Integrated circuit device

Abstract

Abstract PURPOSE: To stabilize an operation of IC using a floating substrate by adjusting so as to have the maximum thickness xd max of a depletion layer when a semiconductor layer in thickness t is equipotential to a source larger than t. CONSTITUTION: An Si n-epitaxial layer is provided on an insulating substrate 1, a p-layer 2 is obtained through patterning, and a gate terminal 4 is provided by way of an insulating film 3. According to this constitution, a change in threshold voltage Vth is retained up until an electron injected in the layer 2 is extinguished; then from operating FET, a different operation is taken and a response changes in the previous pulse condition. A stable operation is not obtainable consequently. Now, a film thickness t of the layer 2 is selected smaller than the maximum value xd max of a depletion layer when the layer 2 is equipotential to a source 5. From adding then voltage + Vg to the gate, xd max is further turned incremental, however, an occurrence of the depletion layer is confined within the thickness t of the layer 2, which becomes constant at maximum value t and makes no change any more thereafter. Thus, MOSFET unchanging in threshold voltage and stable in characteristic is obtainable through adjusting impurity density and thickness t of the layer 2. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Nobuo Sasaki

Bibliographic Details