PURPOSE: To reduce the number of steps and the cost of manufacturing a semiconductor device by covering a semiconductor substrate with a phosphosilicate glass film, and emitting an electron beam to the desired region of the film to remove by wet etching the unemitted region of the film with the beam.

CONSTITUTION: After a PSG film 2 having 8wt% of phosphorus density and 1μm of thickness is deposited on a semiconductor substrate by a chemical vapor- phase growing method with phosphine gas and silane gas, an electron beam 5 is emitted to the film 2 in a vessel which is evacuated in vacuum of 10-3W10-2pa. As a result, a phenomenon that the beam emitted portion of a PSG film 7 is modified and a phenomenon that a thin carbon film 6 is formed on the beam emitted portion of the film 7 simultaneously occur. When the beam emitted PSG film is dipped in a mixture solution of nitric acid + hydrogen fluoride + water, the unemitted portion of the PSG film is completely removed. But the beam emitted portion of the film 7 remains and the PSG film pattern 2a is formed on a semiconductor substrate 1 by the two effects.