Abstract: There are provided a method of inspecting and evaluating semiconductor substrates, good quality semiconductor substrates, a method of manufacturing good quality semiconductor substrates, and a method of manufacturing semiconductor devices using good quality semiconductor substrates.A semiconductor substrate is processed with aqueous basic solution. In this process, the substrate is dipped in the aqueous solution or exposed to a vapor of the aqueous solution. With this process, the surface of the substrate is selectively etched. The substrate surface after the etching process is radiated with a laser beam to measure a light scattered point density. The quality of the substrate can be judged in accordance with the measured density. A thermal treatment may be carried out before or after processing the substrate with the aqueous basic solution. The thermal treatment considerably changes the fine defect density on the surface of the substrate.

Abstract: A method of detecting a defect on the surface of a semiconductor substrate, including: a first etching step of etching a semiconductor substrate by a first etching amount; a first check step of applying a beam to the surface of the substrate underwent the first etching step, and detecting a first reflected beam; a second etching step of etching the substrate etched by the first etching amount, by an additional etching amount, to make the total etching amount a second etching amount; a second check step of applying the beam to the surface of the substrate underwent the second etching step, and detecting a second reflected beam; and a calculation step of calculating the relation between the first and second reflected beams.

Abstract: A semiconductor device is provided having as an insulating oxide film a silicon oxide film containing a metal, such as iron or chromium, of an average concentration of 1.times.10.sup.16 atoms/cm.sup.3 to 1.times.10.sup.19 atoms/cm.sup.3 which can be readily trapped therein.