Andrew Y Kim

Title: The Innovations of Andrew Y Kim

Introduction

Andrew Y Kim is a notable inventor based in Hayward, CA, who has made significant contributions to the field of semiconductor technology. With a total of 3 patents to his name, Kim's work primarily focuses on improving the performance of III-nitride light emitting devices.

Latest Patents

One of Kim's latest patents is titled "Indium gallium nitride smoothing structures for III-nitride devices." This invention involves a smoothing structure containing indium, which is formed between the substrate and the active region of a III-nitride light emitting device. The purpose of this structure is to enhance the surface characteristics of the device layers. In some embodiments, the smoothing structure is a single layer, separated from the active region by a spacer layer that typically does not contain indium. The smoothing layer has a composition of indium lower than that of the active region and is usually deposited at a higher temperature. The spacer layer is deposited while reducing the temperature in the reactor from the smoothing layer deposition temperature to that of the active region. In other embodiments, a graded smoothing region is utilized to further improve surface characteristics.

Another significant patent by Kim is focused on "III-Nitride light emitting devices with low driving voltage." This invention provides III-Nitride light emitting diodes that exhibit improved performance. In one embodiment, the light emitting device includes a substrate, a nucleation layer on the substrate, a defect reduction structure above the nucleation layer, and an n-type III-Nitride semiconductor layer above the defect reduction structure. The n-type layer has a thickness greater than about one micron and a silicon dopant concentration of at least about 10 cm. In another embodiment, the active region of the III-Nitride semiconductor includes at least one barrier layer that is either uniformly doped with an impurity or doped with an impurity having a concentration graded in a direction substantially perpendicular to the active region.

Career Highlights

Andrew Y Kim is currently employed at Lumileds Lighting U.S., LLC, where he continues to innovate in the field of lighting technology. His work has been instrumental in advancing the capabilities of light emitting devices, making them more efficient and effective.

Collaborations

Throughout his career, Kim has collaborated with notable colleagues such as Werner K Goetz and Nathan Fredrick Gardner. These collaborations have