Abstract: The invention provides an improved dry etching method for selectively etching a silicon nitride layer 3 formed on the surface of a SiO.sub.2 layer 2 formed on a p-type semiconductor substrate, the method comprising the steps of supplying a mixed gas of HBr and ClF.sub.3 to a reaction chamber wherein SiBr.sub.4, caused, during the dry etching, by a reaction of the silicon nitride layer 3 and the HBr contained in the mixed gas, partly deposits on an etching wall of the p-type semiconductor substrate 1 while at the same time an excess of the SiBr.sub.4 reacts, between the p-type semiconductor substrate 1 and a wall of the reaction chamber, with the ClF.sub.3 contained in the mixed gas to produce a fluoride. The fluoride thus produced can be easily discharged to the outside, since it is more volatile.

Abstract: A dry etching method for dry etching a silicon oxide film or a multilayer oxide film thereof which enables formation of contact window to good dimensional precision and with stable etching configuration in the process of film etching at submicron level. A compound gas containing a C element or S element or Cl element, and F element (e.g., CF.sub.4) is used as a principal gas, and a compound gas containing a C element and two or more of H elements (e.g., CH.sub.2 F.sub.2) as an additive gas is used, in the process of dry etching silicon oxide film or a multilayer film thereof. By using principal and additive gases having good step coverage of deposit produced by plasma reaction, it is possible to eliminate any etching residue and form contact windows having stable etching configuration and good dimensional accuracy in the process of film etching at submicron level.

Abstract: A dry etching method of a substrate or layer of a semiconductor or other material which includes the steps of providing a metallic chamber having an anode and a cathode which are spaced from each other and mounting the substrate or layer to be etched on the cathode, and applying a potential from a RF power supply to the cathode so that a plasma is generated between the anode and the cathode to produce a bulk region and sheath regions between the cathode and the anode. The frequency of the RF power supply is set at a level higher than 13.56 MHz under which the substrate or layer is subjected to etching with the ions. A polysilicon, SiN or Al alloy layer can be efficiently etched with a Cl-based etching gas.

Abstract: A method of forming contact windows in an insulating layer is disclosed. The contact windows extend down to an underlying metal layer which is formed under the insulating layer. The method comprises the steps of: forming an etching mask layer having openings for defining contact window regions of the insulating layer on the insulating layer; and performing an etching process using an etching gas to which a gas containing nitrogen atoms has been added, thereby etching away the contact window regions of the insulating layer through the openings of the etching mask layer to form the contact windows.

Abstract: A method of fabricating a semiconductor device which includes:(1) a step of forming an opening in a silicon substrate using a first silicon oxide film and a first silicon nitride film formed on the silicon substrate as masks,(2) a step of forming a second silicon oxide film and a second silicon nitride film on the side wall of the opening by the reduced pressure CVD method and anisotropic etching method,(3) a step of performing isotropic dry etching using the first and second silicon oxide films as masks, and(4) a step of performing heat treatment in an oxidizing atmosphere using the first and second silicon nitride films as masks.Thereby, uniform isotropic etching may be accomplished by use of the dry etching method.