Vertical LED with conductive vias

US8212273B2 · kind B2 · utility

Assignee

• PHOTONSTAR LED LIMITED · GB

Inventors

• James Stuart McKenzie · Romsey, GB
• Majd Zoorob · Southampton, GB

Key dates

• Filing date: Jul 18, 2008
• Grant date: Jul 3, 2012
• Expiry date: Apr 13, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/872

Abstract

A light emitting device comprises a novel low-loss array of conductive vias embedded in a dielectric multilayer stack, to act as an electrically-conductive, low-loss, high-reflectivity reflector layer (CVMR). In one example the CVMR stack is employed between a reflective metal bottom contact and a p-GaN semiconductor flip chip layer. The CVMR stack comprises at least (3) layers with at least (2) differing dielectric constants. The conductive vias are arranged such that localized and propagating surface plasmons associated with the structure reside within the electromagnetic stopband of the CVMR stack, which in turn inhibits trapped LED modes coupling into these plasmonic modes, thereby increasing the overall reflectivity of the CVM R. This technique improves optical light extraction and provides a vertical conduction path for optimal current spreading in a semiconductor light emitting device. A light emitting module and method of manufacture are also described.