KR20100048521A - Monitoring apparatus for plasma process and method of the same - Google Patents

Abstract

PURPOSE: An apparatus and a method for monitoring a plasma process are provided to reduce the generation of failure during a wafer etching or deposition process by sensing the abnormal state of plasma. CONSTITUTION: A red-green-blue(RGB) sensor(200) is arranged on the view port side(140) of a plasma process chamber(100) in which an etching and a deposition process for a semiconductor are performed. The RGB sensor measures light generated from plasma in the plasma process chamber based on red, green and blue colors. A master board(300) is connected to the RGB sensor and processes signal from the RGB sensor. The master board controls the operation of the process chamber and displays the state of the operation. An adapter firmly fixes the RGB sensor on the lateral side of the process chamber.

Description

Plasma process monitoring device and plasma process monitoring method {MONITORING APPARATUS FOR PLASMA PROCESS AND METHOD OF THE SAME}

The present invention can detect a minute change in the plasma in real time using an RGB sensor, and when the abnormality occurs in the plasma can be immediately confirmed from the outside, the plasma process monitoring device and plasma process monitoring method capable of fine process control It is about.

In general, the manufacturing process of a semiconductor integrated circuit is composed of various unit processes such as a cleaning process, an ion implantation process, a photographic process, a deposition process, an etching process, and chemical mechanical polishing.

Plasma process technology in the manufacturing process of semiconductor integrated circuits is an essential technology for manufacturing fine semiconductor integrated circuits, and typical unit process technologies using plasma include dry etching and dry deposition.

During the plasma process, in order to realize the fine line width of the semiconductor integrated circuit, the change of the process input parameter should be allowed within a very small range. Examples of the process input parameter include the amount of reaction gas, the pressure of the chamber, and the magnitude of the applied power. have.

On the other hand, when the unit process is repeatedly performed in countless times during the semiconductor integrated circuit production process, a phenomenon in which the plasma process conditions are different from the set parameters may occur due to an error occurring due to an equipment abnormality or an indeterminate reason. have.

In the case of a dry deposition process, a small change in process input parameters can change not only the thickness of the thin film but also the etching characteristics of the thin film.

In the case of a dry etching process, a change in minute process input parameters may affect not only etch rate, selectivity, but also uniformity.

When an etching process using a plasma is performed, an invariant change in the process input parameter may affect the line width of the fine pattern and the inclination of the sidewall, thereby preventing accurate and fine implementation of the integrated circuit.

Determining abnormality of the process by detecting minute changes in process input parameters has been recognized as an important part of the process using plasma. This prevents defective wafers from the error process from being transferred to the next process. Can be.

For this reason, there is a need for the invention of a monitoring method capable of observing abnormalities occurring during the process in addition to the process conditions in real time and confirming precisely.

Here, we can consider some of the conditions that a device for monitoring a plasma process would have to have.

1) The output data should be simple enough to intuitively understand the process status.

2) There should be less time delay due to the processing of output data.

3) The measurement result should be quantitatively analyzed.

4) The installation of the sensor should not affect the actual process progress.

5) The sensitivity of the sensor should be high enough to detect small errors.

6) In terms of process diagnosis, it should be configured so that the operator can easily understand and accurately judge the result of the diagnosis.

Until now, as a device for plasma monitoring, Langmuir probes, self-excited electron spectroscopy (SEERS), optical emission spectroscopy (OES), etc. have been produced and used in the plasma process.

However, these devices have the disadvantage that the sensor is inserted into the chamber and the metal tip is exposed to the plasma (Language probe), or the measurement results are derived in a form that is difficult to intuitively interpret or judge (OES), or Inferior sensitivity (Cears) has limitations such as that it is difficult to accurately and quickly determine the state of the plasma.

In addition, the equipment is formed integrally with the process chamber or provided with a sensor unit in a limited space outside the chamber, there is a problem that the observer can not freely mount the sensor unit in the desired position.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to detect the state of the plasma in the process chamber in real time, sensitively and immediately, and to detect the abnormal state of the plasma in the process chamber. It is to provide a process monitoring device.

Another object of the present invention is to reduce the defect rate of the wafer etching process caused by the plasma state or more, and to enable finer process control.

Still another object of the present invention is to secure a fixing force and a supporting force of the plasma monitoring equipment attached to the outside of the chamber by using a variety of adapters, and to prevent leakage by using a connector to enable more accurate plasma monitoring.

Still another object of the present invention is to provide a plasma monitoring apparatus that is independent of the structure and shape of the chamber and the spatial constraints of the environment outside the chamber.

Still another object of the present invention is to provide a plasma monitoring apparatus regardless of spatial constraints such as the structure and shape of the chamber and the environment outside the chamber.

Plasma process monitoring apparatus according to the present invention for achieving the above object is provided on the side of the plasma process chamber for performing the etching and deposition process of the semiconductor and the light generated from the plasma inside the process chamber, red, green, An RGB sensor unit measuring each blue color, and a master board connected to the RGB sensor unit and processing a signal generated from the RGB sensor unit to control an operation of a process chamber or to display a process state externally; Through the R channel sensor, the G channel sensor, and the B channel sensor provided in the RGB sensor part provided on the outer surface of the viewport of the process chamber, red, green, and blue light are individually separated from the light generated from the plasma gas in the process chamber. An RGB module with a built-in RGB sensor, an adapter for firmly fixing the RGB module to the side of the process chamber, Located between the RGB module and the adapter, it allows for easy removable of the RGB module and is characterized in that comprises a connector for preventing the light leakage.

In addition, the master board, the analog digital converter for converting the RGB signal generated from the RGB sensor unit into a digital signal, and the RGB signal converted into a digital signal is analyzed separately to numerically analyze the current plasma state inside the process chamber. A color analyzer for quantifying, a comparator for comparing the signal transmitted from the color analyzer and an RGB signal value obtained from the plasma in a steady state, a signal transmitted from the color analyzer, and a signal transmitted from the comparator A main processor for collecting and generating a control signal for controlling the operation of the process chamber or for outputting a signal indicating a state of the process chamber, a warning unit for generating an alarm sound or a warning light according to a signal transmitted from the main processor, and the main processor Process parameters inside the process chamber in response to signals from the processor Data is displayed on the screen, the user may be included in the real-time status display unit provided to instantly check the status of the process chamber.

Here, the master board compares the state information of the plasma in the process chamber detected by the RGB sensor unit with the state information of the steady state plasma, and diagnoses an alarm or the like of the alarm unit when the state of the current plasma is out of the state range of the normal state. It may be provided so that the user can detect the fact through the negative screen display.

In addition, in the color analyzer of the master board, the magnitude of the RGB signal measured by the RGB sensor is divided into R-channel data, G-channel data, and B-channel data, respectively, and digitized. The R, G, B channel data and the R, G, B channel data of the process tolerance range are respectively compared for the same channel, and when any one of each channel data is out of the process tolerance range, It may be determined that the plasma has reached an abnormal state.

Alternatively, in the color analyzer of the master board, the magnitude of the RGB signal measured from the RGB sensor is divided into R channel data, G channel data, and B channel data, respectively, and then digitized. Color, saturation, and brightness data are converted, and the hue, saturation, and brightness data transmitted from the color analyzer in the comparator are compared with each other by the same type. When comparing data, if any of the data is out of the process tolerance, it can be determined that the plasma in the process chamber has reached an abnormal state.

Meanwhile, the adapter of the RGB sensor unit may be formed in a '┼' type.

Preferably, it may be provided in a shape that protrudes upwards toward the center of the planar shape of the adapter of the RGB sensor unit.

In addition, a screw groove is formed inside the adapter of the RGB sensor unit, and a screw protrusion is formed on the outer surface of the cylindrical connector having a hollow portion in the center thereof, so that the adapter and the connector can be joined by a bolt-nut coupling method.

Alternatively, a fitting groove is formed inside the adapter of the RGB sensor unit, and a fitting protrusion is formed on the outer surface of the cylindrical connector having a hollow portion in the center thereof, so that the adapter and the connector can be joined in a fitting manner.

On the other hand, the RGB sensor unit is provided on the side of the plasma process chamber for performing the etching and deposition process of the semiconductor and each of the light generated from the plasma inside the process chamber for each of the red, green, blue color, and the RGB sensor unit A master board connected to process a signal generated from an RGB sensor unit to control an operation of a process chamber or to display a process state to the outside, wherein the RGB sensor unit is provided on an outer surface of a viewport of the process chamber; RGB module with built-in RGB sensor that individually receives red, green, and blue light from the light emitted from the plasma gas in the process chamber through the channel sensor, G channel sensor, and B channel sensor, viewport and optical cable of the process chamber And an optical cable adapter to prevent leakage and to transmit the light of plasma transmitted from the light emitting connector to the RGB module. That is located between the optical cable, the optical cable module of the RGB optical cable is connected to the RGB module and may include the fiber-optic cable connector to prevent light leakage.

On the other hand, the plasma process monitoring method for achieving the object of the present invention, measuring the amount of change in the RGB optical data according to the process input parameters, calculating and storing a reference value from the RGB optical data, and the reference value Calculating a process tolerance based on the reference, comparing and analyzing the RGB optical data value obtained during the plasma process with a reference value, and determining whether the RGB optical data value acquired during the plasma process is within the process tolerance. And generating a warning signal when the RGB optical data value acquired during the plasma process is out of the process tolerance, and measuring the change amount of the RGB optical data according to the process input parameter. And a process of separately measuring the variation amount of the G channel data and the B channel data.

Here, in the step of calculating and storing a reference value from the RGB optical data, individual reference values of each of the R channel data, the G channel data, and the B channel data are calculated, and the RGB optical data values obtained during the plasma process are allowed to process. In the step of determining whether it is within the range, if any one of the R channel data, G channel data and B channel data measured in real time is out of the process tolerance range, it may be determined that the plasma in the process chamber has reached an abnormal state.

Alternatively, in calculating and storing a reference value from the RGB optical data, color data, saturation data, and brightness data are calculated by combining R channel data, G channel data, and B channel data, and the color data, saturation data, The individual reference value of each of the brightness data is calculated, and in the step of determining whether the RGB optical data value obtained during the plasma process is within the process tolerance, the process permits any of the measured color data, saturation data and brightness data in real time. If out of range, it may be determined that the plasma in the process chamber has reached an abnormal state.

Through the plasma process monitoring apparatus according to the present invention, it is possible to immediately detect the minute state change inside the process chamber and to detect the abnormal state of the plasma in the process chamber in real time.

As a result, it is possible to reduce the defect rate of the wafer etching process caused by the plasma state or more, and to allow finer process control.

In addition, by using the adapter of a variety of shapes it is possible to secure the fixing force and the supporting force of the plasma monitoring equipment attached to the outside of the chamber, by using a connector may be prevented by light leakage to enable more accurate plasma monitoring.

In addition, the plasma monitoring apparatus may be installed regardless of spatial constraints such as the structure and shape of the chamber and the environment outside the chamber.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

Prior to this, terms used in the present specification and claims should not be construed in a dictionary meaning, and the inventors may properly define the concept of terms in order to explain their invention in the best way. It should be construed as meaning and concept consistent with the technical spirit of the present invention.

Therefore, the embodiments shown in the present specification and the drawings are only exemplary embodiments of the present invention, and not all of the technical ideas of the present invention are presented. Therefore, various equivalents It should be understood that water and variations may exist.

1 is a schematic diagram illustrating a plasma process system to which a plasma process monitoring apparatus according to the present invention is applied, and FIG. 2 is a schematic diagram showing an RGB sensor unit.

1 and 2, the plasma process monitoring apparatus according to the present invention is provided on the side of the plasma process chamber 100 for performing the etching and deposition process of the semiconductor and red light generated from the plasma inside the process chamber RGB sensor unit 200 for measuring each color of green and blue, and connected to the RGB sensor unit to process a signal generated from the RGB sensor unit to control the operation of the process chamber or to display the process state to the outside. Including the master board 300, the RGB sensor unit 200 provided on the outer surface of the viewport 140 of the process chamber 100, through the R channel sensor, G channel sensor, B channel sensor, the process chamber An RGB module 230 having a built-in RGB sensor that individually receives red, green, and blue light from light generated from the plasma gas in the chamber; and firmly fixing the RGB module 230 to a side of the process chamber. An adapter 210 for turning on, and a connector 220 positioned between the RGB module 230 and the adapter 210 to enable easy detachment of the RGB module 230 and to prevent leakage of light may be included. have.

A stage 110 is provided in the process chamber 100 to which the semiconductor wafer W is fixed. When the semiconductor wafer W is fixed to the stage 110, the reaction gas and the gas are injected through the gas injection unit 130. Reaction gas is injected.

Thereafter, when power is applied to the inside of the process chamber by the RF power 120, the reaction gas applied into the process chamber is changed into a plasma state, and the semiconductor wafer W is subjected to a photo and deposition process in another unit process. Dry etching or deposition process is performed.

In this case, a low-temperature vacuum plasma may be used as the plasma for the etching or deposition process to maintain the pressure of the reaction gas at several to several hundred mTorr or less, but is not limited thereto.

Meanwhile, the light generated from the plasma may be collected through the viewport 140 provided on the side wall of the process chamber 100 during the etching or deposition process, and the collected light is transmitted to the RGB sensor unit 200. The state of the plasma according to the process is measured.

Here, the viewport 140, the opening provided in the side wall of the process chamber 100 is provided in a shape that is sealed by two transparent heat-resistant glass window excellent in light transmittance, the transparent heat-resistant pressure-resistant glass window and the process chamber ( It is possible to prevent the gas inside the process chamber from being leaked by heat-resistant silicon or the like between 100), but is not limited to such a configuration.

Preferably, a lens for condensing the light generated from the plasma and amplifying the light intensity may be included.

During the etching process, the temperature of the wafer chuck included in the stage 110 is maintained through the temperature controller 160 in the process chamber 100 according to the process.

Here, the wafer chuck is provided to seat and fix the wafer on the stage 110. Since the wafer chuck is in direct contact with the wafer during the plasma process, the temperature of the wafer and the temperature of the wafer chuck are closely related.

Since the temperature of the wafer and the wafer chuck has a great influence on the etching rate and the process quality of the wafer during the plasma process, the temperature of the wafer chuck needs to be properly controlled by the temperature controller 160.

When the etching process is completed, the temperature inside the chamber is lowered through the temperature controller 160 of the process chamber 100, and the reaction gas and the reaction gas inside the chamber are discharged to the outside through the vacuum pump of the exhaust device 150. Prepare for the next etching process.

Referring to FIG. 2, the RGB sensor unit 200 is provided in a form in which the adapter 210, the connector 220, and the RGB module 230 are connected in a line.

Meanwhile, as shown in FIG. 2, the adapter 210 of the RGB sensor unit 200 may be basically provided in a '┼' type, but for easy coupling with the process chamber 100 having various shapes, ○ 'or' ─ 'type.

Here, the adapter 210 is provided in a '┼' shape, it can withstand the impact applied from the top and bottom and left and right, and can secure the support of the RGB module 230 connected to the adapter 210.

In addition, Figure 3 is a schematic diagram showing a preferred embodiment of the adapter 210, as shown in Figure 3, has a gentle inclination upward toward the center of the planar shape of the adapter 210, or It may be provided in a shape that protrudes vertically, which may be equally applied to the adapter 210 of the '○' or '─' type.

That is, as shown in Figure 3, the shape of the distal end of the adapter 210 in the form of a vertical or gentle inclination, so that the outer surface of the process chamber 100 is formed in a spherical shape or of the process chamber 100 As in the case in which the RGB module 230 is installed at the corner, the adapter 210 can be easily installed without regard to the shape of the process chamber 100 or the installation position of the RGB module 230.

4 is a cross-sectional view illustrating a structure in which the adapter 210, the connector 220, and the RGB module 230 are coupled. According to FIG. 4, the center portion of the adapter 210 is fitted with a connector 220 or a bolter. A screw groove 213 or a fitting groove 215 for nut coupling may be provided, and a plurality of bolt openings for coupling with the process chamber 100 may be provided near the edge of the adapter 210.

On the other hand, the connector 220 is provided in the form of a cylinder having a hollow portion in the central portion, a plate (plate) for preventing the firm fixation and light leakage of the RGB module 230 at the end of the RGB module 230 side of the cylinder It is formed, the area of the plate may be provided in a shape larger than the horizontal cross-sectional area of the cylinder.

In addition, the screw protrusion 223 or the fitting protrusion 225 may be provided on the outer surface of the connector 220, so that the adapter 220 may be easily attached to the adapter 220.

The RGB module 230 is a key component of the present invention, and is a device that receives light generated from plasma in the process chamber 100 and converts it into an electrical signal.

More specifically, the RGB module 230 includes an RGB sensor provided with a plurality of R-channel sensors that receive red light, a G-channel sensor that receives green light, and a B-channel sensor that receives blue light. In the process of converting light received for each channel into an electrical signal, it may be amplified by a predetermined multiple to be converted into more accurate optical data.

At this time, since the sensitivity of the sensor for each RGB channel is different, the amplification factor for each channel sensor may be changed to correct this, but is not limited thereto.

In addition, the structure of the RGB sensor, the sensor for each RGB channel is grouped into the same acceptable color grouped into three parts of R, G, B receiving area

...

[R] [R] [R] [G] [G] [G] [B] [B] [B]

[R] [R] [R] [G] [G] [G] [B] [B] [B]

[R] [R] [R] [G] [G] [G] [B] [B] [B]

...

([R]: R channel sensor, [G]: G channel sensor, [B]: B channel sensor)

Can be arranged to be or in the form of a grid

...

[R] [G] [B] [R] [G] [B] [R] [G] [B]

[B] [R] [G] [B] [R] [G] [B] [R] [G]

[G] [B] [R] [G] [B] [R] [G] [B] [R]

...

May be provided in a repeating structure, or in the form of a stripe

...

[R] [G] [B] [R] [G] [B] [R] [G] [B]

[R] [G] [B] [R] [G] [B] [R] [G] [B]

[R] [G] [B] [R] [G] [B] [R] [G] [B]

...

May be provided in a repeating structure.

Here, since the sensitivity of each RGB channel may vary, the distribution of the sensor for each RGB channel disposed on the entire RGB sensor may be different, but is not limited thereto.

In addition, since the RGB signal generated by the RGB module 230 is an analog electric signal and is generated without limitation of the bandwidth of the signal, different electric signals may be generated according to the change of very minute plasma light.

On the other hand, an opening for coupling with the connector 220 is provided in the RGB module 230, and the light of the plasma passing through the viewport 140 and the connector 220 of the process chamber 100 through the opening is an RGB sensor. It is provided in the shape which can reach | attain.

Here, the opening of the RGB module 230 has a width enough to pass through the screw groove and the locking groove provided on the outside of the cylinder of the connector 220.

The order in which the RGB sensor unit 230 is coupled to the process chamber 100,

1. Attach the adapter 210 of the shape corresponding to the shape of the process chamber 100 to the portion where the viewport 140 is formed

2. Combination of connector 220 and RGB module 230

3. Coupling of the adapter 210 and the connector 220

Same as

In the second step, the RGB module 230 and the connector 220 may be integrally formed, and an open structure or the like is formed in the opening of the RGB module 230 for easy detachment of the plate portion of the connector 220. It may be, but is not limited to such.

Here, the open structure is provided on a side near the opening of the RGB module 230, and after opening the side of the RGB module 230, the cylindrical portion of the connector 220 is connected to the RGB module 230 through the opening of the RGB module 230. 230) After positioning so as to be exposed to the outside, the RGB module 230 and the connector 220 may be coupled in a manner of closing the open structure.

That is, due to the opening of the RGB module 230 and the plate portion of the connector 220 positioned inside the RGB module 230, the RGB module 230 and the connector 220 are not separated from each other.

The adapter 210 and the connector 220 are easily and firmly formed by the screw groove 213 or the fitting groove 215 provided in the adapter and the screw protrusion 223 or the fitting protrusion 225 provided in the connector 220. When the coupling of the two components is completed, the end of the connector 220 is in contact with the outer window of the viewport 140 of the process chamber 100.

In order to prevent light leakage from occurring between the outer window of the viewport 140 and the gap of the distal end of the connector 220, a ring-shaped elastic rubber or resin may be attached to the distal end of the connector 220.

Through such a coupling relationship, the light of the plasma may be transmitted to the RGB module 230 through the connector 220 which is in contact with the viewport 140 of the process chamber 100 to the outside, and the adapter ( The coupling method of the 210 and the connector 220 is provided by the fitting coupling or bolt-nut coupling method it is possible to easily attach to the desk.

In addition, when the RGB sensor unit 200 is configured as described above, signal transmission between the RGB sensor unit 200 attached to the process chamber 100 and the master mode 300 far from the process chamber is performed through a general cable such as a power line. It can be made, there is no restriction in bending of the wire, extension of the length and the like.

5 is a schematic diagram illustrating another embodiment of the RGB sensor unit, and illustrates a different coupling method between the viewport 140 and the RGB module 230.

That is, the optical cable adapter 240 for connecting the viewport 140 and the optical cable 250 to prevent leakage and the optical cable 250 for transmitting the light of the plasma transmitted from the optical cable adapter 240 to the RGB module 230; Located between the optical cable 250 and the RGB module 230, the optical cable 250 is connected to the RGB module 230, and transmits the light of the plasma transmitted from the optical cable 250 to the RGB module 230 The optical cable connector 260 may be additionally included.

Here, the optical cable adapter 240 effectively aggregates the plasma light emitted to the outside through the viewport 140 of the process chamber 100 and transmits it to the optical cable 250, and the ends of the optical cable are outside the viewport 140. Secure it so that it contacts the window correctly.

In addition, the optical cable adapter 240 also serves to protect the ends of the optical cable that is easily damaged.

The optical cable connector 260 fixes the connection between the end of the RGB module direction of the optical cable 250 and the RFB module 230, and seals the connection part so that light does not leak out when the connection is fixed. Will be

Preferably, the optical cable connector 260 may further include a configuration such as a lens that can amplify the light of the plasma transmitted through the optical cable 250 to the extent that distortion does not occur.

By providing the RGB sensor unit 200 in this manner, only the optical cable adapter 240 and the optical cable 250 that occupy a small space are connected to the process chamber 100, and the RGB module 230, which is the remaining component, is arbitrarily selected. It can be arrange | positioned at the place, and the effect which can use a space efficiently can be enjoyed.

FIG. 6 is a block diagram illustrating a master board 300. The master board 300 digitizes an RGB signal transmitted from the RGB sensor unit 200 into digital data and compares the RGB signal with reference data. It is determined that the state of the plasma in the) belongs to the normal state range, and serves to display the information to the outside.

Referring to FIG. 6, the master board 300 separately analyzes an analog-digital converter 310 for converting an RGB signal generated from the RGB sensor unit 200 into a digital signal, and an RGB signal converted into a digital signal. A color analyzer 320 for quantitatively quantifying the plasma state in the current process chamber, and a comparison unit for comparing the signal transmitted from the color analyzer 320 with the RGB signal value obtained from the plasma in a steady state ( 330 and the signal transmitted from the color analyzer 320 and the signal transmitted from the comparator 330 to generate a control signal for controlling the operation of the process chamber 100 or to generate the process chamber 100. The main processor 340 for outputting a signal indicating the state of the warning, the warning unit 350 for generating a warning sound or warning lights in accordance with the signal transmitted from the main processor 340 and the main processor 340 According to the transmitted signal, the process parameter related data in the process chamber 100 is displayed on the screen so that the user can immediately check the state of the process chamber 100 and the comparison unit ( The status diagnosis unit 370 may indicate whether the operation state of the process chamber is normal or malfunctioning according to the signal transmitted from the 330 and the main processor 340.

The analog-to-digital converter 310 may be provided in plurality in order to quickly convert analog RGB signals in real time.

That is, a separate analog-to-digital converter 310 may be provided for each RGB channel, or may be provided in such a manner that a plurality of analog-digital converters 310 are connected and processed in parallel with the entire RGB signal.

In addition, when the RGB signal generated by the RGB sensor unit 200 is converted into a digital signal through the analog-to-digital converter 310, only a typical 8-bit RGB signal system having a color representation level of 0 to 255 for each RGB channel is present. Rather, a more extended 10bit (0 to 1023), or 12bit (0 to 4095), or 14bit (0 to 8195), or 16bit (0 to 65535), or 20bit (0 to 1048575), or 24bit (0 to 16777215 It can be provided as a system, through which it is possible to express minute changes in the signal, but is not limited thereto.

The color analyzer 320 maps the digital RGB signal transmitted from the analog-to-digital converter 310 to three-dimensional coordinates of the R-channel data, the G-channel data, and the B-channel data to be used in the comparison unit 330 which will be described later. To generate basic RGB optical data.

That is, the digital RGB signal transmitted from the analog-to-digital converter 310 is separated for each channel and recombined into a data bundle of (R channel data, G channel data, B channel data).

Alternatively, the color analyzer 320 converts the separated digital data for each RGB channel into hue (H: Hue), saturation (S :), and brightness (B: Brightness), and bundles them into three-dimensional coordinates. It may be arranged.

Here, the color has a value of 0 to 360, the saturation and the brightness is provided with a maximum size according to the number of bits determined by the analog-to-digital converter 310.

First of all, in the case of saturation,

Can be prepared as

In the case of brightness,

It can be prepared as.

For color

When the R value among R, G, and B is the maximum,

When the G value among R, G, and B is the maximum,

When the B value among R, G, and B is the maximum,

If the H value is less than 0, color data is calculated by additionally adding 360, but is not limited thereto.

Preferably, the process progress time data may be included in the 3D data bundle, and the process progress time data may be included together to track the state of the plasma according to the process progress, thereby improving the accuracy of the plasma process. Can increase.

The comparator 330 is real-time RGB optical data ((R, G, B) or (H, S, B) coordinate data) transmitted from the color analyzer 320 and RGB optical data obtained from a plasma in a normal state. Is the component to compare.

FIG. 7 is a graph of three-dimensional coordinates of RGB optical data spaces in the process tolerance range, and when the RGB optical data values measured in real time are included in the RGB optical data spaces in the process tolerance range (A), FIG. If it is determined that the plasma is in a normal state and is not included in the RGB optical data space within the process allowable range (B), it is determined that the current plasma is in an abnormal state.

The same applies to the case where the RGB optical data is provided as the HSB coordinate data, thereby distinguishing the case (C) and the case (D) which do not belong to the process allowable range.

At this time, even if the same state is displayed, the coordinate values expressed in RGB and the coordinate values expressed in HSB are different from each other, and thus the shape of the process allowable range may have a different shape depending on which coordinate axis is represented.

On the other hand, the comparison unit 330 is a process allowable range R, G, B (R data, G channel data and B channel data (or H data, S data, B data) of RGB optical data measured in real time Alternatively, H, S, B) is compared with each other for the same kind of data, and if any of the three optical data values is out of the normal range, a signal is determined that the current plasma state is abnormal.

For example, when the R channel data of the process tolerance range is 20 to 37, the G channel data is 33 to 50, and the B channel data is 79 to 81, the RGB optical data value measured in real time is (21, 42, 80). , The current plasma state is determined to be normal.

However, if the RGB optical data value measured in real time is equal to (19, 35, 81), the R channel data is out of the process tolerance, it is determined that the current plasma state is abnormal.

Here, the RGB optical data in the process allowable range, which is a criterion for determination, uses those obtained from normal process data in the past or pilot process data before the present process.

In addition, since the state of the plasma changes as the process progresses, the RGB optical data of the process allowable range of each process step changes with time, which means that the three-dimensional shape of FIG. 7 changes in size and position with time. It can be expressed in the form.

The main processor 340 is the backbone of the master board 300 that collects various state information from the color analyzer 320, the comparator 33, and the process chamber 100, and generates a control signal according to a situation. .

That is, the main processor 340 is a process input parameter of the process chamber and the actual measured process parameters (gas pressure, gas flow rate, applied power) and RGB optical data transmitted from the color analyzer 320 and the comparison unit ( The control unit 330 receives a signal for determining whether the plasma is normal or not and transmits the numerical value of the process input parameter, the actual process variable, and the RGB optical data to the real time display unit 360 which will be described later.

Here, when the state of the plasma is a normal state, the main processor 340 additionally transmits a signal indicating that the state of the plasma is normal to the state diagnosis unit 370 which will be described later.

However, when the state of the plasma is abnormal, the main processor 340 transmits a warning signal to the warning unit 350 to be described later, and additionally transmits a signal indicating that the state of the plasma is abnormal to the state diagnosis unit 370. Done.

Preferably, it may include a processing method for generating a control signal for changing the state of the plasma to a normal state and transferring it to the process chamber 100, thereby reducing the defective rate of the plasma process.

Here, the control signal may include a signal for changing the amount and pressure of the reaction gas, the process processing time, the intensity of the applied power, the operation of the temperature controller of the process chamber 100.

The warning unit 350 is a component that turns on the warning siren and the warning lamp according to the warning generation signal of the main processor 340 when the plasma state is abnormal.

Here, the warning unit 350 is installed in a control facility and a space that manages the outside of the process chamber 100 or the entire process, and immediately notify the user of an abnormality of the plasma process.

The real-time display unit 360 is an output device for displaying all the information of the current process chamber 100, preferably can be implemented through an LCD touch panel or a conventional LCD monitor, but is not limited thereto.

Here, the information displayed externally through the real-time display unit 360 may include the elapsed time and progress of the process, the process input parameters and actual process variables of the process chamber 100, the real-time RGB optical data obtained from the plasma, and the process tolerance. Information such as an RGB optical data space may be included, but is not limited thereto.

The state diagnosis unit 370 is an output device for displaying whether the current state of the plasma process in the process chamber 100 is included in the process tolerance range, and may be included in the real time display unit 360.

The state diagnosis unit 370 is an apparatus for outputting an abnormality of plasma, in particular, and may additionally display data related to tracking RGB optical data over time.

The above-described RGB sensor unit 200 is a plasma generated from the reaction gas and the reaction gas injected into the process chamber 100 during the semiconductor plasma process, when the gas particles are changed to the normal state-excited state-ground state The amount of change in the emitted light is measured.

8 is a graph showing the change in the numerical value of the RGB optical data according to the change of the process input parameters, Figure 8 (a) is the power applied to the plasma, (b) is the flow rate of the gas, (c) is the change in the gas pressure According to the brightness of the plasma light ('B' value of the RGB optical data composed of HSB), it shows that quantitative data can be prepared from the intensity of the plasma.

That is, as shown in FIG. 8, since different RGB optical data is acquired according to the change of each process input parameter, process tolerance range data and real-time RGB optical data having minute differences according to the progress of the plasma process may be generated. .

In more detail, as the applied electric power and the gas flow rate increase, the luminance of the plasma increases proportionally, and from this relationship, the minute state change of the plasma can be obtained quantitatively.

In addition, in the graph of gas pressure, in FIG. 8 (c), quantitative data according to the state of the plasma can be obtained by detecting the slope of each graph distributed on the left and right of 50 mTorr on the basis of the case where the gas pressure is 50 mTorr. .

The quantitative data acquisition may be obtained not only by the brightness of the plasma light described above, but also by changing the red, green, and blue light measured by the RGB sensor unit 200, and the color and saturation converted therefrom.

Hereinafter, a method of monitoring the state of the plasma in real time and processing when a problem occurs in the state of the plasma will be described using the features and concepts of the above-described elements.

9 is a flowchart illustrating a plasma process monitoring method according to the present invention.

First, in step S10, the amount of change in the RGB optical data is measured according to the change in the process input parameter indicating the pressure, flow rate, and applied power of the gas.

When measuring RGB optical data, RGB signals are recorded as individual R channel data, G channel data, and B channel data through the RGB sensor unit 200 and the color analyzer 320 of the master board 300. .

After that, a reference value is calculated from the RGB optical data measured in step S20 and stored in the main processor 340. At this time, the reference value is separately calculated for each RGB channel data, and an additional additional process is performed. The reference values for the color data H, the saturation data S, and the brightness data B may be generated from the R channel data, the G channel data, and the B channel data.

In step S30, a process allowance range having a minimum value and a maximum value is calculated based on the reference value, and is individually determined according to the values of R, G, and B, or hue (S), saturation (S), and brightness (B). Since the process allowable range is represented by a three-dimensional shape occupying a three-dimensional space implemented by the values of R, G, and B, or values of hue (H), saturation (S), and brightness (B).

Here, the steps S10 to S30 may be performed through a pilot process before the present process or may be performed by referring to the normal process data of the past.

In particular, the minimum value and the maximum value of the process allowable range may be determined depending on whether or not the etching etching state of the wafer under test is in a range judged to be defective according to the process input parameter and the process progress.

The actual process starts at step S40, and detects an abnormal state of the plasma process while continuing through subsequent steps S50 to S80 until the process ends.

In step S50 it will be checked whether the process is finished, if the process is still in progress, the process proceeds to step S60.

In step S60, it is analyzed whether the RGB optical data derived from the RGB signal acquired in real time through the RGB sensor unit 200 is included in the process tolerance range in the comparison unit 330.

When step S70 is performed, it is determined whether the comparison unit 330 belongs to the real-time RGB optical data and the process allowable range. At this time, the R channel data, the G channel data, the B channel data or the like of the RGB optical data is determined. If any of the hue (H) data, the saturation (S) data, and the brightness (B) data is out of the process tolerance, it is determined that the plasma in the process chamber has reached an abnormal state.

If it is determined that the current state of the plasma has reached an abnormal state, step S80 is performed to inform the outside of the state of the plasma through the warning unit 350 and the state diagnosis unit 370, and the state of the plasma continuously. Detect and allow the process to proceed smoothly.

As mentioned above, although the present invention has been described by way of limited embodiments and drawings, the technical idea of the present invention is not limited thereto, and a person having ordinary skill in the art to which the present invention pertains, Various modifications and variations may be made without departing from the scope of the appended claims.

1 is a schematic diagram illustrating a plasma process system to which a plasma process monitoring apparatus according to the present invention is applied.

2 is a schematic diagram showing an RGB sensor unit.

3 is a schematic diagram illustrating various embodiments of an adapter included in an RGB sensor unit.

4 is a cross-sectional view illustrating a coupling structure of an adapter, a connector, and an RGB module.

5 is a schematic diagram showing another embodiment of the RGB sensor unit.

6 is a block diagram illustrating a master board.

7 is a graph showing three-dimensional coordinates of RGB optical data spaces within a process tolerance range.

8 is a graph illustrating RGB optical data values according to changes in process input parameters.

9 is a flowchart illustrating a plasma process monitoring method according to the present invention.

Explanation of symbols on the main parts of the drawings

100: chamber 110: stage

120: RF power 130: gas injection portion

140: viewport 150: exhaust device

160: temperature controller 200: RGB sensor unit

210: adapter 213: screw groove

215: fitting groove 220: connector

223: screw projection 225: fitting projection

230: RGB module 240: optical cable adapter

250: optical cable 260: optical cable connector

300: master board 310: analog to digital converter

320: color analysis unit 330: comparison unit

340: main processor 350: warning

360: real-time display unit 370: status diagnostic unit

W: semiconductor wafer

Claims (15)

An RGB sensor unit provided at a side surface of the plasma process chamber for performing an etching and deposition process of a semiconductor and measuring light generated from plasma in the process chamber for each of red, green, and blue colors; A master board connected to the RGB sensor unit and processing a signal generated from the RGB sensor unit to control an operation of the process chamber or to display a process state externally; In the RGB sensor unit provided on the outer surface of the viewport of the process chamber, An RGB module incorporating an RGB sensor for individually receiving red, green, and blue light from the light generated from the plasma gas in the process chamber through the R-channel sensor, the G-channel sensor, and the B-channel sensor; An adapter for rigidly fixing the RGB module to the side of the process chamber; Located between the RGB module and the adapter, the connector to enable easy detachment of the RGB module and to prevent light leakage; plasma processing monitoring apparatus comprising a. The method of claim 1, On the master board, An analog digital converter for converting an RGB signal generated from the RGB sensor unit into a digital signal; A color analyzer which analyzes RGB signals converted into digital signals individually and converts plasma states into numerically quantified RGB optical data; A comparison unit for comparing the RGB optical data transmitted from the color analyzer and the RGB optical data acquired from the plasma in a steady state; A main processor for collecting the RGB optical data transmitted from the color analyzer and the signal transmitted from the comparator to generate a control signal for controlling the operation of the process chamber or to emit a signal indicating the state of the process chamber; A warning unit generating a warning sound or a warning lamp according to the signal transmitted from the main processor; And a real-time display unit configured to display process parameter related data inside the process chamber on the screen according to the signal transmitted from the main processor so that the user can immediately check the state of the process chamber. Device. The method of claim 2, In the color analyzer of the master board, the magnitude of the RGB signal measured by the RGB sensor is divided into R-channel data, G-channel data, and B-channel data, respectively, and digitized, and R is transmitted from the color analyzer in the comparator. , G, B channel data and R, G, B channel data of process tolerance are compared for each same channel, The plasma process monitoring apparatus, characterized in that, when any one of the respective channel data is out of the process tolerance range when comparing the data, it is determined that the plasma in the process chamber has reached an abnormal state. The method of claim 2, In the color analyzer of the master board, the magnitude of the RGB signal measured from the RGB sensor is divided into R channel data, G channel data, and B channel data, respectively, and then digitized. , The saturation data and the brightness data are converted, and the hue, saturation, and brightness data transmitted from the color analyzer in the comparison unit and the hue, saturation, and brightness data of the process tolerance range are compared for the same type, respectively. In the comparison of the data, when any one of the data is out of the process tolerance range, it is determined that the plasma in the process chamber has reached an abnormal state. The method of claim 1, Plasma process monitoring apparatus characterized in that the adapter of the RGB sensor unit is formed in a '┼' type. The method of claim 5, Plasma process monitoring apparatus characterized in that it is provided in a shape that protrudes upwards toward the center of the planar shape of the adapter of the RGB sensor. The method of claim 6, A screw groove is formed inside the adapter of the RGB sensor unit, and a screw protrusion is formed on the outer surface of the cylindrical connector having a hollow portion at the center thereof, so that the adapter and the connector are connected by a bolt-nut coupling method. Monitoring device. The method of claim 6, Plasma groove is formed inside the adapter of the RGB sensor unit, the fitting projection is formed on the outer surface of the cylindrical connector having a hollow portion in the center, the plasma process monitoring device, characterized in that the adapter and the connector is connected by the fitting method . An RGB sensor unit provided at a side surface of the plasma process chamber for performing an etching and deposition process of a semiconductor and measuring light generated from plasma in the process chamber for each of red, green, and blue colors; A master board connected to the RGB sensor unit and processing a signal generated from the RGB sensor unit to control an operation of the process chamber or to display a process state externally; In the RGB sensor unit provided on the outer surface of the viewport of the process chamber, An RGB module incorporating an RGB sensor for individually receiving red, green, and blue light from the light generated from the plasma gas in the process chamber through the R-channel sensor, the G-channel sensor, and the B-channel sensor; An optical cable adapter for connecting the viewport of the process chamber to the optical cable and preventing leakage; An optical cable for transmitting the light of the plasma transmitted from the light emitting unit connector to the RGB module; And an optical cable connector positioned between the optical cable and the RGB module to connect the optical cable to the RGB module and to prevent leakage. 10. The method of claim 9, On the master board, An analog-digital converter for converting the RGB signal generated from the RGB sensor unit into a digital signal; A color analyzer which analyzes RGB signals converted into digital signals individually and converts plasma states into numerically quantified RGB optical data; A comparison unit for comparing the RGB optical data transmitted from the color analyzer and the RGB optical data acquired from the plasma in a steady state; A main processor for collecting the RGB optical data transmitted from the color analyzer and the signal transmitted from the comparator to generate a control signal for controlling the operation of the process chamber or to emit a signal indicating the state of the process chamber; A warning unit generating a warning sound or a warning lamp according to the signal transmitted from the main processor; And a real-time display unit configured to display process parameter related data inside the process chamber on the screen according to the signal transmitted from the main processor so that the user can immediately check the state of the process chamber. Device. The method of claim 10, In the color analyzer of the master board, the magnitude of the RGB signal measured by the RGB sensor is divided into R-channel data, G-channel data, and B-channel data, respectively, and digitized, and R is transmitted from the color analyzer in the comparator. , G, B channel data and R, G, B channel data of process tolerance are compared for each same channel, The plasma process monitoring apparatus, characterized in that, when any one of the respective channel data is out of the process tolerance range when comparing the data, it is determined that the plasma in the process chamber has reached an abnormal state. The method of claim 10, In the color analyzer of the master board, the magnitude of the RGB signal measured from the RGB sensor is divided into R channel data, G channel data, and B channel data, respectively, and then digitized. , The saturation data and the brightness data are converted, and the hue, saturation, and brightness data transmitted from the color analyzer in the comparison unit and the hue, saturation, and brightness data of the process tolerance range are compared for the same type, respectively. In the comparison of the data, when any one of the data is out of the process tolerance range, it is determined that the plasma in the process chamber has reached an abnormal state. Measuring a change amount of RGB optical data according to a process input parameter; Calculating and storing a reference value from RGB optical data; Calculating a process tolerance based on the reference value; Comparing and analyzing the RGB optical data values obtained during the plasma process with reference values; Determining whether the RGB optical data value acquired during the plasma process is within a process tolerance range; In the plasma process monitoring method comprising the step of: generating a warning signal when the RGB optical data value obtained during the plasma process is outside the process tolerance range, Measuring the change amount of the RGB optical data according to the process input parameter, wherein the change amount of the R channel data, the G channel data, and the B channel data is measured separately. The method of claim 13, In the calculating and storing of the reference value from the RGB optical data, individual reference value values of each of the R channel data, the G channel data, and the B channel data are calculated. In the step of determining whether the RGB optical data value obtained during the plasma process is within the process tolerance range, when any one of the R channel data, the G channel data, and the B channel data measured in real time is out of the process tolerance range, And determining that the plasma has reached an abnormal state. The method of claim 13, In the calculating and storing a reference value from the RGB optical data, color data, saturation data, and brightness data are calculated by combining R channel data, G channel data, and B channel data, and the color data, saturation data, and brightness data. Each individual baseline value is calculated, In the step of determining whether the RGB optical data value obtained during the plasma process is within the process tolerance, when any one of the color data, the saturation data, and the brightness data measured in real time is out of the process tolerance, the plasma in the process chamber is abnormal. A plasma process monitoring method characterized in that it is determined that the state has been reached.

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