CN102709437A

CN102709437A - Miniature light-emitting diode chip with high-reflectivity layers

Info

Publication number: CN102709437A
Application number: CN201210189967XA
Authority: CN
Inventors: 张建宝; 吴继清
Original assignee: HC Semitek Corp
Current assignee: HC Semitek Corp
Priority date: 2012-06-11
Filing date: 2012-06-11
Publication date: 2012-10-03

Abstract

The invention discloses a miniature light-emitting diode (LED) chip with high-reflectivity layers. The chip comprises a P-type GaN layer, an N-type GaN layer, and a P-type soldering-pan and an N-type soldering-pan, which are manufactured on the P-type GaN layer and the N-type GaN layer respectively. The invention has the advantages that the prepared LED chip is small in size, and production cost and a chip size are greatly reduced; a transport electrode diffusion layer on a P-type epitaxial layer is eliminated, so that the machining process of the miniature LED chip is simple compared with that of the conventional LED chip; and in addition, the GaN layers are 7 to 10 mu m thick, so that side light-emitting efficiency is effectively improved, and the problem of low brightness of thee miniature chip is solved.

Description

A kind of micro-led chip with high reflection layer

Technical field

The present invention relates to a kind of micro-led chip with high reflection layer.

Background technology

Light-emitting diode is a kind of semiconductor solid luminescence device that can electric energy be converted into visible light; Because it has energy-saving and environmental protection, life-span length, high brightness, advantage such as low in calories, sturdy and durable, has been widely used in fields such as display screen, backlight, illumination, car light.

Continuous development and maturation along with epitaxial growth and chip fabrication techniques; The luminous efficiency of LED is brought up to 120 lm/W from 5 lm/W in past; Its luminous efficiency nearly is in the past 24 times, and this led chip size that just means same brightness will reduce more in the past greatly, and the one side that reduces of led chip size reduces its production cost greatly; Help further dwindling the volume of LED luminescent device on the other hand, thereby realize the microminiaturization of luminescent device.But because the needs of package lead, the size of metal pad can not be made too for a short time; When led chip is undersized; Metal pad will perhaps shelter from major part from the light absorption that active area sends, and makes that the LED luminous efficiency of miniature sizes is extremely low, can't satisfy the requirement of application market.Thereby, realize microminiaturized just necessary absorption and the occlusion issue that solves metal pad to light of led chip size.

Summary of the invention

The object of the present invention is to provide a kind of micro-led chip,, significantly dwindle the size of led chip, effectively reduce the led chip production cost through improvement to the led chip structure with high reflection layer.。

Technical scheme of the present invention is: a kind of micro-led chip with high reflection layer; This chip comprise P type GaN layer, be positioned at the P type GaN layer on the N type GaN layer and be produced in P type GaN layer and N type GaN layer on P type pad and N type pad; This chip size; Length 50-180 μ m, width 30-100 μ m, the reflex of the high reflection layer of its light that sends below N type pad and P type pad is extracted from the side; N type pad and P type pad have the highly reflecting films layer of high reflex, and this rete is the metal level with low absorption and high reflex.GaN epitaxy layer thickness 7-10 μ m.

The invention has the advantages that: the led chip size that the present invention prepares is minimum, has greatly reduced production cost and chip volume.In order to guarantee that its brightness can be satisfied instructions for use when size reduces, N type pad and P type pad all have high reflection layer among the present invention, utilize the reflex of high reflection layer can major part be extracted by the light that N type pad and P type pad shelter from from the side.No transparency electrode diffusion layer on the P type epitaxial loayer among the present invention, traditional relatively led chip, its course of processing is simple.In addition, GaN epitaxy layer thickness of the present invention surpasses 7 μ m, and thicker epitaxy layer thickness effectively raises the side light extraction efficiency, has solved the low excessively problem of brightness of microchip.

Description of drawings

Fig. 1 is the micro-led chip size figure of band high reflection layer of the present invention;

Fig. 2 is the micro-led chip sectional view of band high reflection layer of the present invention.

101 is P type pad among the figure; 102 is P type epitaxial loayer; 103 is N type pad; 201 is that Sapphire Substrate, 202 is that N type GaN epitaxial loayer, 203 is that N type pad high reflection layer, 204 is N type pad, and 205 is that multiple quantum well active layer, 206 is that P type GaN epitaxial loayer, 207 is that P type pad high reflection layer, 208 is a P type pad.

Embodiment

To preparation method that the present invention takes,, do detailed process explanation with regard to instance below in conjunction with accompanying drawing:

A kind of micro-led chip sectional view with high reflection layer is as shown in Figure 2.By Sapphire Substrate 1, N type GaN epitaxial loayer 2, N type pad high reflection layer 3, N type pad 4, multiple quantum well active layer 5, P type GaN epitaxial loayer 6, P type pad high reflection layer 7, P type pad 8.Below in conjunction with a kind of micro-led manufacturing method of chip with high reflection layer is described further.Mainly comprise following processing step:

1. adopt MOCVD method epitaxial growth N type GaN epitaxial loayer 2 successively on Sapphire Substrate 1, multiple quantum well active layer 5, P type GaN epitaxial loayer 6; Form epitaxial wafer; Then, the P type that utilizes dry etching to etch away epitaxial wafer selectively prolongs layer, makes N type epitaxial loayer expose out.

4. use apparatus for electron beam evaporation; At the vapor deposition Ag of the N type epi-layer surface that exposes elder generation as N type pad high reflection layer 3; Vapor deposition Ti/Al metal is as N type pad 4 then; Deposition Ag is as P type pad high reflection layer 7 on P type GaN epitaxial loayer, and plated metal Ti/Al forms P type pad 8 on high reflection layer.

5. after accomplishing the making of epi-layer surface electrode, it is carried out Rapid Thermal heat treatment under 400 ℃ temperature, make P type and N type pad and epitaxial loayer form good Ohmic contact.

The purpose of above instance is merely explains the present invention preferably, does not comprise full content of the present invention.With the present invention is that basic any change invention all belongs to the claimed range of inventing right.

Claims

1. micro-led chip with high reflection layer; This chip comprise P type GaN layer, be positioned at the P type GaN layer on the N type GaN layer and be produced in P type GaN layer and N type GaN layer on P type pad and N type pad; It is characterized in that: this chip size; Length 50-180 μ m, width 30-100 μ m, the reflex of the high reflection layer of its light that sends below N type pad and P type pad is extracted from the side; N type pad and P type pad have the highly reflecting films layer of high reflex, and this rete is the metal level with low absorption and high reflex.

2. according to the said a kind of micro-led chip of claim 1, it is characterized in that: GaN epitaxy layer thickness 7-10 μ m with high reflection layer.