Light-emitting diode with an electrically conductive window

US5008718A · kind A · utility

Inventors

• Robert M. Fletcher · San Jose, US
• Chihping Kuo · Milpitas, US
• Timothy D. Osentowski · San Jose, US
• Virginia Robbins · Los Gatos, US

Key dates

• Filing date: Dec 18, 1989
• Grant date: Apr 16, 1991
• Expiry date: Dec 18, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/013

Abstract

A light-emitting diode has a semiconductor substrate underlying active p-n junction layers of AlGaInP for emitting light. A transparent window layer of semiconductor different from AlGaInP overlies the active layers and has a lower electrical resistivity than the active layers and a bandgap greater than the bandgap of the active layers, for minimizing current crowding from a metal electrical contact over the transparent window layer. The active layers may be epitaxially grown on a temporary GaAs substrate. A layer of lattice mismatched GaP is then grown on the active layers with the GaP having a bandgap greater than the bandgap of the active layers so that it is transparent to light emitted by the LED. The GaAs temporary substrate is then selectively etched away so that the GaP acts as a transparent substrate. A transparent window layer may be epitaxially grown over the active layers on the face previously adjacent to the GaAs substrate.