Active LED module with LED and transistor formed on same substrate

摘要

An LED module is disclosed containing an integrated driver transistor (e.g, a MOSFET) in series with an LED. In one embodiment, LED layers are grown over a substrate. The transistor regions are formed over the same substrate. After the LED layers, such as GaN layers, are grown to form the LED portion, a central area of the LED is etched away to expose a semiconductor surface in which the transistor regions are formed. A conductor connects the transistor in series with the LED. Another node of the transistor is electrically coupled to an electrode on the bottom surface of the substrate. In one embodiment, an anode of the LED is connected to one terminal of the module, one current carrying node of the transistor is connected to a second terminal of the module, and the control terminal of the transistor is connected to a third terminal of the module.

主权项

1. A lighting device comprising:
a first growth layer having a top surface and a bottom surface; a light emitting diode (LED) having at least a first LED layer of a first conductivity type and a second LED layer of a second conductivity type, the first LED layer and the second LED layer being epitaxially grown over the top surface of the first growth layer, wherein the LED is formed to have a central opening; and a first transistor formed over or in the top surface of the first growth layer, the first transistor comprising a first current carrying node, a second current carrying node, and a control node, wherein the first transistor is at least partially formed in the opening in the LED such that the LED surrounds the first transistor and emits light in an area surrounding the first transistor when the first transistor is turned on, wherein the first current carrying node is electrically coupled to the first LED layer with a metal layer formed over the first growth layer, and wherein the second current carrying node is electrically coupled to a bottom electrode formed on the bottom surface of the first growth layer, such that the first transistor is connected in series with the LED and the LED is turned on by a sufficient forward current flowing between the bottom electrode and the second LED layer when the first transistor is turned on.