Abstract: A current limiter (15) is formed between a silicon substrate (10) and a source region (17) by a channel implant region (20). The channel implant region (20) is not modulated by a gate structure so the maximum voltage that can flow between the silicon substrate (10) and the source region (17) is determined by the doping profile of the ever-present channel implant region (20). A pinch-off structure (12) is used to form a depletion region which can support a large voltage potential between the silicon substrate (10) and the source region (17). In an alternate embodiment, a bipolar device is formed such that a limited current flow can be directed into a base region (32) which is used to modulate a current flow between silicon substrate (30) and an emitter region (38). Using the current limiters (15,35) it is possible to form an AC current limiter (50) that will limit the current flow regardless of the polarity of the voltage placed across two terminals (51,52).

Abstract: A method for fabricating semiconductor substrates with resistivity below 0.02 ohm-cm is provided. This low resistivity is achieved by doping a silicon melt with a phosphorus concentrations above 1.times.10.sup.18. The silicon melt is also doped with a germanium concentration that is 1.5 to 2.5 times that of the phosphorus concentration and a stress and dislocation free crystalline boule is grown. Phosphorus in high concentrations will induce stress in the crystal lattice due to the difference in the atomic radius of silicon atoms versus phosphorus atoms. Germanium compensates for the atomic radius mismatch and also retards the diffusion of the phosphorus as the diffusion coefficient remains relatively constant with a doping of 1.times.10.sup.18 to 1.times.10.sup.21 atoms per cm.sup.3. This will retard phosphorus from diffusing into an overlying epitaxial layer and retard other layers formed on the substrate from being auto-doped.

Abstract: A light sensitive semiconductor device (10) is formed in a well region (12) in a semiconductor substrate (11). A first voltage (30) is applied to a source region (4) of the semiconductor device (10) and to a contact region (13) to the well region (12) to attract holes. A second voltage (31) is applied to the source region (14) and a drain region (16) to provide a current flow. As photons (23) from a light source are absorbed by semiconductor device (10), the source to drain current is decreased.

Abstract: A semiconductor device (10) is formed in a semiconductor substrate (11) that acts as a collector region. A base region (12) is formed in the semiconductor substrate (11) and an emitter region (52) is formed such that it contacts at least a portion of the base region (12). A conductive layer (28) is used to provide electrical connection to the emitter region (52). The portion of the conductive layer (28) above the emitter region (52) is counter-doped to address the problems of an interfacial oxide layer (27) that exists between the emitter region (52) and the conductive layer (28).

Abstract: A method for forming a self-aligned semiconductor device (10) having sidewall spacers (16,17) used to align the formation of a source region (23) and a drain region (24) along with the formation of a gate structure (35). Spacers (16,17) can be formed using a sacrificial structure process where a sacrificial structure (14) is formed which determines the location of a final gate structure (35). The deposition of a dielectric layer over the sacrificial structure (14) and subsequent etch will form spacers (16,17). A second method for forming spacers (18,19), uses a photolithographic process to pattern a dielectric layer without the use of a sacrificial structure process. The spacers (16,17) are used in conjunction with implant mask regions (22) to form the source and drain regions (23,24) which are aligned to the gate structure (35).

Abstract: A telephone apparatus for connection to central office equipment to receive a caller ID signal therefrom and having an operating mode in which line current is less than a threshold at which off-hook state is detected, the line current drawn in said mode being sufficient to allow reception and processing of the caller ID signal. In this way, the telephone apparatus can receive and process the caller ID signal, and so can determine whether the call can be accepted, without the central office equipment recognizing the apparatus as having gone off-hook (i.e. having already accepted the call).

Abstract: A transition control circuit (2) for controlling the transitions of an output signal, at an output node (8) of a driver circuit, in dependence on the logic state of an input signal at an input node (10). The output signal being switchable between a first logic state and a second logic state. The transition control circuit (2) comprises first means (16) and second means (14). The first means (16) is enabled when the output signal has the first logic state and the input signal has the second logic state, and is disabled when the output signal has the second logic state or the input signal has the first logic state. Once enabled, the first means (16) couples the output node (8) to a first supply line (GNDA) whereby the output signal switches to the second logic state. The second means (14) is enabled when the output signal has the second logic state and the input signal has the second logic state, and is disabled when the output signal has the first logic state or the input signal has the first logic state.

Abstract: A history buffer system (12) for allowing the recovery of executed instructions comprises main history buffer (14) for storing addresses of issued instructions and at least one subsidiary history buffer (16, 22) associated with a predetermined type of data, such as fixed or floating point data. The subsidiary history buffer (16, 22) has a plurality of entries (Y, Z), each entry for storing a pointer to a register (18, 26) and the data stored in the register. The main history buffer (14) is arranged to store control data (fxtag, fptag) which associates the entries in a subsidiary history buffer with the appropriate issued instructions of the same data type stored in the main history buffer. The main history buffer (14) may comprise a storage entry for each issued instruction, each storage entry having a field for storing the address of an issued instruction, and at least one tag field (fxtag, fptag) corresponding to the at least one subsidiary history buffer (16, 22) for storing the control data.

Abstract: A IV--IV semiconductor device having a narrowed bandgap characteristic compared to silicon and method is provided. By incorporating carbon into silicon at a substitutional concentration of between 0.5% and 1.1%, a semiconductor device having a narrowed bandgap compared to silicon and good crystalline quality is achieved. The semiconductor device is suitable for semiconductor heterojunction devices that use narrowed bandgap regions.

Abstract: In an apparatus for depositing flux onto a solder work surface, a chamber having a plurality of openings therein is heated by means of a U-shaped current conducting heating element within which the flux chamber resides. This heating element heats the flux within the chamber until it vaporizes and is forced from the chamber through the openings onto the solder work surface.

Abstract: In a selective call receiver, an apparatus and method are provided for accessing one or more operational functions via a plurality of displayed function indicators. The function indicators are categorized in sets with a first set representing a selective call receiver status mode that allows alteration of operating characteristics associated with a selective call receiver, and a second set representing a message read mode for controlling the disposition of received messages.

Abstract: A volume control circuit for an audio transducer comprises a driver circuit driven by a first pulse rate signal to excite the audio transducer and render an audio signal at a desired volume and audio frequency corresponding to the first pulse rate signal, and a control circuit selectively activated to pulse modulate the excitation of the audio transducer during its pulsed excitation periods to alter the volume of the audio signal rendered by the audio transducer. In one embodiment, the control circuit includes a logical AND gate having as one input the first pulse rate signal and as another input a selected signal of either a second pulse rate signal or a signal representative of a logical one, the AND gate selectively activated to pulse rate modulate the first pulse rate signal with the second pulse rate signal which is preferably ultrasonic.

Abstract: A selective call communication system (300), operates to transmit an information signal (501) from a message origination site (305) to a plurality of transmitting sites (310, 311, 312). The transmitting sites (310, 311, 312), in turn, transmit and re-transmit the information signal (504) received from the message origination site (305).

Abstract: A selective call receiver 10 requires an access authorization code prior to presenting selected messages and to override a lockout mode.

Abstract: A selective call receiver comprises circuitry for receiving a first signal having a first address and a first information format, and a second signal having a second address and a second information format; and a device for presenting a message comprising the first and second information formats. The information formats may comprise any of, for example, numeric, alphanumeric, and graphic displays and a voice output.

Abstract: An adaptive battery saving controller for a battery powered communication receiver utilizes a signal quality detector for detecting strong signal and weak signal conditions. During strong signal conditions, the adaptive battery saving controller is capable of suspending the supply of power to the receiver during the reception of message code words not intended for the communication receiver. The adaptive battery saving controller is also capable of suspending the supply of power to the receiver following the detection of a hard address error. During weak signal conditions, the adaptive battery saving controller reverts to conventional battery saving techniques.

Abstract: A paging terminal for transmitting address and variable length message signals to a plurality of remotely located acknowledge back and non-acknowledge back pagers, each having a unique address, includes an input for accepting variable length messages to be sent to a group of M pagers within the plurality of pagers, wherein M is an integer number. A controller orders the acknowledge back pager addresses for transmisison prior to the transmission of addresses for the non-acknowledge back pagers. A transmitter sequentially transmits the ordered addresses corresponding to the group of M pagers as an address batch during a first time period, and sequentially transmits the variable length messages for the group of pagers in a message batch including end of message markers delimiting an associated variable length message during a second time period subsequent to the first time period.

Abstract: In a selective call radio paging device, a plurality of alerts are generated in response to the decoding of a message having an address corresponding to the address assigned to the pager. A specific alert envelope waveform is generated and drives an alerting device of a first type (e.g., a transducer). Inverting means is provided to invert the envelope and cause a second alerting device (e.g., visual) to be activated in a manner complementary to the first. Thus, alerting devices are not operated concurrently, and peak loads on a resident power source are avoided.