Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To make it possible to form a gate metal without yielding a cavity in an opening part even in the opening having a submicron size, by performing etching up to an intermediate part of an insulating film by using a first mask, providing a second mask on the side surface of the insulating film, and providing the opening in the insulating film with the first and second masks as the masks. CONSTITUTION:An insulating film (SiO2 film) 12 is formed on the entire surface of a semiconductor substrate 1. A first mask material (W) is formed on the film 2. An opening is provided by dry etching using SF6 gas. Thus a first mask 3 is formed. with the first mask 3 as a mask, the insulating film 2 is etched by dry etching using CF4 gas, and a second mask material (resist) is formed. A second mask 4 is made to remain only on the side surface of the opening part in the insulating film 2 by dry etching using O2 gas. Then, with the first and second masks 3 and 4 as the masks, the insulating film 2 is etched to the semiconductor substrate 1 by dry etching using CF4 gas. Then, the second mask is removed with an organic solvent, and the first mask is removed by dry etching using SF6 gas. Thus, an opening, whose opening part is expanded, is provided in the insulating film.

Inventors

• 👤 Zenzo Shingu

Bibliographic Details