CN105845786A - Graphical sapphire substrate recycling method - Google Patents

Abstract

The invention discloses a graphical sapphire substrate recycling method, comprising the following steps: baking an LED epitaxial wafer at high temperature in an atmosphere of nitrogen and/or hydrogen to remove an epitaxial layer on a graphical sapphire substrate; using potassium hydroxide solution and/or sodium hydroxide solution to corrode the graphical sapphire substrate baked at high temperature; and using ultrapure water to clean the corroded graphical sapphire substrate to get a graphical sapphire substrate which can be reused. Thus, the utilization rate of graphical sapphire substrates is improved greatly, and the production cost of LED chips is reduced. In addition, the method is simple and easy to implement, safe and convenient, short in recycling period, and good in effect.

Description

A kind of recovery method of graphical sapphire substrate

Technical field

The present invention relates to field of photoelectric technology, particularly to the recovery method of a kind of graphical sapphire substrate.

Background technology

Along with becoming increasingly popular of LED chip, Sapphire Substrate is widely used in outside LED chip Prolong in layer.Sapphire Substrate is divided into plane sapphire substrate and graphical sapphire substrate (Pattern Sapphire Substrate, is called for short: PSS), wherein, and plane sapphire substrate has the polishing of extension level, The surface of graphical sapphire substrate has the size graphic array in micron dimension.Graphical by using Sapphire Substrate, can significantly improve the crystal mass of the epitaxial layer of LED chip, and can pass through substrate Graphic array scattering and reflection improve light extraction efficiency

In the course of processing of LED chip, meeting is bad due to production interruption, output photoelectric properties, or system The reasons such as journey mistake produce scraps sheet.After sheet is scrapped in generation, by graphical blue from scrapping recovery in sheet Gem substrate, to reduce production cost, reduces raw-material waste.

In prior art, generally use mechanical milling method to reclaim graphical sapphire substrate, figure can be destroyed Change the graphic array of sapphire substrate surface, be unfavorable for reusing of graphical sapphire substrate.

Application publication number is that the Chinese patent application of CN103531685A discloses a kind of based on PSS substrate The processing method of epitaxial wafer, comprises the following steps: S1, will include the epitaxial wafer of PSS substrate in vacuum Toast in baking tray stove, remove water oxygen and the organic impurities on epitaxial wafer surface；S2, it is passed through hydrogen and nitrogen The mixed gas of gas is toasted, the GaN layer of decomposed P SS substrate surface；After S3, baking terminate, Concentrated sulphuric acid and hydrogen peroxide mixed liquor is used to clean the granule of PSS substrate surface residual.

Summary of the invention

The invention provides the recovery method of a kind of graphical sapphire substrate, easy to solve prior art Destroy the defect of the graphic array on graphical sapphire substrate surface.

The invention provides the recovery method of a kind of graphical sapphire substrate, comprise the following steps:

Under the atmosphere of nitrogen and/or hydrogen, LED is carried out high-temperature baking, remove figure Change the epitaxial layer in Sapphire Substrate；

Use potassium hydroxide solution and/or sodium hydroxide solution, to the graphical blue treasured after high-temperature baking Corrode at the bottom of stone lining；

Use ultra-pure water that the graphical sapphire substrate after corrosion is carried out.

Alternatively, baking temperature is 1100～1500 DEG C, and baking time is 0.5～2 hour.

Alternatively, under the mixed atmosphere of the nitrogen that hydrogen content is 4% and hydrogen, described LED is toasted During epitaxial wafer, baking temperature is 1300～1400 DEG C, and baking time is 1～3 hour.

Alternatively, under the mixed atmosphere of the nitrogen that hydrogen content is 50% and hydrogen, baking is described During LED, baking temperature is 1200～1300 DEG C, and baking time is 1～3 hour.

Alternatively, when toasting described LED under pure hydrogen environment, baking temperature is 1100～1200 DEG C, baking time is 1～3 hour.

Alternatively, described use potassium hydroxide solution and/or sodium hydroxide solution, after high-temperature baking Graphical sapphire substrate corrode, particularly as follows:

Under the temperature environment of 20～100 DEG C, use potassium hydroxide solution and/or sodium hydroxide solution, Graphical sapphire substrate after high-temperature baking is corroded 10～100 minutes.

Alternatively, corrosion temperature is 70～90 DEG C, and etching time is 20～50 minutes.

Alternatively, the concentration range of described potassium hydroxide solution is 10%～60%.

Alternatively, the concentration range of described potassium hydroxide solution is 20%～30%.

Alternatively, the graphical sapphire substrate after corrosion is carried out by described use ultra-pure water, tool Body is:

At normal temperatures, use ultra-pure water that the graphical sapphire substrate after corrosion is cleaned 10～100 points Clock.

The present invention, by the way of high-temperature baking, decomposes the extension removed on graphical sapphire substrate Layer, then removes the residue on graphical sapphire substrate by the way of chemical wet etching, Re-use the residue after ultra-pure water cleans corrosion, thus obtain the graphical indigo plant being able to reuse that Gem substrate, drastically increases the utilization rate of graphical sapphire substrate, and then reduces LED The production cost of chip.Additionally, the method is simple, safe ready, return period is short, effect The best.

Accompanying drawing explanation

Fig. 1 is the structural representation of the LED in the embodiment of the present invention；

Fig. 2 is the recovery method flow chart of the graphical sapphire substrate in the embodiment of the present invention；

Fig. 3 is that the structure of the graphical sapphire substrate after the high-temperature baking in the embodiment of the present invention is shown It is intended to；

Fig. 4 is the structural representation of the graphical sapphire substrate after the corrosion in the embodiment of the present invention 。

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, to the technical scheme in the embodiment of the present invention It is clearly and completely described, it is clear that described embodiment is only that a part of the present invention is real Execute example rather than whole embodiments.Based on the embodiment in the present invention, ordinary skill The every other embodiment that personnel are obtained under not making creative work premise, broadly falls into this The scope of invention protection.

Embodiments provide the recovery method of a kind of graphical sapphire substrate, be applied to such as figure LED shown in 1, this LED includes graphical sapphire substrate 10 and epitaxial layer 20, it is involuntary that epitaxial layer 20 includes but not limited to be stacked in successively on graphical sapphire substrate 10 Doped gan layer 21, n-type doping GaN layer 22, active layer 23 and P-type layer 24.Based on above-mentioned LED reclaims the method for graphical sapphire substrate, as in figure 2 it is shown, comprise the following steps:

Step 201, under the atmosphere of nitrogen and/or hydrogen, carries out high-temperature baking to LED, Remove the epitaxial layer on graphical sapphire substrate.

Specifically, LED is put into baking container, to baking container in be passed through nitrogen and/ Or hydrogen, LED is toasted, to decompose the epitaxial layer on graphical sapphire substrate. Wherein, baking temperature is 1100～1500 DEG C, and baking time is 0.5～2 hour.

During it should be noted that toast LED under the mixed atmosphere of nitrogen and hydrogen, mixed The content of the hydrogen in conjunction atmosphere is the highest, and cured effect is the most notable, can use shorter baking time With relatively low baking temperature.Toast under the mixed atmosphere of the nitrogen that hydrogen content is 4% and hydrogen During LED, baking temperature is 1300～1400 DEG C, and baking time is 1～3 hour；At hydrogen When content is to toast LED under the nitrogen of 50% and the mixed atmosphere of hydrogen, baking temperature is 1200～1300 DEG C, baking time is 1～3 hour；When toasting LED under pure hydrogen environment, Baking temperature is 1100～1200 DEG C, and baking time is 1～3 hour.

Additionally, the figure after LED is carried out high-temperature baking, on graphical sapphire substrate Between remain GaN, as shown in Figure 3.The GaN of residual throws again at graphical sapphire substrate When entering epitaxial growth, there is the effect of nucleus, be conducive to growing more excellent LED.

Step 202, uses potassium hydroxide solution and/or sodium hydroxide solution, to the figure after high-temperature baking Shape Sapphire Substrate is corroded.

Specifically, under the temperature environment of 20～100 DEG C, use potassium hydroxide solution and/or hydroxide Sodium solution, corrodes the graphical sapphire substrate after high-temperature baking, wherein, and potassium hydroxide solution Concentration range is 10%～60%, and corrosion temperature is 20～100 DEG C, and etching time is 10～100 minutes.

Preferably, the concentration range of potassium hydroxide solution can be 20%～30%, and corrosion temperature is 70～90 DEG C, etching time is 20～50 minutes.

Use potassium hydroxide solution and/or sodium hydroxide solution to the graphic sapphire after high-temperature baking Substrate corrodes, it is possible to removes the loose GaN of graphical sapphire substrate remained on surface, retains GaN layer bottom the figure of graphical sapphire substrate, as shown in Figure 4.The GaN layer retained exists When graphical sapphire substrate puts into epitaxial growth again, there is the effect of nucleus, not only will not reduce Quality when graphical sapphire substrate reuses, and be conducive to improving further LED extension The photoelectricity quality of sheet.

Step 203, uses ultra-pure water to be carried out the graphical sapphire substrate after corrosion.

Specifically, ultra-pure water can be used clear to the graphical sapphire substrate after corrosion at normal temperatures Wash 10～100 minutes, thus by clean for the surface clean of graphical sapphire substrate.Wherein, ultrapure Water is that resistivity is more than 18M Ω * cm (25 DEG C), or the water close to 18.3M Ω * cm (25 DEG C).

After performing above step 201 to step 203, reclaim the graphical sapphire substrate obtained 10, as shown in Figure 4.

The present embodiment, under the mixed atmosphere of the nitrogen that hydrogen content is 10% and hydrogen, uses 1350 DEG C High temperature, to LED toast 2 hours, remove patterned substrate surface GaN epitaxial layer, Re-use the KOH solution that concentration is 40%, the graphical sapphire substrate after high-temperature baking is corroded 30 minutes, and use ultra-pure water to clean the graphical sapphire substrate after corroding, remove remained on surface K ion and the loose GaN solid come off, the graphical sapphire substrate being recycled.

Dry the graphical sapphire substrate reclaimed, by the graphical sapphire substrate of recovery with normal Graphical sapphire substrate together puts into MOCVD (Metal-organic Chemical Vapor Deposition, metallo-organic compound chemical gaseous phase deposition) equipment carries out the growth of UV epitaxial wafer, And carry out the chip checking of 08mil*11mil size.Chip checking result result shows, with employing just The UV epitaxial wafer of normal graphical sapphire substrate growth is compared, and uses the graphic sapphire reclaimed The UV epitaxial wafer of substrate growth has equal chip photo parameter, as shown in the table:

	Vf	WP	LOP	IR
					Normal substrate	3.42	400.99	14.79	0.01
Reclaim substrate	3.43	401.02	15.00	0.01

The graphical sapphire substrate of recovery is together put into normal graphical sapphire substrate MOCVD device carries out the growth of blue light epitaxial wafer, and the chip carrying out 25mil*25mil size is tested Card.Chip checking result shows, with use normal graphical sapphire substrate growth blue light outside Prolong sheet to compare, use the blue light epitaxial wafer of the graphical sapphire substrate growth reclaimed, have more excellent Photoelectric properties, as shown in the table:

	Vf	WD	LOP	IR
					Normal substrate	3.50	450.12	162.29	0.04
Reclaim substrate	3.45	448.26	169.04	0.03

The embodiment of the present invention, by the way of high-temperature baking, is decomposed and is removed on graphical sapphire substrate Epitaxial layer, then removes the residual on graphical sapphire substrate by the way of chemical wet etching Thing, re-uses the residue after ultra-pure water cleans corrosion, thus obtain being able to reuse that graphical Sapphire Substrate, drastically increases the utilization rate of graphical sapphire substrate, and then reduces LED The production cost of chip.Additionally, the method is simple, safe ready, return period is short, effect Good.

The above, the only detailed description of the invention of the present invention, but protection scope of the present invention is not Being confined to this, any those familiar with the art is at the technical scope that the invention discloses In, change can be readily occurred in or replace, all should contain within protection scope of the present invention.Cause This, protection scope of the present invention should described be as the criterion with scope of the claims.

Claims (10)

1. the recovery method of a graphical sapphire substrate, it is characterised in that include following step Rapid:

Under the atmosphere of nitrogen and/or hydrogen, LED is carried out high-temperature baking, remove figure Change the epitaxial layer in Sapphire Substrate；

Use potassium hydroxide solution and/or sodium hydroxide solution, to the graphical blue treasured after high-temperature baking Corrode at the bottom of stone lining；

Use ultra-pure water that the graphical sapphire substrate after corrosion is carried out.

2. the method for claim 1, it is characterised in that baking temperature is 1100～1500 DEG C, baking time is 0.5～2 hour.

3. method as claimed in claim 2, it is characterised in that be the nitrogen of 4% at hydrogen content When toasting described LED under the mixed atmosphere of gas and hydrogen, baking temperature is 1300～1400 DEG C, baking time is 1～3 hour.

4. method as claimed in claim 2, it is characterised in that be the nitrogen of 50% at hydrogen content When toasting described LED under the mixed atmosphere of gas and hydrogen, baking temperature is 1200～1300 DEG C, baking time is 1～3 hour.

5. method as claimed in claim 2, it is characterised in that toast institute under pure hydrogen environment When stating LED, baking temperature is 1100～1200 DEG C, and baking time is 1～3 hour.

6. the method for claim 1, described use potassium hydroxide solution and/or sodium hydroxide Solution, corrodes the graphical sapphire substrate after high-temperature baking, particularly as follows:

Under the temperature environment of 20～100 DEG C, use potassium hydroxide solution and/or sodium hydroxide solution, Graphical sapphire substrate after high-temperature baking is corroded 10～100 minutes.

7. method as claimed in claim 6, corrosion temperature is 70～90 DEG C, and etching time is 20～50 minutes.

8. method as claimed in claim 6, the concentration range of described potassium hydroxide solution is 10%～60%.

9. method as claimed in claim 8, the concentration range of described potassium hydroxide solution is 20%～30%.

10. the method for claim 1, described use ultra-pure water to corrosion after graphical Sapphire Substrate is carried out, particularly as follows:

At normal temperatures, use ultra-pure water that the graphical sapphire substrate after corrosion is cleaned 10～100 points Clock.