Distribution of current blocking layer, LED corresponding to the upper electrode and preparation thereof

Abstract

The invention relates to the distribution of a current barrier layer, a light-emitting diode which is corresponding to an upper electrode and a process for preparation, belonging to the technical field of semiconductor photoelectrons. The structure comprises an upper electrode (10), a current spreading layer (100), an upper limiting layer (300), an active region (200), a lower limiting layer (400), a buffer layer (500), an under-layer (600) and a lower electrode (20), and further comprises a current barrier layer (120) located on the right lower portion of the upper electrode, wherein the distribution of the current barrier layer is corresponding to the upper electrode, a conductive light anti-reflection layer (101) is arranged between the upper electrode and the current spreading layer inside the conductive light anti-reflection layer or the current spreading layer or the upper limiting layer or the active region, or inside adjacent two layers, three layers or four layers, wherein the current barrier layer is realized through the post techniques. The current barrier layer corresponding to the upper electrode nearly completely avoids light and heat loss generated by idle current, thereby increasing the light extraction efficiency of the LED, and increasing the light emitting intensity, and the structure reduces the generation of heat, which is especially suitable for the preparation of large-power LEDs.

Description

technical field [0001] The light-emitting diode with the distribution of the current blocking layer corresponding to the upper electrode and the preparation method thereof relate to a novel LED device structure and belong to the technical field of semiconductor optoelectronics. Background technique [0002] At present, the structure of ordinary light-emitting diodes such as figure 1 Shown: the upper electrode 10 has a diameter of 80-100 μm and a thickness of about Above the circular metal layer, current is injected from the electrode, and the photons generated are emitted from this side of the LED; the lower electrode 20 is the size of the entire surface of the LED device, with a thickness of about Above the metal layer, the main problem of the LED with this structure is: the current injected from the upper electrode 10 passes through the lateral expansion of the current spreading layer 100 and flows through the active region 200 to radiate and recombine to generate photo...

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Problems solved by technology

[0002] At present, the structure of ordinary light-emitting diodes such as figure 1 Shown: the upper electrode 10 has a diameter of 80-100 μm and a thickness of about Above the circular metal layer, current is injected from the electrode, and the photons generated are emitted from this side of the LED; the lower electrode 20 is the size of the entire surface of the LED device, with a thickness of about Above the metal layer, the main problem of the LED with this structure is: the current injected from the upper electrode 10 passes through the lateral expansion of the current spreading layer 100 and flows through the active region 200 to radiate and recombine to generate photons. Because the current epitaxial growth technology is difficult Obtaining a highly doped and thick current spreading layer results in a weak lateral current spreading ability of the current spreading layer. Therefore, most of the current injected from the upper electrode 10 is collected directly below the upper electrode 10, for example: for the front For an AlGaInP-based red LED with a chip size of 300 μm*300 μm, an 8 μm GaP current spreading layer is epitaxially grown by MOCVD (Metal Organic Chemical Vapor Deposition). If the diameter of the upper electrode 10 is 100 μm, it can be known by calculation that: The current accounts for more than 40% of the total injected current

Part of the current will still be collected directly under the upper electrode 10, even greater than the current collected under the bonding pad (see the ratio of the area of ​​the graphic electrode to the area of ​​the bonding pad), and the photons generated by this part of the current in the active region 200 will still be absorbed The blocking or absorption of the electrode 10 turns into a large amount of heat, resulting in problems such as low light efficiency, low brightness, and poor thermal characteristics of the device.

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