Abstract: An integrated bipolar RAM cell and process for its manufacture is disclosed. The RAM cell includes first and second cross-coupled bipolar transistors with first and second load elements coupled to the collectors of the first and second transistors, respectively. The load elements can be, for example, diode clamped resistors or lateral PNP transistors. The load elements include regions which are capable of injecting minority carriers into the collectors of the first and second transistors. To avoid charge storage problems and associated reduced switching speed while maintaining high voltage noise immunity, the charge injecting regions are fabricated having an integrated impurity doping less than or equal to about 1.times.10.sup.13 cm.sup.-2.

Abstract: A gallium arsenide integrated circuit structure is disclosed wherein each transistor has only two of three terminals exposed at the semiconductor surface, thereby decreasing both the area of the structure and parasitic wiring capacitance. A dielectric buried layer overlies a portion of the substrate and isolates a first region from the remaining chip. This first region serves as common terminals of two or more transistors. Aluminum gallium arsenide is formed both above and below the base region for increasing the efficiency of the junction by eliminating the need for a heavily doped emitters, thereby allowing for symmetry of emitter and collector regions both on the semiconductor surface and below.

Abstract: A voltage level translator circuit is provided that translates an input voltage referenced to an ECL supply voltage V.sub.CC to a voltage referenced to a TTL supply voltage V.sub.EE independent of power supply voltage variations. A first and a second embodiment have reference circuits coupled to receive a data input signal for providing a single signal referenced to a first supply voltage terminal to a current mirror. An output circuit is coupled to the current mirror for providing an output signal referenced to the second supply voltage terminal. A third embodiment has a reference circuit coupled to receive a data input signal for referencing a voltage on a first supply voltage terminal to a voltage on a second supply voltage terminal. A voltage setting circuit is coupled to the reference circuit for setting a voltage within the reference circuit.

Abstract: A logic circuit is provided having increased flexibility, increased package density over I2L circuits and improved noise immunity over ISL circuits. A first NPN multi-collector transistor has its collectors coupled wherein each provide an output signal, and a base connected to an input terminal and to the base of a second NPN transistor. The emitter of the second transistor is coupled to receive a first supply voltage, typically ground. The input terminal is coupled to a second supply voltage by a resistor. When monolithically integrated, the emitter and collector of the first and second transistor, respectively, share a common buried epitaxial layer that does not require contact with a metallization layer.

Abstract: Bipolar memory arrays having lower quiescent leakage and higher switching speed are constructed by using coupled SCRs formed from vertical PNP and NPN devices. Buried collectors for the PNP and NPN devices are provided within the same isolation tub. A P type plug is used to connect the P collector of the PNP to the P base of the NPN in a region where the P base and P collector overlap. A single N epi-region serves as the base of the PNP and the collector of the NPN. The P plug is located within this N epi-region but part of the N epi-region adjacent to or around the P plug is left so that internal connection of the PNP base and NPN collector is not cut off by the P plug. The structure is particularly suited for use in large memory arrays. The method of fabrication is also described.

Abstract: An integrated circuit power supply interconnection technique is disclosed having a highly doped, low resistivity substrate for distribution of the integrated circuit's most positive supply voltage. The substrate functions as the most positive voltage point and accomodates devices that are normally connected directly to this most positive supply voltage. A dielectric buried layer overlies a portion of the substrate and isolates the substrate supply voltage from devices that are not connected directly to the most positive supply voltage.

Abstract: An all NPN bandgap voltage reference is provided that includes a Widlar type temperature coefficient compensation circuit. A pair of NPN differentially connected transistors maintain a constant current in the Widlar circuit over variations in power supply voltage V.sub.EE while causing an increase in current in the Widlar circuit as temperature increases for maintaining a constant output voltage.

Abstract: A bipolar transient driver for quickly charging and discharging a capacitive load is provided that comprises a means for biasing the base-emitter voltage of a PNP transistor having a high gain-bandwidth product which draws current away from the load as the transient driver output signal transitions downward. The PNP transistor having a high gain-bandwidth product, as well as one or more remaining PNP transistors disclosed in several embodiments, are monolithically integrated in a vertical structure.

Abstract: A gallium arsenide transistor is provided having a self-aligned base enhancement to emitter region and a method of applying metal to the emitter region. A series of steps provide an NPN structure overlying a substrate and includes an N region of aluminum gallium arsenide overlying a P base region for increasing the efficiency of the base-emitter junction by eliminating the need for a very heavily doped emitter at the surface of the chip. Two masking layers, one overlying the other, are deposited over the N emitter region and are patterned by known photoresist methods. The P base region is enhanced by implanting beryllium ions therein and partially into the N collector region. This ion implantation is blocked by the masking layers, creating a base enhancement region aligned with the emitter region. An etching process then undercuts the lower masking layer before the upper masking layer is removed. A photoresist is deposited on the surface and the lower masking layer is removed.

Abstract: A monolithically integrated memory cell having an improved clamped diode load is provided for improving write pulse width and write recovery times. A pair of latchable cross-coupled multi-emitter NPN transistors have a first emitter connected to a stand-by current drain line, and a second emitter coupled to a first bit line and a second bit line, respectively. The base of each transistor is cross-coupled to the collector of the other transistor. The base of each transistor is further coupled to the select line by a PNP transistor. The base of each PNP transistor is coupled to the collector of the respective cross-coupled transistor and is further coupled to the select line by a diode connected NPN transistor.

Abstract: A memory circuit is disclosed having a plurality of memory cells coupled between a plurality of word lines and a plurality of bit lines such that each cell is uniquely coupled between a pair of word lines and a pair of bit lines. A sensing circuit is coupled to each pair of bit lines for determining the state of a selected cell. A column decode circuit is coupled to each pair of bit lines for selecting that pair of bit lines. A read current source is coupled between the bit lines and a voltage source for sinking a read current through the bit lines. A logic selectable write current source is coupled between the bit lines and the voltage source for sinking a write current when writing the memory cells for charging and discharging diffusion capacitance within the selected memory cell. Current flows through the logic selectable write current source only during the write mode.