METHOD FOR MANUFACTURING SILICON EPITAXIAL WAFER

摘要

A silicon single crystal substrate (1) is manufactured by CZ method and is doped with boron to have a resistivity of 0.02 O·cm or less. On the silicon single crystal substrate, a silicon epitaxial layer (2) is vapor-phase grown, and low-temperature heat treatment is performed in an oxidizing atmosphere at a temperature of 450°C or higher but not higher than 750°C for a time that permits the thickness (t1) of a silicon oxide film (3) formed on the silicon epitaxial layer (2) to be 2nm or less, and an oxygen precipitation nucleus (11) is formed in the silicon single crystal substrate (1). Then, the silicon oxide film (3) formed by first cleaning after the low-temperature heat treatment is etched by a cleaning solution composed of a mixed solution of ammonia, hydrogen peroxide and water. Thus, the final thickness of the remaining silicon oxide film formed during heat treatment in the oxidizing atmosphere for forming the oxygen precipitation nucleus can be kept at a level of a native oxide even without employing fluorinated acid cleaning, and furthermore, particle increase after the cleaning can be suppressed.