Abstract: A method of forming a silicone resin film for protecting a semiconductor substrate on the substrate for a certain period of time and then removing the film from the substrate including the steps of: (a) forming the silicone resin film, on at least one portion of the substrate; (b) treating the film with an organic solvent, so that a majority of the film is dissolved in the organic solvent and thereby removed from the substrate and that a residue remains on the substrate; (c) oxidizing the residue to silicon oxide; and (d) treating the silicon oxide with an aqueous solution containing at least one of hydrogen fluoride and ammonium fluoride, so as to dissolve the silicon oxide in the solution and to thereby remove the silicon oxide from the substrate is described. The silicone resin film formed on the substrate can be easily completely removed, without damaging the electrical characteristics of the semiconductor.

Abstract: A method of manufacturing a semiconductor device by which an element region for electronic circuits or the like is formed on the surface of a semiconductor substrate, a diaphragm region is formed in the bottom surface of the semiconductor substrate, and a plurality of openings having different areas and shapes are formed in the semiconductor substrate. The method includes a step of forming a first diaphragm region in the bottom surface of a semiconductor substrate, a step of partially forming a second diaphragm region in the first diaphragm region, the second diaphragm region being thinner than the first diaphragm region, and a step of forming an opening by removing part or the whole of the second diaphragm region.

Abstract: An etching process for a silicon semiconductor substrate to produce a semiconductor pressure sensor or a semiconductor acceleration sensor. The etching process comprises the following steps: (a) carrying out an etching of the semiconductor without application of a voltage to the semiconductor so as to accomplish a pre-etching step, the pre-etching step including dipping the semiconductor in hydrazine hydrate; and (b) carrying out an electrochemical etching of the semiconductor by applying pre-etching step so as to accomplish a final etching step, the final etching step including dipping the semiconductor in an alkali system etching solution containing at least hydrazine (N.sub.2 H.sub.4), potassium hydroxide (KOH), and water (H.sub.2 O), the alkali system etching solution containing potassium hydroxide in an amount of not less than 0.3% by weight.

Abstract: A semiconductor device is produced through electrolytic etching process. The device comprises a P-type silicon substrate. An N-type epitaxial layer is formed on the silicon substrate. P-type regions are defined in the N-type epitaxial layer. N-type regions are defined in some of the P-type regions. A first wiring layer connects to predetermined ones of the P-type regions. A second wiring layer connects to predetermined ones of the N-type regions. The semiconductor device has a given part which has such a possibility that a predetermined magnitude of leakage current flows therethrough between the first and second wiring layers when subjected to the electrolytic etching process. The semiconductor device further has a circuit which is electrically connected to one of the first and second wiring layers. The circuit is capable of removing the possibility of the leakage current flow through the given part when opened.