Method for fabricating multi-trench structure

Abstract

Provided is a method for fabricating a multi-trench structure, including steps of: performing anisotropic etching on a semiconductor substrate so as to form a vertical trench; growing a first epitaxial layer on the semiconductor substrate in which the vertical trench has been formed, so that the first epitaxial layer covers the top of the vertical trench to form a closed structure; performing anisotropic and isotropic etching on the closed structure, so as to form a trench array, and to make the trench array communicate with the vertical trench, the trench array including a number of trenches or vias, upper portions of a number of trenches or vias being separated from each other, and lower portions thereof communicating with each other to form a cavity; and growing a second epitaxial layer to cover the trench array, so as to form a closed multi-trench structure. With two times of growth of the epitaxial layers, the multi-trench structure remains stable and solid in a fabricating process, which prevents phenomena of film breakage or falling off in the fabricating process.

Dependencies are inferred from the claim text.