Abstract: There is provided a vapor deposition apparatus for forming a thin film which includes plural reaction gas supply ports at the top portion of a hollow reactor, an exhaust port at the bottom of the reactor, a rotational substrate holder provided inside the reactor on which a wafer substrate is mounted. A straightening vane having plural gas holes formed therein is provided on an upper portion of the reactor. The reactor is partitioned into upper and lower portions which have different inside diameters, with the inner diameter of the upper portion being smaller than the inner diameter of lower portion. The lower end of the upper portion and the upper end of the lower portion are linked by a linking portion which has a predetermined shape to make continuous the hollow inside of the reactor. A thin film is formed on the surface of a wafer substrate, which is placed on the rotational substrate holder, by supplying a reaction gas into the reactor.

Abstract: A vapor deposition apparatus includes a cylindrical hollow reactor having gas supply ports at its upper portion and an exhaust port at its bottom portion. A rotational substrate holder, which seats a wafer substrate, is concentrically placed inside the reactor. The reactor has a straightening vane having gas holes concentrically positioned at its upper portion. Reaction gas is supplied into the reactor to form a thin film on the surface of the wafer substrate on the rotational substrate holder by vapor deposition. In one embodiment, the straightening vane is configured so that the flow rate of the reaction gas in the center portion covering the area of the wafer substrate and the gas flow rate of the reaction gas in the outer portion of the center portion are different from each other. In another embodiment, the reactor is sectioned into upper and lower portions. The inner diameter of the upper portion is smaller than the inner diameter of the lower portion.

Abstract: In a measurement method for measuring the epitaxial film thickness of a multilayer epitaxial wafer, a reflectivity spectrum of a multilayer epitaxial wafer having at least two epitaxial layers of different electric characteristics is measured by using infrared radiation in a far infrared region of at least 500 cm.sup.-1 or less, and frequency-analysis is performed on the reflection spectrum thus obtained by a maximum entropy method, and the film thickness of each epitaxial layer is calculated on the basis of the analysis spectrum thus obtained.