Patent ID: 8546265

Claim:
A method for manufacturing a silicon structure, the method comprising, in a process of etching a silicon region in a substrate provided with an etch stop layer with use of plasmas generated by alternately supplying an etching gas and an organic deposit forming gas, to thereby form a first opening and a second opening in the silicon region, the second opening being smaller in width than the first opening, the method comprising the steps of: etching a portion in the silicon region at a highest etching rate under a high-rate etching condition such that the portion does not reach the etch stop layer; subsequently etching under a transition etching condition in which an etching rate is decreased with time-dependently from the highest etching rate in the high-rate etching condition; and thereafter, etching the silicon region under a low-rate etching condition of a lowest etching rate in the transition etching condition until the second opening reaches the etch stop layer.