Patent ID: 6372082
Filing Date: 2002-04-16
Classification: H01L

Abstract:
An apparatus for fabricating a semiconductor device, said apparatus comprising:(a) a reaction chamber for accommodating a semiconductor wafer having on a surface thereof a layer to be etched which is covered by an etch mask having a pattern of remaining portions and opening portions; (b) gas supply means for introducing an etch gas into said reaction chamber; (c) plasma generation means for bringing said etch gas into the state of plasma to perform a dry etching process to selectively etch away said layer through said etch mask to form projections underneath said remaining portions and recesses underneath said opening portions; and (d) control means for controlling at least either one of the pressure and the flow rate of said etch gas in said reaction chamber, to have a critical dimension difference, which is a difference in lateral dimension between the bottom of said projection and said remaining portion, fall in a predetermined range, said control means including: (d-1) adjustment means for adjusting at least either one of the pressure and the flow rate of said etch gas; (d-2) memory means for storing, in the form of a database, a critical dimension difference versus gas pressure relationship and a critical dimension difference versus gas flow rate relationship obtained from pre-measurement of an already-etched sample which is formed of the same material as said layer and is covered by the same pattern as said layer; (d-3) arithmetic means for performing, based on said relationships, arithmetic operations to find a gas pressure and a gas flow rate in order for said projection to have a bottom having a desired dimension; (d-4) transfer means for providing results of said arithmetic operation to said adjustment means.