. Adder adds together the converted electric signals. Third light detector converts light energy of the other divided interference light beam into an electric signal. Comparator compares the electric signal from the third light detector with the output of the adder as a reference value, to generate a detection output of a predetermined phase.