KR100951475B1 - Plasma etching apparatus and plasma etching method thereof - Google Patents

Abstract

A plasma etching apparatus and a plasma etching method applied thereto are disclosed. A plasma etching method of the present invention is a plasma etching method comprising the steps of: providing 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 apply a source power to the reaction chamber; A plasma etching method for forming a lens-like pattern on a substrate by using an etching apparatus, the plasma etching method comprising the steps of: (a) forming a first source power having a DC bias voltage generated by a bias power applied to a chuck, 1 bias power to the antenna and the chuck to perform a plasma etching process; (b) performing a plasma etching process by applying a second source power and a second bias power to the antenna and the chuck such that the DC bias voltage has a second set voltage value, respectively; And (c) performing a plasma etching process by applying a third source power and a third bias power to the antenna and the chuck such that the DC bias voltage has a third set voltage value, respectively. According to the present invention, it is possible to improve the brightness of a light emitting device or a flat display by forming a lens shape pattern that is close to a hemisphere shape on a substrate used for manufacturing a light emitting element or a flat display.

Plasma, Etching, Source Power, Bias Power, DC Bias Voltage

Description

TECHNICAL FIELD [0001] The present invention relates to a plasma etching apparatus and a plasma etching method applicable to the plasma etching apparatus.

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 pattern on a substrate used for manufacturing a light emitting device or a flat display.

The plasma etching apparatus is an apparatus for generating a plasma to form a fine pattern on a substrate used for manufacturing a semiconductor or a flat display, and performing an etching process.

Such a 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.

In the capacitive coupled plasma system, an electrode designed to be capable of applying high frequency power (RF power) is a structural feature. As the name suggests, plasma is generated by a charge electric field formed due to charge distributed on the surface of the electrode maintain.

The inductively coupled plasma system has a coil-shaped antenna structurally, and plasma is generated and maintained by an induced electric field formed by applying high frequency power to the antenna.

Generally, a plasma etching apparatus includes a reaction chamber for providing a space in which a plasma is generated, a chuck provided inside the reaction chamber and supporting the substrate, and an electric field provided at an upper portion of the reaction chamber to generate a plasma An antenna, a source power supply for supplying a source power to the antenna, and a bias power supply for supplying a bias power to the chuck. Here, the application of the bias power to the chuck is to apply the source power to the antenna so that the plasma generated in the reaction chamber can be pulled toward the substrate to collide with the surface of the substrate.

1 is a schematic view showing a general configuration of a light emitting diode (LED) which is a kind of light emitting device. 1, the light emitting diode includes a substrate 30 on which a lens pattern 30a is formed, an N-type semiconductor layer 20 laminated on the substrate 30, A P-type semiconductor layer 10 to be stacked, and the like.

As shown in FIG. 1, the formation of the lens-like pattern 30a on the substrate 30 used for fabricating the light emitting diode is intended to improve the brightness of the light emitting diode. At this time, the closer the lens shape of the lens pattern 30a formed on the substrate 30 is to the semi-spherical shape, the higher the brightness of the light emitting diode.

The lens shape pattern 30a is formed on the substrate 30 by a conventional plasma etching method as described below.

2 is a flowchart for explaining an example of a conventional plasma etching method for forming a lens-like pattern on a substrate. Referring to FIG. 2, an example of a conventional plasma etching method will be briefly described below.

First, when a substrate to be etched is introduced into the reaction chamber, the process gas is injected into the reaction chamber through a gas supply port formed in the side wall of the reaction chamber (S10). At this time, the substrate is drawn into the reaction chamber in a state in which a photomask having a predetermined pattern suitable for the lens shape pattern to be etched is applied.

Next, a plasma etching process is performed in which a single-size source power and a bias power are respectively applied to the antenna and the chuck to form a lens-like pattern on the substrate (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, a step of discharging the process gas in the reaction chamber to the outside through the gas outlet formed in the reaction chamber is performed (S30 ).

As described above, in the conventional plasma etching method, a source power and a bias power are applied to form a lens-like pattern on a substrate (S20), a single-size source power and a bias power Antenna and chuck respectively.

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

FIG. 3 is a magnified photograph of a lens shape 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. FIG. 4 is a magnified photograph of a lens shape 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, respectively.

Referring to FIGS. 3 and 4, when a single-size source power and a bias power are applied to perform a plasma etching process, a lens shape pattern close to a hemispherical shape is not formed, regardless of whether the bias power is increased or not. It can be confirmed that a lens-like pattern in the form of a tent is formed. The substrate on which the lens shape pattern of the Mongolian tent shape is formed has a problem in that the luminance is lower than that of the substrate on which the lens shape pattern of the hemispherical shape is formed when the light emitting diode or the flat display is manufactured.

It is an object of the present invention to provide a plasma etching apparatus capable of improving the luminance of a light emitting device or a flat display by forming a lens shape pattern close to a hemisphere shape on a substrate used for manufacturing a light emitting device or a flat display, .

According to an aspect of the present invention, there is provided a plasma processing apparatus comprising: 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 receive a source power; (A) a DC bias voltage generated by a bias power applied to the chuck has a first set voltage value, and a second set voltage value generated by a bias voltage applied to the chuck, 1 source power and a first bias power to the antenna and the chuck to perform a plasma etching process; (b) applying a second source power and a second bias power to cause the DC bias voltage to have a second set voltage value to the antenna and the chuck, respectively, to perform a plasma etching process; And (c) performing a plasma etching process by applying a third source power and a third bias power to cause the DC bias voltage to have a third set voltage value to the antenna and the chuck, respectively Is achieved by a plasma etching method.

Here, the first to third source powers and the first to third bias powers 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 second set voltage value may be set to be lower than the first set voltage value and the third set voltage value.

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

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

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

Wherein the step of (a) is a step of determining a width of a bottom of the lens shape, (b) is a step of determining a height of the lens shape, and the step (c) May be determined.

According to the present invention, there is provided a plasma etching apparatus for forming a lens-like pattern on a substrate, comprising: a reaction chamber for providing a space in which a plasma is generated; An antenna provided at an upper portion of the reaction chamber; A source power supply for supplying a source power to the antenna;

A chuck provided inside the reaction chamber; A bias power supply for supplying a bias power to the chuck; A voltage measuring module for measuring a DC bias voltage generated by a bias power applied to the chuck; And a controller for 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 such that a DC bias voltage measured by the voltage measuring module has predetermined values, respectively In the plasma etching apparatus.

Here, the controller may perform a plasma etching process by applying a first source power and a first bias power to the antenna and the chuck such that a DC bias voltage measured by the voltage meter has a first set voltage value And then applying a second source power and a second bias power to cause the DC bias voltage to have a second set voltage value respectively to the antenna and the chuck to perform a plasma etching process, The source power and the bias power may be controlled so as to apply a third source power and a third bias power to the antenna and the chuck, respectively, so as to perform a plasma etching process.

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

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

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

A plasma etching process for forming a lens-like pattern on a substrate by applying a source power and a bias power is performed by dividing the plasma etching process into a plurality of steps of different sizes of a source power and a bias power, It is possible to improve the luminance of the light emitting device or the flat display by forming a lens shape pattern that is close to the hemisphere shape on the substrate used for manufacturing the flat display.

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

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in order to avoid unnecessary obscuration of the present invention.

First, the "substrate" to be described below refers to a wafer which is a substrate used for semiconductor fabrication and a glass substrate which is a substrate used for manufacturing a flat panel display (FPD). However, for convenience of description, The substrate is referred to as a substrate. For reference, a substrate used for semiconductor fabrication includes a substrate for a light emitting device such as a light emitting diode (LED), a substrate for a memory semiconductor, etc. A glass substrate used for manufacturing a flat display includes a substrate for an LCD (Liquid Crystal Display) , A substrate for a plasma display panel (PDP), and the like.

FIG. 5 is a schematic configuration view of a plasma etching apparatus according to an embodiment of the present invention, and FIG. 6 is a block diagram illustrating 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 fabricating a light emitting diode (LED). In order to improve the brightness of a light emitting diode, a semi- A plasma etching process is performed to form a lens shape pattern of FIG. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to a plasma etching apparatus that performs an etching process on various substrates as described above.

Referring to FIGS. 5 and 6, the plasma etching apparatus 100 according to the present embodiment includes a reaction chamber 110 for providing a space in which a plasma is generated, a substrate tray (not shown) provided under the reaction chamber 110, An antenna 150 provided at an upper portion of the reaction chamber 110 to induce an electric field for generating a plasma and an antenna 150 disposed between the reaction chamber 110 and the antenna 150 A source case 170 for supplying a source power to the antenna 150 and a source power source 170 for supplying a bias power to the chuck 120. [ A voltage measuring module 185 for measuring a DC bias voltage generated by the bias power applied to the chuck 120, a bias power source 180 for applying a bias power to the chuck 120, 180 for controlling the display device.

The reaction chamber 110 has a cylindrical shape as a whole and provides a space for generating and reacting plasma for plasma etching the substrate 30. A side wall of the reaction chamber 110 is provided with a gas supply port 114 for injecting a process gas into the reaction chamber 110 and a substrate tray 130 for reaction by the transfer robot 12 in the load lock chamber 10. [ A slot 112 for opening and closing the slot 112 is formed between the slot 112 formed in the reaction chamber 110 and the load lock chamber 10, . In the reaction chamber 110, a clamp 116 for fixing the substrate tray 130 to the chuck 120 is provided.

The substrate tray 130 is used to simultaneously perform a plasma etching process on a plurality of substrates 30. The substrate tray 130 includes a lower plate 132 to which a plurality of substrates 30 are loaded, An upper plate 134 for fixing the substrate 30 loaded in 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 can perform the 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 inside the reaction chamber 110 and supports the substrate tray 130. The chuck 120 is electrically connected to the bias power source 180 so as to attract the plasma generated in the reaction chamber 110 toward the substrate 30 to collide with the surface of the substrate 30, And serves as a lower electrode.

The antenna 150 is entirely in the form of a coil and is electrically connected to the source power source 170 and the ground case 160 as shown in FIG. The antenna 150 receives a source power from the source power source 170 and induces an electric field for generating plasma in the reaction chamber 110.

A process of generating plasma by the antenna 150 will be briefly described below. When the source power is applied to the antenna, a current flows through the antenna 150, and this current forms a magnetic field that changes temporally around the antenna 150. This magnetic field forms an induction field in the reaction chamber 110, Which heats the electrons to generate a plasma that is inductively coupled to the antenna. As described above, the plasma etching apparatus 100 performs a plasma etching process using ions and radicals produced by colliding electrons in the generated plasma with neighboring neutral gas particles.

5, the antenna 150 is composed of two circular single-wire coils disposed on the same plane. The antenna 150 includes an external antenna 151, And an inner antenna 152 disposed at a predetermined interval. The outer antenna 151 and the inner antenna 152 are connected in parallel to one source power supply 170 and the outer antenna 151 and the inner antenna 152 are connected in parallel to each other by electrically connecting one end thereof to the source power supply 170 And the other end is electrically connected to the ground case and grounded. However, the antenna to which the present invention is applied is not limited to that shown in Fig. 5, and various types of antenna systems can be applied.

The insulating plate 140 is disposed between the reaction chamber 110 and the antenna 150 to reduce the accumulating electric field and to transmit the induced electric field to the plasma more effectively. That is, the insulating plate 140 reduces the capacitive coupling between the antenna 150 and the plasma, so that the energy by the RF power supply 180 can be more effectively transferred to the plasma by inductive coupling. 5, the insulating plate 140 is supported by the lower flange 162 of the grounding case 160. The grounding case 160 may be formed of a metal or the like, And is fixed by the fixing jig 145.

The grounding case 160 is a metal case of a generally cylindrical shape and is provided on the upper side of the antenna 150 so that the antenna 150 is not exposed to the outside, and the grounding ends of the antenna 150 are electrically connected Provides a grounded area.

5, the plasma etching apparatus 100 includes a vacuum pump (not shown) for maintaining the inside of the reaction chamber 110 in a vacuum and discharging gases generated during the reaction, (Not shown) formed therein.

The source power supply 170 supplies a source power in the form of high frequency power (RF power) to the antenna 150 in order to generate a plasma inside the reaction chamber 110. The source power 170 may apply a varying amount of source power to the antenna 150 within a certain range, and the magnitude of the source power is controlled by the controller 190. Meanwhile, the source power source 170 is electrically connected to the antenna 150 through an impedance matcher 171 for matching the internal impedance of the source power source 170 with the impedance of the path through which the source power is supplied.

The bias power supply 180 applies a bias in the form of high frequency power (RF power) to the chuck 120 so that the plasma generated in the reaction chamber 110 can be pulled toward the substrate 30 to collide with the surface of the substrate 30 Power supply. The bias power source 180 may apply bias powers of various sizes to the chuck 120 within a certain range, and the magnitude of the bias power is controlled by the controller 190. Meanwhile, the bias power supply 180 is electrically connected to the antenna 150 through an impedance matching unit 181 for matching the internal impedance of the bias power supply 180 with the impedance of the path through which the bias power is supplied.

The voltage measurement module 185 may be implemented in various types of modules that measure voltage in a conventional electrical device and measures the DC bias voltage generated by the bias power applied to the chuck 120. [ In the present embodiment, the voltage measurement module 185 is physically provided in the impedance matcher 181, but may be provided separately from the impedance matcher 181. [ This voltage measurement module 185 provides the controller 190 with the measured value of the DC bias voltage.

The value of the DC bias voltage measured by the voltage measurement module 185 is determined by the magnitude of the source power applied to the antenna 150 by the source power supply 170 and the magnitude of the source power applied to the chuck 120 by the bias power supply 180 The magnitude of the bias power. 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 in the same photomask shape is different according to the magnitude of the DC bias voltage.

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

In general, the width of the bottom of the lens shape is determined mainly at an initial stage of the entire plasma etching process, and the height of the lens shape is mainly determined at an intermediate stage of the entire plasma etching process. The slope inclination of the lens shape is, Of the population. The relationship between the magnitude of the DC bias voltage and the shape of the lens is as follows. The smaller the DC bias voltage is, the higher the height of the lens shape and the slope of the slope become, and the lower width of the lens shape tends to decrease. On the other hand, in order to form a lens-like pattern close to the hemispherical shape on the substrate 30, it is preferable that the lower width of the lens shape is set large, the height of the lens shape is high, and the inclination angle of the lens shape is set low.

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

5, the controller 190 controls the source power supply 170 and the bias power supply 180 such that the DC bias voltage measured by the voltage measurement 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, so that the DC bias voltage Lt; / RTI >

The controller 190 may be implemented as software or firmware in a conventional personal computer or the like and the process operator may use a display module (e.g., a monitor) connected to a personal computer The magnitude of the bias power supplied from the bias power supply 180, and the like, as well as the magnitude of the DC bias voltage measured by the voltage measurement module 185, the magnitude of the source power supplied from the source power supply 170,

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

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

First, when the substrate tray 130 in which a 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 process gas is injected into the reaction chamber 110 through the gas supply port 114 formed in the side wall of the reaction chamber 110 at step S110. At this time, the substrate 30 to be subjected to the plasma etching is introduced into the reaction chamber 110 in a state in which a photomask having a predetermined pattern suitable for a lens shape pattern to be etched is applied.

Next, a plasma etching process is performed in which a source power and a bias power are respectively applied to the antenna 150 and the chuck 120 to form a hemispherical lens pattern on the substrate 30 (S120). The step of performing the plasma etching process (S120) is divided into three steps (S121, S122, S123) based on the change of the magnitude of the source power and the bias power, which will be described in detail below.

First, a first source power and a first bias power, which cause a DC bias voltage generated by the bias power applied to the chuck 120 to have a first set voltage value, are applied to the antenna 150 and the chuck 120, respectively And a plasma etching process is performed (S121).

Since the step S121 corresponds to the initial stage of the entire plasma etching process, the step S121 has the greatest influence on the determination of the width of the bottom of the lens shape. Accordingly, the first set voltage value has a relatively high range of 550V to 600V as compared with the step S122 described later.

Here, the first source power and the first bias power may be determined by measuring the DC bias voltage through the voltage measurement module 185 with respect to the plasma etching apparatus 100 before performing the plasma etching process, while measuring the magnitude of the source power and the bias power , It is experimentally determined whether or not the DC bias voltage satisfies the first set voltage value in the range of 550V to 600V.

Second, a second source power and a second bias power, which cause the DC bias voltage measured by the voltage measurement module 185 to have a second set voltage value, are applied to the antenna 150 and the chuck 120, respectively, An etching process is performed (S122).

Since the step S122 corresponds to an intermediate stage of the entire plasma etching process, the step S122 has the greatest influence on the height of the lens shape. Accordingly, the first set voltage value has a relatively low range of 350V to 380V as compared to the step S121 described above. Since the value of the DC bias voltage (the second set voltage value) is set to a relatively low level in step S122, it should be performed for a relatively long time compared to the step S121 and the step S123 described later. (S120) in which the plasma etching process is performed in the plasma etching process.

Here, the second source power and the second bias power may be determined by measuring the DC bias voltage through the voltage measurement module 185 with respect to the plasma etching apparatus 100, before performing the plasma etching process, while measuring the magnitude of the source power and the bias power It is experimentally determined in advance whether the DC bias voltage satisfies the second set voltage value in the range of 350 V to 380 V. [

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

Since the step S123 corresponds to the finishing step in the entire plasma etching process, the step S123 has the greatest influence on the slope inclination of the lens shape. Accordingly, the third set voltage value has a relatively high range of 550V to 600V as compared to the step S122 described above.

Here, the third source power and the third bias power are determined by measuring the DC bias voltage through the voltage measurement module 185 with respect to the plasma etching apparatus 100 before performing the plasma etching process, and measuring the magnitude of the source power and the bias power It is experimentally determined in advance whether or not the DC bias voltage satisfies the third set voltage value in the range of 550V to 600V.

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

The substrate on which the lens shape pattern is formed by the series of steps for the plasma etching process as described above is pulled 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 range of the third set voltage value, which are suggested to be suitable for forming a lens- The range is experimentally obtained by repeating a number of tests by the applicant of 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 The bias power should be set so that the DC bias voltage has a second set voltage value in the range of 350 to 380 V, the third source power and the third bias power are set such that the DC bias voltage has a third set voltage value in the range of 550 to 600 V In the case of the above-described plasma etching apparatus 100, two preferable examples of the sizes of the specific source power and the bias power are as follows.

<First Preferred Example>

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

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

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

&Lt; Second Preferred Example &

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

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

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

8 is an enlarged photographic view of a lens pattern formed on a substrate when a plasma etching method according to the present embodiment is performed by applying a source power and a bias power according to the first preferred embodiment shown above, Is a magnified photograph of a lens shape pattern finally formed on a substrate when a plasma etching method according to the present embodiment is performed by applying a source power and a bias power according to the second preferred embodiment described above.

Referring to FIGS. 8 and 9, the plasma etching method according to the present embodiment can form a lens shape pattern that is close to a hemispherical shape on a substrate in comparison with a conventional plasma etching method (see FIGS. 3 and 4) .

As described above, in the plasma etching method according to the present embodiment, a plasma etching process for forming a lens-like pattern on a substrate by applying a source power and a bias power is performed in three steps of a magnitude of a source power and a magnitude of a bias power It is possible to improve the brightness of the light emitting diode by forming a lens shape pattern which is close to the hemispherical shape on the substrate used for manufacturing the light emitting diode.

Meanwhile, the plasma etching method according to the present invention differs from the present embodiment in that a plasma etching process for forming a lens-like pattern on a substrate by applying a source power and a bias power is performed by a plasma etching process in which the size of a source power and the size of a bias power It is needless to say that the present invention can be carried out by dividing into more than two steps.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

1 is a schematic view showing a general configuration of a light emitting diode (LED) which is a kind of light emitting device.

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

3 is an enlarged photograph of an example of a lens shape pattern formed on a substrate in the plasma etching method of FIG.

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

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

6 is a block diagram for explaining control of the plasma etching apparatus of FIG.

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

8 is an enlarged photograph of an example of a lens shape pattern formed on a substrate by applying the plasma etching method of FIG.

9 is an enlarged photograph of another example of a lens shape pattern formed on a substrate by applying the plasma etching method of FIG.

Description of the Related Art

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

Claims (12)

A plasma etching apparatus includes a reaction chamber for providing a space for generating a plasma, an antenna provided at an upper portion of the reaction chamber to receive a source power, and a chuck to which bias power is applied, A plasma etching method for forming a lens shape pattern on a substrate, (a) applying a first source power and a first bias power to each of the antenna and the chuck such that a DC bias voltage generated by the bias power applied to the chuck has a first set voltage value, and performing a plasma etching process ; (b) applying a second source power and a second bias power to cause the DC bias voltage to have a second set voltage value to the antenna and the chuck, respectively, to perform a plasma etching process; And (c) applying a third source power and a third bias power to cause the DC bias voltage to have a third set voltage value, respectively, to the antenna and the chuck to perform a plasma etching process, The first to third source powers and the first to third bias powers are preset through a process of changing a source power and a bias power while measuring the DC bias voltage before performing a plasma etching process . delete The method according to claim 1, Wherein the second set voltage value is a value Wherein the first set voltage value and the third set voltage value are set to be lower than the first set voltage value and the third set voltage value. The method according to claim 1, Wherein the first set voltage value is a value selected from a range of 550 to 600 V, the second set voltage value is a value selected from a range of 350 to 380 V, and the third set voltage value is a value selected from a range of 550 to 600 V. Plasma etching method. The method according to claim 1, The step (b) Wherein the plasma etching is performed for a relatively long time compared to the step (a) and the step (c). The method according to claim 1, The substrate is a sapphire substrate used for fabricating a light emitting diode (LED) Wherein the lens shape pattern is formed on the sapphire substrate to improve the brightness of the light emitting diode. The method according to claim 1, Wherein the step (a) is a step for determining a lower width of the lens shape, The step (b) is a step for determining the height of the lens shape, Wherein the step (c) is a step for determining a slope inclination of the lens shape. A plasma etching apparatus for forming a lens-like pattern on a substrate, A reaction chamber for providing a space in which a plasma is generated; An antenna provided at an upper portion of the reaction chamber; A source power supply for supplying a source power to the antenna; A chuck provided inside the reaction chamber; A bias power supply for supplying a bias power to the chuck; A voltage measuring module for measuring a DC bias voltage generated by a bias power applied to the chuck; And A plasma etching process is performed by applying a first source power and a first bias power to each of the antenna and the chuck such that a DC bias voltage measured by the voltage measurement module has a first set voltage value, A second source power and a second bias power for causing a bias voltage to have a second set voltage value are applied to the antenna and the chuck, respectively, to perform a plasma etching process, and then the DC bias voltage is set to a third set voltage value And a controller for controlling the source power and the bias power to apply a third source power and a third bias power to the antenna and the chuck to perform a plasma etching process, The first to third source powers and the first to third bias powers are preset through a process of changing a source power and a bias power while measuring the DC bias voltage before performing a plasma etching process . delete delete 9. The method of claim 8, Wherein the first set voltage value is a value selected from a range of 550 to 600 V, the second set voltage value is a value selected from a range of 350 to 380 V, and the third set voltage value is a value selected from a range of 550 to 600 V. Plasma etching apparatus. 9. The method of claim 8, The substrate is a sapphire substrate used for fabricating a light emitting diode (LED) Wherein the lens shape pattern is formed on the sapphire substrate to improve the brightness of the light emitting diode.

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