Semiconductor device and manufacture thereof

摘要

This invention relates to a semiconductor device having an MIS capacitor having a low capacitance value and an MIS capacitor having a high capacitance value, and to a manufacturing method thereof. According to this invention, in a semiconductor device having a first MIS capacitor and a second MIS capacitor having a higher capacitance than the capacitance of the first MIS capacitor formed on a substrate, the first MIS capacitor consists of a lower conductive material region formed on the substrate, a multilayer dielectric film consisting of a first insulating film, serving as both an interlayer insulating film and a dielectric film, and a second insulating film serving as a dielectric film of the second MIS capacitor, and an upper conductive material film, and the capacitance of the first MIS capacitor is determined by an area of the dielectric film formed by the second insulating film. In a manufacturing method, a first conductive material region and a second conductive material region are formed by doping a semiconductor substrate with impurities; the first insulating film, serving as both the interlayer insulating film and the dielectric film, is formed on the first and second conductive material regions; an opening portion of the first insulating film on the second conductive material region is formed; the second insulating film, serving as a part of the dielectric film of the first MIS capacitor and the dielectric film of the second MIS capacitor, is formed on the first insulating film and in the opening portion; a conductive material film, serving as an upper electrode of the first MIS capacitor and an upper electrode of the second MIS capacitor, is formed on the second insulating film; and the capacitance of the first MIS capacitor is determined by the formation area of the conductive material film. By doing so, the semiconductor device comprised of the first MIS capacitor having a capacitance value of 100 fF or less and the second MIS capacitor having a capacitance value exceeding 100 fF can be provided.