A method is described for planarizing isolated regions (12) and active regions (22) of a semiconductor wafer (10). Semiconductor wafer (10) is provided with islands of dielectric (12) that cover portions of the semiconductor wafer (10), while leaving other portions of the semiconductor wafer (10) exposed. The dielectric islands (12) have a polysilicon layer (13) that covers the dielectric islands' (12) top surface. A blanket layer of silicon is deposited on the polysilicon layer (13) that covers...

A substantially planar dielectric wafer is formed by utilizing a polysilicon filler to remove surface irregularities (15, 15'). The polysilicon filler is formed by filling surface irregularities (15, 15') with polysilicon (19) and polishing the polysilicon (19) to form a substantially planar surface. A polishing stop (18) terminates the polishing and prevents damage to the wafer's isolated tubs (13). The polishing stop (18) can also be used as a mask during field oxide growth. The polysilicon fi...

Optical isolation means electrically isolates the electrical network ground of a logical contention bus from a transmitter coupled to the bus and having a local logic ground and a receiver coupled to the bus and having a remote logic ground. Optical isolation means may comprise a light source, such as a light emitting diode, and a light sensitive receiver optically coupled to and electrically isolated from the light source.

A process for making complementary transistor devices in an epitaxial layer of a first conductivity type having a deep vertical isolation sidewall between the N and P channel transistors by providing a backfilled cavity in the epitaxial layer, the sidewalls of the cavity being coated with layers of material, the first layer being a silicate doped with the same conductivity type as the epitaxial layer in contact with the epitaxial layer and overcoated with an isolation and diffusion barrier layer...

An apparatus for calibrating a force measuring instrument of the type that includes a force sensitive element submerged in a liquid. The apparatus comprises a magnetic object having a known weight when submerged in the liquid, and an electromagnet. The electromagnet includes a core having a first end that extends beneath the surface of the liquid to a position near the upper surface of the force sensitive element. The electromagnet further includes a coil surrounding a portion of the core, means...

An apparatus for controllably actuating an electrical device in response to movement of a control member is useful, for example, in an industrial vehicle, including a chassis, a power supply electrically isolated from the chassis, and a steering assembly having a rotatably connected steering wheel. The subject apparatus includes a control member mounted on and rotatable with the steering wheel. An excitation circuit is provided for supplying a predetermined excitation signal to a receiving circu...

The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surfaces. This photodetector includes an absorptive region, a first region overlying the absorptive region and having a higher concentration zone and a surrounding peripheral zone and a second region overlying the first region. The high electric field in the avalanche region is then restricted to the higher conductivity central zone thereby reducing the electri...

A portable television camera comprises a relatively small housing including a solid-state imager for generating image-representative signals, and signal processing circuitry coupled to the imager for generating a video signal from the image representative signals. The noise performance of the solid-state imager is degraded by a temperature rise within the small housing caused by the heat generated from the signal processing circuitry. A thermal isolation is used for dividing the housing into a f...

The use of pulse width modulation rather than analog excitation to control the resistance of a light emitting diode--photoresistor pair is described. In particular, for two LED/LDR opto-isolators in a totem pole configuration, the duty cycle of the first opto-isolator is arranged to equal 1 minus the duty cycle of the second opto-isolator. Thus, both opto-isolators are always active resulting in the ratiometric output being proportional to the duty cycle, and the output impedance being constant.

A circuit arrangement is provided for a command source directing operation of a subsequent circuit. This command source circuit, based on using cross-coupled transistors, is electrically isolated from the subsequent circuit when no commands are being generated, and provides an output of constant polarity for input command signals of either constant or varying polarity.