KR20090010349A - Wafer cutting method and jig for wafer multi-bonding - Google Patents

Abstract

A wafer cutting method and jig for wafer multi-bonding is provided to reduce a wafer fabrication time and cost by arranging separated a plurality of insertion holes to be faced with each other. A plurality of wafers separated from the base substrate for the film growth is arranged. A plurality of arranged wafers(300) is welded, and the wafer welded by the multiple is processed to be the same size through one machining. The welded wafers are individually separated, and the arrangement of a plurality of wafers is performed through the separated jig of structure in which a plurality of insertion holes is spaced apart by the fixed interval. The azimuth plane of each wafer is in accord with the arrangement of a plurality of wafers. Wafer is the gallium nitride film or the thick film which grows from the different substrate or same substrate.

Description

WAFER CUTTING METHOD AND JIG FOR WAFER MULTI-BONDING

The present invention relates to a wafer processing method and a jig for multiple wafer bonding, and proposes a method for processing a large area gallium nitride thick film in large quantities at one time, and a jig capable of multiple wafer bonding and alignment.

Gallium nitride is a semiconductor material having an energy bandgap of 3.39 eV and a direct transition type, and is useful for manufacturing light emitting devices in a short wavelength region. Because of the high nitrogen vapor pressure at the melting point, gallium nitride single crystal requires high temperature of 1500 ℃ or higher and 20000 atmosphere of nitrogen atmosphere, which makes it difficult to mass-produce it. Difficult to use

Until now, gallium nitride films have been grown on heterogeneous substrates by vapor phase growth methods such as metal organic chemical vapor deposition (MOCVD) or hydraulic vapor phase epitaxy (HVPE). The MOCVD method is difficult to use to obtain a GaN substrate of tens or hundreds of micrometers because the growth rate is too slow even though a high quality film can be obtained. For this reason, a growth method using HVPE is mainly used to obtain a GaN thick film.

A sapphire substrate is most commonly used as a dissimilar substrate for manufacturing a gallium nitride film because sapphire has a hexagonal structure such as gallium nitride, which is inexpensive and stable at high temperatures. However, sapphire causes strain at the interface due to gallium nitride and lattice constant difference (about 16%) and coefficient of thermal expansion (about 35%), which causes lattice defects and cracks in the crystals. It is difficult to grow a high quality gallium nitride film and shorten the life of the device fabricated on the gallium nitride film.

Gallium nitride grown on a heterogeneous substrate or the same substrate as sapphire needs to be separated from the base substrate and processed into a size desired by a customer. For example, as shown in FIG. 1, the gallium nitride (110a) thin film or thick film grown on the base substrate 100 is separated from the substrate, and the separated individual gallium nitride (110b) thin film or thick film is shown in FIG. 2. As described above, the edge is cut to form a diameter D of a desired size and the crystal azimuth surface 111 is formed.

The gallium nitride wafer grown on the base substrate has a problem in that the wafer size is not constant due to cracks, etc., and when the individual processing is performed, the processing process is complicated and the cost is increased in the mass processing of the wafer. In addition, there is a problem in that the processing accuracy (wafer size, crystal orientation surface) of each wafer is changed by the individual processing of the wafers.

Accordingly, it is an object of the present invention to provide a method for precisely and rapidly processing wafers in large quantities.

Another object of the present invention is to provide a method for precisely processing a plurality of wafers in the same size and forming an azimuth surface in one machining process.

In order to achieve the above object, the present invention aligns a plurality of wafers separated from the base substrate for thin film or thick film growth, bonds the plurality of aligned wafers, and multi-bonds the wafers in the same size through a single processing process. Processing, and separating the bonded wafers individually.

Alignment of the plurality of wafers is preferably performed through a jig having a structure in which a plurality of insertion grooves are spaced at predetermined intervals. It is also desirable to match the azimuth of each wafer upon alignment of the plurality of wafers.

The joining of the plurality of wafers may use a joining member that can be removed using a soluble bonding agent or wax or other post-bonding heating or solvent.

For precise processing of multi-bonded wafers, a master sample is prepared, the shape of the master sample is measured, data conversion is performed, the data is transferred to a processing apparatus, and the processing apparatus is driven through the transferred data to multi-bond. The processed wafers can be processed simultaneously.

The present invention is also a container-type structure having at least one surface open to the outside, a plurality of insertion grooves formed in the structure, the plurality of insertion grooves spaced at a predetermined interval arranged jig for wafer bonding, characterized in that arranged To provide.

It is preferable that a soft pad is attached to two opposite inner surfaces of the insertion groove, and in this case, the distance between the soft pads attached to the two inner surfaces of the insertion groove is preferably less than or equal to the thickness of the wafer to be processed. In addition, it is preferable that the length excluding the pair of insertion grooves facing each other in the structure is larger than the wafer processing limit.

According to the present invention, a plurality of wafers can be processed simultaneously in one processing step. In particular, while processing a plurality of wafers in the same size can form an azimuth surface, it is possible to significantly reduce the wafer processing time and processing cost.

The present invention provides a processing method for cutting a large amount of wafers of a thin film or a thick film grown on a base substrate such as gallium nitride at once and a structure for aligning and bonding a plurality of wafers for this processing.

Figure 3 is a perspective view showing an embodiment of a jig (200) for multiple wafer bonding according to the present invention, at least one surface is a container-type structure is open to the outside, a plurality of spaced apart at predetermined intervals inside the structure The insertion groove 210 of the two sides facing each other are arranged opposite to each other.

The intervals between the insertion grooves 210 may be formed to be the same, and the number of insertion grooves may be appropriately changed according to the number of wafers for simultaneous processing. The material of the structure does not need to be particularly limited as long as it can maintain physical support, and metals, plastics and other materials may be used.

It is preferable that the soft pads 230 are attached to two opposite inner surfaces of the insertion groove, as can be seen in FIG. This soft pad facilitates the alignment of the wafers inserted into the alignment grooves as will be described later, mitigates external impacts on the wafers and at the same time allows the wafers to be fixed inside the jig. Therefore, as the material of the soft pad, a material such as rubber or urethane having elasticity will be preferable.

The spacing w between the soft pads attached to the two inner surfaces of the insertion groove is preferably less than the thickness of the wafer to be processed to secure the wafer.

5 is a plan view of a jig for multiple bonding wafers according to the present invention. The overall height of the jig should be about 1/2 or more of the height of the wafer to be processed, but the horizontal length of the jig needs to be appropriately designed in consideration of the degree of wafer processing. The total length Lt of the jig is designed to be larger than the length (diameter) of the wafer to be processed. The length Lo excluding the lengths of the two insertion grooves facing each other of the jig is preferably at least the processing limit of the wafer to be inserted and aligned in the insertion groove 235, that is, the diameter of the wafer on which the processing is finally completed.

6 is a wafer to be processed in a jig according to the present invention, and the gallium nitride wafers 110b separated from the substrate after being grown on a heterogeneous substrate are inserted and aligned between the soft pads 230 of the insertion groove 210. It is showing. Unlike the present embodiment, the present invention may be usefully applied to the processing of wafers of other materials separately grown through the base substrate in addition to the gallium nitride wafer.

The plurality of wafers are aligned at equal intervals and the space between the wafers is empty. Although the space between the wafers 205 is shown relatively large for ease of understanding, the smaller the space between the wafers is desirable if the space between the wafers can be filled.

A liquid bonding member (for example, wax) is filled into the jig for mutual bonding of a plurality of wafers inserted and aligned in the jig. After the bonding members are solidified and the aligned wafers are bonded to each other, the multiple bonded wafers 300 are removed from the jig as shown in FIG. 7 to prepare for processing.

Although the bonding member 400 between the wafers 110b is preferably located below the wafer processing region (G region), the bonding member 400 may be partially polished or cut during the wafer processing process. Although the edges of the wafers 110b are mutually nonuniform, they are all processed into wafers 110c of the same size (ie, the same diameter D) as shown in FIG. 8 by simultaneous machining. One surface of the multi-bonded wafer 300a processed into a circle may be partially polished to form a crystal orientation surface C together.

In order to form the crystal azimuth planes on a plurality of wafers in one machining process, it is necessary to insert the wafers into the jig so that the azimuth planes are arranged in a predetermined direction while the wafer azimuth planes are marked by using an azimuth measuring device in advance. desirable.

The finally processed wafers separate the wafers 300b separately by removing the bonding member (FIG. 9).

The processing of the multi-bonded wafer can use, for example, a processing apparatus in which the processing portion is linearly moved while rotating the workpiece to polish or cut the outer surface of the workpiece.

In this case, a data network transmission method may be used for processing precision and speed of processing. For example, referring to the flowchart of FIG. 10, a plurality of wafers of different sizes are inserted into a jig as shown in FIG. 3 (step S1), and a wafer is filled by filling a bonding member between the aligned wafers. Joining is made into one integrated mass (step S2).

In order to precisely and quickly process a multi-bonded wafer, a master sample of a desired shape is finally prepared by processing (step S3 '), the shape of the master sample is measured, data conversion is performed, and the data is transferred to a processing apparatus. Transmit (step S4 ').

The processing apparatus is driven through the transferred data to simultaneously process the multi-bonded wafers at once (step S3), and the wafers are separated (step S4) to complete the simultaneous processing process.

Appropriate software may be used to measure the shape of the master sample and convert the measured values into computer-recognized data, and network transfer of data may employ known techniques. In addition, in order to drive the machining apparatus by the transmitted data, appropriate software for controlling the driving unit for moving the position of the machining unit (for example, the grinding unit or the cutting unit) based on the transmitted data may be used.

The present invention has been exemplarily described through the preferred embodiments, but the present invention is not limited to such specific embodiments, and various forms within the scope of the technical idea presented in the present invention, specifically, the claims. May be modified, changed, or improved.

1 is a schematic view showing a state in which a wafer grown on a base substrate is separated.

2 is a perspective view of an individually processed wafer.

Figure 3 is a perspective view of a jig for multiple bonding wafer in accordance with the present invention.

4 is an enlarged view of a portion A of FIG. 3;

5 is a plan view of the jig of FIG.

6 is a plan view showing a state in which the wafer is charged and aligned in the jig of FIG.

7 is a side view showing a multiple bonded wafer separated from a jig for processing.

Figure 8 is a perspective view showing a multi-junction wafer completed processing.

9 is a perspective view showing the wafers separated individually;

10 is a flow chart showing an example of a wafer processing method according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

200: jig 210: insertion groove

230: soft pad 300: multi-bonded wafer

Claims (11)

Aligning a plurality of wafers separated from the film growth base substrate, Bonding a plurality of aligned wafers, Multi-bonded wafers are processed to the same size in one machining process, Separating the bonded wafers individually Wafer processing method. The wafer processing method of claim 1, wherein the plurality of wafers are aligned through a jig having a structure in which a plurality of insertion grooves are spaced at predetermined intervals. The wafer processing method according to claim 1, wherein the azimuth of each wafer coincides when the plurality of wafers are aligned. The method of claim 1, wherein the bonding of the plurality of wafers is a soluble binder or wax. The method of claim 1, wherein the wafer is a gallium nitride thin film or a thick film grown and separated from a heterogeneous substrate or a homogeneous substrate. The method of claim 1, wherein the processing of the multi-bonded wafer is By processing, finally prepare the master sample of the desired shape, Performing a data transformation by measuring the shape of the master sample, Transfer the data to the processing apparatus, A wafer processing method characterized by simultaneously processing multiple bonded wafers at once by driving a processing apparatus through the transmitted data. The method of claim 1, comprising simultaneously processing the multiple bonded wafers to form a crystallographic orientation. A container structure having at least one surface open to the outside, It is formed in the structure, characterized in that the plurality of insertion grooves spaced at predetermined intervals are arranged to face each other Jig for multi-wafer bonding. The jig for multi-wafer bonding according to claim 8, wherein soft pads are attached to two opposite inner surfaces of the insertion groove. The jig for multi-junction wafers according to claim 9, wherein a distance between the soft pads attached to two inner surfaces of the insertion groove is equal to or less than a thickness of the wafer to be processed. The jig for multi-junction wafers according to claim 8, wherein the length of the structure except for a pair of oppositely facing insertion grooves is larger than a wafer processing limit.

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