KR101229832B1 - Method of fabricating semiconductor substarte and method of fabricating lighe emitting device - Google Patents
Method of fabricating semiconductor substarte and method of fabricating lighe emitting device Download PDFInfo
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- KR101229832B1 KR101229832B1 KR1020090079436A KR20090079436A KR101229832B1 KR 101229832 B1 KR101229832 B1 KR 101229832B1 KR 1020090079436 A KR1020090079436 A KR 1020090079436A KR 20090079436 A KR20090079436 A KR 20090079436A KR 101229832 B1 KR101229832 B1 KR 101229832B1
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Abstract
Disclosed are a semiconductor substrate manufacturing method and a light emitting device manufacturing method. According to one embodiment of the present invention, in a method of manufacturing a semiconductor substrate, a first semiconductor layer is formed on a substrate, a metal material layer is formed in a pattern shape on the first semiconductor layer, and the first semiconductor layer is formed on the first semiconductor layer. And forming a second semiconductor layer on the metallic material layer, forming a cavity in the first semiconductor layer below the metallic material layer, and heating the substrate after forming the second semiconductor layer. Thereby growing the cavity in the first semiconductor layer. Accordingly, the growth substrate can be removed by the growth of the cavity, so that it is not necessary to separate the growth substrate using a laser, and thus the substrate manufacturing cost can be reduced.
Description
The present invention relates to a semiconductor substrate manufacturing method and a light emitting device manufacturing method, and more particularly, to a semiconductor substrate manufacturing method and a light emitting device manufacturing method using a novel peeling method of a growth substrate.
BACKGROUND OF THE INVENTION Light emitting diodes (hereinafter referred to as LEDs) using gallium nitride (GaN) -based semiconductors have been used in various devices such as signal signals and backlights of liquid crystal panels. It is known that the luminous efficiency of LED is influenced by dislocation density and defect of a crystal. Crystal growth of GaN-based semiconductors is performed on dissimilar substrates such as sapphire, but it is considered that lattice mismatch and mismatch of thermal expansion coefficients occur between the GaN layer and the substrate, leading to an increase in high potential density and defects.
Here, it is preferable to perform crystal growth of a GaN type semiconductor on the board | substrate of the same material, such as a GaN substrate. On the other hand, GaN is difficult to form a GaN melt due to the high dissociation rate of nitrogen, etc., making it difficult to manufacture a GaN substrate. In order to peel GaN bulk crystals grown for GaN substrates as GaN substrates, mechanical polishing and laser peeling are used, but it is very difficult to reproduce practically sized GaN substrates. In particular, peeling using a laser requires a large amount of time, causing a cost increase of the GaN substrate.
In addition, in the paper "Polycrystalline GaN for light emitter and field electron emitter applications" S. Hasegawa, S. Nishida, T. Yamashita, H. Asahi, Thin Solid Films 487 (2005) 260-267, W, Mo An example of crystal growth of GaN using plasma assisted molecular beam epitaxy on high melting point metal substrates of Ta, Ta, and Nb, and on Si substrates is shown.
However, as described above, the manufacture of GaN substrates is very difficult and expensive, so that light emitting devices such as LEDs and laser diodes are often manufactured by growing GaN layers on dissimilar substrates such as sapphire. However, the increase in the high potential density and defects described above hinders the improvement of the light emitting performance of the LED. In addition, the sapphire substrate has a lower thermal conductivity than the GaN substrate and lowers the heat radiation of the device. This causes the long life of the LED or laser diode to be prevented.
In order to solve the problem of sapphire, on the other hand, after growing the GaN layer using these dissimilar substrates as a growth substrate, a secondary substrate is attached, and using an excimer laser, GaN at the interface between the sapphire and the GaN layer, which is a growth substrate, is grown. Laser lift-off methods have been developed to locally decompose the layer to remove sapphire. This method is particularly used for manufacturing light emitting devices having vertical structures suitable for large area light emitting diodes (power chips) and the like.
However, as described above, peeling of the growth substrate using a laser requires a large amount of time, thereby increasing the manufacturing cost of the light emitting element. In addition, in order to irradiate a laser through sapphire, it is necessary to increase the laser transmittance of sapphire and polish the exposed surface of sapphire. For this reason, the thickness of sapphire becomes thin and it is unsuitable to use again.
The technical problem to be solved by the present invention is to provide a semiconductor substrate manufacturing method and a light emitting device manufacturing method that can remove the growth substrate without using a laser.
The technical problem to be solved by the present invention is to provide a semiconductor substrate manufacturing method and a light emitting device manufacturing method capable of reusing the growth substrate without the need to polish the growth substrate.
According to one Embodiment of this invention, the manufacturing method of a semiconductor substrate is provided. The method forms a first semiconductor layer on a substrate, forms a metallic material layer in a pattern shape on the first semiconductor layer, and forms a second semiconductor layer on the first semiconductor layer and on the metallic material layer. And forming a cavity in the first semiconductor layer below the metallic material layer, wherein the cavity is formed by the first semiconductor layer below the metallic material layer and the metallic material layer. Reacting to form the first semiconductor layer is etched, and after forming the second semiconductor layer, heating the substrate to grow the cavity in the first semiconductor layer.
The substrate can be easily peeled from the second semiconductor layer by the growth of the cavity.
The metallic material layer is formed on the first semiconductor layer in a stripe shape at regular intervals and widths, and the second semiconductor layer is formed to a thickness covering the metallic material layer.
It is preferable that a part of the metallic material layer is formed of an oxide film, and the oxide film forms a mask for the first semiconductor layer.
The metallic material layer may be formed to a thickness in which a plurality of holes are formed in the process of forming the second semiconductor layer.
The metallic material layer is formed by using a metallic material having a higher melting point than the heating temperature when the second semiconductor layer is formed.
In addition, a part of the metallic material layer is formed of an oxide film, and the oxide film forms a mask for the first semiconductor layer and forms a plurality of holes in the process of forming the second semiconductor layer. And forming the second semiconductor layer using an organometallic vapor phase growth method, reacting the first semiconductor layer below the portion where the metallic material layer is formed with the metallic material layer and nitrogen to form a plurality of the plurality of semiconductor layers. Evaporation from the pores can form the cavity.
The metallic material layer is tantalum, the film thickness is in the range of 5 nm to 100 nm, and the surface of the tantalum on the first semiconductor layer may include tantalum and tantalum oxide.
In addition, the substrate may be a sapphire substrate or a silicon-based substrate.
Meanwhile, the heating of the substrate may be performed so that the substrate temperature is 300 ° C. or higher, and preferably, the substrate temperature may be 900˜1100 ° C. FIG.
The metallic material layer may be formed of a metal selected from the group consisting of Ta, Ni, Cr, Pt, and Mo, or an alloy thereof.
According to one embodiment of the present invention, a light emitting device manufacturing method is provided. The method comprises forming a first semiconductor layer on a first substrate, forming a metallic material layer in a pattern shape on the first semiconductor layer, and forming a second semiconductor on the first semiconductor layer and the metallic material layer. While forming a layer, a cavity is formed in the first semiconductor layer below the metallic material layer, a first compound semiconductor layer is formed on the second semiconductor layer, and the first compound semiconductor is formed. Forming an active layer on the layer, forming a second compound semiconductor layer on the active layer, attaching a second substrate on the second compound semiconductor layer, and heating the first substrate to The cavity is grown, wherein the cavity is formed by reacting the metallic material layer with the first semiconductor layer below the metallic material layer to etch the first semiconductor layer. The. The substrate can be easily peeled from the second semiconductor layer by the growth of the cavity.
The metallic material layer is formed on the first semiconductor layer in a stripe shape at regular intervals and widths, and the second semiconductor layer is formed to a thickness covering the metallic material layer.
It is preferable that a part of the metallic material layer is formed of an oxide film, and the oxide film forms a mask for the first semiconductor layer.
The metallic material layer may be formed to a thickness in which a plurality of holes are formed in the process of forming the second semiconductor layer.
The metallic material layer is formed by using a metallic material having a higher melting point than the heating temperature when the second semiconductor layer is formed.
In addition, a part of the metallic material layer is formed of an oxide film, and the oxide film forms a mask for the first semiconductor layer, and forms a plurality of holes in the process of forming the second semiconductor layer. And forming the second semiconductor layer by an organometallic vapor phase growth method, reacting the first semiconductor layer below the portion where the metallic material layer is formed with the metallic material layer and nitrogen to form the plurality of holes. Can be evaporated from to form the cavity.
The metallic material layer is tantalum, the film thickness is in the range of 5 nm to 100 nm, and after formation on the first semiconductor layer, the surface of the tantalum on the first semiconductor layer may include tantalum and tantalum oxide. Can be.
In addition, the first substrate may be a sapphire substrate or a silicon-based substrate.
Meanwhile, the heating of the first substrate may be performed so that the temperature of the first substrate is 300 ° C. or more, and preferably, the substrate temperature may be 900˜1100 ° C. FIG.
The metallic material layer may be formed of Ta, Ni, Cr, Pt, or Mo, or an alloy thereof.
In addition, heating the first substrate may be performed while attaching the second substrate.
According to the present invention, the substrate can be easily removed by forming a cavity between the growth substrate and the semiconductor layer formed thereon and growing the cavity. Therefore, growth substrates such as sapphire can be removed without using a laser, and semiconductor substrates such as GaN substrates and light emitting devices can be manufactured at low cost. In addition, it is possible to grow the cavity by heating in a process such as secondary substrate bonding, it is possible to peel the growth substrate without additional process for removing the growth substrate can simplify the light emitting device manufacturing process.
EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail based on attached drawing. In addition, embodiment described below is only one form of this invention, respectively, and this invention is not limited to this embodiment.
(Embodiment 1)
FIG. 1: is a figure which shows the outline of the manufacturing method of the
In FIG. 1A, 101 is a sapphire (Al 2 O 3 ) substrate as a growth substrate. First, a
Next, in FIG. 1B, a Ta layer (metallic material layer) 103 having a thickness of about 50 nm is formed into a stripe shape by using EB (Electron Beam) deposition and lift-off on the
Next, in FIG. 1C, the
On the other hand, the
Next, in FIG. 1D, the formation of the
Next, in FIG. 1E, the
The
As mentioned above, by forming the
(Example 1)
Next, the specific example of the manufacturing method of the said
The
As shown in the spectral diagram by EDX in FIG. 3, GaN of the
In Example 1, it was observed that the
In FIG. 5, (A) is a SEM cross-sectional photograph of the
In the SEM cross-sectional photograph of the
As described above, in the
In addition, the setting conditions of the MOCVD apparatus shown in the said Example 1 are an example, What is necessary is just the conditions which can advance the growth of 1st GaN layer mentioned above, and formation of the
In the first embodiment, although the
In the
In addition, although the sapphire substrate was used as a growth substrate in the first embodiment, the substrate is not particularly limited as long as it is a substrate capable of growing a GaN layer such as a silicon-based substrate.
(Example 2)
In the second embodiment, a process of forming the
12 shows a
In the
In the cross-sectional view shown in FIG. 12, the
In addition, the setting conditions of the MOCVD apparatus shown in the said Example 2 are an example, What is necessary is just the conditions which can advance the growth of the above-mentioned 1st GaN layer, and formation of the
In Example 2, although the
In the
(Example 3)
In the third embodiment, a process of forming the
13 shows a
In the
In addition, the setting conditions of the MOCVD apparatus shown in the said Example 3 are an example, What is necessary is just the conditions which can advance the growth of the above-mentioned 1st GaN layer, and formation of the
In the third embodiment, although the
(Example 4)
In the fourth embodiment, a process of forming the
14 shows a
In the
In addition, the setting conditions of the MOCVD apparatus shown in the said Example 4 are an example, What is necessary is just the conditions which can advance the growth of the above-mentioned 1st GaN layer, and formation of the
In the fourth embodiment, the
(Comparative Example 1)
Next, the comparative example with respect to Example 1 mentioned above is demonstrated. In this comparative example, a specific example of forming the
In Comparative Example 1, the heating temperature was set to 1045 ° C. while TMGa was flowed at 87 μmol / min using TMGa as the source gas, and crystal growth was performed for 5 hours.
The
The result of EDX analysis of the surface of the said particulate matter is shown in FIG. In FIG. 8, (A) is the spectral diagram which EDX analyzed the granular material of FIG. 7 (B), (B) is the EDX diagram of Ga which EDX analyzed the granular material of FIG. 7 (B), (C) is It is EDX diagram of N which EDX analyzed the granular material of FIG. Ga and N and some Ta were observed as shown in the spectral diagram of FIG. 8 (A), and Pa and N were observed as shown in the EDX diagram of FIGS. 8 (B) and (C).
Moreover, the result of EDX analysis of the cross section of a granular material is shown to FIG. 9 and FIG. In FIG. 9, (A) is the SEM cross-sectional photograph which enlarged the void part as a granular material of FIG. In FIG. 10, (A) is the EDX figure of Ga which EDX analyzed the cross section of FIG. 9 (A), (B) is the EDX figure of N which EDX analyzed the cross section of FIG. 9 (A), (C) is It is EDX figure of Ta which EDX analyzed the cross section of FIG. 9 (A).
As shown in the spectral diagram of FIG. 9B, Ga and N of the
From the above observation results, it was found that the granular material deposited on the surface of the
As described above, in the setting conditions of the MOCVD apparatus of Comparative Example 1, since the flow rate of TMGa was set to 87 μmol / min more than that of Example 1, it was found that the above-mentioned granular material precipitated on the substrate and was not usable as the substrate. It became. Therefore, it turned out that the preferable flow volume X of TMGa which a granular material does not precipitate on a board | substrate is the range of X <87 micromol / min.
(About Ta 2 O 5 formation of Ta layer)
In Examples 1 to 4, an example of changing the thickness of the
The
In the first to fourth embodiments, the Ta 2 O 5 region oxidized by the
Therefore, the thickness of the
(Embodiment 2)
Next, the case where LED is formed as an example of the semiconductor element formed on the
11 is a partial cross-sectional view for illustrating the LED according to the second embodiment.
In FIG. 11, a plurality of
In this case, the
The
In addition, the
In this manner, after the plurality of
As described above, by manufacturing the plurality of
In the second embodiment, the
Therefore, by forming semiconductor elements such as LEDs and laser diodes using the
(Embodiment 3)
Next, the light emitting element manufacturing method using growth substrate peeling is demonstrated with reference to FIG.
17 is a cross-sectional view illustrating a method of manufacturing a light emitting device according to the third embodiment.
In FIG. 17A, as described with reference to FIGS. 1A to 1D, the
In FIG. 17B, a first conductivity type
The first conductive compound semiconductor layer, the active layer, and the second conductive compound semiconductor layer may be gallium nitride-based compound semiconductors, and may be formed using an organometallic vapor phase growth method. The
While growing the first conductivity type
Thereafter, a
In FIG. 17C, the
The heating of the
In addition, although the neighboring
In FIG. 17D, after the
In FIG. 17E, the
The first conductive semiconductor layer may be a gallium nitride-based n-type compound semiconductor, and the second conductive semiconductor layer may be a gallium nitride-based p-type compound semiconductor. Accordingly, a roughened surface may be formed on the release surface, for example, the surface of the first conductivity
In the third embodiment, a method of manufacturing a light emitting device having a vertical structure has been described. However, as described in the second embodiment, after the
In the present embodiment, the
As described above, after growing the gallium nitride-based compound semiconductor layers on a growth substrate such as sapphire, the growth substrate can be easily peeled off without using a laser, thereby reducing the manufacturing cost of the LED. In addition, it is not necessary to perform the sapphire polishing necessary for the laser lift off process, so that it is possible to reuse the sapphire substrate.
In the above embodiments, the use of Ta as the metallic material layer has been described. However, the present invention is not limited to this, and Ta, Pt, Ni, Cr or Mo may be used, or an alloy of these metals or an alloy such as a metal and a semiconductor may be used. It may be used and may be a metallic material that exerts an etching effect on the first GaN layer described above.
BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the manufacturing method of the semiconductor substrate which concerns on
2 is a SEM cross-sectional photograph of a semiconductor substrate according to Example 1. FIG.
3 is a spectral diagram of EDX according to Example 1. FIG.
4 is a SEM cross-sectional photograph of the enlarged region of FIG. 2, (B) is an EDX of Ga, (C) is an EDX of Al, and (D) is an EDX diagram of O.
5 is a SEM cross-sectional photograph of a semiconductor substrate, and (B) is a SEM surface photograph of a semiconductor substrate according to Example 1. FIG.
6 is an EDX diagram of the semiconductor substrate according to Example 1, (A) is an EDX diagram of Ga, and (B) is an EDX diagram of Ta.
7 is a SEM photographic image of a semiconductor substrate, and (B) is a SEM surface photograph of a semiconductor substrate according to Comparative Example 1. FIG.
8 is a spectral diagram of EDX of FIG. 7B, (B) is EDX diagram of Ga of FIG. 7B, and (C) is N of FIG. 7B. EDX is also.
9 is a SEM cross-sectional photograph of a void according to Comparative Example 1, and (B) is an EDX spectrum diagram of (A).
Fig. 10 is a diagram showing ED ED of Ga of Fig. 9A, (B) according to Comparative Example 1, Fig. 9B shows ED ED of N of Fig. 9A, and Fig. 9C shows Ta of Fig. 9A. EDX is also.
11 is a cross-sectional view showing the configuration of an LED array according to
12 is a SEM cross-sectional photograph of a semiconductor substrate according to Example 2. FIG.
13 is a SEM cross-sectional photograph of a semiconductor substrate according to Example 3. FIG.
14 is a SEM cross-sectional photograph of a semiconductor substrate according to Example 4. FIG.
Fig. 15 is a diagram schematically showing an example in which a Ta layer having a thickness of 5 nm is changed to Ta 2 O 5 , and (B) is a diagram schematically illustrating an example in which the surface of a Ta layer having a thickness of 100 nm is changed to Ta 2 O 5 . It is a figure shown normally.
Fig. 16 (A) is a SEM surface photograph of a substrate on which a Ta mask having a thickness of 5 nm is formed, and (B) is a SEM cross-sectional photograph of a substrate on which a Ta 2 O 5 mask having a thickness of 10 nm is formed.
17 is a cross-sectional view illustrating a method of manufacturing a light emitting device according to
Claims (20)
Priority Applications (13)
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KR1020090079436A KR101229832B1 (en) | 2009-08-26 | 2009-08-26 | Method of fabricating semiconductor substarte and method of fabricating lighe emitting device |
CN201510088799.9A CN104658890B (en) | 2009-08-26 | 2010-07-22 | Manufacture the method for semiconductor base and the method for manufacture light-emitting device |
CN201080038363.4A CN102640307B (en) | 2009-08-26 | 2010-07-22 | Method for manufacturing a semiconductor substrate and method for manufacturing a light-emitting device |
EP10812163.3A EP2472604B1 (en) | 2009-08-26 | 2010-07-22 | Method for manufacturing a light-emitting device |
CN201510089036.6A CN104716023B (en) | 2009-08-26 | 2010-07-22 | Manufacture the method for semiconductor base and the method for manufacture light-emitting device |
CN201510088677.XA CN104795313B (en) | 2009-08-26 | 2010-07-22 | Manufacture the method for semiconductor base and the method for manufacture light-emitting device |
PCT/KR2010/004816 WO2011025149A2 (en) | 2009-08-26 | 2010-07-22 | Method for manufacturing a semiconductor substrate and method for manufacturing a light-emitting device |
JP2012526622A JP5847083B2 (en) | 2009-08-26 | 2010-07-22 | Method for manufacturing light emitting device |
CN201510088718.5A CN104795314B (en) | 2009-08-26 | 2010-07-22 | The method for manufacturing light-emitting device |
US12/805,958 US8026119B2 (en) | 2009-08-26 | 2010-08-26 | Method of fabricating semiconductor substrate and method of fabricating light emitting device |
US13/137,124 US8183075B2 (en) | 2009-08-26 | 2011-07-21 | Method of fabricating semiconductor substrate and method of fabricating light emitting device |
US13/506,295 US8329488B2 (en) | 2009-08-26 | 2012-04-10 | Method of fabricating semiconductor substrate and method of fabricating light emitting device |
US13/694,058 US8609449B2 (en) | 2009-08-26 | 2012-10-25 | Method of fabricating semiconductor substrate and method of fabricating light emitting device |
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JP2002223008A (en) | 2000-10-17 | 2002-08-09 | Koninkl Philips Electronics Nv | Light emitting element |
KR20100079466A (en) * | 2008-12-31 | 2010-07-08 | 광주과학기술원 | Method for fabricating of light emitting diode |
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JP2002223008A (en) | 2000-10-17 | 2002-08-09 | Koninkl Philips Electronics Nv | Light emitting element |
KR20100079466A (en) * | 2008-12-31 | 2010-07-08 | 광주과학기술원 | Method for fabricating of light emitting diode |
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