CN102903818A

CN102903818A - High-power GaN (gallium nitride)-based light emitting diode structure and manufacturing method thereof

Info

Publication number: CN102903818A
Application number: CN2011102113744A
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: 2013-01-30

Abstract

The invention discloses a high-power GaN (gallium nitride)-based light emitting diode structure and a manufacturing method thereof, and relates to the technical field of photo-electricity. The high-power GaN-based light emitting diode comprises a substrate, an N-type GaN layer, an active light-emitting layer and a P-type GaN layer, wherein the N-type GaN layer, the active light-emitting layer and the P-type GaN layer grow on the substrate epitaxially sequentially, a transparent conductive layer is arranged on the P-type GaN layer, a P-type electrode is arranged at one end of the transparent conductive layer, and an N-type electrode is arranged at the other end of the N-type GaN layer and opposite to the P-type electrode. The high-power GaN-based light emitting diode structure is characterized in that the transparent conductive layer is divided into multiple conductive blocks with small areas, and the conductive blocks are connected by metal electrodes and connected to the P-type electrode. Compared with the prior art, the high-power GaN-based light emitting diode structure has the advantages that heavy-current injection efficiency is increased effectively so that light emitting efficiency and reliability of light emitting diode devices are improved.

Description

A kind of GaN based high power light-emitting diodes structure and preparation method thereof

Technical field

The present invention relates to field of photoelectric technology, particularly GaN based high power light-emitting diodes structure and preparation method thereof.

Background technology

Luminescent device based on semiconductor material with wide forbidden band is the emphasis of Semiconductor Optic Electronics area research and exploitation always.Particularly succeeding in developing take the III-V group nitride material as representative blue-green light-emitting diode so that light-emitting diode can realize that full color is luminous, and progressively marched toward the white-light illuminating epoch.Light-emitting diode because have low energy consumption, long-life, the advantage such as lightweight, volume is little, be widely used at present the fields such as signal demonstration, display backlight source, traffic signals indication, outdoor advertising display and Landscape Lighting.But from present actual conditions, still there are the problems of the aspects such as technology and price in large-power light-emitting diodes in the extensive use in domestic lighting market, in these problems, most important is exactly luminous efficiency and the thermal stability problems of light-emitting diode under the large Injection Current condition.

At present, the common manufacture method of GaN based high power light-emitting diodes is that the employing interdigital electrode configuration utilizes the method for etching to form N-type electrode contact zone, then prepare P type and N-type Ohm contact electrode, carry out at last the attenuate of substrate 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, so that P type ohmic contact problem is technological difficulties in the LED device of positive bright dipping always.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 tends to cause the performance of burning electrode and affecting product.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, the method need to utilize dry etching technology the large tracts of land tube core to be separated into the tube core of small size, then utilize air bridge technology that the P electrode of each small size tube core is coupled together, such manufacture method has increased chip making technology difficulty, reduce product yield, be difficult to carry out large-scale volume production.

Goal of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the purpose of this invention is to provide a kind of GaN based high power light-emitting diodes structure and preparation method thereof.Electric current injection efficiency in the large electric current injection of its energy Effective Raise situation, thereby luminous efficiency and the reliability of raising LED device.

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

A kind of GaN based high power light-emitting diodes structure, it comprises substrate and successively epitaxially grown n type gallium nitride layer, active illuminating layer, P type gallium nitride layer on substrate.The top of P type gallium nitride layer is transparency conducting layer, and the end on the transparency conducting layer is equipped with P type electrode, on the n type gallium nitride layer, the other end relative with P type electrode be equipped with the N-type electrode.Its design feature is, described 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 GaN based high power light-emitting diodes structure, described conductive layer is block-shaped to be square, rectangle, parallelogram or and the small area structure of other arbitrary shape.

A kind of manufacture method of GaN based high power light-emitting diodes structure the steps include:

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

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

3) utilize the method for photoetching and evaporation to prepare transparency conducting layer at P type gallium nitride layer;

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

5) utilize the method for photoetching and evaporation to prepare P type electrode and N-type electrode, and the preparation metal electrode will couple together between each conductive layer piece;

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

The present invention is owing to having adopted said structure and method, the transparency conducting layer on LED P-type GaN surface is separated into the conductive layer piece of a plurality of small sizes, and will connect with metal electrode between each conductive layer piece again, utilize ohmic contact characteristic good 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 large Injection Current condition.Simultaneously, the method technique is simple, and rate of finished products is high, is applicable to carry out the large-scale industry volume production.

The invention will be further described below in conjunction with the drawings and specific embodiments.

Description of drawings

Fig. 1 is structural representation of the present invention;

Fig. 2 is the plan structure schematic diagram of Fig. 1.

Embodiment

Referring to Fig. 1 and Fig. 2, GaN based high power light-emitting diodes structure of the present invention comprises substrate 11 and successively epitaxially grown 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, and the end on the transparency conducting layer 13 is equipped with P type electrode 141, on the n type gallium nitride layer 121, the other end relative with P type electrode 141 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 GaN based high power light-emitting diodes structure of the present invention is:

1) substrate 11 usefulness 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;

3) utilize the method for photoetching and evaporation at P type gallium nitride layer 123 preparation transparency conducting layers 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 will couple together between each conductive layer piece 131;

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

In manufacturing process of the present invention, the material that substrate 11 generally is complementary by lattice constant and ray structure consists of, 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 consisted of, 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 of metals such as aluminium, silver, chromium, nickel, platinum, gold.

Claims

1. GaN based high power light-emitting diodes structure, it comprises substrate (11) and successively epitaxially grown 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 upper, the other end relative with P type electrode (141) is equipped with N-type electrode (142); It is characterized in that, described 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).

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

3. the manufacture method of a GaN based high power light-emitting diodes structure the steps include:

1) 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);

3) utilize the method for photoetching and evaporation at P type gallium nitride layer (123) preparation 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) join with P type electrode (141) with coupling together between each conductive layer piece (131);

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