CN101192635A

CN101192635A - Grid type separate luminous diode epitaxial slice and method of manufacture

Info

Publication number: CN101192635A
Application number: CNA2006101187148A
Authority: CN
Inventors: 江忠永; 刘榕; 兰叶
Original assignee: Hangzhou Silan Azure Co Ltd
Current assignee: Hangzhou Silan Azure Co Ltd
Priority date: 2006-11-24
Filing date: 2006-11-24
Publication date: 2008-06-04

Abstract

The invention discloses a grid-like separated LED epitaxial wafer. The epitaxial wafer comprises an epitaxial substrate, a grid-like mask layer which is positioned on the epitaxial substrate and an epitaxial layer which is arranged between the grid-like mask layers on the epitaxial substrate. The invention also discloses a method for manufacturing the grid-like separated LED epitaxial wafer, which comprises the following processes: a mask layer is deposited on the epitaxial wafer; a photoetching glue layer is made on the mask layer; the mask layer between grids on the grid-like photoetching glue layer is removed; the grid-like photoetching glue layer is removed and the mask layer is left; an epitaxial wafer is deposited on the exposure part of the epitaxial substrate. The grid-like separated LED epitaxial wafer can effectively remove wafer warping caused by the stress between the epitaxial layer film and the epitaxial substrate. Therefore, the invention is beneficial for generating LED materials with a higher uniformity (providing a basis for realizing wafer epitaxy with larger size) and can increase the rate of good products in chip processing.

Description

The LED epitaxial slice of grid type separate and manufacture method thereof

Technical field

The present invention relates to a kind of gallium nitride based LED epitaxial slice structure and manufacture method thereof of LED epitaxial slice and manufacture method thereof, especially grid type separate of grid type separate.

Background technology

The technology of a core is the epitaxial growth of semi-conducting material in light-emitting diode (LED) manufacture process.It has determined the consistency and the stability of the every photoelectric parameter of chip.At present, rely on the reddish yellow light led chip of quaternary AlGaInP system to adopt the method preparation of gas phase epitaxy of metal organic compound (MOCVD) usually (with reference to people U.S. patent of invention Semiconductor light emitting device such as H.Sugawara, the patent No. is 5,153,889), the size industrial level of its epitaxial wafer has reached 3 inches.And the blue green light LED chip extension of AlGaInN system still is in 2 inches levels at present (with reference to people U.S. patent of invention Method for manufacturing agallium nitride group compound semiconductor such as K.Manabe, number 6,984,536).Usually the substrate that adopts is sapphire and carborundum.The blue green light LED extension adopts larger sized substrate challenge mainly to be how to solve the homogeneity question of material growth.The uniformity of material growth divides three aspects to understand, and the one, the parameter uniformity on each slice, thin piece; The 2nd, the uniformity in each growth heat between sheet and the sheet; The 3rd, the uniformity between different heats.Here major concern is uniformity on the single epitaxial wafer.Its influencing factor mainly contains two aspects, and the one, the uniformity of substrate heating in the growth course; The 2nd, the uniformity of surface source gas flow.Substrate heating be subjected to a great extent evenly that the stress state of epitaxial wafer influences in the epitaxial process.In the process of the InGaN/GaN multilayer chiop structure that adopts MOCVD growth stratiform, warpage generally can take place because being in stress state in epitaxial wafer.Stress source mainly contains two kinds: the one, and the coefficient of thermal expansion mismatch stress that variations in temperature is introduced between epitaxial process layer and the layer; Another kind is the epitaxial material stress that the gradual change of crystal structure causes in growth course.A kind of situation that in traditional epitaxial wafer manufacturing process, occurs as shown in Figure 1 and since epitaxial substrate 12 by with heating base 11 thermal contact conductances, so the disk warping phenomenon that stress causes can make that the heating-up temperature of epitaxial substrate 12 is inhomogeneous.And adopt large-sized more epitaxial substrate 12, and the 12 Internal and external cycle temperature difference can be big more at the bottom of the lining extension, and epitaxial loayer 13 material homogeneities of growth are also just poor more.This causes disk always to have the chip parameter off-gauge of subregion to close requirement easily, has therefore limited the yields of large scale epitaxial substrate 12 greatly.In addition, epitaxial wafer is in bigger stress state can influence product in follow-up chip processing procedure rate of finished products.When being mainly reflected in epitaxial substrate 12 attenuates, epitaxial wafer stress makes the epitaxial substrate 12 behind the attenuate splintering problem occur easily, and is very big to the effectiveness affects of rate of finished products and follow-up test letter sorting engineering.The method of therefore, epitaxial growth low-stress material is the key technology that LED makes.

Summary of the invention

The present invention is intended to solve the problem that stress causes between above-mentioned epitaxial substrate and the epitaxial loayer, a kind of GaN base LED material epitaxy method that can eliminate epitaxial loayer stress is provided, adopt this method can form the LED epitaxial slice of grid type separate, promote the uniformity and the yields of chip material with this, thereby provide solution for further enlarging the epitaxial substrate size.

The key of GaN base LED material epitaxy method of the present invention is the substrate that adopts latticed block to isolate, by the block discrete LED epitaxial loayer of MOCVD method preparation.Because epitaxial loayer is the block shape, the stress between itself and substrate is significantly reduced.Therefore, the heating uniformity of substrate improves during the material growth, and this will obviously promote the uniformity of light-emitting semiconducting material.The GaN base LED epitaxial wafer structure of described grid type separate comprises: an epitaxial substrate; One latticed mask layer is arranged on the described epitaxial substrate; One epitaxial loayer is arranged between the described latticed mask layer on the described epitaxial substrate.

Reasonable is that described epitaxial loayer is a gallium nitride layer.

Reasonable is that the thickness range of described mask layer is 5 * 10 ²～5 * 10 ⁴Dust.

Reasonable is that the grid of described latticed mask layer comprises square, rectangle, rhombus and regular hexagon.

Reasonable is that the material of described latticed mask layer comprises silicon dioxide, silicon nitride, silicon oxynitride, tungsten.

The manufacture method of the LED epitaxial slice of grid type separate provided by the invention comprises: step 1, deposition one mask layer on epitaxial substrate; Step 2 is made one and is latticed photoresist layer on described mask layer; Step 3 is removed the mask layer between the grid of described latticed photoresist layer; Step 4 is removed described latticed lithography layer, stays mask layer; Step 5, deposition one epitaxial loayer on the described epitaxial substrate that exposes.

Reasonable is that described epitaxial loayer is a gallium nitride layer.

The present invention can promote the photoelectric parameter uniformity of extension chip with this, provides the basis for realizing larger sized disk extension.

Description of drawings

Below, with reference to accompanying drawing, for those skilled in the art that, from detailed description of the present invention, above-mentioned and other purposes of the present invention, feature and advantage will be apparent.

Shown in Figure 1 is because the disk warpage issues that membrane stress causes, the disk of warpage because and have the space between the heated substrates, can cause the disk heating inhomogeneous;

Fig. 2 a is the schematic surface of grid type separate GaN base LED epitaxial wafer of the present invention;

Fig. 2 b is a partial enlarged drawing among Fig. 2 a;

Fig. 2 c is Fig. 2 a generalized section;

Fig. 3 a～3e provides the making flow chart of grid type separate GaN base LED epitaxial wafer of the present invention.

Embodiment

Fig. 2 a～2c provides the structural representation with latticed mask layer epitaxial wafer of the present invention, and this epitaxial wafer comprises epitaxial substrate 21 and is arranged in latticed mask layer 22 on this substrate 21.The geometry of this grid can be designed to square, rectangle, rhombus, regular hexagon or the like according to chip particle profile.The physical dimension of grid is consistent with the die size of design, in the 250-1500 micrometer range.The thickness range of latticed mask layer 22 is 5 * 10 ²～5 * 10 ⁴Dust.The zone that latticed mask layer 22 is covered is exactly the scribe line position of chip.

Fig. 2 c provides the cross-sectional view of the latticed GaN base LED epitaxial wafer of the present invention, and this LED comprises epitaxial substrate 21, and this epitaxial substrate 21 can be sapphire, carborundum, silicon or zinc oxide or the like; Latticed mask layer 22, the material of this mask layer 22 can be silicon dioxide (SiO ₂), silicon nitride (Si ₃N ₄), silicon oxynitride (SiNO), tungsten (W) or the like.The geometry of mask layer 22 can be designed to square, rectangle, rhombus, regular hexagon or the like according to chip particle profile.Size is determined that by chip in the 250-1500 micrometer range, thickness range is 5 * 10 ²～5 * 10 ⁴Dust.The zone that latticed mask layer 22 covers is exactly the scribe line position of chip.The block GaN base LED epitaxial loayer 23 of grid type separate.

Latticed GaN base LED epitaxial wafer manufacturing process of the present invention as shown in Figure 3, comprising: 1) make with the epitaxial substrate of latticed mask; 2) the block LED epitaxial loayer of grid type separate is made.

Substrate making step with latticed mask specifically describes as follows:

1) referring to Fig. 3 a, the method by plasma reinforced chemical vapour deposition method, low-pressure chemical vapor deposition method deposition or physical sputtering on epitaxial substrate 31 deposits a mask layer 32, and THICKNESS CONTROL is 5 * 10 ²～5 * 10 ⁴In the dust scope;

2) on mask layer 32, make photoresist mask pattern 33 subsequently, shown in Fig. 3 b by photoetching technique;

3) by wet etching (hydrofluoric acid etc.) or dry etching (Cl ₂, BCl ₃) method part mask material 32 is removed, shown in Fig. 3 c;

4) with an organic solvent (as acetone) removes photoresist mask pattern 33, stays mask layer 32, shown in Fig. 3 d;

5) the block LED epitaxial loayer making of grid type separate is the GaN base LED 34 by method deposit multilayer structure on the substrate 31 that exposes of metal-organic chemical vapor deposition equipment.Because mask layer 32 can hinder the GaN crystal and grow thereon, therefore final acquisition LED epitaxial loayer 34 is the grid type separate structure, shown in Fig. 3 e.

So far, the LED epitaxial wafer manufacturing process of grid type separate of the present invention is finished.This method can realize more that the large scale disk is delayed time outward and obtain the high chip material of uniformity, for epitaxial material process more efficiently provides the foundation.Because the stress of extension disk is effectively controlled, can improve the yields of chip manufacture effectively simultaneously.

Obtain describing by above-mentioned example example of the present invention, but it is illustrative.In fact, under the situation of the principle of the invention, can also carry out various forms of modifications to it.In addition, the content that the present invention covered is limited by appended claims.

Claims

1. the LED epitaxial slice of grid type separate, described epitaxial wafer comprises:

One epitaxial substrate;

One latticed mask layer is arranged on the described epitaxial substrate;

One epitaxial loayer is arranged between the described latticed mask layer on the described epitaxial substrate.

2. the LED epitaxial slice of grid type separate according to claim 1 is characterized in that, described epitaxial loayer is a gallium nitride layer.

3. the LED epitaxial slice of grid type separate according to claim 2 is characterized in that, the thickness range of described mask layer is 5 * 10 ²～5 * 10 ⁴Dust.

4. according to the LED epitaxial slice of claim 2 or 3 described grid type separates, it is characterized in that the grid of described latticed mask layer comprises square, rectangle, rhombus and regular hexagon.

5. the LED epitaxial slice of grid type separate according to claim 4 is characterized in that, the material of described latticed mask layer comprises silicon dioxide, silicon nitride, silicon oxynitride, tungsten.

6. the manufacture method of the LED epitaxial slice of grid type separate comprises:

Step 1, deposition one mask layer on epitaxial substrate;

Step 2 is made one and is latticed photoresist layer on described mask layer;

Step 3 is removed the mask layer between the grid of described latticed photoresist layer;

Step 4 is removed described latticed lithography layer, stays mask layer;

Step 5, deposition one epitaxial loayer on the described epitaxial substrate that exposes.

7. the manufacture method of the LED epitaxial slice of grid type separate according to claim 6 is characterized in that,

Described epitaxial loayer is a gallium nitride layer.

8. the LED epitaxial slice of grid type separate according to claim 7 is characterized in that, the thickness range of described mask layer is 5 * 10 ²～5 * 10 ⁴Dust.

9. according to the LED epitaxial slice of claim 7 or 8 described grid type separates, it is characterized in that the grid of described latticed mask layer comprises square, rectangle, rhombus and regular hexagon.

10. the LED epitaxial slice of grid type separate according to claim 9 is characterized in that, the material of described latticed mask layer comprises silicon dioxide, silicon nitride, silicon oxynitride, tungsten.