Abstract: A semiconductor circuit in which a plurality of transistors is provided, the collector regions/contacts and the base regions/contacts of the transistors being mutually self-aligned. In one embodiment, the collectors have conductive layer contacts (such as metal) and are self-aligned to polysilicon base contacts while in another embodiment the base contacts are comprised of a conductive (metal) layer while polysilicon is used for the collector contacts. The collectors of these transistors can be butted to a field oxide to reduce the extrinsic base area and to minimize excess charge storage in the base region. The base contacts, whether polysilicon or metal, etc. provide alternate base current paths so that the removal of the extrinsic base area does not adversely affect the total amount of base current which can flow.

Abstract: A MOSFET which is capable of being placed in two states, one of which is quasi-stable and a memory cell which includes such a device is disclosed. The device basically consists of a pair of diffusions of one conductivity type disposed in a substrate of opposite conductivity type. The channel region between the diffusions is ion implanted or diffused with a dopant which forms a channel of the same conductivity type as the diffusions. A gate electrode is spaced from the channel region by a thin oxide and the gate and substrate are biased so that two states of the device are possible. One is a stable, equilibrium or conducting state wherein an opposite conductivity type inversion layer is formed at the surface of the now buried channel. Another state is a quasi-stable, nonequilibrium, nonconductive state wherein the channel region between the diffusions is depleted of mobile charge carriers.

Abstract: A field effect transistor (FET) comprising a floating gate and a control gate in a stacked relationship with each other and being self-aligned with each other and self-aligned with respect to source and drain regions. The fabrication technique employed comprises delineating both the floating gate and control gate in the same lithographic masking step.

Abstract: A field effect transistor (FET) comprising a floating gate and a control gate in a stacked relationship with each other and being self-aligned with each other and self-aligned with respect to source and drain regions. The fabrication technique employed comprises delineating both the floating gate and control gate in the same lithographic masking step.

Abstract: A charge-coupled random access memory cell is formed in a semiconductor body divided into three adjacent regions. The first region has an impurity diffused therein and serves alternately as a source and a drain for charge carriers. The second or gate region has a predetermined threshold voltage and the third or storage region has a lower threshold voltage. A single unitary metal electrode extends in superimposed relation to the second and third regions. Upon the application of potentials to the first region and the electrode, charge carriers may be stored in or removed from the third region so as to write a "1" or a "0" in the cell.