Method of etching a semiconductor device by an ion beam

Abstract

A method of etching a semiconductor device having multi-layered wiring by an ion beam is disclosed which method comprises the steps of: extracting a high-intensity ion beam from a high-density ion source; focusing the extracted ion beam; causing the focused ion beam to perform a scanning operation by a voltage applied to a deflection electrode; forming a first hole in the semiconductor device by the focused ion beam to a depth capable of reaching an insulating film formed between upper and lower wiring conductors so that the first hole has a curved bottom corresponding to the undulation of the upper wiring conductor, and the upper wiring conductor is absent at the bottom of the first hole; and scanning a portion of the bottom of the first hole with the focused ion beam to form a second hole in the insulating film to a depth capable of reaching the lower wiring conductor, thereby preventing the shorting between the upper and lower wiring conductors. Further, a method of forming a hole of a predetermined shape at a surface area having a step-like portion of a semiconductor device by an ion beam is disclosed which method comprises a pre-etching step of scanning the high-level region of the step-like portion with the ion beam so that the high-level region becomes equal in level to the low-level region of the step-like portion, and a main step of scanning the whole of the surface area with the ion beam till the hole of the predetermined shape is formed in the semiconductor device.