KR20090041088A - The fabricating method of pattened sapphire substrate using imprinting - Google Patents

Abstract

A method for fabricating a sapphire substrate patterned by using an imprinting process is provided to improve efficiency of illuminance by using the sapphire substrate with various surface patterns as a reflector through difference of a refractive index. A molder with an engraved pattern is manufactured. The polymer resin is laminated on a sapphire substrate(20). The molder with the engraved pattern is covered on the sapphire substrate laminated with the polymer resin. When the molder is covered on the sapphire substrate, the polymer resin is cured by applying the heat or UV after giving the pressure. The sapphire substrate and the molder are separated. The molder is made by using at least one of silicon, polymer resin, nickel, and silica or more. The polymer resin is thermosetting polymer resin or UV curable polymer resin.

Description

The Fabricating Method of Pattened Sapphire Substrate Using Imprinting}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor substrate, and more particularly, to pattern deformation caused by a bad pattern mass production and a hard baking process due to misalignment of an interface pattern of an exposure pattern when an etch obstacle is manufactured by a stepper device. The present invention relates to a method for manufacturing a patterned sapphire substrate using an imprinting process in which an imprinting process is applied to a sapphire substrate processing process by using a molder in which a predetermined pattern is engraved.

The coherent growth technology of gallium nitride is an innovative technique for manufacturing semiconductor lasers and light emitting diodes. Since the development of blue light emitting diodes through coherent growth of gallium nitride in Japan, coherent growth technology of gallium nitrides has developed a lot, and demand will continue to increase.

The growth technology of gallium nitride is mainly achieved through metal organic chemical vapor deposition and molecular beam epitaxy. A growth substrate is required to make a gallium nitride growth layer. The growth substrate should use a substrate having the same or similar lattice constant as gallium nitride, and commonly used silicon carbide and sapphire substrates.

However, these substrates do not have an accurate lattice constant of gallium nitride, which creates many defects in the growth layer of gallium nitride. A common way to minimize this problem is to grow gallium nitride using a patterned sapphire substrate.

The patterned sapphire substrate process is to produce polymer etch barriers using flat lithography on flat sapphire substrates, and to create patterns with regular patterns on the surface of the substrate through dry or wet etching. In many places, this technique has been used to reduce the defects of gallium nitride coherent growth films, thereby increasing luminous efficiency and yield.

Lithographic printing processes of the conventional patterned sapphire substrate manufacturing process has a contact and a non-contact method, when using a non-contact lithography method to define a polymer pattern of several micro or less.

Such non-contact lithography often uses a device called "stepper," which is a method of defining a pattern group by exposing a certain area instead of exposing one wafer at a time. At this time, distortion and damage of the pattern appear due to misalignment at the interface of the patterns having different exposure exposure order, thereby lowering the yield.

Photosensitizers used in lithography are materials that interfere with etching when dry or wet etching is performed. It is an exposure apparatus which can define the width | variety and the width | variety of the said photosensitive agent pattern, and the photosensitive agent exposed by the said exposure apparatus will have a predetermined pattern using a developing solution.

However, the patterned photoresist is weak to external impact and chemical action during etching, so it proceeds with "hard baking", which is left at a temperature of more than 100 ° C for a few minutes. However, this process applies high heat to the photoresist, which is a polymer, so that the pattern defined by the exposure collapses or the pattern is deformed.

When etching with the deformed pattern as described above, the deformed pattern is also transferred to the sapphire substrate, which causes a problem of lowering the yield.

Also, in lithographic printing, the pattern of photoresist is defined as the link between the molecules of photoresist that is exposed and exposed to light. The problem with such lithography is that the light is only exposed on top of the photoresist, so the pattern is only in the form of a column.

For example, there are cylinders, square columns, pentagonal columns. This pattern of etch obstacles limits the patterns that can be made because they are partially transferred to the patterns of the sapphire substrate after etching. In particular, in the case of the sapphire substrate having the most used cone-shaped pattern is manufactured using the photoresist pattern of the cylinder as an etch obstacle. However, since the plasma etch transfers the pattern of the etch barrier, after the etching process is finished, a pattern defect such as a non-uniform pattern or a cylindrical shape appears. In addition, even though it is said that a pattern other than pillars is made through lithographic printing, it is not reliable in terms of mass production.

The present invention solves the problems of mass production of defective patterns due to misalignment in lithographic printing process, pattern deformation caused by hard baking, and reduction of device yield, and various patterns of sapphire. The present invention relates to a method for manufacturing a sapphire substrate which can be formed on a substrate, thereby improving the efficiency of roughness according to the use purpose of the device, and improving productivity by reducing the manufacturing time by simplifying the process steps.

The first manufacturing method of the sapphire substrate according to the present invention for achieving the above object,

Manufacturing a molder in which a pattern is formed in an intaglio;

Stacking a polymer resin on a sapphire substrate;

Covering the molder having the intaglio pattern on the sapphire substrate on which the polymer resin is laminated;

Applying pressure in a state where the molder is covered on the sapphire substrate, and then curing the polymer resin by applying heat or ultraviolet (UV);

Separating the sapphire substrate and the molder

It is made, including.

The second manufacturing method of the sapphire substrate according to the present invention,

Manufacturing a molder in which a pattern is formed in an intaglio;

Stacking a polymer resin on the molder;

Covering the sapphire substrate on a molder in which the polymer resin is laminated;

Applying pressure in a state in which the sapphire substrate is covered on the molder, and then curing the polymer resin by applying heat or ultraviolet (UV);

Separating the sapphire substrate and the molder

It is made, including.

In the first and second manufacturing methods, the intaglio pattern is characterized in that at least one or more of a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, or a polygonal truncated cone.

In the first and second manufacturing methods, the molder is manufactured using at least one or more of silicon, polymer resin, nickel and silica.

In the first and second production method, the polymer resin is characterized in that the thermosetting polymer resin or ultraviolet curable polymer resin.

In the first and second manufacturing method, the polymer resin is characterized in that formed to a thickness of 3um.

According to the sapphire substrate manufacturing method according to the present invention having the configuration as described above,

Since the pattern is transferred 1: 1 between the molder and the sapphire substrate, poor yield is reduced, and unlike lithography, the pattern is made without a "hard baking" process, thereby reducing the yield caused by the deformation of the pattern. You can prevent it.

In addition, unlike lithography, in which a variety of processes are applied, the imprinting process is simple, thereby reducing the process period.

In addition, since the etching obstacles of the various patterns manufactured according to the present invention may make various surface patterns of the sapphire substrate, the sapphire substrate after the manufacture serves as a reflector due to the refractive index difference, the patterns produced on the sapphire substrate Influence on the roughness of the device of the device has the effect of increasing the efficiency of the roughness according to the use of the device.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; First, it should be noted that the same components or parts in the drawings represent the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the gist of the present invention.

1 to 5 are process charts showing a first method of manufacturing a sapphire substrate according to the present invention, FIGS. 6 to 10 are process charts showing a second method of manufacturing a sapphire substrate according to the present invention, and FIG. FIG. 12 schematically illustrates the surface of a sapphire substrate manufactured by the method for manufacturing a sapphire substrate according to the present invention. FIG. 12 is a computer calculation of the influence on the roughness of a semiconductor device when the sapphire substrate shown in FIG. 11 is used. One graph shows the results compared to the existing substrate.

A first manufacturing method of the sapphire substrate will be described with reference to FIGS. 1 to 5.

Referring to FIG. 1, first, a molder 10 in which patterns 11, 12, and 13 are formed in an intaglio is manufactured. The intaglio pattern 11, 12, 13 is at least one of a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, or a polypyramid.

The present invention has an advantage that the pattern can be formed in a desired shape such as a cone, a polygonal pyramid, a truncated cone or a polypyramid, unlike the conventional method, by using a molder 10 having a pattern formed in an intaglio. Of course, the shape of the pattern is only an example, but is not limited thereto.

In this case, the molder 10 is manufactured using at least one of materials such as silicon, polymer resin, nickel, and silica. The method of processing the molder differs depending on the material of the molder, which can be manufactured by a known method.

Next, referring to FIG. 2, the polymer resin 30 is laminated on the sapphire substrate 20. In this case, the polymer resin 30 is a thermosetting polymer resin or an ultraviolet curable polymer resin, and specifically, the polymer resin is controlled to a uniform thickness by using equipment such as spin coating on a sapphire substrate, and in the case of thickness, the polymer is laminated. The thickness can be controlled using the viscosity of and the rotation rate per minute of spin coating. The control of the thickness is important as one of the factors that determine the thickness of the polymer resin remaining in the unwanted portion after completing the imprinting process.

As a preferred embodiment, the polymer resin is preferably formed to a thickness of 3um. When the polymer resin is formed to a thickness of 3um, after the pressurization process and heat or ultraviolet curing process to be described later, if the molder and the sapphire substrate is separated, the pattern is left only approximately 0.0001um height, formed in a pattern It is possible to minimize the residue other than the polymer resin on the sapphire substrate.

Next, referring to FIG. 3, the molder 10 on which the patterns 11, 12, and 13 are formed at the intaglio is formed on the sapphire substrate 20 on which the polymer resin 30 is stacked.

Next, referring to FIG. 4, a predetermined pressure is applied while the molder 10 is covered on the sapphire substrate 20. Thereafter, depending on the type of polymer resin laminated on the sapphire substrate, heat or ultraviolet (UV) is applied to cure the polymer resin 30. At this time, the process varies depending on the type of the polymer laminated.

For example, "Chemoptics CO-150 model", an ultraviolet curable polymer resin, needs to be exposed to ultraviolet light of 2500mJ / cm ² or more in a nitrogen atmosphere after applying appropriate pressure after attaching with a molder. After finishing baking at about 160 ℃ is separated from the molder. In the case of a thermosetting polymer resin (PMMA: Polymethly Methacrylate), after bonding with a molder, an appropriate pressure and a temperature of 100 ° C. or more are applied and separated from the molder.

Next, referring to FIG. 5, the sapphire substrate 20 and the molder 10 are separated using a known separation device. When the molder and the sapphire substrate are separated, the polymer resin stacked on the sapphire substrate may have patterns 11a, 12a, and 13a according to the intaglio shape of the molder. 11 is a diagram illustrating this by simulation. In FIG. 11, (a) is a conventional sapphire substrate, and a pattern is not formed, (b) is a pattern formed in a hemispherical shape, and (c) is a pattern formed in a cone shape.

In addition, the patterned polymer resin is used as an etching obstacle in a subsequent etching process. After the etching process, a conventional semiconductor device manufacturing process is performed.

A second manufacturing method of the sapphire substrate will be described with reference to FIGS. 6 to 10.

Referring to FIG. 6, first, a molder 10 in which patterns 11, 12, and 13 are formed in an intaglio is manufactured. The description of the pattern and the molder is the same as the first manufacturing method of the sapphire substrate described above.

Next, referring to FIG. 7, unlike the first manufacturing method in which the polymer resin is laminated on the sapphire substrate, the polymer resin 30 is laminated on the molder 10. In this case, the description of the polymer resin is the same as the first manufacturing method of the sapphire substrate described above.

Next, referring to FIG. 8, the sapphire substrate 20 is covered on the molder 10 in which the polymer resin 30 is stacked.

Next, referring to FIG. 9, a predetermined pressure is applied while the sapphire substrate 20 is covered on the molder 10. Thereafter, depending on the type of polymer resin laminated on the sapphire substrate 20, heat or ultraviolet (UV) is applied to cure the polymer resin 30. At this time, the process varies depending on the type of the polymer laminated, which is the same as the case of the first manufacturing method described above.

Next, referring to FIG. 10, the sapphire substrate 20 and the molder 10 are separated using a known separation device. When the molder and the sapphire substrate are separated, the polymer resin stacked on the sapphire substrate is patterned according to the intaglio shape of the molder. 11 is a diagram illustrating this by simulation. In FIG. 11, (a) is a conventional sapphire substrate, and a pattern is not formed, (b) is a pattern formed in a hemispherical shape, and (c) is a pattern formed in a cone shape.

In addition, the patterned polymer resin is used as an etching obstacle in a subsequent etching process. After the etching process, a conventional semiconductor device manufacturing process is performed.

Conventional dry or wet etching is influenced by the pattern of the etching obstacle to obtain a transferred pattern. In addition, since the conventional lithography can only define the width and width of the pattern, it is impossible to form a pattern of various shapes except a cylinder or a polygonal column.

However, unlike the conventional method, the first and second manufacturing methods of the present invention have the advantage of being able to form a pattern in a desired shape such as a cone, a polygonal pyramid, a truncated cone or a polypyramid, unlike the conventional method. . Of course, the shape of the pattern is only an example, but is not limited thereto.

The substrate of sapphire formed with various patterns can be used as a reflecting plate after the device process is completed and may affect the roughness depending on the purpose of manufacturing the device.

FIG. 12 is a graph illustrating a computer-calculated result of the influence on the roughness of a semiconductor device in comparison with a conventional substrate when the sapphire substrate shown in FIG. 11 is used.

Referring to this, it can be seen that the sapphire substrate shown in FIG. 11 has a 7.84% increase in illuminance compared to a flat plate (ie, a sapphire substrate having a pattern formed by a cylinder or a polygonal pillar). Therefore, it can be seen that the variety of patterns can vary the properties of the reflector to have a positive effect on the illuminance.

As described above with reference to the drawings illustrating a method for manufacturing a sapphire substrate according to the present invention, the present invention is not limited by the embodiments and drawings disclosed herein, but to those skilled in the art within the technical scope of the present invention Of course, various modifications can be made.

1 to 5 is a process chart showing a first manufacturing method of a sapphire substrate according to the present invention,

6 to 10 is a process chart showing a second manufacturing method of the sapphire substrate according to the present invention,

11 is a schematic view showing a simulation of the surface of the sapphire substrate produced by the method for manufacturing a sapphire substrate according to the present invention;

FIG. 12 is a graph illustrating a computer-calculated result of the influence on the roughness of a semiconductor device in comparison with a conventional substrate when the sapphire substrate shown in FIG. 11 is used.

<Description of the symbols for the main parts of the drawings>

10: Molder 20: Sapphire substrate

30: polymer resin 11-13: pattern

Claims (10)

Manufacturing a molder in which a pattern is formed in an intaglio; Stacking a polymer resin on a sapphire substrate; Covering the molder having the intaglio pattern on the sapphire substrate on which the polymer resin is laminated; Applying pressure in a state where the molder is covered on the sapphire substrate, and then curing the polymer resin by applying heat or ultraviolet (UV); Separating the sapphire substrate and the molder Patterned sapphire substrate manufacturing method using an imprinting process comprising a. The method according to claim 1, The engraved pattern is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that at least one or more of a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, or a polygonal truncated cone. The method according to claim 1, The molder is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that using at least one of silicon, polymer resin, nickel, silica. The method according to claim 1, The polymeric resin is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that the thermosetting polymer resin or ultraviolet curable polymer resin. The method according to claim 1, The polymer resin is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that formed to a thickness of 3um. Manufacturing a molder in which a pattern is formed in an intaglio; Stacking a polymer resin on the molder; Covering the sapphire substrate on a molder in which the polymer resin is laminated; Applying pressure in a state in which the sapphire substrate is covered on the molder, and then curing the polymer resin by applying heat or ultraviolet (UV); Separating the sapphire substrate and the molder Patterned sapphire substrate manufacturing method using an imprinting process comprising a. The method according to claim 6, The engraved pattern is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that at least one or more of a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, or a polygonal truncated cone. The method according to claim 5, The molder is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that using at least one of silicon, polymer resin, nickel, silica. The method according to claim 5, The polymeric resin is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that the thermosetting polymer resin or ultraviolet curable polymer resin. The method according to claim 6, The polymer resin is a patterned sapphire substrate manufacturing method using an imprinting process, characterized in that formed to a thickness of 3um.

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