Skyworks Solutions, Inc.

Cosemi Technologies, Inc.

Charles F Krumm

Nguyen X Nguyen

Richard S Burton

Kyushik Hong

Debora L Green

Noureddine Matine

A vertical cavity surface emitting laser (VCSEL) is disclosed that has a relatively low vertical resistance between the Ohmic contact to the upper distributed Bragg reflector (DBR) and the active layer, and a structure to substantially confine the current flow to the laser cavity so that the VCSEL can produce a more efficient and substantially single-mode output. In particular, the VCSEL includes a substrate, a lower DBR disposed over the substrate, an active layer disposed over the lower DBR, and an upper DBR. The upper DBR includes a groove and an Ohmic contact situated within the groove to lower the vertical resistance between the contact and the active layer. An ion implanted layer is also formed along the side wall of the active layer to substantially confine the current flow to the laser cavity.

Vertical cavity surface emitting laser (VCSEL) and related method

According to one exemplary embodiment, a heterojunction bipolar transistor comprises an emitter. The heterojunction bipolar transistor further comprises a first emitter cap comprising a first high-doped layer, a low-doped layer, and a second high-doped layer, where the first high-doped layer is situated on the emitter, the low-doped layer is situated on the first high-doped layer, and the second high-doped layer is situated on the low-doped layer. The first high-doped layer, the low-doped layer, and the second high-doped layer form an emitter ballast resistor. According to this exemplary embodiment, the low-doped layer has a thickness and a dopant concentration level such that the resistance of the low-doped layer is substantially independent of the dopant concentration level, but corresponds to the thickness of the low-doped layer.

Structure and method in an HBT for an emitter ballast resistor with improved characteristics

Growing community of inventors

Newport Coast, CA, United States of America

Charles F Krumm