The present invention relates to a light emitting diode and its fabricating method, especially to an AlGaInN light emitting diode and its fabricating method.
Since Light emitting diodes (LEDs) have the advantage of low production cost, simple structure, less consuming power, small size and easy installation, they are widely applied in light sources and display devices. In the market of blue-light light emitting diode, AlGaIhnN light emitting diodes gain more attentions then others.
Traditionally, an AlGaInN LED epitaxy structure is first formed on a substrate, and then a conductive substrate is bonded to the AlGaInN LED epitaxy structure by an adhesive layer. The substrate is removed subsequently. To obtain the AlGaInN LED epitaxy structure of high quality, the preferred material of the substrate is sapphire. Traditionally, the sapphire substrate may be removed from the AlGaInN LED structure by using a laser beam. The laser beam passes through the sapphire substrate, and decomposes the n-type semiconductor layer of the AlGaInN LED epitaxy structure, contacting the substrate, into Ga and N.sub.2. Then, Ga is melted by heat of a designated temperature, making the sapphire substrate easily removed from the AlGaInN LED epitaxy structure. During the removing step, the adhesive layer might be decomposed, if the laser beam ever illuminates the adhesive layer, making the conductive substrate separating from the AlGaInN LED epitaxy structure. This is a possible drawback.
Yoo et al. of U.S. Pat. No. 6,818,531, which disclosed a method for manufacturing vertical GaN LED, has overcome the drawback mentioned above. Referring to
In addition, as the laser beam is employed on the sapphire substrate, the increase of the strain between the adhesive layer 124 and the AlGaInN LED epitaxy structure 125 results in instability of the AlGaInN LED epitaxy structure, which also causes peeling between each layer of the epitaxy structure.
One aspect of the present invention is to provide a method of fabricating a light emitting diode. In the steps of removing the substrate, the transparent dielectric layer protects the light emitting diode epitaxy structure, and improves the adhesion of the conductive substrate and the light emitting diode epitaxy structure, so that the conductive substrate will not peel from the light emitting diode epitaxy structure.
Another aspect of the present invention is to provide a light emitting diode having a transparent dielectric layer on the sidewall of the light emitting diode epitaxy structure to protect the light emitting diode epitaxy structure, and to avoid peeling occurrence between each layer of the light emitting diode epitaxy structure.
Still another aspect of the present invention is to provide a light emitting diode having a transparent dielectric layer on the sidewall of the light emitting diode epitaxy structure to enhance the sidewall output of the light from the light emitting diode.
The method of fabricating a light emitting diode of the present invention comprises the following steps. A light emitting diode epitaxy structure is formed on a substrate. The light emitting diode epitaxy structure is then etched to form a recess. A transparent dielectric layer is formed in the recess, and then a conductive substrate is bonded to the light emitting diode epitaxy structure. The substrate is subsequently removed.
The light emitting diode of the present invention includes a conductive substrate, a light emitting diode epitaxy structure and a transparent dielectric layer. The light emitting diode epitaxy structure is on the conductive substrate, and the transparent dielectric layer is on the sidewall of the light emitting diode epitaxy structure.
Referring to
Referring to
The transparent dielectric material is then filled in the recess 207, as shown in
A conductive substrate 212 is next bonded to an upper surface of the LED epitaxy structure 201, as shown in
As shown in
Finally, the anode 214 is fabricated on the top of the LED epitaxy structure 201 and the cathode 216 is fabricated under the conductive substrate 212, respectively, and then the transparent dielectric layer 208 is cut by a conventional cutting step to form a final structure of the LED 20, as shown in
The LED 20, shown in
By means of the detailed descriptions of what is presently considered to be the most practical and preferred embodiments of the subject invention, it is the expectation that the features and the gist thereof are plainly revealed. Nevertheless, these above-mentioned illustrations are not intended to be construed in a limiting sense. Instead, it should be well understood that any analogous variation and equivalent arrangement is supposed to be covered within the spirit and scope to be protected and that the interpretation of the scope of the subject invention would therefore as much broadly as it could apply.
Number | Date | Country | Kind |
---|---|---|---|
94101801 A | Jan 2005 | TW | national |
This application is a divisional of U.S. application Ser. No. 11/109,345, filed Apr. 19, 2005, which claims the right of priority based on Taiwan Patent Application No. 094101801 filed on Jan. 21, 2005.
Number | Name | Date | Kind |
---|---|---|---|
6818531 | Yoo et al. | Nov 2004 | B1 |
6878563 | Bader et al. | Apr 2005 | B2 |
7459373 | Yoo | Dec 2008 | B2 |
20040115849 | Iwafuchi et al. | Jun 2004 | A1 |
20040248377 | Yoo et al. | Dec 2004 | A1 |
20050151136 | Liu | Jul 2005 | A1 |
20060099730 | Lee et al. | May 2006 | A1 |
20060154390 | Tran et al. | Jul 2006 | A1 |
Number | Date | Country | |
---|---|---|---|
20100279443 A1 | Nov 2010 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 11109345 | Apr 2005 | US |
Child | 12833648 | US |