KR20240006173A - Scrubber efficiency measurement device for scrubber process - Google Patents

Abstract

A scrubber can be said to be an important primary environmental facility that purifies perfluorinated compounds, acidic gases, volatile organic compounds, and dust and discharges them into the atmosphere. The treatment methods for exhaust gases include combustion, heat, plasma, catalyst, and adsorbents. Thus, contaminants are treated. Recently, the need for high-efficiency equipment using low levels of energy has increased, and the importance of technology for monitoring the concentration of gases emitted and real-time monitoring in order to maintain high efficiency characteristics over the long term is increasing.
When equipment ages or fails, operation may continue in a situation where the conditions cannot be met. In order to exclude such abnormal situations, a measurement and feedback system that continuously monitors the operating status of the scrubber and continuously measures the reduction efficiency for exhaust gases to increase the reduction efficiency above a certain level is essential.
To this end, the present invention provides a gas measuring device that can be used in a scrubber and a means for calculating scrubber efficiency using the same. This configuration has the effect of preventing and delaying global warming by further reducing the gases emitted from the scrubber.

Description

Scrubber efficiency measurement device for scrubber process{.}

The present invention relates to a scrubber for treating gases and by-products discharged as by-products of semiconductor processing. More specifically, it relates to a technology for measuring the gas removal efficiency of the scrubber.

According to the prior art prior to the invention of this application, a preheating unit for preheating and activating the process gas used in the semiconductor and LCD manufacturing process so that the thermal reaction of the gas can actively occur; a thermal reaction unit that heats the process gas activated while passing through the preheating unit inside a high-temperature reaction chamber to cause a thermal reaction; a separation unit that collects solid particles generated during thermal reaction and separates the particles from gas; a dust collection unit that collects solid particles separated from the separation unit; A technology including cold and hot air supply means for supplying hot air and cold air to the preheating unit and the separation unit, respectively, is disclosed.

Another prior technology concerns a scrubber for semiconductor waste gas treatment using a cyclone. The technical problem to be solved is to efficiently filter solid powder and non-decomposable nitrogen fluoride in semiconductor waste gas, and also to use a cyclone without pressure loss. A technology for providing a scrubber for processing semiconductor waste gas is disclosed.

Registered Patent Publication No. 10-0303150 Registered Patent Publication No. 10-1519553

A scrubber can be said to be an important primary environmental facility that purifies perfluorinated compounds, acidic gases, volatile organic compounds, and dust and discharges them into the atmosphere. The treatment methods for exhaust gases include combustion, heat, plasma, catalyst, and adsorbents. Thus, contaminants are treated. Recently, the need for high-efficiency equipment using low levels of energy has increased, and the importance of technology for monitoring the concentration of gases emitted and real-time monitoring in order to maintain high efficiency characteristics over the long term is increasing.

When equipment ages or fails, operation may continue in a situation where the conditions cannot be met. In order to exclude such abnormal situations, a measurement and feedback system that continuously monitors the operating status of the scrubber and continuously measures the reduction efficiency for exhaust gases to increase the reduction efficiency above a certain level is essential.

The present invention provides the following problem solving means to solve the above problems.

In order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration and discharge concentration of the incoming gas fed into the scrubber were used to measure the efficiency of the scrubber as follows. A scrubber efficiency calculation method is provided to calculate the scrubber efficiency using (Equation 2) and (Equation 3).

......(식 2)

......(Equation 2)

......(식 2)

......(Equation 2)

.

.

......(식 2)

......(Equation 2)

.....(Equation 3)

In addition, in order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration of the incoming gas and the discharged concentration are used to measure the efficiency as shown below ( Using Equation 2) and (Equation 4), we provide a scrubber efficiency calculation method that calculates the scrubber efficiency by considering the global warming potential.

......(식 2)

......(Equation 2)

......(식 2)

......(Equation 2)

.

.

......(식 2)

......(Equation 2)

......(Equation 4)

Additionally, in the gas measuring device for measuring scrubber efficiency, a light source that generates light with a frequency of 4.56um to 11um; and a measurement cell for allowing light generated from the light source to pass through a sample gas. and a sample gas inflow path that supplies sample gas to the measurement cell. and

an outlet through which the sample gas is discharged; and a multi-infrared sensor that receives and measures light from the light source that has passed through the measurement cell containing the sample gas. And the multi-infrared sensor has center frequencies of 4.56.um, 4.66um, 11.00um, and 7.5um, respectively, and measures scrubber efficiency, characterized in that it consists of a bandpass filter with a bandwidth of 0.1um left and right from the center frequency. Provides a gas measuring device for

In addition, by dividing the measured value of the signal that passed through the 4.56.um, 4.66um, and 11.00um band filters of the multi-infrared sensor by the value of the signal measured by the bandpass filter that passed the 7.5um, the size of the measured signal Provides a gas measuring device for measuring scrubber efficiency, which is characterized in that it standardizes and measures regardless of the intensity of light generated from the light source.

In addition, a gas measuring device for measuring scrubber efficiency is provided, wherein the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 5 below.

...(식 5)

...(Equation 5)

In addition, a gas measuring device for measuring scrubber efficiency is provided, wherein the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 6 below.

......(Equation 6)

With the above configuration, the efficiency of the scrubber is measured, and this is fed back and controlled to the operation of the scrubber, thereby further reducing the gas emitted from the scrubber, which has the effect of preventing and delaying global warming.

Figure 1 shows a conceptual diagram of the input input and output produced in the etching process.
Figure 2 shows a conceptual diagram of the input input and output produced in the chemical vapor deposition process.
Figure 3 is a conceptual diagram of a general NDIR (Non-Dispersive Infrared Gas Analyzers) gas measurement system.
Figure 4 is a cross-sectional view of a multi-NDIR gas sensor.
Figure 5 is a configuration diagram of the scrubber efficiency measurement device of the present invention.
Figure 6 is an absorption spectrum of NF3 gas used to measure scrubber efficiency of the present invention.
Figure 7 is an absorption spectrum of CF4 gas used to measure scrubber efficiency of the present invention.

Today, as global warming has become a reality and damage from bad weather is increasing in each country, efforts are being made in each country to prevent global warming. The most representative global warming gas is the increase in CO2 due to the use of fossil fuels, but unlike fossil fuels, F-series gases are classified as greenhouse gases that are up to tens of thousands of times more powerful than CO2 gases, and these gases are widely used in industrial sites. In particular, with the development of ICT technology, it is a gas that is widely used in the cleaning stage, including wafer etching, in the semiconductor process.

The semiconductor and display industries are becoming increasingly larger and more highly integrated due to the rapid increase in demand for memory due to the expansion of smartphones and the use of big data, leading to the expansion of production lines to produce them. In the semiconductor manufacturing process, large amounts of perfluorochemicals that cause warming are used during the process or cleaning process. Accordingly, the importance of processing unreacted gases and by-products produced from process reactions is increasing, and the emissions after the semiconductor process are increasing. The resulting gas must be treated and released into the atmosphere.

As shown in Figures 1 and 2, the gaseous substances used in the semiconductor process are CHF3, CH2F2, CF4, C3F8, C4F8, NF3, SF6, C4F6, C5F8, etc., and the energy sources are LNG and electric power. , the effluents are wafers, CHF3, CH2F2, CF4, C3F8, C4F8, NF3, SF6, C4F6, C5F8, CO2, NO, N2O, CO, and HC series of unreacted gas components.

Equipment that reduces the above gases so that they are not directly discharged into the atmosphere is commonly referred to as a scrubber. The scrubber is manufactured to treat unreacted or reaction by-products.

The scrubber can be said to be an important primary environmental facility that purifies perfluorinated compounds, acidic gases, volatile organic compounds, dust, etc. and releases them into the atmosphere, and the treatment methods for the exhaust gas include combustion, heat, plasma, catalyst, and adsorbent. It is used to treat pollutants. Recently, the need for high-efficiency equipment using low levels of energy has increased, and the importance of technology for monitoring the concentration of gases emitted and real-time monitoring in order to maintain high efficiency characteristics over the long term is increasing.

Currently, the development and application of scrubbers are manufactured and supplied under optimal conditions that can generate continuous reduction efficiency, but when equipment ages or fails, operation may continue in a situation where the conditions cannot be satisfied. In order to exclude such abnormal situations, a measurement and feedback system that continuously monitors the operating status of the scrubber and continuously measures the reduction efficiency for exhaust gases to increase the reduction efficiency above a certain level is essential.

However, a device that measures the efficiency of a scrubber measures the ratio of the gas discharged after removal or treatment to the gas input into the scrubber.

Scrubber gas reduction efficiency can be evaluated according to the gas reduction efficiency, and the reduction efficiency can be evaluated in the simple method below.

......(식 1)

......(Equation 1)

However, in the present invention, in order to measure the comprehensive reduction efficiency of the scrubber for various gases, a method for evaluating the scrubber efficiency for each gas for various measurable gases was developed as follows.

......(식 2)

......(Equation 2)

......(식 2)

......(Equation 2)

.

.

......(식 2)

......(Equation 2)

....(Equation 3)

The scrubber's combined gas reduction efficiency can be calculated by calculating the measured efficiency for each gas separately using (Equation 2) and averaging it using (Equation 3).

However, in the present invention, the treatment efficiency of the scrubber can also be calculated as the degree of impact on global warming.

For this purpose, (Equation 3) can be transformed into (Equation 4).

......(Equation 4)

* Global Warming Potential (GWP) indicates the extent to which other greenhouse gases contribute to global warming based on the impact of carbon dioxide on global warming. In other words, it is the amount of solar energy absorbed by 1 kg of individual greenhouse gas divided by the amount of solar energy absorbed by 1 kg of carbon dioxide. It can be said to be an index of the warming effect per unit mass. Considering carbon dioxide as 1, methane is 21, nitrous oxide is 310, hydrofluorocarbon is 1,300, and sulfur hexafluoride is 23,900. The Kyoto Protocol uses global warming potential to calculate greenhouse gas emissions (Wikipedia).

In other words, the efficiency of the scrubber is expressed by multiplying the reduction efficiency of the scrubber's composite gas by the global warming index based on carbon dioxide, thereby providing a means of indicating whether the removal of gases that have a significant impact on global warming is large or small.

To this end, the present invention measures three gases at the front and rear ends of the scrubber and measures the efficiency of the scrubber using Equations 2 and 3 and Equations 2 and 4 above.

However, in order to accurately measure the efficiency of the scrubber, a means for accurately measuring the gas input to the scrubber and the gas coming out of the scrubber is essential.

In the present application, the NDIR gas measurement method is intended to be used. Figure 3 shows a general NDIR optical measurement method. This is a system configuration for measuring various gases as a method for measuring signals when using one light source and one detector. In other words, it is equipped with one light source and one detector, and all gas components to be measured are measured by sequentially rotating the band-pass filter wheel and measuring the size of the signal detected by the one detector for each filter. The type of gas can be determined by combining signals, and the concentration of the gas can be measured using the ratio of the magnitudes of the signals.

However, since the bandpass filter is sequentially rotated and measured, there is a disadvantage in that measurement time is required.

In the present application, a gas measurement sensor using a multi-infrared sensor as shown in Figure 4 using a complex optical filter is intended to be used.

In addition, the present invention seeks to measure the efficiency of the scrubber by dividing it into two types. In order to measure the combustion efficiency of the BURN method, the gas concentration of CO and CO2 is measured, and the semiconductor gas removal efficiency of the scrubber is measured by the concentration of NF3 gas.

Therefore, when a system is configured to sample gas from a scrubber and measure the concentration of the gas to be measured using an NDIR measuring device as shown in FIG. 5, three gases are measured by the NDIR sensor. For this purpose, we plan to use the multi-infrared sensor shown in Figure 4 above. It is generally known that CO gas can be measured at 4.66um, and CO2 can be measured at 4.56.um.

In addition, as shown in Figure 6, for the NF3 gas used to measure the efficiency of the scrubber in the present invention, no signal is measured at 5.00um where CO and CO2 are measured, and the largest signal is measured at 11.00um. there is.

Additionally, since the intensity of the light source may also change due to surrounding noise or fluctuations in power supply voltage, the intensity of the light source can be measured and used as a signal to determine the level of the overall signal.

To this end, the multi-infrared sensor of the present invention can be configured using bandpass filters of 4.56.um, 4.66um, 11.00um, and 7.5um. The wavelength of 7.4um used to measure the intensity of the light source is that the light source must be able to generate a light wavelength of at least 4.56um to 11um, so a wavelength without gas interference was selected within that range, and other wavelengths without gas interference were selected. It is also possible to use wavelengths.

Using Equations 2 and 3 above, the combined gas reduction efficiency of the invention of this application is expressed as Equation 5 below because only one gas is measured.

...(식 5)

...(Equation 5)

If you calculate the complex gas reduction index using this value,

.....(Equation 6)

can be calculated.

In particular, the complex gas reduction index is a value that represents the global warming index per 1 kg, so it is a value that actually indicates global warming and can be used as an indicator to raise awareness of global warming prevention by indicating the efficiency of the scrubber.

Additionally, the combustion efficiency of the scrubber can be calculated using the measured ratio of CO and CO2. The combustion efficiency of the scrubber can be calculated as shown in Equation 7 below.

......(식 7)

......(Equation 7)

General combustion efficiency is generally expressed as the percentage of the actual combustion amount relative to the complete combustion amount when burning combustible materials. However, for the BURN scrubber, it is more useful to indicate the performance of the scrubber by expressing it as the remaining amount of C (carbon) that must be completely burned, so it was calculated as Equation 7 and expressed as the combustion efficiency of the scrubber.

The following problem solving means are provided so that the above-mentioned effects can be achieved.

In order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration and discharge concentration of the incoming gas fed into the scrubber were used to measure the efficiency of the scrubber as follows. A scrubber efficiency calculation method is provided to calculate the scrubber efficiency using (Equation 2) and (Equation 3).

......(식 2)

......(Equation 2)

......(식 2)

......(Equation 2)

.

.

......(식 2)

......(Equation 2)

......(Equation 3)

In addition, in order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration of the incoming gas and the discharged concentration are used to measure the efficiency as shown below ( Using Equation 2) and (Equation 4), we provide a scrubber efficiency calculation method that calculates the scrubber efficiency by considering the global warming potential.

......(식 2)

......(Equation 2)

......(식 2)

......(Equation 2)

.

.

......(식 2)

......(Equation 2)

......(Equation 4)

Additionally, in the gas measuring device for measuring scrubber efficiency, a light source that generates light with a frequency of 4.56um to 11um; and a measurement cell for allowing light generated from the light source to pass through a sample gas. and a sample gas inflow path that supplies sample gas to the measurement cell. and

an outlet through which the sample gas is discharged; and a multi-infrared sensor that receives and measures light from the light source that has passed through the measurement cell containing the sample gas. And the multi-infrared sensor has center frequencies of 4.56.um, 4.66um, 11.00um, and 7.5um, respectively, and measures scrubber efficiency, characterized in that it consists of a bandpass filter with a bandwidth of 0.1um left and right from the center frequency. Provides a gas measuring device for

In addition, by dividing the measured value of the signal that passed through the 4.56.um, 4.66um, and 11.00um band filters of the multi-infrared sensor by the value of the signal measured by the bandpass filter that passed the 7.5um, the size of the measured signal Provides a gas measuring device for measuring scrubber efficiency, which is characterized in that it standardizes and measures regardless of the intensity of light generated from the light source.

In addition, a gas measuring device for measuring scrubber efficiency is provided, wherein the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 5 below.

...(식 5)

...(Equation 5)

In addition, a gas measuring device for measuring scrubber efficiency is provided, wherein the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 6 below.

......(Equation 6)

Claims (6)

In order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration and discharge concentration of the incoming gas fed into the scrubber were used to measure the efficiency of the scrubber as follows. Scrubber efficiency calculation method that calculates the efficiency of the scrubber using (Equation 2) and (Equation 3).

......(Equation 2)

......(Equation 2)
.
.

......(Equation 2)

......(Equation 3) In order to measure the efficiency of the scrubber used to reduce the process gas and cleaning gas used in the chemical vapor deposition process or the etching process during the semiconductor process, the concentration of the incoming gas and the discharged concentration were used to calculate the efficiency of the scrubber as shown below (Equation 2) ) and (Equation 4) to calculate the scrubber efficiency considering the global warming potential.

......(Equation 2)

......(Equation 2)
.
.

......(Equation 2)

......(Equation 4) In the gas measuring device for measuring scrubber efficiency,
A light source that generates light with a frequency of 4.56um to 11um; and
a measurement cell for allowing light generated from the light source to pass through a sample gas; and
a sample gas inflow path that supplies sample gas to the measurement cell; and
an outlet through which the sample gas is discharged; and
a multi-infrared sensor that receives and measures light from the light source that has passed through the measurement cell containing sample gas; and
The multi-infrared sensor has center frequencies of 4.56.um, 4.66um, 11.00um, and 7.5um, respectively, and is for measuring scrubber efficiency, characterized in that it consists of a bandpass filter with a bandwidth of 0.1um left and right from the center frequency. Gas measuring device. According to paragraph 3,
By dividing the measured value of the signal that passed through the 4.56.um, 4.66um, and 11.00um band filters of the multi-infrared sensor by the value of the signal measured by the bandpass filter that passed the 7.5um, the size of the measured signal is A gas measuring device for measuring scrubber efficiency, characterized in that it measures and standardizes regardless of the intensity of light generated from the light source. According to paragraph 3,
A gas measuring device for measuring scrubber efficiency, characterized in that the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 5 below.

...(Equation 5) According to paragraph 3,
A gas measuring device for measuring scrubber efficiency, characterized in that the efficiency of the gas measuring device for measuring scrubber efficiency is calculated using Equation 6 below.

......(Equation 6)