Light-emitting semiconductor device of improved efficiency
US7498609B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 2005 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Jul 6, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/84
Abstract
An LED comprises a semiconductor region including an active layer for generating light. An anode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflective metal layer is bonded to the other major surface of the light-generating semiconductor region via an ohmic contact layer. Sufficiently thin to permit the passage of light therethrough, the ohmic contact layer is formed in an open-worked pattern to leave exposed part of the second major surface of the semiconductor region. A transparent, open-worked anti-alloying layer is interposed between the light-generating semiconductor region and the reflective metal layer, covering that part of the second major surface of the light-generating semiconductor region which is left exposed by the ohmic contact layer. The anti-alloying layer prevents the light-generating semiconductor region and reflective metal layer from alloying during heat treatments conducted in the curse of LED manufacture. A greater percentage of the light from the light-generating semiconductor region is reflected by the reflective metal layer for emission from the first major surface of the light…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.