Finisar Corporation

Actel Corporation, Inc.

Linda Liu

Wenn-Jei Chen

Yeouchung Yen

Huan-Chung Tseng

Chris Togami

Darin James Douma

Philip D Shapiro

John Christian Moller

Tom Downey

A shield device for preventing the emission of electromagnetic interference ('EMI') from an optoelectronic device, such as an optical transceiver, is disclosed. In particular, an EMI shield is disclosed for placement within an optical transceiver module in order to intercept and absorb EMI produced by electronic components included within the transceiver. This absorption by the EMI shield prevents EMI from escaping the optical transceiver module and interfering with other electronic components that are typically placed in close proximity to the transceiver. The EMI shield in one embodiment includes a sheet of EMI absorbing material that is sized for placement within the transceiver. The EMI shield can be interposed between an outer shell of the transceiver and electronic components located on a printed circuit board that is disposed within the transceiver. The proximity of the EMI shield to the EMI-producing electronic components maximizes EMI absorption by the shield.

Internal EMI shield for an optoelectronic module

The method and apparatus for monitoring a photo-detector generates a highly compliant mirror current across a broad range of photo-detector current levels. The apparatus for monitoring includes: a pair of bipolar transistors and a first non-linear isolation element. The pair of transistors are connected in a mirror configuration with a sense transistor one of the pair of transistors sensing a photo-detector current and with a mirror transistor one of the pair of transistors mirroring the photo-detector current with a mirror current. The first non-linear isolation element has at least two terminals a first of which couples to the collector of the mirror transistor. The first non-linear isolation element exhibits a non-linear voltage drop between the at least two terminals in response to varying levels of the mirror current to improve compliance between the mirror current and the detector current. Methods and means for monitoring a photo-detector are also disclosed.

Method and apparatus for monitoring a photo-detector in an optical transceiver

The present invention is directed to providing an electrostatic discharge ('ESD') protection cell for use in an integrated circuit device including antifuses. The ESD protection cell is formed simultaneously with the antifuses that it protects and provides protection from ESD during the fabrication of the antifuses. The concept is to use thin undoped or doped polysilicon on top of antifuse material as a block etching mask for the formation of the ESD protection cells by using common etching techniques. This polysilicon mask is placed where the antifuses will be and not where the ESD protection cells will be. The polysilicon mask is then merged with a top polysilicon electrode during later processing. During the block etching process, the antifuse material layer is compromised in the region about the ESD protection cells. Where the antifuse material layer is an O--N--O sandwich, the top oxide and nitride layers may be etching during the block etching process leaving the thin bottom oxide layer and some or no residual bottom oxide of the ONO composite antifuse material layer for forming the ESD protection cell. Since etching into the bottom oxide of the ONO composite antifuse material layer will not degrade, but will enhance the ESD protection capability of the ESD protection cell, it is perfectly acceptable to also etch the bottom oxide layer as well as long as proper process control is allowed. The ESD protection cell may be used with antifuses having diffusion or polysilicon type bottom electrodes and polysilicon top electrodes. An advantage of this structure is its ability to be fabricated at high temperature for improved film characteristics and reliability.

Method for forming an ESD protection device for antifuses with top

ESD protection device for antifuses with top polysilicon electrode

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San Jose, CA, United States of America

Linda Liu