Light emitting device with bonded interface
View Patent ↗In some embodiments of the invention, a transparent substrate AlInGaP device includes an etch stop layer that may be less absorbing than a conventional etch stop layer. In some embodiments of the invention, a transparent substrate AlInGaP device includes a bonded interface that may be configured to give a lower forward voltage than a conventional bonded interface. Reducing the absorption and/or the forward voltage in a device may improve the efficiency of the device.
1. A device comprising:
a first semiconductor structure that includes:
an AlGaInP etch stop layer, having a thickness of less than 800 Å, that forms a first semiconductor surface of the first semiconductor structure;
an AlGaInP light emitting layer disposed between an n-type region and a p-type region, a bandgap of the AlGaInP etch stop layer being at least as large as a bandgap of the AlGaInP light emitting layer; and
a window layer through which light emitted by the light emitting layer is emitted from the device, the light emitting layer being disposed between the etch stop layer and the window layer; and
a second semiconductor structure that includes a second semiconductor surface that is directly bonded to the first semiconductor surface.
2. The device of claim 1 , wherein the etch stop layer comprises (Al x Ga 1−x ) y In 1−y P; where x is not greater than 0.3, and y is at least 0.5.
3. The device of claim 1 , wherein the etch stop layer comprises (Al x Ga 1−x ) y In 1−y P; where x is not greater than 0.4, and y is at least 0.55.
4. The device of claim 1 , wherein a thickness of the etch stop layer is less than 250 Å.
5. The device of claim 1 , wherein the second semiconductor structure comprises a transparent GaP layer at least 10μm thick.
6. The device of claim 1 , wherein the etch stop layer is formed from a material that stops an etchant that etches GaAs.