Lucent Technologies Inc.

Agere Systems Inc.

Bell Telephone Laboratories

Orval George Lorimor

Robert Eugene Frahm

Dennis Ronald Zolnowski

Keon M Lee

Chia C Chang

Adrian R Hartman

Philip J Anthony

Dirk Joachim Muehlner

Mahmoud A El Hamamsy

Gee-Kung Chang

Wilbur Dexter Johnston, Jr

An improved PIN photodiode provides enhanced linearity by confining the light absorption region of the diode wholly within the depletion region. The photodiode exhibits improved linearity over prior art designs because the thickness of the absorption region is no longer a function of changes in the size of the depletion region during device operation. Keeping the absorption region wholly within the depletion region ensures that the charge carriers generated by incident illumination will increase the conductivity of the semiconductor material.

Linear pin photodiode

A PIN photodiode comprising a p region containing a p type dopant, an n region containing an n type dopant, an i region positioned intermediate the p region and the n region, and a relatively thick, undoped buffer region positioned between the n region and the i region which substantially decreases the capacitance of the PIN photodiode such that the photodiode bandwidth is maximized. Typically, the buffer region is formed as a layer of indium phosphide that is at least approximately 0.5 &mgr;m in thickness.

Pin photodiode having a wide bandwidth

Linear PIN photodiode

The invention is a photodetector device and a lightguide circuit incorporating the device. The photodetector device includes a semiconductor region for absorbing light which is incident on an edge surface of the device. The region above the absorbing region is narrow at the edge and fans out in the direction of light propagation in the device.

Edge receptive photodetector devices

An apparatus may be used to deposit metal or conductive layers upon semiconductor wafers using an electrochemical process. The apparatus comprises a housing for retaining a first electrode (e.g., anode) and a second electrode (e.g., cathode), in a fixed spaced-apart relation to each other, with the surface area of the anode exceeding the surface area of the cathode (the wafer). The back surface of the wafer is mounted on a handling disk; the disk has an aperture for accessing the wafer and is held in the housing. A contact probe passes through the aperture to touch the back surface of the wafer, the probe having a spring-loaded spherical radius head for depressurizing the head as it touches the wafer. This apparatus permits a uniform current distribution as the contact probe is not interposed between the electrodes, and the larger surface area of the anode relative to the wafer enhances the production of uniform and reproducible films. The housing may be comprised of at least two separable parts so that access may be readily gained to the inner cavity of the housing, thus enhancing the ease with which the device may be used. The handling disk as well as the spring-loaded probe head reduce the risk of wafer damage.

Electrodeposition apparatus for coating wafers

An optically toggled bidirectional normally-on switch is provided with protection against bilateral voltage and bidirectional current surges by the inclusion of a pair of oppositely poled thyristors. One version uses a large junction-type field-effect transistor in its main path and a pair of smaller junction-type transistors in the subsidiary path. A photodiode array controls the gate voltage on each of the transistors and turns them off when illuminated. A control node in the subsidiary path is connected to the gates of the SCRs so that excess current in this path turns on the appropriately-poled thyristor to provide an additional shunt path for the current.

Optically toggled bidirectional switch

Growing community of inventors

Warren, NJ, United States of America

Orval George Lorimor