Twin nodes capacitance memory

Abstract

A semiconductor memory produced in a unipolar technology includes a cell which has a pair of inversion capacitors with one terminal of each capacitor connected to one of a pair of bit/sense lines, the other terminal of each capacitor is coupled to a source of charges by a pulse from a word line. The charges produced from the source may be in the form of pulses injected into the capacitors. To provide a word organized array of these cells, each word includes a source of charges produced at the surface of a semiconductor substrate and a plurality of pairs of inversion capacitors formed also at the surface of the semiconductor in spaced apart relationship from the charge source. Information is written into the pairs of capacitors by applying complementary voltages to each pair of bit/sense lines coupled to the pairs of capacitors while a word pulse produces inversion layers at the surface of the substrate between the capacitors to interconnect serially the charge source with each of the capacitors. The complementary voltages have a first and a second magnitude. When voltages of the first and second magnitudes are applied to first and second bit/sense lines, respectively, of a pair of bit/sense lines, a 1 bit of information is stored in the associated cell, and when voltages of the second and first magnitudes are applied to the first and second bit/sense lines, respectively, of the same pair of bit/sense lines, a 0 bit of information is stored in the associated cell. The capacitor of the pair of capacitors having the larger voltage applied thereto stores the greater amount of charge. By employing a differential sense amplifier and floating the pair of bit sense line when a word pulse again connects the charge source with each of the capacitors, the greater charge can be detected by noting the polarity of the different voltage between the two capacitors of the pair of capacitors.