CN202217701U

CN202217701U - High-power GaN-based LED (Light Emitting Diode) structure

Info

Publication number: CN202217701U
Application number: CN2011202680321U
Authority: CN
Inventors: 吴东海; 李志翔
Original assignee: NANTONG TONGFANG SEMICONDUCTOR CO Ltd
Current assignee: NANTONG TONGFANG SEMICONDUCTOR CO Ltd
Priority date: 2011-07-27
Filing date: 2011-07-27
Publication date: 2012-05-09
Anticipated expiration: 2021-07-27

Abstract

The utility model relates to a high-power GaN-based LED (Light Emitting Diode) structure, relating to the field of photoelectric technology. The high-power GaN-based LED structure comprises a substrate, and an N-type gallium nitride layer, an active luminous layer and a P-type gallium nitride layer which sequentially grow on the substrate in a way of extending outwards, wherein a transparent conducting layer is arranged above the P-type gallium nitride layer; one end of the transparent conducting layer is provided with a P-type electrode; and an N-type electrode is arranged on the N-type gallium nitride layer at the other end opposite to the P-type electrode. The high-power GaN-based LED structure is structurally characterized in that the transparent conducting layer is divided into a plurality of conducting layer blocks with small area, and all the conducting layer blocks are connected with one another by metal electrodes and are connected to the P-type electrode. Compared with the prior art, the high-power GaN-based LED structure effectively improves the current injection efficiency under the condition that high current is injected, so that the luminous efficiency and the reliability of an LED device can be improved.

Description

A kind of high-power GaN based light-emitting diode structure

Technical field

The utility model relates to field of photoelectric technology, particularly high-power GaN based light-emitting diode structure.

Background technology

Luminescent device based on semiconductor material with wide forbidden band is the emphasis of Semiconductor Optic Electronics area research and exploitation always.Be succeeding in developing of representative blue-green light-emitting diode particularly, make light-emitting diode can realize that full color is luminous, and progressively march toward the white-light illuminating epoch with the III-V group nitride material.Light-emitting diode is owing to have low energy consumption, long-life, in light weight, advantage such as volume is little, has been widely used at present that signal demonstrations, display backlight source, traffic signals are indicated, fields such as outdoor advertising display screen and Landscape Lighting.But from present actual conditions; Still there are the problems of aspects such as technology and price in the extensive use of large-power light-emitting diodes in domestic lighting market; In these problems, most important is exactly the luminous efficiency and the thermal stability problems of light-emitting diode under the big injection current condition.

At present; The common manufacture method of high-power GaN based light-emitting diode is that the employing interdigital electrode configuration utilizes the method for etching to form N type electrode contact area; Prepare P type and N type Ohm contact electrode then, carry out the attenuate of substrate at last and cut into single GaN base LED chip.Because P type GaN carrier concentration is on the low side, injection current can not effectively be converted into excess carrier, makes that P type ohmic contact problem is technological difficulties always in the LED device of positive bright dipping.In order to make injection current evenly expansion between P type and N type electrode; P type electrode should cover larger area P type GaN layer; But excessive P type electrode area can produce the active layer emergent ray again and block; Cause low light extraction efficiency, and if the operating current skewness tend to cause and burn electrode and influence performance of products.Openly Chinese patent CN1624940A " manufacture method of high power gallium nitride LED " has proposed a kind of method of utilizing air bridge technology to prepare the high power gallium nitride LED tube core; This method need utilize dry etching technology the large tracts of land tube core to be separated into the tube core of small size; Utilize air bridge technology that the P electrode of each small size tube core is coupled together then; Such manufacture method has increased chip making technology difficulty; Reduce the product yield, be difficult to carry out large-scale volume production.

Summary of the invention

In order to overcome the deficiency that exists in the above-mentioned prior art, the purpose of the utility model provides a kind of high-power GaN based light-emitting diode structure.It can effectively improve the electric current injection efficiency under the big electric current injection situation, thereby improves the luminous efficiency and the reliability of LED device.

In order to reach the foregoing invention purpose, the technical scheme of the utility model realizes as follows:

A kind of high-power GaN based light-emitting diode structure, it comprises substrate and epitaxially grown successively n type gallium nitride layer, active illuminating layer, P type gallium nitride layer on substrate.The top of P type gallium nitride layer is a transparency conducting layer, and the end on the transparency conducting layer is equipped with P type electrode, on the n type gallium nitride layer, with the relative other end of P type electrode be equipped with N type electrode.Its design feature is, said transparency conducting layer is separated into the conductive layer piece of a plurality of small sizes, couples together with metal electrode between each conductive layer piece and all is connected to P type electrode.

In above-mentioned high-power GaN based light-emitting diode structure, said conductive layer is block-shaped to be square, rectangle, parallelogram or and the small area structure of other arbitrary shape.

The utility model is owing to adopted said structure; The transparency conducting layer on LED P-type GaN surface is separated into the conductive layer piece of a plurality of small sizes; And again with connecting with metal electrode between each conductive layer piece; Utilize good Ohmic contact characteristic between transparency conducting layer and the P type GaN, can obtain higher electric current injection efficiency and more uniform CURRENT DISTRIBUTION, improve luminous efficiency and the reliability of LED device under big injection current condition.Simultaneously, the utility model technology is simple, and rate of finished products is high, is applicable to and carries out the large-scale industry volume production.

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the plan structure sketch map of Fig. 1.

Embodiment

Referring to Fig. 1 and Fig. 2, the high-power GaN based light-emitting diode of the utility model structure comprises substrate 11 and epitaxially grown successively n type gallium nitride layer 121, active illuminating layer 122, P type gallium nitride layer 123 on substrate 11.The top of P type gallium nitride layer 123 is a transparency conducting layer 13, and the end on the transparency conducting layer 13 is equipped with P type electrode 141, on the n type gallium nitride layer 121, with the P type electrode 141 relative other ends be equipped with N type electrode 142.Transparency conducting layer 13 is separated into the conductive layer piece 131 of a plurality of small sizes, couples together with metal electrode 132 between each conductive layer piece 131 and all is connected to P type electrode 141.Conductive layer piece 131 be shaped as square, rectangle, parallelogram or and the small area structure of other arbitrary shape.

The manufacture method step of the high-power GaN based light-emitting diode of the utility model structure is:

1) on substrate 11 with the metallo-organic compound chemical vapor deposition techniques respectively epitaxial growth n type gallium nitride layer 121, active illuminating layer 122 and, P type gallium nitride layer 123;

2) utilize photoetching and dry etching technology to etch the N type and contact the gallium nitride district;

3) utilize the method for photoetching and evaporation on P type gallium nitride layer 123, to prepare transparency conducting layer 13;

4) utilize lithographic technique large-area transparency conducting layer 13 to be separated into the conductive layer piece 131 of a plurality of small sizes;

5) utilize the method for photoetching and evaporation to prepare P type electrode 141 and N type electrode 142, and preparation metal electrode 132 is with coupling together between each conductive layer piece 131;

6) substrate 11 is carried out attenuate from the back side, and high-power GaN based light-emitting diode is divided into singulated dies along cutting apart of designing.

In the utility model manufacturing process, the material that substrate 11 generally is complementary by lattice constant and ray structure constitutes, and for example, for GaN based light-emitting diode material, this substrate 11 is generally sapphire Al ₂O ₃Transparency conducting layer 13 is by can printing opacity and the homodisperse material of electric current is constituted, for example indium tin oxide ITO.Metal electrode 132 between the conductive layer piece 131 of P type electrode 141 and N type electrode 142 and each small size is made up of metals such as aluminium, silver, chromium, nickel, platinum, gold.

Claims

1. high-power GaN based light-emitting diode structure; It comprises substrate (11) and epitaxially grown successively n type gallium nitride layer (121), active illuminating layer (122), P type gallium nitride layer (123) on substrate (11); The top of P type gallium nitride layer (123) is transparency conducting layer (13); End on the transparency conducting layer (13) is equipped with P type electrode (141), and n type gallium nitride layer (121) is gone up, is equipped with N type electrode (142) with the relative other end of P type electrode (141); It is characterized in that said transparency conducting layer (13) is separated into the conductive layer piece (131) of a plurality of small sizes, couple together with metal electrode (132) between each conductive layer piece (131) and all be connected to P type electrode (141).

2. high-power GaN based light-emitting diode structure according to claim 1 is characterized in that, said conductive layer piece (131) is shaped as square, rectangle, parallelogram or and the small area structure of other arbitrary shape.