Method of multi-stage substrate etching and terahertz oscillator manufactured using the same method

Abstract

A method of multi-stage substrate etching is provided. The method comprises the steps of: forming a first mask pattern on one surface of a first substrate; forming a hole by etching the first substrate using the first mask pattern as an etching mask; forming a second mask pattern on one surface of a second substrate; forming a hole by etching the second substrate to a predetermined depth using the second mask pattern as an etching mask; bonding the first and second substrates together such that an etched surface of the first substrate faces an etched surface of the second substrate; forming a third mask pattern on the second substrate; and forming a hole passing through the second substrate by etching the second substrate using the third mask pattern as an etching mask, whereby it is prevented the occurrence of a radius of curvature in the bottom surface and the overhang structure occurring on a step surface, so that etching quality is improved, a precise bonding between the substrates is obtained using the alignment key positioned on each substrate, and a multi-layer process is carried out.