Thermal Nitride capacitors for high density RAMs

Capacitors using thin (<200Å) insulating layers prepared by plasma-thermal nitridation of silicon surface have been examined and applied to double polysilicon dynamic RAM cells. Leakage currents through the film are discussed as to the retention of stored charge. Dynamic operating characteristics of experimental double polysilicon cells ensure good retention of stored charge with plasma-thermal nitride film capacitors. The output voltage of a cell can be enhanced with the higher dielectric constant of the film.