Semiconductor device

#1. Field of the Invention

#The present invention relates to a semiconductor integrated circuit having a plurality of functional blocks and, more particularly, to a semiconductor integrated circuit comprising a semiconductor device having a tunnel junction which has small capacitance and in which single-electron tunnel effect takes place.

#2. Description of the Related Art

#The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.

#FIG. 1 is a circuit diagram showing a single-electron transistor;

#FIG. 2 is a circuit diagram of a semiconductor device comprising a MOS transistor and a single-electron transistor;

#A semiconductor integrated circuit according to a first aspect of the invention comprises a first circuit block including a small tunnel junction device, and a second circuit block a field effect transistor. The second circuit block is mutually connected to the first circuit block.

#Single-electron transistors are liable to be affected by noise because the current flowing in the single-electron transistors is in the order of nA, and the voltage applied thereof is in the order of mV. Nonetheless, by connecting input/output section including a field-effect transistor to the second circuit block arranged around the first circuit block, the single-electron transistors incorporated in the first circuit block are free from the influence of the voltage (several volts) operating the field-effect transistor. They are hardly affected by the noise which the external circuit may generate. Hence, the integrated circuit can operate stably. In other words, the integrated circuit can be provided in the form of a noise-free, high-efficiency LSI.

#An integrated circuit according to the second aspect of the invention comprises two circuit blocks. The first circuit block includes a single-electron transistor having a small tunnel-junction. The second circuit block is arranged around the first circuit block and includes field-effect transistors.