KR20090102255A - Plasma etching apparatus and plasma etching method thereof - Google Patents

Abstract

PURPOSE: A plasma etching device and a plasma etching method are provided to improve brightness of a light emitting device or a flat display by forming a lens shaped pattern on a substrate. CONSTITUTION: A plasma etching apparatus includes a reactive chamber, an antenna, and a chuck. The reactive chamber provides the space in which the plasma is generated. An antenna is prepared in the upper part of the reactive chamber and a source power is applied to the antenna. The chuck is prepared in the reactive chamber and the bias power is applied to the chuck. A plasma etching process is performed by applying a first source power and a first bias power to the antenna and the chuck respectively(S121). The plasma etching process is performed by applying a second source power and a second bias power to the antenna and the chuck(S122). The plasma etching process is performed by applying a third source power and a third bias power to the antenna and the chuck(S123).

Description

Plasma Etching Apparatus and Plasma Etching Method Applied thereto {PLASMA ETCHING APPARATUS AND PLASMA ETCHING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma etching apparatus and a plasma etching method, and more particularly, to a plasma etching apparatus and a plasma etching method for forming a lens-shaped pattern on a substrate used for fabricating a light emitting device or a flat panel display.

The plasma etching apparatus is a device which generates a plasma to perform a etching process to form a fine pattern on a substrate used in semiconductor manufacturing or a flat panel display manufacturing.

The plasma etching apparatus is classified into a capacitively coupled plasma (CCP) method and an inductively coupled plasma (ICP) method according to a plasma generation method.

The capacitively coupled plasma type has a structure that has an electrode designed to apply high frequency power (RF power). As the name suggests, the plasma is generated by the electric field formed due to the electric charges distributed on the surface of the electrode. maintain.

The inductively coupled plasma method has a structurally coiled antenna, and plasma is generated and maintained by an induction electric field formed by applying high frequency power to the antenna.

In general, a plasma etching apparatus includes a reaction chamber providing a space in which a plasma is generated, a chuck provided below the reaction chamber to support a substrate, and an electric field provided above the reaction chamber to generate a plasma. An antenna, a source power supply for supplying source power to the antenna, and a bias power supply for supplying bias power to the chuck. In this case, the bias power is applied to the chuck to apply the source power to the antenna so that the plasma generated in the reaction chamber can be attracted to the substrate and collide with the surface of the substrate.

1 is a view schematically showing a general configuration of a light emitting diode (LED), which is a type of light emitting device. Referring to FIG. 1, a light emitting diode is formed on a substrate 30 having a lens-shaped pattern 30a, an N-type semiconductor layer 20 stacked on the substrate 30, and a portion of the N-type semiconductor layer 20. It consists of the P-type semiconductor layer 10 etc. which are laminated | stacked.

As shown in FIG. 1, the formation of the lenticular pattern 30a on the substrate 30 used for manufacturing the light emitting diode is to improve the brightness of the light emitting diode. At this time, as the lens shape of the lens pattern 30a formed on the substrate 30 is closer to the shape of a semi sphere, the luminance of the light emitting diode is increased.

Such a lenticular pattern 30a is usually formed on the substrate 30 by a conventional plasma etching method as follows.

2 is a flowchart illustrating an example of a conventional plasma etching method for forming a lens-shaped pattern on a substrate. 2, an example of a conventional plasma etching method will be described below.

First, when the substrate to be plasma-etched is introduced into the reaction chamber and placed on the chuck, a step of injecting process gas into the reaction chamber through a gas supply hole formed on the sidewall of the reaction chamber is performed (S10). At this time, the substrate is drawn into the reaction chamber with a photo mask having a predetermined pattern suitable for the lenticular pattern to be etched.

Next, a plasma etching process is performed to form a lens-shaped pattern on the substrate by applying a single source power and a bias power to the antenna and the chuck, respectively (S20).

Next, when the step of performing the plasma etching process by applying the source power and the bias power as described above is completed, the step of discharging the process gas in the reaction chamber to the outside through the gas outlet formed in the reaction chamber (S30) ).

As described above, in the conventional plasma etching method, the source power and the bias power are applied to form a lens-shaped pattern on the substrate (S20), regardless of the progress of the plasma etching process. Applied to the antenna and chuck respectively.

However, the above-described conventional plasma etching method forms a lens-like pattern close to the hemispherical shape because the lens-shaped pattern is formed on the substrate by applying a single source power and a bias power regardless of the progress of the plasma etching process. There is a problem that is difficult to do.

3 is an enlarged image of a lens-shaped pattern formed on a substrate when a plasma etching process is performed by applying a source power of 1200 W and a bias power of 550 W in the plasma etching method of FIG. 2. 4 is an enlarged image of a lens-shaped pattern formed on a substrate when a plasma etching process is performed by applying a source power of 1200 W and a bias power of 200 W to the antenna and the chuck in the plasma etching method of FIG. 2.

3 and 4, in the case of performing a plasma etching process by applying a single source power and a bias power, whether the size of the bias power is increased or decreased, a lens-shaped pattern close to the hemispherical shape is not formed, and Mongolia is not formed. It can be seen that a lens-shaped pattern in the form of a tent is formed. The substrate in which the Mongolian tent-shaped lens pattern is formed has a problem in that luminance is lowered compared to the substrate on which the hemispherical lens-shaped pattern is formed when manufacturing a light emitting diode or a flat panel display.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma etching apparatus capable of improving the luminance of a light emitting device or a flat panel display by forming a lens-shaped pattern close to a hemispherical shape on a substrate used for manufacturing a light emitting device or a flat panel display, and a plasma etching method applied thereto. To provide.

According to the present invention, there is provided a reaction chamber for providing a space in which a plasma is generated, an antenna provided at an upper portion of the reaction chamber, to which source power is applied, and a chuck provided at an inside of the reaction chamber to apply bias power. A plasma etching method for forming a lens-shaped pattern on a substrate using a plasma etching apparatus, comprising: (a) a first to cause a DC bias voltage generated by a bias power applied to the chuck to have a first set voltage value; Applying a source power and a first bias power to the antenna and the chuck, respectively, to perform a plasma etching process; (b) applying a second source power and a second bias power to the antenna and the chuck to cause the DC bias voltage to have a second set voltage value, respectively, to perform a plasma etching process; And (c) applying a third source power and a third bias power to the antenna and the chuck to cause the DC bias voltage to have a third set voltage value, respectively, to perform a plasma etching process. It is achieved by a plasma etching method.

The first to third source power and the first to third bias power may be preset through a process of changing the source power and the bias power while measuring the DC bias voltage before performing the plasma etching process. Can be.

The second set voltage value may be set lower than the first set voltage value and the third set voltage value.

The first set voltage value may be a value selected from a range of 550 V to 600 V, the second set voltage value may be a value selected from a range of 350 V to 380 V, and the third set voltage value may be a value selected from a range of 550 V to 600 V.

The step (b) may be performed for a relatively long time compared with the step (a) and the step (c).

The substrate is a sapphire substrate used for manufacturing a light emitting diode (LED), and the lens-shaped pattern may be formed on the sapphire substrate to improve the brightness of the light emitting diode.

Step (a) is a step for determining the lower width of the lens shape, step (b) is a step for determining the height of the lens shape, step (c) is a slope of the inclined surface of the lens shape May be a step for determining.

The above object is, according to the present invention, a plasma etching apparatus for forming a lens-shaped pattern on a substrate, comprising: a reaction chamber for providing a space in which plasma is generated; An antenna provided above the reaction chamber; A source power source for supplying source power to the antenna;

A chuck provided in the reaction chamber; A bias power supply for supplying bias power to the chuck; A voltage measuring module measuring a DC bias voltage generated by the bias power applied to the chuck; And a controller controlling the source power source and the bias power source to apply source power and bias power to the antenna and the chuck, respectively, to cause the DC bias voltage measured by the voltage measuring module to have predetermined values. It is achieved by a plasma etching apparatus.

Here, the controller performs a plasma etching process by applying a first source power and a first bias power to the antenna and the chuck, respectively, to allow the DC bias voltage measured by the voltage meter to have a first set voltage value. Next, a plasma etching process is performed by applying a second source power and a second bias power to the antenna and the chuck, respectively, to cause the DC bias voltage to have a second set voltage value. The source power source and the bias power source may be controlled to apply a third source power and a third bias power having a third set voltage value to the antenna and the chuck, respectively, to perform a plasma etching process.

The first to third source power and the first to third bias power may be preset through a process of changing the source power and the bias power while measuring the DC bias voltage before performing the plasma etching process. .

The first set voltage value may be a value selected from a range of 550 V to 600 V, the second set voltage value may be a value selected from a range of 350 V to 380 V, and the third set voltage value may be a value selected from a range of 550 V to 600 V.

The substrate is a sapphire substrate used for manufacturing a light emitting diode (LED), and the lens-shaped pattern may be formed on the sapphire substrate to improve the brightness of the light emitting diode.

According to the present invention, a plasma etching process for forming a lens-shaped pattern on a substrate by applying a source power and a bias power is performed by dividing the source power and the bias power into a plurality of steps of varying the magnitude of the source power and the bias power. It is possible to improve the luminance of the light emitting device or the flat panel display by forming a lens-like pattern close to the hemispherical shape on the substrate used for manufacturing the flat panel display.

1 is a view schematically showing a general configuration of a light emitting diode (LED), which is a type of light emitting device.

2 is a flowchart illustrating an example of a conventional plasma etching method for forming a lens-shaped pattern on a substrate.

3 is an enlarged view illustrating an example of a lens-shaped pattern formed on a substrate in the plasma etching method of FIG. 2.

4 is an enlarged image illustrating another example of a lens pattern formed on a substrate in the plasma etching method of FIG. 2.

5 is a schematic configuration diagram of a plasma etching apparatus according to an embodiment of the present invention.

FIG. 6 is a block diagram illustrating the control of the plasma etching apparatus of FIG. 5.

7 is a flowchart illustrating a plasma etching method according to an embodiment of the present invention.

FIG. 8 is an enlarged view of an example of a lens-shaped pattern formed on a substrate by applying the plasma etching method of FIG. 7.

9 is an enlarged view of another example of a lens-shaped pattern formed on a substrate by applying the plasma etching method of FIG. 7.

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

100: plasma etching apparatus

110: reaction chamber 120: chuck

130: substrate tray 140: insulating plate

150: antenna 160: grounding case

170: source power 180: bias power

185: voltage measurement module 190: controller

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, descriptions of functions or configurations already known will be omitted to clarify the gist of the present invention.

First, "substrate" to be described below refers to a wafer, which is a substrate used for semiconductor manufacturing, and a glass substrate, which is a substrate used for flat panel display (FPD) fabrication, and the like. It will be referred to as a substrate instead. For reference, substrates used in semiconductor manufacturing include light emitting diode substrates such as light emitting diodes (LEDs) and memory semiconductor substrates. Glass substrates used in flat panel displays include liquid crystal display (LCD) substrates. And substrates for plasma display panels (PDPs).

5 is a schematic configuration diagram of a plasma etching apparatus according to an embodiment of the present invention, Figure 6 is a block diagram for explaining the control of the plasma etching apparatus of FIG.

The plasma etching apparatus 100 according to the present embodiment is an apparatus for performing an etching process on a sapphire substrate used for manufacturing a light emitting diode (LED), and has a semi sphere shape on the sapphire substrate to improve the brightness of the light emitting diode. A plasma etching process of forming a lens-shaped pattern of is performed. However, the present invention is not limited thereto, and of course, the present invention may be applied to a plasma etching apparatus that performs an etching process on various substrates as described above.

5 and 6, the plasma etching apparatus 100 according to the present embodiment includes a reaction chamber 110 that provides a space in which plasma is generated, and a substrate tray (not shown) inside the reaction chamber 110. A chuck 120 supporting the 130 and an antenna 150 disposed above the reaction chamber 110 to induce an electric field for generating plasma, and disposed between the reaction chamber 110 and the antenna 150. The insulating plate 140, the grounding case 160 provided above the antenna 150, the source power 170 supplying source power to the antenna 150, and the bias power to the chuck 120. A bias power supply 180 for supplying a bias power, a voltage measurement module 185 for measuring a DC bias voltage generated by the bias power applied to the chuck 120, a source power supply 170, and a bias power supply ( A controller 190 for controlling 180.

The reaction chamber 110 has a cylindrical shape as a whole and provides a space in which a plasma for plasma etching the substrate 30 is generated and reacted. The substrate tray 130 is reacted by a gas supply port 114 for injecting process gas into the reaction chamber 110 and a transfer robot 12 in the load lock chamber 10 on the side wall of the reaction chamber 110. A slot 112 for introducing into the chamber 110 is formed, and a slot valve 20 for opening and closing the slot 112 between the slot 112 formed in the reaction chamber 110 and the load lock chamber 10. Is prepared. In addition, a clamp 116 is provided in the reaction chamber 110 to fix the substrate tray 130 to the chuck 120.

The substrate tray 130 is used to simultaneously perform a plasma etching process on a plurality of substrates 30. The substrate tray 130 is disposed on the lower plate 132 and the lower plate 132 on which the plurality of substrates 30 are loaded. And an upper plate 134 for fixing the substrate 30 inserted into the lower plate 132, and a fixing member 136 for fixing the upper plate 134 to the lower plate 132. However, unlike the present embodiment, the present invention may perform a plasma etching process by placing only the substrate 30 itself on the chuck 120 without using the substrate tray 130.

The chuck 120 is provided below the inside of the reaction chamber 110 to support the substrate tray 130. In addition, the chuck 120 is electrically connected to the bias power source 180 to draw the plasma generated in the reaction chamber 110 toward the substrate 30 so as to collide with the surface of the substrate 30 so that the bias power is applied. It serves as a lower electrode.

The antenna 150 is a coil-shaped structure as a whole, and is electrically connected to the source power source 170 and the ground case 160 as shown in FIG. 5. The antenna 150 receives source power from the source power source 170 to induce an electric field for generating plasma in the reaction chamber 110.

When the plasma is generated by the antenna 150 will be described briefly as follows. When source power is applied to the antenna, a current flows in the antenna 150, and this current forms a magnetic field that changes in time around the antenna 150, and this magnetic field forms an induction electric field inside the reaction chamber 110 and induces an electric field. The electrons heat the electrons to generate a plasma inductively coupled with the antenna. As such, the plasma etching apparatus 100 performs a plasma etching process using ions and radicals generated by electrons in the generated plasma collide with surrounding neutral gas particles.

In this embodiment, the antenna 150, as shown in Figure 5, consisting of two circular single-circuit coils arranged on the same plane, the outer antenna 151 and the inner antenna 151 inside An inner antenna 152 is disposed at predetermined intervals. In this case, the outer antenna 151 and the inner antenna 152 are connected in parallel to one source power source 170, and each of the outer antenna 151 and the inner antenna 152 is electrically connected to the source power source 170. The other end is electrically connected to the grounding case and grounded. However, the antenna applied to the present invention is not limited to that shown in FIG. 5, and various types of antenna systems may be applied.

The insulating plate 140 is disposed between the reaction chamber 110 and the antenna 150 to reduce the capacitive electric field and to transmit the induced electric field to the plasma more effectively. That is, the insulating plate 140 reduces the capacitive (capacitive) coupling between the antenna 150 and the plasma to more effectively transfer energy by the high frequency power source 180 to the plasma by inductive coupling. Here, the insulating plate 140 is made of a disc shape made of a material such as ceramic and is also referred to as a 'Faraday shield' or 'ceramic window', and is supported by the lower flange 162 of the ground case 160 as shown in FIG. And is fixed by the fixing jig 145.

Grounding case 160 is a cylindrical metal grounded as a whole, is provided on the upper side of the antenna 150 to prevent the antenna 150 is exposed to the outside, while the ground ends of the antenna 150 are electrically connected Provide a grounded area.

On the other hand, the plasma etching apparatus 100, although not shown in Figure 5, the vacuum chamber (not shown) and the reaction chamber 110 for maintaining the inside of the reaction chamber 110 in a vacuum and discharge the gas generated during the reaction A gas discharge port (not shown) is further provided.

The source power source 170 supplies source power in the form of high frequency power (RF power) to the antenna 150 to generate a plasma in the reaction chamber 110. The source power source 170 may apply source power of various sizes to the antenna 150 within a predetermined range, and the magnitude of the source power is controlled by the controller 190. On the other hand, the source power source 170 is electrically connected to the antenna 150 through an impedance matcher 171 for matching the internal impedance with the impedance of the path to which the source power is supplied.

The bias power source 180 biases the plasma generated in the reaction chamber 110 toward the substrate 30 and collides with the surface of the substrate 30 so as to bias the chuck 120 in the form of a high frequency power (RF power). Supply power. The bias power source 180 may apply various sizes of bias power to the chuck 120 within a predetermined range, and the magnitude of the bias power is controlled by the controller 190. Meanwhile, the bias power source 180 is electrically connected to the antenna 150 through an impedance matcher 181 for matching the internal impedance with the impedance of the path to which the bias power is supplied.

The voltage measuring module 185 may be implemented by various types of modules for measuring voltage in a general electric device, and measures the DC bias voltage generated by the bias power applied to the chuck 120. In the present embodiment, the voltage measuring module 185 is physically provided inside the impedance matcher 181, but may be provided separately from the impedance matcher 181. The voltage measuring module 185 provides the controller 190 with a value of the measured DC bias voltage.

The value of the DC bias voltage measured by the voltage measuring module 185 is the magnitude of the source power applied to the antenna 150 by the source power supply 170 and the chuck 120 by the bias power supply 180. Depends on the amount of bias power being In addition, the magnitude of the DC bias voltage affects the shape of the pattern formed on the substrate 30 by the plasma etching process. That is, the shape of the pattern formed on the substrate 30 after the plasma etching process even in the shape of the same photo mask is different depending on the magnitude of the DC bias voltage.

On the other hand, in the case of forming a lenticular pattern on the substrate 30 used for fabricating the light emitting diode as in the present embodiment, the closer the lens shape is to the semi sphere shape, the brightness of the light emitting diode is improved. Therefore, in order to improve the brightness of the light emitting diode, it is required to form a lens-shaped pattern close to the hemispherical shape on the substrate 30.

In general, the lower width of the lens shape is mainly determined at the initial stage of the entire plasma etching process, the height of the lens shape is mainly determined at the middle stage of the overall plasma etching process, and the slope of the inclined plane of the lens shape is the finishing step of the entire plasma etching process. Tends to be largely determined by. In addition, looking at the correlation between the magnitude of the DC bias voltage and the lens shape, as the magnitude of the DC bias voltage is smaller, the height of the lens shape and the slope of the inclined plane become higher and the lower width of the lens shape tends to be smaller. On the other hand, in order to form a lens pattern close to the hemispherical shape on the substrate 30, it is preferable that the lower width of the lens shape is set high, the height of the lens shape is set high, and the inclination of the inclined plane of the lens shape is set low.

The plasma etching method according to the present invention includes a plasma etching process of forming a predetermined pattern on the substrate 30 by applying source power and bias power to the antenna 150 and the chuck 120, respectively. And, as will be described later in detail, such a plasma etching process is divided into at least three stages, wherein the values of the DC bias voltage required in each stage of the plasma etching process are set to different values.

Referring to FIG. 5, the controller 190 controls the source power source 170 and the bias power source 180 such that the DC bias voltage measured by the voltage measuring module 185 has preset values. That is, the controller 190 controls the source power source 170 and the bias power source 180 to change the magnitude of the source power and the bias power in each step in the plasma etching process, thereby adjusting the DC bias voltage preset in each step. Provide values.

The controller 190 may be implemented in software or firmware in a general personal computer. The process worker may operate a display module (for example, a monitor) connected to a personal computer in which the controller 190 is installed. Through this, the value of the DC bias voltage measured by the voltage measuring module 185, the magnitude of the source power supplied from the source power source 170, and the magnitude of the bias power supplied from the bias power source 180 can be checked.

A detailed description of the method of controlling the source power source 170 and the bias voltage 180 by the controller 190 will be described in detail in parallel with the description of the plasma etching method according to an embodiment of the present invention to be described later. .

7 is a flowchart illustrating a plasma etching method according to an embodiment of the present invention. 7, the plasma etching method according to an embodiment of the present invention will be described in detail.

First, when the substrate tray 130 into which the plurality of substrates 30 are loaded by the transfer robot 12 in the load lock chamber 10 is introduced into the reaction chamber 110 and placed on the chuck 120, the reaction chamber Injecting the process gas into the reaction chamber 110 through the gas supply port 114 formed on the sidewall of the 110 (S110). At this time, the substrate 30 to be subjected to plasma etching is introduced into the reaction chamber 110 in a state where a photo mask having a predetermined pattern suitable for the lens-shaped pattern to be etched is applied.

Next, a plasma etching process is performed in which a source power and a bias power are applied to the antenna 150 and the chuck 120 to form a hemispherical lens-shaped pattern on the substrate 30 (S120). Performing the plasma etching process (S120) is divided into three steps (S121, S122, S123) on the basis of the size of the source power and the size of the bias power is changed, it will be described in detail below.

First, the first source power and the first bias power for causing the DC bias voltage generated by the bias power applied to the chuck 120 to have a first set voltage value are respectively applied to the antenna 150 and the chuck 120. In operation S121, a plasma etching process is performed by applying.

Since the S121 step corresponds to an initial step of the entire plasma etching process, the step S121 has the greatest influence in determining the lower width of the lens shape. Accordingly, the first set voltage value has a relatively high range of 550V to 600V compared to the step S122 to be described later.

Here, the first source power and the first bias power are the magnitudes of the source power and the bias power while measuring the DC bias voltage through the voltage measuring module 185 with respect to the plasma etching apparatus 100 before performing the plasma etching process. Through the process of changing to determine whether the DC bias voltage satisfies the first set voltage value in the range of 550V to 600V is experimentally preset.

Secondly, the second source power and the second bias power, which cause the DC bias voltage measured by the voltage measuring module 185 to have the second set voltage value, are applied to the antenna 150 and the chuck 120, respectively, to provide plasma. The etching process is performed (S122).

Since step S122 corresponds to an intermediate step of the entire plasma etching process, the step S122 has the greatest influence in determining the height of the lens shape. Accordingly, the first set voltage value has a relatively low range of 350V to 380V compared to the above-described step S121. In addition, since the value of the DC bias voltage (second set voltage value) is set to be relatively low, step S122 should be performed for a relatively long time compared to the above-described step S121 and step S123, which will be described later. In the step of performing a plasma etching process by applying a (S120) is preferably set to occupy a time range of 70% to 80%.

Here, the second source power and the second bias power are the magnitudes of the source power and the bias power while measuring the DC bias voltage through the voltage measuring module 185 with respect to the plasma etching apparatus 100 before performing the plasma etching process. Through the process of changing to determine whether the DC bias voltage satisfies the second set voltage value in the range of 350V to 380V is experimentally preset.

Third, the third source power and the third bias power, which cause the DC bias voltage measured by the voltage measuring module 185 to have a third set voltage value, are applied to the antenna 150 and the chuck 120, respectively. The etching process is performed (S123).

Since the step S123 corresponds to the finishing step of the entire plasma etching process, the step S123 has the greatest influence in determining the slope of the inclined plane of the lens shape. Accordingly, the third set voltage value has a range of 550V to 600V relatively higher than the above-described step S122.

Here, the third source power and the third bias power are the magnitudes of the source power and the bias power while measuring the DC bias voltage through the voltage measuring module 185 with respect to the plasma etching apparatus 100 before performing the plasma etching process. Through the process of changing to determine whether the DC bias voltage satisfies the third set voltage value in the range of 550V to 600V is experimentally preset.

Next, when the step of performing the plasma etching process by applying the source power and the bias power as described above is completed, a process gas in the reaction chamber 110 is formed in the reaction chamber 110 by a vacuum pump (not shown). A step of discharging to the outside through the gas discharge port (not shown) is performed (S130).

The substrate in which the lens-shaped pattern is formed by the series of steps for the plasma etching process as described above is drawn out through the load lock chamber 10 by the transfer robot 12 in the load lock chamber 10.

On the other hand, in the plasma etching method according to the present embodiment, the range of the first set voltage value, the range of the second set voltage value, and the third set voltage value suggested to be suitable for forming a lens-shaped pattern close to the hemispherical shape on the substrate. Ranges are values obtained experimentally by the Applicant by repeating numerous tests on the plasma etching apparatus 100 described above.

In addition, in the plasma etching method according to the present embodiment, the first source power and the first bias power should be set such that the DC bias voltage has a first set voltage value in the range of 550V to 600V, and the second source power and the second source power. The bias power should be set such that the DC bias voltage has a second set voltage value in the range of 350 V to 380 V, and the third source power and the third bias power set so that the DC bias voltage has a third set voltage in the range of 550 V to 600 V. In the case of the plasma etching apparatus 100 described above, two preferable examples of the specific size of the source power and the bias power are as follows.

<First Preferred Example>

S121 stage: source power 800W / bias power 550W

S122 step: source power 800W / bias power 250W

S121 stage: source power 800W / bias power 500W

<2nd preferable example>

S121 stage: source power 1500W / bias power 700W

S122 step: source power 1500W / bias power 350W

S121 stage: source power 1500W / bias power 700W

FIG. 8 is an enlarged image of a lens-shaped pattern finally formed on a substrate when the plasma etching method according to the present embodiment is performed by applying the source power and the bias power according to the first preferred example shown in FIG. 9. Is a magnified image of a lens-shaped pattern finally formed on a substrate when the plasma etching method according to the present embodiment is performed by applying the source power and the bias power according to the second preferred example presented above.

Referring to FIGS. 8 and 9, the plasma etching method according to the present embodiment can form a lenticular pattern close to the hemispherical shape on the substrate as compared with the conventional plasma etching method (see FIGS. 3 and 4). You can see clearly.

As described above, the plasma etching method according to the present embodiment includes three steps of varying the magnitude of the source power and the bias power in the plasma etching process of applying the source power and the bias power to form a lens-shaped pattern on the substrate. By dividing into, the luminance of the light emitting diode can be improved by forming a lens-shaped pattern close to the hemispherical shape on the substrate used for manufacturing the light emitting diode.

On the other hand, the plasma etching method according to the present invention, unlike the present embodiment, the plasma etching process for forming a lens-shaped pattern on the substrate by applying the source power and the bias power to vary the magnitude of the source power and the bias power 4 Of course, it can be divided into more than one step.

It is apparent to those skilled in the art that the present invention is not limited to the above-described embodiments, and that various modifications and changes can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

Claims (12)

A substrate using a plasma etching apparatus including a reaction chamber providing a space in which a plasma is generated, an antenna provided on an upper portion of the reaction chamber, to which source power is applied, and a chuck provided on the inside of the reaction chamber to apply bias power; In the plasma etching method of forming a lens-shaped pattern on, (a) a plasma etching process is performed by applying first source power and first bias power to the antenna and the chuck, respectively, such that the DC bias voltage generated by the bias power applied to the chuck has a first set voltage value; Making; (b) applying a second source power and a second bias power to the antenna and the chuck to cause the DC bias voltage to have a second set voltage value, respectively, to perform a plasma etching process; And and (c) applying a third source power and a third bias power to the antenna and the chuck to cause the DC bias voltage to have a third set voltage value, respectively, to perform a plasma etching process. Etching method. The method of claim 1, The first to third source power and the first to third bias power may be preset through a process of changing the source power and the bias power while measuring the DC bias voltage before performing the plasma etching process. Plasma etching method. The method of claim 1, The second set voltage value is, Plasma etching method characterized in that the lower than the first set voltage value and the third set voltage value. The method of claim 1, The first set voltage value is selected in the range of 550V to 600V, the second set voltage value is selected in the range of 350V to 380V, and the third set voltage value is selected in the range of 550V to 600V. Plasma etching method. The method of claim 1, In step (b), Plasma etching method, characterized in that performed for a relatively long time compared to the step (a) and (c). The method of claim 1, The substrate is a sapphire substrate used for light emitting diode (LED) fabrication, The lenticular pattern is formed on the sapphire substrate to improve the brightness of the light emitting diodes. The method of claim 1, Step (a) is a step for determining the lower width of the lens shape, Step (b) is a step for determining the height of the lens shape, The step (c) is a plasma etching method, characterized in that for determining the slope of the inclined surface of the lens shape. In the plasma etching apparatus for forming a lens-shaped pattern on a substrate, A reaction chamber providing a space in which a plasma is generated; An antenna provided above the reaction chamber; A source power source for supplying source power to the antenna; A chuck provided in the reaction chamber; A bias power supply for supplying bias power to the chuck; A voltage measuring module measuring a DC bias voltage generated by the bias power applied to the chuck; And And a controller controlling the source power source and the bias power source to apply a source power and a bias power to the antenna and the chuck, respectively, so that the DC bias voltage measured by the voltage measuring module has predetermined values. Plasma etching apparatus. The method of claim 8, The controller, A plasma etching process is performed by applying first source power and first bias power to the antenna and the chuck, respectively, such that the DC bias voltage measured by the voltage meter has a first set voltage value, and then the DC bias A plasma etching process is performed by applying a second source power and a second bias power to the antenna and the chuck, each of which causes a voltage to have a second set voltage value, and then the DC bias voltage has a third set voltage value. And controlling the source power source and the bias power source to apply a third source power and a third bias power to the antenna and the chuck to perform a plasma etching process. The method of claim 9, The first to third source power and the first to third bias power may be preset through a process of changing the source power and the bias power while measuring the DC bias voltage before performing the plasma etching process. Plasma etching apparatus. The method of claim 9, The first set voltage value is selected in the range of 550V to 600V, the second set voltage value is selected in the range of 350V to 380V, and the third set voltage value is selected in the range of 550V to 600V. Plasma etching apparatus. The method of claim 8, The substrate is a sapphire substrate used for light emitting diode (LED) fabrication, And the lens shape pattern is formed on the sapphire substrate to improve the brightness of the light emitting diode.