摘要:
The anode (40) and cathode contact (32) of the diode are contiguously located on a semiconductor surface and separated by an insulating coating (36) on cathode contact (32). Preferably the anode (40) consists of two regions (40) separated by coated cathode contact (32) and laterally surrounded by recessed oxide area (16). The method of making includes the steps of forming cathode contact (32) of a layer of conductive material and applying insulative coating (36) onto it where after this step at least one area of the semiconductor surface adjoining coated cathode contact (32) is exposed, of blanket depositing a metal layer and causing the reaction of the metal with the semiconductor material to produce anode (40) that is self-aligned with respect to cathode contact (32). The diode may be incorporated into merged transistor logic devices in large scale integration applications.
摘要:
A Transistor-Transistor Logic (TTL) gate circuit is disclosed comprising an input transistor T1, an inverter transistor T2, an output transistor T3 and a pull-up transistor T4. When T2, T3 are non-conducting, VB appears at the output 12 and when T2, T3 are conducting, the output is substantially at earth. To achieve fast switching of T3 a different smaller amount of base current is applied to the inverter transistor T2 than is applied to the base of the output transistor T3. As shown, a current mirror circuit (T5, T6) can be used to control the amount of base current flowing between the input transistor (T1) collector terminal and the base terminal of the inverter transistor (T2). The mirror circuits limit the base current of T2 to an amount less than the base current that flows between the input transistor collector terminal and the base terminal of the output transistor T3. The value of R3 also limits the current though T2. In another embodiment, a resistor in series with the base of the inverter transistor performs the same function as the current mirror circuit.
摘要:
A semiconductor device includes a single crystal semiconductor material (14) having an N conductivity type region (10) and a P conductivity type region (12) which are electrically interconnected by a layer (18) of said semiconductor material in polycrystalline form doped to make an electrical contact with the N type region (10), a layer (20) of a combination of said semiconductor material and a refractory metal and a layer (24) of said semiconductor material in polycrystalline form doped to form an electrical contact with the P type region (12).
摘要:
In a planar semiconductor integrated circuit, a buried isolating layer (9) confines equal area PN junctions of a vertical bipolar transistor (3) and a lateral bipolar transistor (5) to the intrinsic regions of the transistors. This avoids the formation of parasitic PN junctions and so leads to improved performance when the transistors are operated in saturation as in TTL circuits. A method of making such an integrated circuit involves the simultaneous deposition of polycrystalline semiconductor on the isolating layer and monocrystalline semiconductor onto the substrate through holes in the isolating layer. Alternatively, a thin nucleating film may be first deposited on the isolating layer so that monocrystalline semiconductor can be deposited on the isolating layer as well as on the substrate.
摘要:
Self-aligned semiconductor circuits and process for manufacturing the circuits in which a plurality of transistors (206, 208, 240; 206, 208, 242) is provided, the collector regions/contacts (240,228; 242, 228) and the base regions/contacts (254, 252; 256, 252) 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 (240, 242) of these transistors can be butted to a recessed field oxide (214) to reduce the extrinsic base area and to minimize excess charge storage in the base region (208). 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.
摘要:
A Transistor-Transistor Logic (TTL) gate circuit is disclosed comprising an input transistor T1, an inverter transistor T2, an output transistor T3 and a pull-up transistor T4. When T2, T3 are non-conducting, VB appears at the output 12 and when T2, T3 are conducting, the output is substantially at earth. To achieve fast switching of T3 a different smaller amount of base current is applied to the inverter transistor T2 than is applied to the base of the output transistor T3. As shown, a current mirror circuit (T5, T6) can be used to control the amount of base current flowing between the input transistor (T1) collector terminal and the base terminal of the inverter transistor (T2). The mirror circuits limit the base current of T2 to an amount less than the base current that flows between the input transistor collector terminal and the base terminal of the output transistor T3. The value of R3 also limits the current though T2. In another embodiment, a resistor in series with the base of the inverter transistor performs the same function as the current mirror circuit.
摘要:
Bipolar logic circuits such as inverters and NAND circuits are disclosed which are of extremely low DC power dissipation and very high speed. The basic circuit is an inverter circuit which incorporates at least a single switchable transistor (3). The emitter (6) of the NPN transistor (3) is connected to a potential level which may be ground while the collector is connected via a load device, a resistor or a complementary PNP transistor (2), to a positive power supply potential. The base (8) of the NPN transistor (3) is connected to a source (10) of standby current and via a parallel combination of a capacitor (14) and diode (12) to an input terminal (15). When the NPN transistor (3) is switched OFF by the application of a negatively going signal, standby current from the current source (10) is switched to ground via the diode (12) which has a lower switching point than the emitter-base diode of the NPN transistor. The capacitor (14) in parallel with the diode, is charged during this period so that when a positive going transient is applied at the input, the diode is backward-biased and the transient is applied along with the standby current to the base (8) of the NPN transistor, switching it to the conducting or ON state. In addition to the basic logic circuit, a two-input NAND circuit which includes a pair of PNP bipolar transistors and a pair of NPN bipolar transistors disclosed.
摘要:
This invention relates generally to the accessing of random access access memory arrays and, more specifically to circuits and techniques for increasing the data valid time of such memory arrays without increasing either the access or cycle times of the array. This is accomplished by providing, during a read cycle, a read signal directly to an output driver (32) and simultaneously providing, via a parallel path, a latch output to the same driver (32). The latch output is provided under control of the read signal and a returning portion of a clock pulse such that the latch output overlaps the direct read signal from a sense/read amplifier (31). An output is provided from the latch (33) until it is reset and may last well into the next read cycle even when a new read signal is present. The technique utilized, in addition to providing a longer data valid time, eliminates a response of the latch (33) to spurious read signals because a latch output is not provided until the clock is deactivated and such spurious read signals are not present during the returning portion of the clock cycle. The approach utilized also has the advantage that delays associated with prior art serially disposed latches (33) are eliminated.
摘要:
This invention relates generally to the accessing of random access access memory arrays and, more specifically to circuits and techniques for increasing the data valid time of such memory arrays without increasing either the access or cycle times of the array. This is accomplished by providing, during a read cycle, a read signal directly to an output driver (32) and simultaneously providing, via a parallel path, a latch output to the same driver (32). The latch output is provided under control of the read signal and a returning portion of a clock pulse such that the latch output overlaps the direct read signal from a sense/read amplifier (31). An output is provided from the latch (33) until it is reset and may last well into the next read cycle even when a new read signal is present. The technique utilized, in addition to providing a longer data valid time, eliminates a response of the latch (33) to spurious read signals because a latch output is not provided until the clock is deactivated and such spurious read signals are not present during the returning portion of the clock cycle. The approach utilized also has the advantage that delays associated with prior art serially disposed latches (33) are eliminated.