SEMICONDUCTOR CAPACITANCE ELEMENT AND MANUFACTURE THEREOF

• Main Authors: AKAISHI YOSHIO, MATSUDA JUNICHI
• Format: Patent
• Language: English
• Published: 05.02.1992
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To increase the capacitance value of a capacitance element by constituting the element of a capacitance element of polycrystalline silicon and amorphous silicon and by removing either polycrystalline silicon or amorphous silicon to roughen the surface of this electrode. CONSTITUTION:A capacitor electrode (storage node)8 made of phosphorus- containing polysilicon which takes a contact with an N<+> type source region 7 is formed as the first conductive layer. This capacitor electrode 8 is formed in a state of mixture of polycrystalline silicon and amorphous silicon 21. A grain boundary exists in the boundary of amorphous silicon and polycrystalline silicon and is therefore diffused with many impurities upon diffusion of phosphorus by about 1X10 -5X10 cm<-1>. Therefore, etching for example with an HF etching solution allows selective removal of the grain boundary in particular, thereby removing the surface polycrystalline silicon and roughening the surface.