Lucent Technologies Inc.

Agere Systems Inc.

Chia C Chang

Robert Eugene Frahm

Orval George Lorimor

Dennis Ronald Zolnowski

Keon M Lee

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

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.

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Berkeley Heights, NJ, United States of America

Chia C Chang