KR100778384B1 - Diagnostic Device And Method Of Measuring Quantity Of Precursor For CVD Process - Google Patents

Abstract

The present invention detects the level of the precursor remaining in the container through the transmission and reception of ultrasonic waves during the chemical vapor deposition process, but by delaying for a certain time to remove the filtering and noise to determine a more accurate residual amount of chemistry, characterized in that The present invention relates to an apparatus and diagnostic method for predicting the amount of precursor remaining in a container during a deposition process.

An ultrasonic sensor device (410) for transmitting the ultrasonic wave toward the surface of the precursor (200a) and receiving the ultrasonic wave reflected from the surface by delaying the ultrasonic wave for a predetermined time; Ultrasonic control unit adjusts the threshold voltage to about half the maximum amplitude and removes values not exceeding the threshold voltage by filtering, and compares the filtered data with the preset reference level to apply an alarm output signal when the level is below the reference level. 410, including;

During the semiconductor manufacturing process, the wafer is removed during the chemical vapor deposition process to remove the noise and check only the voltage above the threshold voltage to measure the level of the precursor more accurately in real time to prevent damage due to precursor depletion in advance. By preventing it, there is an effect that can significantly reduce the product failure rate.

Chemical vapor deposition, vessels, precursors, residuals, diagnostics

Description

Diagnostic Device and Method of Measuring Quantity of Precursor For CVD Process in Chemical Vapor Deposition Process

1 is a block diagram of a precursor remaining amount diagnostic apparatus in a container according to the present invention,

Figure 2 is a block diagram of the ultrasonic sensor device and the control unit of the present invention.

Figure 3 is a waveform diagram of the ultrasonic transmission signal and the reception signal of the present invention.

Figure 4 is a real distance graph of the present invention.

Figure 5 is a flow chart for a method for diagnosing the remaining amount of precursor in the container during the chemical vapor deposition process according to the present invention.

Explanation of symbols on main parts of drawing

100: cylinder 100a: carrier gas

110: first pipe 200: container

200a: precursor 210: second pipe

300 reactor 300a wafer

410: ultrasonic sensor device 420 ultrasonic control unit

500: alarm generator

The present invention relates to an apparatus and diagnostic method for detecting the amount of precursor remaining in the container during the chemical vapor deposition process, and more particularly, by detecting the level of the precursor remaining in the container through the transmission and reception of ultrasonic waves, The present invention relates to an apparatus and diagnostic method for predicting the amount of precursor remaining in a container during a chemical vapor deposition process by allowing filtering and noise to be removed to more accurately check the remaining amount.

The importance of chemical vapor deposition in semiconductor processing as well as in general coating technology is increasing. In particular, as the line width decreases, there is a growing interest in a chemical vapor deposition process using a chemical precursor having excellent step coverage characteristics as a limitation of the existing physical vapor deposition process. In addition to the chemical vapor deposition process, an atomic layer deposition process having more excellent layer covering properties is also used.

In general, a chemical vapor deposition process vaporizes a liquid chemical precursor in a container in various ways, allowing the vaporized chemical gas to be injected into a reactor and deposited on a substrate.

In particular, in semiconductor lines and the like, usually several dozen or more wafers are continuously deposited using chemical precursors in the reactor, and serious problems occur when the chemical precursors are exhausted.

Therefore, a post-diagnosis method such as checking the state of the chemical precursor deposited on the wafer after the deposition process is taken, and there is a lack of the provision of various diagnostic structures that can diagnose the remaining amount of the precursor in real time during the process. Holding it.

In order to solve this problem, a method of calculating the number of depositions of a wafer and replacing the precursor before it is consumed in a container has been proposed.

However, due to the nature of the precursor it is difficult to obtain accurate data on the consumption per hour, the conventional method is less effective.

Accordingly, the present invention has been made in view of the above-described conventional problems, and has an object of checking the precursor residual amount using ultrasonic waves, but removing noise to ensure more accurate data.

As a means for achieving the above object,

The present invention is a cylinder 100 containing a carrier gas (100a); A first pipe 110 having one side piped to the cylinder 100 so that the carrier gas 100a flows; A container in which a liquid precursor 200a is contained, and the other side of the first pipe 110 is enclosed in the precursor 200a so that the carrier gas 100a bubbles and vaporizes the precursor 200a. 200); A second pipe 210 which is piped to the container 200 so that one side is disposed on the water surface of the precursor 200a and the precursor 200a and the carrier gas 100a are transferred; A reactor (300) in which a chemical vapor deposition process is performed on the precursor (200a) with respect to the wafer (300a) in which the other side of the second pipe (210) is piped and embedded; An ultrasonic sensor device (410) for transmitting the ultrasonic wave toward the surface of the precursor (200a) and receiving the ultrasonic wave reflected from the surface by delaying a predetermined time; Ultrasonic control unit adjusts the threshold voltage to about half the maximum amplitude and removes values not exceeding the threshold voltage by filtering, and compares the filtered data with the preset reference level to apply an alarm output signal when the level is below the reference level. It is characterized by including the configuration (410).

In addition, the ultrasonic sensor device, the ultrasonic receiving unit 411 for receiving a signal after filtering by delaying a predetermined time of sound waves coming back from the surface of the container; A reception amplifier 412 for amplifying a signal of a sound wave received by the ultrasonic receiver after a predetermined time delay; A comparator 413 for comparing the received sound wave input through the reception amplifier with a reference signal and converting the received sound wave into a digital signal if higher than the reference signal; Characterized by the transmitter 414 for generating a frequency for emitting sound waves under the control of the ultrasonic controller.

In the chemical vapor deposition process,

Bubbling and vaporizing the liquid precursor 200a (S1000); Chemically depositing a wafer (300a) with the precursor (200a) (S2000); Emitting ultrasonic waves toward the surface of the precursor 200a by the ultrasonic sensor 410 attached to the lower portion of the container 200 (S3000); Receiving the ultrasonic wave while removing the data corresponding to the thickness of the sustain vessel to delay the reception time for a predetermined time (S4000); Removing noise less than the reference voltage from the received data (S5000); Comparing noise level data of the precursor calculated after removing noise with a reference level already set (S6000); If the level of the precursor 200a is higher than the reference level, the deposition process may be continued, and thus, the deposition process on the wafer 300a is continued, and the ultrasonic sensor 410 generates ultrasonic waves again. Emitted toward the surface of the, characterized in that consisting of a step (S7000) to repeat the steps up to the determination by the ultrasonic control unit 420.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram of a precursor remaining amount diagnostic apparatus in a container according to the present invention,

Figure 2 is a block diagram of the ultrasonic sensor device and the control unit of the present invention.

Figure 3 is a waveform diagram of the ultrasonic transmission signal and the reception signal of the present invention,

The precursor remaining amount diagnostic apparatus of the present invention continuously measures the level of the precursor 200a which decreases as the precursor 200a deposits the wafer 300a in the process of chemically depositing the precursor 200a on the wafer 300a. The main feature is that the ultrasonic sensor device 410 and the ultrasonic control unit 420 are additionally installed so that when the water level of the precursor 200a in the liquid phase is lower than the set reference level, an alarm sound or a warning screen is outputted. This can lead to interruption of the process.

Looking at the overall configuration of the present invention, the cylinder 100 containing the carrier gas (100a), one side piped to the cylinder 100, the first pipe 110, the liquid precursor (200a) containing the first The other side of the pipe 110 is stored in the precursor 200a pipe 200 and the second pipe 210 and the second pipe which is piped to the container 200 so that one side is disposed above the surface of the precursor 200a Ultrasonic sensor device having a device for chemical vapor deposition consisting of the reactor 300, the other side of the pipe 210 and the wafer 300a is contained, and is installed in the lower portion of the container 200 to transmit and receive ultrasonic waves 410 and the ultrasonic control unit 420 for calculating the level of the precursor 200a through the ultrasonic signal and determining a relative height relative to the reference level, and the level of the precursor 200a is higher than the reference level according to the determination result. When low, the alarm generator 500 that generates a warning sound is sequentially connected It is sex.

The cylinder 100 contains a high pressure carrier gas 100a and is piped to the vessel 200 by the first pipe 110. One side of the first pipe 110 is piped to the cylinder 100, the other side is introduced into the container 200 is stored in the precursor precursor 200a of the liquid. Therefore, the carrier gas 100a is injected into the precursor 200a through the first pipe 110 and thereby the precursor 200a is bubbled.

In addition, the second pipe 210 is piped to the vessel 200, one side of the second pipe 210 is introduced into the vessel 200 is disposed on the water surface of the precursor 200a. According to the above-mentioned bubbling, the vaporized precursor 200a is discharged through the second pipe 210.

The second pipe 210 is connected to the reactor 300. Therefore, the vaporized precursor 200a flows into the reactor 300 to perform chemical vapor deposition on the embedded wafer 300a.

As the chemical vapor deposition process proceeds, the amount of the precursor 200a contained in the container 200 gradually decreases, and at some point, the process can no longer be performed. Therefore, in order to minimize the occurrence of defective products due to the lack of the precursor 200a and to know the exact time of replacement of the precursor 200a, it is necessary to grasp the remaining amount of the precursor 200a, that is, the level of the precursor 200a in real time. need.

To this end, in the present invention, after the ultrasonic wave is emitted from the lower end of the precursor 200a to the surface of the precursor 200a and receives the ultrasonic wave reflected from the surface of the precursor 200a, the level of the remaining precursor 200a is determined. It is configured to determine whether the precursor 200a is insufficient compared with the water level serving as a reference.

The ultrasonic sensor device 410 attached to the lower part of the container 200 transmits the ultrasonic waves toward the surface of the precursor 200a and detects the ultrasonic waves reflected from the surface, and the ultrasonic control unit 420 detects the ultrasonic waves. Receives and detects an analog signal for each ultrasound transmitted / received.

Hereinafter, the configuration of the ultrasonic sensor device 410 and the ultrasonic control unit 420, which are the key components of the present invention, will be described in detail.

The ultrasonic sensor device 410 of the present invention includes an ultrasonic receiver 411 for receiving a signal after filtering by delaying a predetermined time of sound waves coming back from the surface of the container;

A reception amplifier 412 for amplifying a signal of a corresponding sound wave received by the ultrasonic receiver 411 after a predetermined time delay;

A comparator 413 for comparing the received sound wave input through the reception amplifier 412 with a reference signal and converting the received sound wave into a digital signal if higher than the reference signal;

An ultrasonic controller 420 for converting a time at a time higher than a reference signal according to the digital signal input through the comparator, and for outputting an alarm sound when the distance is lower than the reference signal;

The transmitter 414 generates a frequency for emitting sound waves under the control of the ultrasonic controller 420.

In the ultrasonic sensor device 410 made as described above, the ultrasonic control unit 420 first outputs a control signal and emits a predetermined sound wave to the surface of the container using the ultrasonic transmitter 414.

Thereafter, the ultrasonic waves are reflected through the surface of the container and input to the ultrasonic receiver, and at the same time, the ultrasonic waves reflected through the bottom surface of the container and the contact surface of the liquid are also input to the ultrasonic receiver.

The present invention allows the ultrasonic receiver 411 to delay the reception time for a predetermined time in order to filter the ultrasonic waves reflected through the bottom surface of the container and the contact surface of the liquid phase.

This is because the technical content of the present invention is to measure the height of the surface of the precursor contained in the container, because the thickness of the bottom of the container is also measured at the same time to cause an error, so in the present invention, a certain time after the ultrasonic firing to filter the signal This will help to filter out noise caused by the thickness of the bottom of the container.

In addition, the present invention is to extract only a signal of a reference voltage or more, if a large noise is received, so that the ultrasonic control unit 420, for this purpose, if a predetermined signal is amplified and input, only the signal of a predetermined reference or more separated Process and convert the time at that time into a distance.

If the converted distance is less than the reference value and the remaining precursor is less than the reference amount, an alarm sound is output to induce the precursor to be replaced.

5 is a flowchart illustrating a method for diagnosing the remaining amount of the precursor 200a in the container 200 during the chemical vapor deposition process according to the present invention. As shown in FIG. 5,

The carrier gas 100a in the cylinder 100 bubbles and vaporizes the liquid precursor 200a in the container 200 and transports the same to the reactor 300 (S1000).

The precursor 200a transferred to the reactor 300 is chemically deposited on the wafer 300a contained in the reactor 300 (S2000).

When this step is performed continuously, the ultrasonic sensor device 410 attached to the bottom of the vessel 200 to measure the level of the precursor 200a in the vessel 200 pulses toward the surface of the precursor 200a. The ultrasound is emitted (S3000). The ultrasonic wave is reflected from the surface of the precursor 200a and returns to the ultrasonic receiver 410 again, which is received by the ultrasonic receiver 420 (S4000).

In this case, the ultrasonic controller removes the data corresponding to the thickness of the sustain vessel by delaying the reception time for a predetermined time before the reception step.

In operation S5000, noise less than the reference voltage is removed from the received data.

Thereafter, the data level of the digital signal is analyzed to calculate the level of the precursor 200a. The principle of operation is that when the ultrasonic wave is emitted to a specific object and the time until the ultrasonic wave is measured has a relationship of "distance = velocity x elapsed time", it passes through the speed of the ultrasonic wave and the time interval of digitization of the ultrasonic signal. Knowing the time, it is possible to measure the distance, that is, the level of the precursor 200a.

In other words, the noise is so large that it can be confused with the sleep echo peaks, so the threshold voltage is adjusted to about half of the maximum amplitude so that the values not exceeding the threshold voltage are removed by filtering to prevent the echo peaks and noises from being confused. With the result of this operation, the level of the precursor 200a is compared with the reference level already set (S6000).

In this case, if the level of the precursor 200a is lower than the reference level, the deposition process cannot continue, so the ultrasonic controller 410 outputs a signal to generate a warning sound, and generates a warning sound through the alarm generator 500. Is displayed.

However, the present invention has been illustrated as an alarm generator 500 for emitting sound as an output means for the warning state, but is not limited to this, other means for warning the user, for example, a monitor for outputting the warning screen image Alternatively, a lamp that emits light of a certain color may be possible.

However, if the level of the precursor 200a is higher than the reference level, the deposition process may be continued, and thus the deposition process on the wafer 300a is continued, and the ultrasonic sensor 410 may generate ultrasonic waves again. Emitted toward the surface of the water 200a, the steps until the determination by the ultrasonic control unit 420 is repeated (S7000).

4 is a graph illustrating measurement results obtained by connecting the ultrasonic sensor device and the ultrasonic controller 410 and 420 according to the present invention to an oscilloscope. As shown in FIG. 4, the X axis represents time in seconds and the Y axis represents amplitude.

For the convenience of calculation, and that the fluid water, the velocity of ultrasonic waves in water is about 1024m / sec, of the ultrasonic waves reflected by the water surface of the water in the 't _1' the time at which ultrasonic waves are transmitted pulse generation time 't _2' The time interval up to was measured as about 38.9 ms.

The present invention implements a delay time of 5us to ignore the data measured during the time, and 5us corresponds to the thickness of the actual floor surface.

As mentioned above, "distance = velocity x elapsed time", so "reciprocation of ultrasonic waves = 1024 m / sec (speed of ultrasonic waves in water) × 48.9 ㎲ (time interval from 't ₁ ' to 't ₂ ') ", You will get a value of about 50mm. Since this is a round trip distance, only one-way distance is calculated, and the water level of about 25mm comes out, which indicates that an accurate value is obtained.

In the above-described apparatus and method for diagnosing the remaining amount of the precursor 200a in the container 200 during the chemical vapor deposition process according to the present invention, the precursor 200a according to the present invention is limited to any specific precursor 200a. In addition, since the level measurement of the precursor 200a through ultrasonic waves is possible in all the precursors 200a, the precursor 200a may be used in all precursors 200a such as inorganic, organic, and organometallic compounds used for chemical vapor deposition.

In addition, the present invention can be used not only for chemical vapor deposition but also for other vapor deposition processes using the liquid precursor 200a, for example, atomic layer deposition.

In addition, in the present invention, although the carrier gas stored in the cylinder 100 is a system for bubbling the precursor 200a contained in the container 200 to be transported to the reactor 300, but is not limited to this injection type (injection type) It is also possible to inject the precursor 200a into the reactor 300.

On the other hand, when the carrier gas is injected into the precursor container during the process bubbling or when refilling the precursor in the container, the surface of the instantaneously shakes the ultrasonic measurement is impossible. Therefore, it is impossible to monitor or the alarm malfunctions. In order to improve this point, in the present invention, when the hourly rank change suddenly changes more than a certain level, the level of change is excluded from the program.

In other words, if such a program does not enter, it will be difficult to monitor properly due to the shaking of the water level when bubbling or refilling, and the alarm will malfunction.

According to the above-described apparatus for detecting the amount of precursor remaining in a container during a chemical vapor deposition process and a method for diagnosing the same, the ultrasonic wave is delayed in the chemical vapor deposition process of a wafer during the semiconductor manufacturing process to remove noise and check only a voltage above a threshold voltage. By measuring the level of the precursor more accurately in real time, there is an effect that can significantly reduce the product defect rate by preventing damage due to precursor depletion in advance.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (3)

delete Bomb 100 containing the carrier gas (100a); A first pipe 110 having one side piped to the cylinder 100 so that the carrier gas 100a flows; A container in which a liquid precursor 200a is contained, and the other side of the first pipe 110 is enclosed in the precursor 200a so that the carrier gas 100a bubbles and vaporizes the precursor 200a. 200); A second pipe 210 which is piped to the container 200 so that one side is disposed on the water surface of the precursor 200a and the precursor 200a and the carrier gas 100a are transferred; A reactor (300) in which a chemical vapor deposition process is performed on the precursor (200a) with respect to the wafer (300a) in which the other side of the second pipe (210) is piped and embedded; An ultrasonic sensor device (410) for transmitting the ultrasonic wave toward the surface of the precursor (200a) and receiving the ultrasonic wave reflected from the surface by delaying the ultrasonic wave for a predetermined time; By adjusting the threshold voltage to about half of the maximum amplitude, the values not exceeding the threshold voltage are removed by filtering, and the alarm output signal is applied when the level is below the reference level by comparing the filtered data with the already set reference level. An ultrasonic controller 410 excluding an alarm when the change suddenly changes more than a predetermined level; The ultrasonic sensor device includes an ultrasonic receiver 411 for receiving a signal after filtering by delaying a predetermined time of sound waves coming back from the surface of the container; A reception amplifier unit 412 for amplifying a signal of a sound wave received by the ultrasonic receiver after a predetermined time delay; A comparator 413 for comparing the received sound wave input through the reception amplifier with a reference signal and converting the received sound wave into a digital signal if higher than the reference signal; Precursor residual amount diagnostic apparatus in the container during the chemical vapor deposition process, characterized in that consisting of a transmitting unit for generating a frequency for emitting sound waves under the control of the ultrasonic control unit. In the chemical vapor deposition process, Bubbling and vaporizing the liquid precursor 200a (S1000); Chemically depositing a wafer (300a) with the precursor (200a) (S2000); Emitting ultrasonic waves toward the surface of the precursor 200a by the ultrasonic sensor 410 attached to the lower portion of the container 200 (S3000); Receiving the ultrasonic wave while removing the data corresponding to the thickness of the sustain vessel to delay the reception time for a predetermined time (S4000); Removing noise less than the reference voltage from the received data (S5000); Comparing noise level data of the precursor calculated after removing noise with a reference level already set (S6000); If the level of the precursor 200a is lower than the reference level, an alarm is output. If the level of the precursor 200a is high, the deposition process can be continued. Therefore, the deposition process for the wafer 300a continues, and the rank change per hour rapidly increases by a certain level. When changing, except for the alarm, the ultrasonic sensor 410 emits ultrasonic waves toward the surface of the precursor 200a again, and repeats the steps until the determination by the ultrasonic control unit 420 (S7000). A method for diagnosing the remaining amount of precursor in a container during a chemical vapor deposition process, characterized in that the.

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