FLIP-CHIP LIGHT-EMITTING DEVICE WITH MICRO-REFLECTOR
A Flip-chip light-emitting device with integral micro-reflector. The flip-chip light-emitting device emits reflected light provided by a light-emitting layer. The micro-reflector reflects light that might otherwise be lost to internal refraction and absorption, so as to increase light-emitting efficiency.
This application is a division of applicant's earlier application, Ser. No. 10/906,572, filed Feb. 24, 2005, the entirety of which is incorporated by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention provides a light-emitting device, and more particularly, a flip-chip light-emitting device with a micro-reflector.
2. Description of the Prior Art
The applications of light-emitting diodes include optical display devices, traffic signals, data storing devices, communication devices, illumination devices, and medical apparatuses, and are getting more extensive. Therefore it is important to increase the brightness of light-emitting diodes, and to simplify manufacturing processes in order to decrease the cost of the light-emitting diode.
Please refer to
The claimed invention provides a flip-chip light-emitting device with a micro-reflector. The micro-reflector includes a transparent patterned light-emitting stack layer, and a reflective layer formed over the transparent patterned light-emitting stack layer. The transparent patterned light-emitting stack layer and the transparent patterned layer may be formed into a variety of shapes, including semicircular, pyramidical, conical, and so on, and can be continuous or discontinuous. The transparent patterned light-emitting stack layer generated by means of etching on a light-emitting stack layer of the flip-chip light-emitting device, of evaporation deposition, or of a bonding method. The reflective layer is formed over the transparent patterned light-emitting stack layer by means of evaporation deposition, so that the reflective layer includes the specific shapes to form a micro-reflector. The micro-reflector reflects vertical light with incoming light provided by a light-emitting area, so that the normal incidence light is unaffected by the critical angle for improving light extraction.
The claimed invention provides another flip-chip light-emitting device with a micro-reflector. The micro-reflector includes a transparent patterned layer. The transparent patterned layer generated by means of etching on a semiconductor layer of the flip-chip light-emitting device, of evaporation deposition, or of a bonding method. Then the reflective layer is formed over the transparent patterned layer, so that the reflective layer includes the transparent patterned shapes to form a micro-reflector.
Briefly described, the claimed invention discloses a flip-chip light-emitting device with a micro-reflector. The flip-chip light-emitting device with a micro-reflector includes a substrate, a first semiconductor stack layer formed over the substrate with a first surface and a second surface, a light-emitting layer formed over the first surface, a second semiconductor stack layer formed over the light-emitting layer, a micro-reflector formed over the second semiconductor stack layer with a transparent patterned layer and a reflective layer forming over the transparent patterned layer, a first electrode formed over the micro-reflector, and a second electrode formed over the second surface.
The substrate comprises at least one material selected from a material group consisting of GaP, glass, SiC, GaN, ZnSe, and sapphire, or other substitute materials. The reflective layer comprises at least one material selected from a material group consisting of In, Sn, Al, Au, Pt, Zn, Ge, Ag, Ti, Pb, Pd, Cu, AuBe, AuGe, Ni, Cr, PbSn, AuZn, and indium tin oxide, or other substitute materials. The shape of the transparent patterned layer corresponds to at least one graph profile selected from a graph profile group consisting of semicircular, pyramidical, conical, or other substitute graph profiles. The first semiconductor stack layer comprises at least one material selected from a material group consisting of AlGalnP, AlInP, AlN, GaN, AlGaN, InGaN, and AlInGaN, or other substitute materials. The light-emitting layer comprises at least one material selected from a material group consisting of AlGalnP, GaN, InGaN, and AlInGaN, or other substitute materials. The second semiconductor stack layer comprises at least one material selected from a material group consisting of AlGaInP, AlInP, AlN, GaN, AlGaN, InGaN, and AlInGaN, or other substitute materials.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Please refer to
Please refer to
Please refer to
In the above-mentioned three embodiments, a transparent conductive layer can be formed between the second electrode and the reflective layer. The shape of the transparent patterned corresponds to at least one graph profile selected from a graph profile group consisting of semicirclular, pyramidical, and conical, or other substitute graph profiles. The transparent substrate includes at least one material selected from a material group consisting of GaP, glass, SiC, GaN, ZnSe, and sapphire, or other substitute materials. The reflective layer includes at least one material selected from a material group consisting of In, Sn, Al, Au, Pt, Zn, Ge, Ag, Ti, Pb, Pd, Cu, AuBe, AuGe, Ni, Cr, PbSn, AuZn, and indium tin oxide, or other substitute materials. The transparent conductive layer includes at least one material selected from a material group consisting of indium tin oxide, cadmium tin oxide, antimony tin oxide, zinc oxide, zinc tin oxide, Be/Au, Ge/Au, and Ni/Au, or other substitute materials. The first cladding layer includes at least one material selected from a material group consisting of AlGaInP, AlInP, AlN, GaN, AlGaN, InGaN, AlInGaN, and ZnSe, or other substitute materials. The light-emitting layer includes at least one material selected from a material group consisting of AlGaInP, GaN, InGaN, AlInGaN, and ZnSe, or other substitute materials. The second cladding layer includes at least one material selected from a material group consisting of AlGaInP, AlInP, AlN, GaN, AlGaN, InGaN, AlInGaN, and ZnSe, or other substitute materials. The second contact layer includes at least one material selected from a material group consisting of GaP, GaAs, GaAsP, InGaP, AlGaInP, AlGaAs, GaN, InGaN, AlGaN, and ZnSe, or other substitute materials. The first contact layer includes at least one material selected from a material group consisting of GaP, GaAs, GaAsP, InGaP, AlGaInP, AlGaAs, GaN, InGaN, AlGaN, and ZnSe, or other substitute materials. The insulating layer includes at least one material selected from a material group consisting of SiNx and SiO2, or other substitute materials.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims
1. A flip-chip light-emitting device with a micro-reflector comprising:
- a substrate;
- a first semiconductor stack layer formed over the substrate;
- a light-emitting layer formed over the first semiconductor stack layer;
- a second semiconductor stack layer formed over the light-emitting layer; and
- a micro-reflector formed over the second semiconductor stack layer comprising a transparent patterned layer and a reflective layer formed over the transparent patterned layer.
2. The flip-chip light-emitting device with a micro-reflector of claim 1 further comprising a transparent adhesive layer between the first semiconductor stack layer and the substrate.
3. The flip-chip light-emitting device with a micro-reflector of claim 2 further comprising a first reaction layer between the transparent adhesive layer and the substrate.
4. The flip-chip light-emitting device with a micro-reflector of claim 2 further comprising a second reaction layer between the transparent adhesive layer and the first semiconductor stack layer.
5. The flip-chip light-emitting device with a micro-reflector of claim 4 further comprising a transparent conductive layer between the second reaction layer and the first semiconductor stack layer.
6. The flip-chip light-emitting device with a micro-reflector of claim 2 further comprising a transparent conductive layer between the transparent adhesive layer and the first semiconductor stack layer.
7. The flip-chip light-emitting device with a micro-reflector of claim 1 wherein the shape of the transparent patterned layer corresponds to a graph profile selected from a graph profile group consisting of semicircular, pyramidical, and conical.
8. The flip-chip light-emitting device with a micro-reflector of claim 1 wherein the shape of the reflective layer corresponds to a graph profile selected from a graph profile group consisting of semicircular, pyramidical, and conical.
9. The flip-chip light-emitting device with a micro-reflector of claim 1 wherein the shape of the transparent patterned layer corresponds to a discontinuous distributed geometric graph profile.
10. The flip-chip light-emitting device with a micro-reflector of claim 1 wherein the reflective layer comprises a material selected from a material group consisting of Sn, Al, Au, Pt, Zn, Ag, Ti, Pb, Pd, Ge, Cu, AuBe, AuGe, Ni, PbSn, AuZn, and indium tin oxide.
11. The flip-chip light-emitting device with a micro-reflector of claim 1 wherein the substrate is connected to the micro-reflector by direct wafer bonding.
Type: Application
Filed: Aug 16, 2006
Publication Date: Dec 21, 2006
Inventor: Wen-Huang Liu (Hsinchu)
Application Number: 11/465,117
International Classification: H01L 33/00 (20060101);