PROCEDE DE FABRICATION D'UN CIRCUIT INTEGRE ET NOTAMMENT D'UNE MEMOIRE EPROM COMPORTANT DEUX COMPOSANTS DISTINCTS ISOLES ELECTRIQUEMENT

1. Process for the production, on a semiconductor substrate (8), of an integrated circuit having at least two separate electrically insulated components, a first component (2) having a first insulant (10) surmounted by first (12) and second (14) stacked gates, which are separated by a second insulant (16), and a second component (22) having a third insulant (30) surmounted by a third gate (28), the first (10), second (16) and third (30) insulants having different, clearly defined thicknesses, characterized in that it comprises the following stages : a) producing a first insulant layer (110) on the substrate (8), b) covering the first insulant layer (110) with a first conductive layer (112), in which the first gate (12) will be formed, c) formation of a second insulant layer (112) on the first conductive layer (116), d) carrying out a first etching of the second insulant layer (116) and the first conductive layer (112) so as to only retain said second insulant and said conductive material in the region in which the first component will be produced, e) elimination of the first insulant layer (110) region located at the point where the second component will be produced, f) producing a third insulant layer (130) in said location, g) covering the structure obtained with a second conductive layer (114), h) producing the second (14) and third (28) gates by etching the second conductive layer (114) and i) producing the first gate (12) with the aid of a second etching of the second insulant layer (116) and the first conductive layer (112).