KR101217467B1 - Plasma generation apparatus which can estimate whether substrate is correctly loaded or not and estimating method thereof - Google Patents

Abstract

The present invention is a chamber having a reaction space therein; A substrate support installed in the chamber; A plasma electrode installed on the substrate stabilizer; A process RF power source connected to the plasma electrode; Capacitance measurement means connected to the plasma electrode to measure capacitance inside the chamber; The present invention relates to a plasma generator including determination means for determining whether the substrate is normally loaded using the measured value of the capacitance measuring means, and a method for determining whether the substrate is normally loaded using the same.

According to the present invention, it is possible to automatically check whether the substrate is properly placed on the substrate support before applying the main RF power in the plasma generator. Therefore, the arcing phenomenon or the deposition of the surface of the substrate stabilizer, which occurs when the substrate is twisted, can be prevented, so that the life span of the substrate stabilizer can be prevented and the process reproducibility of the apparatus can be secured.

Plasma, Capacitance, Substrate Loading

Description

Plasma generation apparatus which can determine whether the substrate is normally loaded or not and method for determining the same {Plasma generation apparatus which can estimate whether substrate is correctly loaded or not and estimating method

1 is a block diagram of a general plasma generator

2 is an equivalent circuit diagram of a plasma generator;

3 is a block diagram of a plasma generating apparatus according to an embodiment of the present invention

4 is a view showing a state in which a low pass filter is installed in front of a measuring sensor

5A and 5B show capacitances formed inside a chamber with and without a substrate, respectively;

6 is a flowchart illustrating a process of determining whether a substrate is normally loaded according to an embodiment of the present invention.

Description of the Related Art [0002]

10 plasma generator 11 chamber

12 substrate substrate 13 gas distribution plate

14 plasma electrode 15 gas supply pipe

16: RF power source 17: matcher

18: exhaust port 20: switch

30: measuring sensor 40: RF power for measurement

50: low pass filter

The present invention relates to a plasma generating apparatus for performing an etching and deposition process on a wafer or glass (hereinafter referred to as a 'substrate') by using a plasma. Specifically, the present invention relates to whether a substrate is normally loaded on a substrate support of the plasma generating apparatus. It relates to a device and a method for determining whether or not.

In general, in order to manufacture a semiconductor device or a liquid crystal display, a predetermined circuit pattern must be formed on a substrate. To this end, a process of depositing a thin film on the substrate and patterning the same is performed several times to several tens of times.

Such a process is performed inside a substrate processing apparatus designed for an optimal environment for a corresponding process, and recently, a plasma generating apparatus for treating a substrate using plasma has been widely used.

Plasma generator is applied in various fields such as PECVD (Plasma Enhanced Chemical Vapor Deposition) device for thin film deposition, etching device for etching and patterning deposited thin film, sputter, ashing device, etc. According to the method, it is divided into Capacitively Coupled Plasma (CCP) device and Inductively Coupled Plasma (ICP) device.

CCP device is a device that generates a plasma using the RF electric field formed between the two electrodes by applying RF power to the parallel plate electrodes facing each other, ICP device using an induction electric field induced by an antenna installed outside the chamber It is a device for generating a plasma inside the chamber.

FIG. 1 schematically shows a general configuration of a capacitively coupled plasma generator 10, in which a substrate support 12 for placing a substrate s inside a chamber 11 having a reaction region therein is installed. The upper portion of the substrate support 12 is provided with a plurality of injection holes and the gas distribution plate 13 is usually made of aluminum, the lower portion of the chamber 11 to discharge residual gas and process by-products The exhaust port 18 is provided.

The gas distribution plate 13 is coupled to the lower portion of the plasma electrode 14 having a flat plate shape, and since the plasma electrode 14 is also mainly made of aluminum, the gas distribution plate 13 and the plasma electrode 14 are electrically connected to each other. Will be connected.

Between the gas distribution plate 13 and the plasma electrode 14 is provided with a buffer region for primary diffusion of the process gas, the gas supply pipe 15 for supplying the process gas to the buffer region is connected to the central portion of the plasma electrode 14 On the other hand, the RF power source 16 providing the RF power is connected. A matcher 17 for matching impedance is provided between the RF power supply 16 and the plasma electrode 14.

The process sequence of the plasma generating apparatus 10 is as follows.

First, the substrate s is loaded into the substrate support 12 through a substrate entrance, not shown, and then a process atmosphere is formed through vacuum pumping.

Subsequently, when the process gas is injected into the chamber through the gas distribution plate 13 and the RF power source 16 is applied to the plasma electrode 14, the RF electric field is formed between the plasma electrode 14 and the grounded chamber 11. Is formed. More precisely, an RF electric field is formed between the gas distribution plate 13 electrically connected to the plasma electrode 14 and the grounded substrate stabilizer 12 and the chamber 11.

FIG. 2 shows an equivalent circuit of the plasma generator, in which the plasma electrode 14 and the grounded chamber 11 play the same role as the capacitance electrode. When RF power is applied, electrons are accelerated by the RF electric field formed between them and collide with neutral gas to generate plasma, which is a mixture of active species, ions and electrons, and the active species or ions thus generated enter the substrate s. To perform the deposition or etching process.

Since the substrate support 12 serves as a ground electrode, the substrate support 12 is made of a metal material such as SUS or aluminum, and a protective film is formed on an edge and a side of the upper surface through anodizing to prevent arcing and oxidation.

Therefore, when the substrate s is placed on the substrate support 12, the portion that has not been treated with a protective film must be accurately placed in place so that the plasma is not exposed to the plasma.

However, even though the substrate s is not placed in the correct position of the substrate support 12 due to an error in the transportation process of the substrate s, the substrate s is twisted or damaged during transportation, the substrate s is not placed at all. It may become.

In this case, arcing is generated between the surface of the substrate stabilizer 12 and the plasma, thereby shortening the life of the product, and causing a problem that the process reproducibility is greatly reduced by depositing a thin film on the upper surface of the substrate stabilizer 12.

In particular, in the plasma generation apparatus for liquid crystal display devices that handle transparent glass, there is a limit in detecting the settled state of the glass by an optical method, and therefore, it is required to provide a new method for accurately determining the settled state of the substrate.

The present invention is to solve this problem, it is an object to enable the automatic check whether the substrate is properly placed on the substrate support before proceeding with the plasma generating apparatus,

The present invention to achieve the above object, a chamber having a reaction space therein; A substrate support installed in the chamber; A plasma electrode installed on the substrate stabilizer; A process RF power source connected to the plasma electrode; Capacitance measurement means connected to the plasma electrode to measure capacitance inside the chamber; The present invention provides a plasma generating apparatus including determining means for determining whether the substrate is normally loaded using the measured value of the capacitance measuring means.

The capacitance measuring means, the measurement RF power source connected to the plasma electrode; And a measuring sensor provided between the plasma electrode and the measuring RF power source.

The measuring RF power is provided at a frequency of 100 KHz or less.

The process RF power supply and the measurement RF power supply are selectively connected to the plasma electrode by selection means.

The selecting means includes an output terminal connected to the plasma electrode; A first input terminal connected to the process RF power source; A second input terminal connected to the measurement RF power source; One end is connected to the output terminal and the other end includes a switching member selectively connected to the first and second input terminals.

The process RF power source is connected to the plasma electrode by a power supply line, and the measurement RF power source is connected to the power supply line between the plasma electrode and the process RF power source, and at the front end of the measurement RF power source. The pass filter is installed.

The judging means compares the measured value of the measuring means with a reference value and determines that the substrate is normally loaded if it is within a predetermined tolerance range, and determines that the substrate is defective if it is out of the tolerance.

In another aspect, the present invention, a substrate having a reaction space therein, a substrate stabilizer installed in the chamber, the plasma generating apparatus including a plasma electrode positioned on the substrate stabilizer, the substrate is normally placed on the substrate stabilizer CLAIMS 1. A method for determining whether or not a method is provided, the method comprising: applying a measurement RF power source to the plasma electrode; Measuring capacitance between the chamber and the substrate stabilizer and the plasma electrode; A method of determining whether a substrate is normally loaded includes determining whether the substrate is normally loaded by comparing the measured capacitance with a reference capacitance.

The step of applying the RF power for measurement, characterized in that made before applying the process RF power to the plasma electrode.

The determining may include determining that the difference between the measured capacitance and the reference capacitance is within a predetermined tolerance, and determining that the defect is out of the tolerance.

If it is determined that the determination step is normal, the process is applied to the plasma electrode by applying RF power for the process, and if it is determined that the failure is characterized in that to generate an alarm.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

3 shows a plasma generating apparatus according to an embodiment of the present invention, the same reference numerals are used for the same components as those of FIG.

The present invention is characterized in that the plasma generating device 10 is provided with means for measuring the capacitance appearing between the plasma electrode 14, the grounded chamber 11, and the substrate stabilizer 12.

The capacitance between the plasma electrode 14, the grounded chamber 11, and the substrate stabilizer 12 is measured using a measuring sensor after supplying the measurement RF power to the plasma electrode 14.

For this purpose, a measurement RF power supply 40 is connected to the plasma electrode 14, and a measurement sensor 30 capable of measuring capacitance is provided between the plasma electrode 14 and the measurement RF power supply 40.

Since the measurement sensor 30 may use a general capacitance measurement device, a detailed description thereof will be omitted. In addition, hereinafter, the RF power source 16 is referred to as a process RF power source 16 to distinguish it from the measurement RF power source 40.

In general, the process RF power supply 16 applies a high frequency power of 13.56 MHz to the plasma electrode 14, but the measurement RF power supply 40 of the present invention provides a frequency of 100 KHz or less, and the inside of the chamber 11 Since only capacitance is measured instantaneously, RF power of several hundred W or less is applied for a short time.

The measurement RF power supply 40 and the process RF power supply 16 may be connected to the plasma electrode 14 independently of each other, but for the sake of simplicity, one power supply line 19 is connected to the plasma electrode 14. In addition, it is preferable to select the measurement RF power supply 40 and the process RF power supply 16 by using the switch 20 installed in the power supply line 19.

That is, as shown in FIG. 3, the switch 20 includes an output terminal connected to the power supply line 19, a first input terminal connected to the matcher 17 and a process RF power supply 16, a measurement sensor 30, and the like. It has a second input terminal connected to the measurement RF power supply 40, and serves to select the first and second input terminals.

The switch 20 may be omitted and a low pass filter (LPF) 50 may be installed in front of the measurement sensor 30 connected to the measurement RF power supply 40 as shown in FIG. 4.

Since the measurement RF power supply 40 is for measuring capacitance in the chamber before the process RF power supply 16 is applied in earnest, the power of the measurement RF power supply 40 affects the process RF power supply 16. Not crazy

When the high-frequency process RF power supply 16 is applied in earnest, the low-pass filter 50 cuts the high-frequency power supply so that the measurement RF power supply 16 is not affected.

On the other hand, in general, the capacitance (C) between the parallel electrodes is given by C = ε ₀ ε _r (A / d), where ε ₀ is the dielectric constant, ε _r is the relative dielectric constant of the material interposed between the electrodes _, A is The area of the electrode, d, is the spacing of the electrodes.

Therefore, the capacitance C ₀ when the substrate s is placed on the substrate support 12 as shown in FIG. 5A and the capacitance C ₁ when the substrate s is not placed as shown in FIG. 5B have different values. This is because A, d, and ε ₀ are invariant, whereas in the former case, the ε _r value of the substrate s is reflected, whereas in the latter case, it is not.

As shown in FIG. 5B, the amount of dielectric material interposed between the electrodes is different from the case where the substrate s is placed in place, as well as when the substrate s is not placed at all. Because of this, the capacitance value is different.

Therefore, the capacitance when the substrate s is placed in the correct position is measured in advance and inputted as the reference capacitance C ₀ , and then the capacitance is measured every time the substrate s is loaded to measure the measured value and C ₀ . In comparison, if the difference is within the tolerance, it is determined to be normal, and if it is out of the tolerance, it is judged to be normal or not, and it is determined whether the substrate s is placed in the correct position.

6 is a flowchart illustrating a process of determining whether the substrate s is properly placed on the substrate support 12 according to an embodiment of the present invention.

First, when the robot enters the chamber 11 to settle the substrate s and withdraws, the process atmosphere is formed by vacuum pumping, and then the measurement RF power 40 is applied before the process RF power 16 is applied. After application, the capacitance between the plasma electrode 14 and the grounded substrate stabilizer 12 is measured through the measurement sensor 30. (ST10, ST11)

The measured capacitance is compared with the reference capacitance C ₀ to determine whether the difference is within a tolerance range. (ST30)

If it is within the tolerance, it is determined that the substrate s is normally placed, and the process is applied by applying the process RF power source 16 (ST40, ST50).

If the tolerance is out of tolerance, alarms such as warning lights and warning sounds are generated for the operator to know that the board (s) is broken or damaged (ST60). In this case, the worker must remove the damaged board or remove the damaged board. (ST70)

On the other hand, in the plasma generating apparatus of the present invention, the switching operation of the switch 20, the application of the measuring RF power supply 40, and a series of processes for measuring the capacitance in the measuring sensor 30 are preferably performed automatically. Therefore, a device control unit (not shown) that controls the overall operation of the plasma generating device controls the operation of the switch 20, the measurement sensor 30, and the measurement RF power supply 40, and the measurement result of the measurement sensor 30. It is desirable to determine whether the substrate is normally loaded by comparing with the reference capacitor.

According to the present invention, it is possible to automatically check whether the substrate is properly placed on the substrate support before applying the main RF power in the plasma generator. Therefore, the arcing phenomenon or the deposition of the surface of the substrate stabilizer, which occurs when the substrate is twisted, can be prevented, so that the life span of the substrate stabilizer can be prevented and the process reproducibility of the apparatus can be secured.

Claims (11)

A chamber having a reaction space therein; A substrate support installed in the chamber; A plasma electrode installed on the substrate stabilizer; A process RF power source connected to the plasma electrode; Capacitance measurement means connected to the plasma electrode to measure capacitance inside the chamber; Judging means for judging whether or not the substrate is normally loaded by using the measured value of the capacitance measuring means; It includes a plasma electrode is connected to the measurement RF power supply, the process RF power supply and the measurement RF power supply is a plasma generating device that is selectively connected to the plasma electrode by a selection means The method of claim 1, The capacitance measuring means, A measurement sensor provided between the plasma electrode and the measurement RF power source; Plasma generator comprising a The method of claim 1, The measurement RF power supply is a plasma generator provided at a frequency of less than 100KHz delete The method of claim 1, The selection means, An output terminal connected to the plasma electrode; A first input terminal connected to the process RF power source; A second input terminal connected to the measurement RF power source; A switching member having one end connected to the output terminal and the other end selectively connected to the first and second input terminals; Plasma generator comprising a delete The method of claim 1, The determination means compares the measured value of the measuring means with a reference value and determines that the substrate is normally loaded if it is within a predetermined tolerance range, and determines that the substrate is defective if it is out of the tolerance. A plasma generating apparatus comprising a chamber having a reaction space therein, a substrate stabilizer installed inside the chamber, and a plasma electrode positioned above the substrate stabilizer, wherein the plasma generating apparatus determines whether the substrate is normally placed on the substrate stabilizer. In the method, Applying the measurement RF power selected by the selection means to the plasma electrode, a process RF power source and a measurement RF power source; Measuring capacitance between the chamber and the substrate stabilizer and the plasma electrode; Determining whether the substrate is normally loaded by comparing the measured capacitance with a reference capacitance; Method of determining whether or not the normal loading of the substrate including 9. The method of claim 8, The step of applying the RF power for measurement, the method of determining whether or not the normal loading of the substrate, characterized in that before the process RF power applied to the plasma electrode. 9. The method of claim 8, In the determining step, if the difference between the measured capacitance and the reference capacitance is within a predetermined tolerance, it is determined to be normal, and if it is out of the tolerance, it is determined to be normal. 9. The method of claim 8, If it is determined in the determination step that the process is applied to the plasma electrode RF power is applied to the process, if it is determined that the failure of the normal loading of the substrate, characterized in that for generating an alarm

Images