Abstract: An apparatus for and a method of measuring a boundary surface of a sample are disclosed in which a ratio of the light quantity of a part of reflected light from a sample which travels in the vicinity of the optical axis of the reflected light, to the light quantity of another part of the reflected light which is directed to a position deviating from the optical axis by a predetermined distance is used to accurately measure a boundary surface of a sample. Since the accuracy of measurement is increased by using the above ratio, light capable of passing through the sample can be used as incident light. Thus, a deep hole in the surface of the sample and a void such as an air bubble in a living being sample, which cannot be measured by the prior art, can be measured very accurately.

Abstract: A pattern defect inspection apparatus detects presence or absence of a defect in a pattern formed on a semiconductor wafer by scanning the pattern normally to the surface thereof by a coherent light beam of a predetermined spot size, detecting reflected diffraction lights generated thereby and processing the detected lights. It comprises an abnormal direction signal detector including photo-detectors having wide light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from a normal pattern do not normally reach, a normal pattern detector including photo-detectors having large light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from the normal pattern reach, and a defect discriminator for determining if the abnormal direction signals are due to a true defect or not in accordance with the signals from the abnormal direction signal detector and the normal pattern detector.

Abstract: In forming a film of a purposive substance on a substrate by a chemical vapor deposition (CVD), the size of the film-forming substance particles formed in a reactor is detected as an electrical signal and flow rates of respective gases introduced into the reactor are controlled in response to this electrical signal. According to this control method, the fogging phenomenon owing to formation of the film-forming substance in the gas flow can be effectively prevented.