Method of producing a semiconductor device having tapered through holes

Abstract

A method of producing a semiconductor device having a tapered through hole without wet etching or masking with polysilicon is disclosed. The method may include forming an interlayer insulating film (2) and first insulating film (7) over a lower wiring layer (1). With a photoresist layer (3) as a mask, dry etching may form a recess (8) in the surface of interlayer insulating film (2). After removing photoresist (3), a second insulating film (9) may be formed over first insulating film (7) and within recess (8). Second insulating film (9) may be etched back to form a sidewall (9a) within recess (8). A through hole (10) may then be formed by etching under conditions that result in an etch speed ratio between an interlayer insulating film (2) and sidewall (9a) in the range of about 10. A through hole (10) can thus be formed having a tapered shape and desired slope.

Dependencies are inferred from the claim text.