CN103489972A

CN103489972A - LED structure resistant to electrostatic breakdown

Info

Publication number: CN103489972A
Application number: CN201310463035.4A
Authority: CN
Inventors: 李淼; 陈起伟; 邓觉为; 游桥明
Original assignee: XI'AN SHENGUANG HAORUI PHOTOELECTRIC TECHNOLOGY Co Ltd
Current assignee: XI'AN SHENGUANG HAORUI PHOTOELECTRIC TECHNOLOGY Co Ltd
Priority date: 2013-09-24
Filing date: 2013-09-24
Publication date: 2014-01-01

Abstract

The invention discloses an LED structure resistant to an electrostatic breakdown. A built-in diode structure can be formed at a weak position of a material through growth of the material so as to play a role similar to a capacitor and a Zener diode, therefore, under the condition of instant impact by a large current, the current can be dispersed quickly so as to ensure that a basic structure is not damaged. The LED structure resistant to the electrostatic breakdown comprises an N-GaN layer, an MQW layer and a P-GaN layer, wherein the N-GaN layer, the MQW layer and the P-GaN layer grow sequentially on a substrate material. The LED structure resistant to the electrostatic breakdown is characterized in that a layer of n-type InxAlyGal-x-yN materials further grow on the P-GaN layer, or the n-type InxAlyGal-x-yN materials and p-type InxAlyGal-x-yN materials grow in an overlapping mode, wherein the x is greater than or equal to zero and less than or equal to 0.15, and the y is greater than or equal to zero and less than or equal to 0.25.

Description

A kind of antistatic LED structure punctured

Technical field

The invention belongs to photoelectric material and device technology field, be specifically related to the structural design of a kind of LED element itself.

Background technology

GaN is that the LED structure is wide-band gap material, and resistivity is higher, and such chip is difficult for disappearing because of the induced charge of generation of static electricity in process of production, is accumulated to suitable degree, can produce very high electrostatic potential.When surpassing the ability to bear of material, punch-through electric discharge can occur.Its positive and negative electrode of the LED chip of Sapphire Substrate all is positioned at above chip, and spacing is very little; For the InGaN/AlGaN/GaN double heterojunction, the InGaN active layer is tens nanometers only, very little to the ability to bear of static, very easily by electrostatic breakdown, make component failure.GaN base LED compares with traditional LED, and antistatic effect is poor is its distinct shortcoming, and the Problem of Failure that static causes has become affects very stubborn problem of conforming product rate and use popularization one.

For can make GaN be LED as early as possible suitability for industrialized production enter the batch production field, improve its antistatic property and become the task of top priority.

Chinese patent 201994295U has mentioned a kind of LED chip design of high-antistatic; by between the first solder joint and the second solder joint, electrically being parallel to a zener; in LED chip two ends parallel connection zener; absorb the impact of electrostatic high-pressure by zener; thereby realize the purpose of protection LED chip, but this scheme needs extra zener and cause cost payout to increase.

Chinese patent 101335313 has been mentioned a kind of method that improves antistatic effect of gallium nitride based LED, it by inserting a unadulterated gallium nitride layer in the nGaN of original gallium nitride based LED construction layer, or add a unadulterated gallium nitride layer between the barrier layer of nGaN layer and multi-layer quantum well, make increases by an electric capacity in original gallium nitride based LED construction, thereby has improved the antistatic effect of this gallium nitride based LED.Because making it, the N-shaped defect of GaN material itself is difficult to form the internal capacitance effect by non-insertion of mixing layer, and therefore all not obvious for buffering and the anlistatig lifting effect of electric current;

Chinese patent 101071836 has been mentioned a kind of epitaxial wafer growth method that improves galliumnitride base LED chip antistatic capability, form the electric current release channel in the pGaN layer, and to the epitaxial film of growth once lower the temperature, the intensification annealing in process to be to eliminate part accumulative total stress, improve the crystal mass of pGaN epitaxial loayer, therefore improved the anti-ESD ability of GaN base LED chip.But, due to high resistant and the high dislocation density of pGaN itself, its internal current dispersion effect is not obvious, so this antistatic property designed for LED has the lifting DeGrain;

At present, the technical thought of main flow remains each functional layer: as the lifting of uGaN/nGaN/MQW and pGaN crystal mass reduces the antistatic effect of dislocation defects and then boost device.

Summary of the invention

The present invention has designed a kind of novel LED element, growth by material can realize forming built-in diode structure in the material weak location, form effect similar and electric capacity and Zener diode, in the situation that instantaneous large-current impacts, dissufion current fast, and then guarantee that basic structure is not destroyed.

Technical scheme of the present invention is as follows:

This antistatic LED structure punctured, be included in nGaN layer, mqw layer, the pGaN layer of growing successively on backing material, it is characterized in that: one deck N-shaped InxAlyGa1-x-yN material of also growing on the pGaN layer, or overlapping N-shaped InxAlyGa1-x-yN and the p-type InxAlyGa1-x-yN material of having grown also; Wherein, 0.15>=x>=0,0.25>=y>=0.

Based on above-mentioned basic scheme, the present invention also further does following optimal design:

On the pGaN layer before growing n-type InxAlyGa1-x-yN material, the non-InxAlyGa1-x-yN material of mixing of the one deck of can also growing, thickness 0-50nm.Wherein, 0.15>=x>=0,0.25>=y>=0.

The thickness of said n type InxAlyGa1-x-yN, p-type InxAlyGa1-x-yN is 1nm-50nm.

For the overlapping structure of growing n-type InxAlyGa1-x-yN and p-type InxAlyGa1-x-yN, the cycle of repetition is 1-5.

The top layer of this LED structure is provided with one deck contact layer, in order to between electrode, to form ohmic contact preferably.

The present invention has the following advantages:

The present invention can obviously improve the antistatic property of LED by the diode structure on the pGaN of built-in formation, and original LED antistatic effect HMM2000V percent of pass 80% brings up to 90%, and on average antistatic<2500V brings up to and approaches 4000V.

The accompanying drawing explanation

Fig. 1 is conventional LED structure (and circuit element of equivalence).

Fig. 2 is a kind of LED structure (and circuit element of equivalence) that only increases N-shaped InAlGaN of the present invention.

Fig. 3 is a kind of LED structure (and circuit element of equivalence) that increases N-shaped InxAlyGa1-x-yN and p-type InxAlyGa1-x-yN material alternating layer of the present invention.

Fig. 4 is the LED structure (and circuit element of equivalence) that increases again one deck N-shaped InxAlyGa1-x-yN on Fig. 3 basis.

Embodiment

As shown in the figure, the present invention is continued growth N-shaped InxAlyGa1-x-yN material (Fig. 2) after traditional LED structure p-type layer growth finishes, or the overlapping structure (Fig. 3) of N-shaped InxAlyGa1-x-yN and p-type InxAlyGa1-x-yN.Wherein, 0.15>=x>=0,0.25>=y>=0.

The 1 layer of non-InxAlyGa1-x-yN material mixed of can growing before growing n-type InxAlyGa1-x-yN material after the p-type layer, thickness 0-50nm.Wherein, 0.15>=x>=0,0.25>=y>=0;

For the LED structure shown in Fig. 2, Fig. 3, Fig. 4, the thickness of N-shaped InxAlyGa1-x-yN and p-type InxAlyGa1-x-yN is preferably between 1nm-50nm.

For the overlapping structure of N-shaped InxAlyGa1-x-yN and p-type InxAlyGa1-x-yN, the cycle of repetition is that 1-5 gets final product.

After finishing, above structure growth can form ohmic contact preferably to follow between electrode by 1 layer of contact layer of continued growth.

Through experiment, confirm:

After on the pGaN of original LED, increasing the N-shaped In0.05Al0.1Ga0.85N material of one deck 5nm, the LED antistatic property rises to 2600V by 1500V; After pGaN and the interspersed non-In0.05Al0.1Ga0.85N mixed of one deck 2nm of N-shaped In0.05Al0.1Ga0.85N, the LED antistatic property rises to 3100V by 2600V;

By the non-In0.05Al0.1Ga0.85N mixed of one deck 2nm that first grows on the pGaN of original LED, afterwards after the N-shaped In0.05Al0.1Ga0.85N material of continued growth one deck 5nm, after increasing the p-type In0.1Al0.05Ga0.85N material of one deck 3nm, the LED antistatic property is risen to and is greater than 4000V by 1500V again.

Claims

1. the antistatic LED structure punctured, be included in N-GaN layer, mqw layer, the P-GaN layer of growing successively on backing material, it is characterized in that: one deck N-shaped InxAlyGa1-x-yN material of also growing on the P-GaN layer, or overlapping N-shaped InxAlyGa1-x-yN and the P type InxAlyGa1-x-yN material of having grown also; Wherein, 0.15>=x>=0,0.25>=y>=0.

2. the antistatic LED structure punctured according to claim 1 is characterized in that: on the P-GaN layer before growing n-type InxAlyGa1-x-yN material, and the non-InxAlyGa1-x-yN material of mixing of the one deck of can also growing, thickness 0-50nm.Wherein, 0.15>=x>=0,0.25>=y>=0.

3. the antistatic LED structure punctured according to claim 1 and 2, it is characterized in that: the thickness of N-shaped InxAlyGa1-x-yN, P type InxAlyGa1-x-yN is 1nm-50nm.

4. the antistatic LED structure punctured according to claim 3, it is characterized in that: for the overlapping structure of growing n-type InxAlyGa1-x-yN and P type InxAlyGa1-x-yN, the cycle of repetition is 1-5.

5. the antistatic LED structure punctured according to claim 1 is characterized in that: the top layer of this LED structure is provided with one deck contact layer, in order to between electrode, to form ohmic contact preferably.