KR102634683B1 - RF Generator To Detect Arcs Generated During RF Sputtering - Google Patents

Abstract

The present invention relates to an RF generator for detecting an arc generated during an RF sputtering process, and more specifically, to an RF generator capable of measuring a power value generated inside a deposition chamber during an RF sputtering process, and detecting an arc generated inside the deposition chamber based on the size of the measured power value, and the time during which a power value greater than a preset size is continuously measured. An RF generator for detecting an arc generated during an RF sputtering process includes: an RF power supply unit; a power measurement unit; and an arc detection unit. According to one embodiment of the present invention, by detecting the occurrence of an arc and cutting off the RF power, it is possible to prevent the arc from growing larger or the wafer or RF sputtering equipment from becoming defective.

Description

RF Generator To Detect Arcs Generated During RF Sputtering}

The present invention is an RF generator that detects arcs generated during the RF sputtering process. Specifically, the present invention is an RF generator that detects arcs generated during the RF sputtering process. Specifically, the present invention is an RF generator that detects an arc generated in a vacuum-filled deposition chamber by generating alternating current with a specific frequency to a target loaded on the cathode side. In the process of performing RF sputtering by applying power, the power value generated inside the deposition chamber is measured, and the magnitude of the measured power value is measured; It relates to an RF generator capable of detecting an arc generated inside the deposition chamber based on the time when a power value greater than a preset value is continuously measured.

The eight processes required to produce and ship a semiconductor are called the eight major semiconductor processes, including wafer manufacturing process; oxidation process; photo process; etching process; deposition process; metal wiring process; EDS process; and packaging process; this corresponds to this. In particular, the above deposition process can be largely divided into PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) methods, and among various PVD methods, sputtering is used. A lot of processes are used.

Sputtering corresponds to the process of forming a thin film by colliding ionized gas atoms with a target material. In other words, sputtering is a process in which ions with high energy collide with a target at high speed and metal particles that fall off are deposited on the substrate. It includes DC sputtering, RF sputtering, and reactive ion sputtering. sputtering), etc.

DC sputtering is a process of applying DC (direct current power) into a chamber equipped with a sputtering target to transform the inert gas in the chamber into a plasma state and depositing it. RF sputtering is a process of depositing RF (Radio) into a chamber equipped with a sputtering target. This corresponds to a process of converting the inert gas in the chamber into a plasma state and depositing it by applying voltage, that is, AC (alternating current power).

Meanwhile, during this RF sputtering process, an arc may occur when RF power is applied into the chamber, and this arc may cause damage to the silicon wafer or cause equipment failure. Therefore, it is necessary to prevent damage to RF sputtering equipment by detecting arcs generated within the chamber and taking measures such as blocking RF power when arcs occur.

Meanwhile, in the case of conventional technologies for detecting such arcs, most of them are judged and operated using an analog method. More specifically, in the case of the conventional technology operating in an analog manner, it is designed as a comparator with an arc determination reference value through a variable resistor, and as a result, there is a problem in that it is difficult to change the arc determination reference value. In addition, the analog conventional technology responds immediately to the arc determination reference value, making it difficult to determine whether the measured power value is an arc signal or a noise signal, and it is difficult to set the cutoff time for RF power, so blocking and restoration of RF power can be repeated. there is. As such, there is a need for arc detection technology that solves the above-mentioned problems.

The present invention is an RF generator that detects arcs generated during the RF sputtering process. Specifically, the present invention is an RF generator that detects arcs generated during the RF sputtering process. Specifically, the present invention is an RF generator that detects an arc generated in a vacuum-filled deposition chamber by generating alternating current with a specific frequency to a target loaded on the cathode side. In the process of performing RF sputtering by applying power, the power value generated inside the deposition chamber is measured, and the magnitude of the measured power value is measured; The object is to provide an RF generator capable of detecting an arc generated inside the deposition chamber based on the time when a power value greater than a preset value is continuously measured.

In order to solve the above problems, an embodiment of the present invention is an RF generator that detects an arc generated during an RF sputtering process, and includes an RF power supply unit that supplies RF power with a preset frequency to a matching box; A power measurement unit that measures the power value inside a deposition chamber equipped with an RF sputtering target; And an arc detection unit that determines whether an arc occurs in the deposition chamber based on the power value, wherein the arc detection unit determines a reference size based on the power value measured during a preset time period before the determination point. A reference size value derivation step of deriving a value; A reference time value deriving step of receiving a reference time value for a time when a power value greater than the reference magnitude value is continuously measured from an external source; If the size of the measured power value is greater than the reference size value and the power value larger than the reference size value is measured and maintained longer than the reference time value, arc occurrence judgment to determine that an arc has occurred in the deposition chamber. step; and a power cut-off command step of transmitting a power cut-off command to the RF power supply unit when an arc occurs in the deposition chamber.

In one embodiment of the present invention, the arc detection unit further includes an average power value calculation unit that calculates the average power value in the corresponding section at each preset period with respect to the power value measured by the power measurement unit, In the reference size value derivation step, the reference size value may be derived based on the sum of the most recently calculated average power value and a preset offset value based on the determination time.

In another embodiment of the present invention, the arc detection unit further includes an average power value calculation unit that calculates the average power value in the corresponding section at each preset period with respect to the power value measured by the power measurement unit, The reference size value deriving step includes calculating a first reference size value by adding the most recently calculated average power value and a preset offset value based on the determination time; The second standard size value is calculated by adding the first standard size value and the offset value multiplied by the first weight, wherein the second standard size value is a second value smaller than the first standard size value. Reference size value derivation step; And the third standard size value is calculated by adding the first standard size value and the offset value multiplied by the second weight, wherein the third standard size value is a value smaller than the second standard size value. 3 step of deriving a standard size value; wherein the first weight and the second weight correspond to a value greater than 0 and less than 1, but the first weight may correspond to a value greater than the second weight.

In one embodiment of the present invention, the reference time value deriving step includes: a first reference time value deriving step of determining a reference time value received from the outside as a first reference time value; A second reference time value deriving step of determining a time shorter than the first reference time value as a second reference time value by a preset ratio; and a third reference time value derivation step of determining a time shorter than the second reference time value by a preset ratio as the third reference time value.

In one embodiment of the present invention, the RF generator further includes a predictive maintenance unit that performs predictive maintenance of the device on which the RF sputtering is performed based on a score counted by applying a preset rule to the measured power value, , the predictive maintenance unit counts the size score whenever the measured power value exceeds any one of the first reference size value, the second reference size value, and the third reference size value, but the power value The first size score counted when the power value exceeds the first reference size value is greater than the second size score counted when the power value exceeds the second reference size value, and the second size score is the power value. A size score calculation step that is greater than the third size score counted when the third reference size value is exceeded; A time score is calculated according to the time when a power value greater than the third reference size value is continuously measured. However, if the continuously measured time is more than the first reference time value, the first time score is counted, and the continuous If the time measured is less than the first reference time value or more than the second reference time value, a second time score smaller than the first time score is counted, and the continuously measured time is less than the second reference time value. A time score calculation step of counting a third time score smaller than the second time score when the third reference time value is greater than the third reference time value; and a notification generation step of generating a notification to be delivered to the user when the combined score of the size score and the time score is greater than or equal to a preset reference value.

In one embodiment of the present invention, when the power cut-off command step is performed, the RF power supply unit blocks the RF power for a first time and then re-supplies the RF power to the matching box, and the arc detection unit Whether or not an arc occurs can be determined after a second period of time has elapsed from the time the RF power is resupplied.

According to one embodiment of the present invention, the occurrence of an arc can be detected and RF power can be blocked, thereby preventing the arc from growing or defects in the wafer or RF sputtering equipment.

According to an embodiment of the present invention, it is possible to distinguish between an arc signal and a noise signal, thereby achieving the effect of accurately determining whether an arc has occurred.

According to one embodiment of the present invention, by setting the RF power blocking time and standby time, it is possible to achieve the effect of preventing unnecessary RF power blocking for arc generation.

According to one embodiment of the present invention, it is possible to perform predictive maintenance of a device in which RF sputtering is performed through predictive maintenance points counted according to preset rules.

According to one embodiment of the present invention, it is possible to ensure the stability of the device in which RF sputtering is performed through a blocking time determined according to the predictive maintenance score.

Figure 1 schematically shows the internal configuration of a device in which RF sputtering is performed and an RF generator according to an embodiment of the present invention.
Figure 2 schematically shows a graph of power values measured inside a deposition chamber according to an embodiment of the present invention.
Figure 3 schematically shows steps for detecting an arc in an RF generator according to an embodiment of the present invention.
Figure 4 schematically shows the process of performing the reference time value derivation step according to an embodiment of the present invention.
Figure 5 schematically shows a process for determining whether an arc has occurred according to a reference time value according to an embodiment of the present invention.
Figure 6 schematically shows the internal configuration of a reference size value deriving unit according to an embodiment of the present invention.
Figure 7 schematically shows the internal configuration of a reference time value deriving unit according to an embodiment of the present invention.
Figure 8 schematically shows the internal configuration of a predictive maintenance unit according to an embodiment of the present invention.
Figure 9 schematically shows an algorithm for counting size scores and time scores according to an embodiment of the present invention.
Figure 10 schematically shows the measured power value and the sum score counted according to the time at which the power value was measured according to an embodiment of the present invention.
Figures 11 and 12 schematically show a process in which magnitude scores and time scores are accumulated and counted in the same power value graph according to an embodiment of the present invention.
Figure 13 schematically shows the execution steps of the notification creation step according to an embodiment of the present invention.
Figure 14 schematically shows a graph of power values measured inside the deposition chamber after the power cut-off command step according to an embodiment of the present invention.
Figure 15 schematically shows the process of determining the blocking time according to the sum score according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments and/or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth to facilitate a general understanding of one or more aspects. However, it will also be appreciated by those skilled in the art that this aspect(s) may be practiced without these specific details. The following description and accompanying drawings set forth in detail certain example aspects of one or more aspects. However, these aspects are illustrative and some of the various methods in the principles of the various aspects may be utilized, and the written description is intended to encompass all such aspects and their equivalents.

Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In addition, in the embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, are generally understood by those skilled in the art to which the present invention pertains. It has the same meaning as Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the embodiments of the present invention, have an ideal or excessively formal meaning. It is not interpreted as

Figure 1 schematically shows the internal configuration of an RF generator 1000 and a device in which RF sputtering is performed according to an embodiment of the present invention.

As shown in FIG. 1, an RF generator 1000 that detects an arc generated during RF sputtering includes an RF power supply unit 1100 that supplies RF power with a preset frequency to a matching box; A power measurement unit 1200 that measures the power value inside a deposition chamber equipped with an RF sputtering target; and an arc detection unit 1300 that determines whether an arc occurs within the deposition chamber based on the power value.

Specifically, Figure 1 shows an RF sputtering device in which RF sputtering is performed, and the RF sputtering device includes a deposition chamber, a matching box, and an RF generator 1000. A sputtering target and a substrate are provided inside the deposition chamber. When a gas such as argon is injected into the deposition chamber and RF power is applied, a plasma discharge process is performed, resulting in The target material is deposited on the substrate.

The RF generator 1000 includes an RF power supply unit 1100 that supplies RF power to be applied to the deposition chamber to the matching box; A power measurement unit 1200 that measures the power value inside the deposition chamber; and an arc detection unit 1300 that determines whether an arc occurs within the deposition chamber. More specifically, the RF power supply unit 1100 supplies RF power of a preset frequency to the matching box. According to a preferred embodiment, the preset frequency corresponds to 13.56 MHz, and the output impedance of the RF power corresponds to 50 Ohm.

Meanwhile, in order for the RF generator 1000 to efficiently supply power to the deposition chamber, the phases of voltage and current must be matched, and this matching process is performed in the matching box. In other words, the RF power generated by the RF power supply unit 1100 is transmitted to the deposition chamber through the matching box, and an RF sputtering process is performed using the transmitted RF power.

When the RF sputtering process is performed, the power value inside the deposition chamber is measured by the power measurement unit 1200. According to one embodiment of the present invention, the power value may correspond to a voltage value, and according to another embodiment of the present invention, the power value may correspond to a reflect power value.

The power value measured by the power measurement unit 1200 is transmitted to the arc detection unit 1300, and the arc detection unit 1300 determines whether an arc has occurred inside the deposition chamber based on the received power value. do. More specifically, the power measurement unit 1200 transmits the power value measured inside the deposition chamber and the time when the power value above a certain level is continuously measured to the arc detection unit 1300, and the arc detection unit 1300 Unit 1300 represents the measured power value; and the measured time; are all taken into consideration to determine whether an arc has occurred.

Figure 2 schematically shows a graph of power values measured inside a deposition chamber according to an embodiment of the present invention.

Specifically, the power value graph as shown in FIG. 2 is generated by the power measurement unit 1200. The power value graph shows the power value measured inside the deposition chamber over time when the RF power applied to the inside of the deposition chamber is cut off and re-supplied after an arc occurs.

As described above, the arc generated within the deposition chamber can cause damage to the wafer provided inside the deposition chamber or damage the RF sputtering device, so the arc is detected as quickly as possible and the RF It is important to prevent the above damage by turning off the power. The present invention is a technology to solve this problem. Hereinafter, a method for detecting arcs occurring inside a deposition chamber and increasing the stability of the RF sputtering device will be described.

Meanwhile, the power value graphs shown in FIG. 2, as well as FIGS. 4, 5, 11, 12, and 14 correspond to graphs prepared based on actual measured values for convenience of explanation, and the power value graphs of the present invention described in this specification The principle can be equally applied to various types of power value measurement result data actually used in the present invention.

FIG. 3 schematically shows steps for detecting an arc in the RF generator 1000 according to an embodiment of the present invention.

As shown in FIG. 3, an RF generator 1000 that detects an arc generated during the RF sputtering process includes an RF power supply unit 1100 that supplies RF power with a preset frequency to a matching box; A power measurement unit 1200 that measures the power value inside a deposition chamber equipped with an RF sputtering target; And an arc detection unit 1300 that determines whether an arc occurs in the deposition chamber based on the power value, wherein the arc detection unit 1300 measures A reference size value deriving step of deriving a reference size value based on the power value; A reference time value deriving step of receiving a reference time value for a time when a power value greater than the reference magnitude value is continuously measured from an external source; If the size of the measured power value is greater than the reference size value and the power value larger than the reference size value is measured and maintained longer than the reference time value, arc occurrence judgment to determine that an arc has occurred in the deposition chamber. step; And when an arc occurs in the deposition chamber, a power cut-off command step of transmitting a power cut-off command to the RF power supply unit 1100 is performed.

Specifically, with reference to the description of FIGS. 1 and 2, when the power measurement unit 1200 measures the power value inside the deposition chamber and generates a power value graph, information related to the power value graph is transmitted to the arc detection unit. It is transmitted to the reference size value deriving unit 1310 and the standard time value deriving unit 1320 of (1300). The reference size value deriving unit 1310 performs a reference size value deriving step based on the information received from the power measuring unit 1200, and the reference time value deriving unit 1320 performs a reference size value deriving step based on the information received from the power measuring unit 1200. The standard time value derivation step is performed based on the information received from. A more detailed description of the reference size value derivation step will be described later in FIG. 4.

The reference size value and the reference time value derived through the reference size value derivation step and the reference time value derivation step are transmitted to the arc occurrence determination unit 1330, and the arc occurrence determination unit 1330 determines the reference size value, An arc occurrence determination step is performed to determine whether an arc has occurred inside the deposition chamber based on information related to the reference time value and the power value graph. If, as a result of performing the arc occurrence determination step, it is determined that an arc has occurred, the corresponding judgment information is transmitted to the power cut-off command unit 1340, and by the power cut-off command unit 1340, the RF power supply unit 1100 The power cut-off command step is performed to transmit the power cut-off command.

Figure 4 schematically shows the process of performing the reference time value derivation step according to an embodiment of the present invention.

As shown in FIG. 4, the arc detection unit 1300 is an average power value calculation unit that calculates the average power value in the corresponding section at each preset period with respect to the power value measured by the power measurement unit 1200. ; , wherein the reference size value deriving step derives the reference size value based on the sum of the most recently calculated average power value and a preset offset value based on the determination time.

Schematically, Figure 4(a) shows the process of calculating the average power value based on the power value graph, and Figure 4(b) shows the process of deriving the reference size value based on the average power value. .

Specifically, the reference size value calculation unit 1310 includes an average power value calculation unit, and the average power value calculation unit, as shown in (a) of FIG. 4, generates a corresponding time section (FIG. 4) at each preset period. In , an average power value calculation step is performed to calculate the average power value of the first section, second section, and third section).

That is, when the power value is measured for the time length of the preset period, the average power value calculation unit derives the average power value during the corresponding period. For example, when the preset period is set to 2 seconds (sec), the average power value calculation unit calculates the average power value for 2 seconds based on a specific point in time, and performs this process every 2 seconds.

Thereafter, the reference size value deriving unit 1310 adds an offset value to the average power value to derive the reference size value of the corresponding section, as shown in (b) of FIG. 4. At this time, the offset value, which is a positive real value, may correspond to a value received from the user as an embodiment of the present invention, and may correspond to a value previously stored in the RF generator 1000 as another embodiment of the present invention. You can.

As shown in (a) of FIG. 4, whether or not an arc occurs in the second section is determined by the first reference size value, which is the most recently calculated reference size value, that is, the average in the first section, which is the section immediately before the second section. It is determined based on the first reference size value corresponding to the sum of the power value and the offset value. Likewise, whether an arc occurs in the third section is determined based on the second reference size value corresponding to the sum of the average power value and the offset value in the second section, which is the section immediately before the third section. Meanwhile, as an embodiment of the present invention, whether or not an arc occurs in a section for which a reference size value has not yet been set (for example, the first section in FIG. 4) is determined based on a preset or pre-stored reference size value. After the reference size value is derived through the above-described reference size value derivation step, whether or not an arc occurs can be determined based on the reference size value derived at each preset cycle.

As such, the present invention has a technical feature of setting a reference size value based on the power value measured near the point of judgment of arc occurrence, and through this, it is possible to demonstrate the effect of determining the arc by minimizing the influence of noise. .

Figure 5 schematically shows a process for determining whether an arc has occurred according to a reference time value according to an embodiment of the present invention.

As shown in Figure 5. In the reference time value derivation step, a reference time value for the time when a power value greater than the reference magnitude value is continuously measured is received from the outside, and in the arc occurrence determination step, the magnitude of the measured power value is the reference magnitude value. If a power value larger than the reference size value is measured and maintained longer than the reference time value, it is determined that an arc has occurred in the deposition chamber.

Specifically, in the case of the prior art, which determines the arc only based on the size of the past power value, there was a problem that the accuracy of the arc judgment was low because it was difficult to distinguish between the arc signal and the noise signal. In order to solve the above problem, the inventor of the present invention set the time at which a power value larger than the reference size value is continuously measured as a judgment parameter to have the effect of improving the accuracy of arc judgment. did.

In other words, the present invention sets the reference value for the measured time to the reference time value, and when a power value larger than the reference size value is maintained longer than the reference time value and is measured, it is said that an arc has occurred in the deposition chamber. Judgment is a technical feature. The reference time value is preferably received from outside, and can be varied at the discretion of the user.

Figure 5 shows a power value graph with the most recently calculated reference size value overlaid. As an embodiment of the present invention, as shown in FIG. 5, assume that there are two sections where a power value greater than the reference magnitude value is measured. At this time, the first section corresponds to a section in which a power value greater than the reference size value by t seconds is measured, and the second section corresponds to a section in which a power value greater than the reference size value by T seconds is measured. Referring to FIG. 3, the arc occurrence determination unit 1330 determines whether t and T correspond to a value greater than the reference time value. That is, when t is less than the reference time value, the first section is determined to be a noise signal, and when T is greater than the reference time value, the second section is determined to be an arc signal.

Figure 6 schematically shows the internal configuration of the reference size value deriving unit 1310 according to an embodiment of the present invention.

Schematically, the reference size value deriving unit 1310, as an embodiment of the present invention, may have a configuration as shown in (a) of FIG. 6, and (b) of FIG. 6 is the first reference size value. The performance process of the derivation step, Figure 6 (c) shows the performance process of the second standard size value derivation step, and Figure 6 (d) shows the performance process of the third standard size value derivation step.

As shown in FIG. 6, the reference size value deriving step is to calculate a first reference size value by adding the most recently calculated average power value and a preset offset value based on the judgment time. derivation stage; The second standard size value is calculated by adding the first standard size value and the offset value multiplied by the first weight, wherein the second standard size value is a second value smaller than the first standard size value. Reference size value derivation step; And the third standard size value is calculated by adding the first standard size value and the offset value multiplied by the second weight, wherein the third standard size value is a value smaller than the second standard size value. 3 step of deriving a standard size value; wherein the first weight and the second weight correspond to a value greater than 0 and less than 1, and the first weight corresponds to a value greater than the second weight.

Specifically, in order to calculate the sum score in the predictive maintenance unit 1400, which will be described later, the reference size value deriving unit 1310 performs a first reference size value derivation step, a second standard size value derivation step, and a third standard size value derivation step. Perform the value derivation step.

The first reference size value deriving step performed by the first reference size value deriving unit 1311, as shown in (b) of FIG. 6, uses the most recently calculated average power value and a preset offset value. The first reference size value is derived by adding up, and the reference size value mentioned in the description of FIG. 4 may correspond to the first reference size value.

When the first standard size value is derived, the second standard size value deriving unit 1312 performs a second standard size value deriving step of calculating the second standard size value, as shown in (c) of FIG. 6. Perform. More specifically, the second reference size value is calculated based on the average power value and the offset value used in the first reference size value derivation step, and the average power value is calculated by multiplying the offset value by the first weight. It can be derived by adding up. At this time, the first weight corresponds to a real number greater than 0 and less than 1, and the offset value corresponds to a positive real number, so the second standard size value is derived as a value smaller than the first standard size value. .

Afterwards, when the second standard size value is derived, the third standard size value deriving unit 1313 performs a third standard size value deriving step of calculating the third standard size value, as shown in (d) of FIG. 6. Perform. More specifically, the third reference size value is calculated based on the average power value and the offset value used in the first reference size value derivation step and the second reference size value derivation step, and a second weight is applied to the offset value. It can be derived by adding the average power value to the multiplied value. At this time, the second weight corresponds to a real number greater than 0 and less than 1, but corresponds to a value smaller than the first weight, and the offset value corresponds to a positive real number. That is, the third standard size value is derived as a value smaller than the second standard size value, and the second standard size value is derived as a value smaller than the first standard size value.

Figure 7 schematically shows the internal configuration of the reference time value deriving unit 1320 according to an embodiment of the present invention.

Schematically, the reference time value deriving unit 1320, as an embodiment of the present invention, may have a configuration as shown in (a) of FIG. 7, and (b) of FIG. 7 is the second reference time value. The execution process of the derivation step, Figure 7(c) shows the execution process of the third reference time value derivation step.

As shown in Figure 7, the reference time value deriving step includes a first reference time value deriving step of determining a reference time value received from the outside as a first reference time value; A second reference time value deriving step of determining a time shorter than the first reference time value as a second reference time value by a preset ratio; and a third reference time value deriving step of determining a time shorter than the second reference time value by a preset ratio as the third reference time value.

Specifically, like the reference time value deriving unit 1320 described above in the description of FIG. 6, in order to calculate the summed score in the predictive maintenance unit 1400 described later, the reference time value deriving part 1320 is the first Reference time value derivation step; The second reference time value derivation step and the third reference time value derivation step are performed.

The first reference time value deriving step performed by the first reference time value deriving unit 1321 determines the reference time value received from the outside as the first reference time value, referring to the description of FIG. 5. When the first reference time value is derived, the second reference time value deriving unit 1322 performs a second reference time value deriving step of calculating the second reference time value, as shown in (b) of FIG. 7. Perform. More specifically, the second reference time value can be derived by multiplying the first reference time value by a preset ratio. For example, if the first reference time value is 100 us (micro second) and the preset ratio corresponds to 60%, the second reference time value is derived as 60 us.

Afterwards, when the second reference time value is derived, the third reference time value deriving unit 1323 calculates the third reference time value, as shown in (c) of FIG. 7. Follow the steps. More specifically, the third reference time value can be derived by multiplying the second reference time value by a preset ratio, and the preset ratio is the same as the preset ratio used in the second reference time value derivation step. Corresponds to the value. For example, if the first reference time value is derived as 100 us and the second reference time value as 60 us, the third reference time value is derived as 60 us * 0.6 = 36 us. At this time, the preset ratio corresponds to a ratio expressed as a percentage between 0 and less than 100. That is, the third reference time value is derived as a value smaller than the second reference time value, and the second reference time value is derived as a value smaller than the first reference time value.

Figure 8 schematically shows the internal configuration of the predictive maintenance unit 1400 according to an embodiment of the present invention.

As shown in FIG. 8, the RF generator 1000 is a predictive maintenance unit that performs predictive maintenance of the device on which the RF sputtering is performed based on a score counted by applying a preset rule to the measured power value. It further includes (1400).

Specifically, the predictive maintenance unit 1400 includes a size score calculation unit 1410 that performs a size score calculation step, as shown in FIG. 8; A time score calculation unit 1420 that performs a time score calculation step; and a notification generator 1430 that performs a notification generation step, comprising: the size score calculation step; The time score calculation step; A more detailed description of the execution process of the notification generation step will be described later in the description of FIGS. 9 to 13.

Figure 9 schematically shows an algorithm for counting the magnitude score and time score according to an embodiment of the present invention, and Figure 10 shows the measured power value and the time at which the power value was measured according to an embodiment of the present invention. The summed score being counted is schematically shown.

As shown in FIGS. 9 to 10, the predictive maintenance unit 1400 determines that the measured power value is one of the first reference size value, the second reference size value, and the third reference size value. The size score is counted each time it exceeds, and the first size score counted when the power value exceeds the first reference size value is the second size score counted when the power value exceeds the second reference size value. A size score calculation step wherein the second size score is greater than the third size score, which is counted when the power value exceeds the third reference size value. And a time score is calculated according to the time when a power value greater than the third reference size value is continuously measured, and if the continuously measured time is more than the first reference time value, the first time score is counted, and If the continuously measured time is less than the first reference time value or more than the second reference time value, a second time score smaller than the first time score is counted, and the continuously measured time is the second reference time value. If it is less than or equal to the third reference time value, a time score calculation step of counting a third time score smaller than the second time score is performed.

Specifically, Figure 9 shows the process of calculating the size score and time score in the size score calculation unit 1410 and the time score calculation unit 1420, and the size score calculation unit 1410 and the time score calculation unit ( 1420) This corresponds to a configuration in which each configuration can operate independently and simultaneously.

Upon receiving information about the power value graph from the power measurement unit 1200, the size score calculation unit 1410 determines whether a power value exceeding the third reference size value has been measured. At this time, if the power value exceeding the third standard size value is not measured, the predictive maintenance unit 1400 does not perform a separate score counting process. If the power value exceeding the third reference size value is measured, it is determined whether the time at which the power value exceeding the third reference size value was measured exceeds the third reference time value. If the measured time does not exceed the third reference time value, the predictive maintenance unit 1400 does not perform a separate score counting process.

Meanwhile, when a power value exceeding the third reference size value is measured and the measured time exceeds the third reference time value, a counting process of the size score and time score is performed. More specifically, if the measured power value is greater than the third standard magnitude value and less than the second standard magnitude value, the third magnitude score is counted, and if it is greater than the second standard magnitude value but less than the first standard magnitude value, the second magnitude score is counted. It is counted, and if it exceeds the first standard size value, the first size score is counted.

In addition, if the measured time exceeds the third standard time value and is less than or equal to the second standard time value, the third time score is counted, and if it is greater than the second standard time value and is less than or equal to the first standard time value, the second time score is counted. , if the first time size value is exceeded, the first time score is counted.

Meanwhile, the size score calculation step and the time score calculation step described above are performed independently of the arc occurrence determination step described above. In other words, the predictive maintenance unit 1400 of the present invention determines the durability or stability of the RF sputtering device if the accumulated value of the size score and time score counted due to noise signals, etc. exceeds a certain level even if no arc is generated. Its technical feature is to carry out a predictive maintenance process to prevent problems from occurring in advance.

The process of counting the size score and time score shown in FIG. 9 can be performed independently of each other, and the predictive maintenance unit 1400 performs independently and derives the calculated score based on the sum of the size score and time score. The predictive maintenance process is performed according to the predictive maintenance score. Figure 10 is an embodiment of the present invention, where the third size score and the third time score are 1 point, the second size score and the second time score are 2 points, and the first size score and the first time score are 3 points. However, this corresponds to a value arbitrarily set for convenience of explanation. In fact, in the present invention, a score different from the above-described embodiment may be set, and each of the first to third size scores is the first It may correspond to a different score from each of the through 3rd time scores.

As shown in FIG. 10, when the measured power value exceeds the first reference size value and the measured time exceeds the second reference time value and is less than or equal to the first reference time value, the total points counted for the corresponding power value signal corresponds to 9 points. The reason why the score counted for the corresponding signal is 9 points instead of 5 points will be explained later in the description of FIGS. 11 and 12.

Figures 11 and 12 schematically show a process in which magnitude scores and time scores are accumulated and counted in the same power value graph according to an embodiment of the present invention.

Schematically, FIG. 11 shows a process in which magnitude scores are accumulated and counted for a specific signal, and FIG. 12 shows a process in which time scores are accumulated and counted for the signal shown in FIG. 11. In other words, FIGS. 11 and 12 are processes performed simultaneously in the RF generator 1000, but will be described separately for convenience of explanation.

Specifically, Figure 11 shows a specific signal in which the measured power value increases step by step, as an embodiment of the present invention. When the signal shown in FIG. 11 is measured, the magnitude score calculation unit 1410 counts the third magnitude score when the power value of the corresponding signal exceeds the third reference magnitude value, and the power value of the corresponding signal is the third standard magnitude value. 2 When the standard size value is exceeded, the second size score is counted, and the size score of the corresponding signal is counted by adding the second size score to the third size score counted immediately before.

In other words, if it is determined to be a continuous signal, the magnitude score is not calculated according to the maximum power value of the signal, but the magnitude score is counted by accumulating corresponding magnitude scores as the power value sequentially increases. The predictive maintenance unit 1400 determines that the signal is a continuous signal when a power value exceeding the second standard magnitude value or the first standard magnitude value is measured before the power value of the corresponding signal is measured below the third standard magnitude value. do.

Likewise, Figure 12 shows the same specific signal as the power value graph shown in Figure 11. When the signal shown in FIG. 12 is measured, the time score calculation unit 1420 measures the time from when the power value of the signal exceeds the third standard magnitude value to the time when it is measured below the third standard magnitude value. Accordingly, the time score of the corresponding signal is counted.

In other words, if the power value of the specific signal does not fall below the third standard magnitude value from the time it exceeds the third standard magnitude value until the third standard time value passes, the third time score is counted, and the second standard If the time value does not fall below the third standard size value until the time value passes, the second time score is counted, and the time score of the corresponding signal is counted by adding the second time score to the third time score counted immediately before. .

If the magnitude score and time score for a specific signal are calculated according to the method described above and then added together, a result similar to the table shown in FIG. 10 is obtained. By counting the predictive maintenance score through this method, it is possible to perform predictive maintenance on the RF sputtering device through separate management even for signals classified as noise rather than arc.

Meanwhile, as an embodiment of the present invention, even when a suddenly high power value is measured, the magnitude score or time score is sequentially counted in the manner described above. In other words, even if a power value similar to the average power value is measured and then a power value exceeding the first reference size value is measured, as shown in FIG. 9, the measured power value is sequentially measured starting from the third reference size value. Since the corresponding size scores are counted during comparison, the size scores or time scores are accumulated and counted in the same manner as described above.

Figure 13 schematically shows the execution steps of the notification generation step according to an embodiment of the present invention.

As shown in FIG. 13, the predictive maintenance unit 1400 performs a notification generation step to generate a notification to be delivered to the user when the sum score of the size score and the time score is greater than or equal to a preset reference value.

Specifically, when the size score and the time score are calculated through the above-described process, as an embodiment of the present invention, the predictive maintenance unit 1400 sends the combined score of the size score and the time score to the notification generator 1430. ) is transmitted. Meanwhile, according to another embodiment of the present invention, the summed score may be calculated by the notification generator 1430.

The notification generator 1430 determines whether the summed score exceeds a preset standard value, and continues to count the summed score if the summed score is less than the preset standard value. That is, until the sum score is initialized, the power value measured by the power measurement unit 1200 and the size score and time score according to the measurement time continue to be counted.

If the combined score exceeds the preset standard value, the notification generator 1430 may generate a notification to be delivered to the user, and the notification may include data in the form of at least one of text, audio, and video. It can be included. By delivering the above notification to the user, it can be effective in helping maintain the RF sputtering device. When the above notification is generated, the accumulated and counted sum score is initialized and then the sum score is counted again starting from 0.

Meanwhile, according to one embodiment of the present invention, the preset reference value may be reset each time the sum score is initialized. More specifically, for example, if the preset standard value is 100 points, each time the sum score is initialized, a 10% decrease from the previous preset standard value is reset to the standard value, so that the sum score counted thereafter is 90 points. If it exceeds it, a notification can be generated. Preferably, the notification generated based on the reset reference value may include information called a regenerated notification, and this configuration can have the effect of encouraging users to be aware of maintenance.

Additionally, there are various causes that may cause arc or noise, such as impurities contained in the target, pores contained in a low-density target, and oxides generated on the target surface. However, the user cannot check the inside of the chamber during each process. Since there is no such thing, it is important to detect it on its own and minimize problems that may occur due to arcs or noise. In order to minimize such problems, the present invention adopts the above-described predictive maintenance process, which has the effect of ensuring the stability of the device in which RF sputtering is performed.

Figure 14 schematically shows a graph of the power value measured inside the deposition chamber after the power cut-off command step according to an embodiment of the present invention, and Figure 15 shows the cut-off time determined according to the sum score according to an embodiment of the present invention. The process is schematically shown.

As shown in Figures 14 and 15, when the power cut-off command step is performed, the RF power supply unit 1100 blocks the RF power for a first time and then re-supplies the RF power to the matching box. , the arc detection unit 1300 determines whether an arc occurs after a second time has elapsed from the time the RF power is resupplied.

Specifically, if it is determined that an arc has occurred through the arc occurrence determination step, the power cutoff command unit 1340 performs a power cutoff command step of transmitting a power cutoff command to the RF power supply unit 1100. The RF power supply unit 1100, which receives the power cut-off command, stops supplying power for a first time corresponding to the cut-off time, and then supplies RF power again to the deposition chamber through the matching box after the first time has elapsed. Meanwhile, the above-described reference size value derivation step and arc occurrence determination step are not performed from the time the RF power is resupplied, but are performed after a second time corresponding to the waiting time. Perform.

During the waiting time, noise signals are frequently generated, and if the noise during this period is determined to be an arc, unnecessary RF power blocking may occur. Therefore, by setting the above-described standby time, it is possible to achieve the effect of preventing unnecessary RF power blocking from occurring. Meanwhile, it is preferable that the first time and the second time correspond to values that are preset or received from the outside.

Additionally, the blocking time may be determined according to the summed score. More specifically, as shown in (a) of FIG. 15, when the power cut-off command step is performed, the predictive maintenance unit 1400 may transmit the accumulated sum score to the power cut-off command unit 1340. . The power cut-off command unit 1340 can reset the cut-off time by multiplying the cut-off time that is already being applied by the cut-off time weight determined based on the function shown in (b) of FIG. 15. The function shown in (b) of FIG. 15 has a y-intercept of 1, a monotonically increasing graph in the region where x > 0, and the maximum value corresponds to X (X is a positive real number).

That is, as the value of the summed score received by the power cut-off command unit 1340 increases, the value of the cut-off time weight determined also increases, and the length of the reset cut-off time increases accordingly. In other words, when arcs or noises occur frequently or relatively large arcs or noises occur, the value of the sum score increases, and the blocking time also increases accordingly. Through this, sufficient blocking time can be secured considering the stress accumulated in the RF sputtering device, and as a result, the durability and stability of the RF sputtering device can be increased.

According to one embodiment of the present invention, the occurrence of an arc can be detected and RF power can be blocked, thereby preventing the arc from growing or defects in the wafer or RF sputtering equipment.

According to an embodiment of the present invention, it is possible to distinguish between an arc signal and a noise signal, thereby achieving the effect of accurately determining whether an arc has occurred.

According to one embodiment of the present invention, by setting the RF power blocking time and standby time, it is possible to achieve the effect of preventing unnecessary RF power blocking for arc generation.

According to one embodiment of the present invention, it is possible to perform predictive maintenance of a device in which RF sputtering is performed through predictive maintenance points counted according to preset rules.

According to one embodiment of the present invention, it is possible to ensure the stability of the device in which RF sputtering is performed through a blocking time determined according to the predictive maintenance score.

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent. Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims (6)

As an RF generator that detects the arc generated during the RF sputtering process,
RF power supply unit that supplies RF power with a preset frequency to the matching box;
A power measurement unit that measures the power value inside a deposition chamber equipped with an RF sputtering target; and
It includes an arc detection unit that determines whether an arc occurs within the deposition chamber based on the power value,
The arc detection unit,
A reference size value deriving step of deriving a reference size value based on the power value measured during a preset time period before the judgment point;
A reference time value deriving step of receiving a reference time value for a time when a power value greater than the reference magnitude value is continuously measured from an external source;
If the size of the measured power value is greater than the reference size value and the power value larger than the reference size value is measured and maintained longer than the reference time value, arc occurrence judgment to determine that an arc has occurred in the deposition chamber. step; and
An RF generator that performs a power cut-off command step of transmitting a power cut-off command to the RF power supply unit when an arc occurs in the deposition chamber.
In claim 1,
The arc detection unit,
It further includes an average power value calculation unit that calculates the average power value in the corresponding section at each preset period with respect to the power value measured by the power measurement unit,
The RF generator wherein the reference size value deriving step derives the reference size value based on the sum of the most recently calculated average power value and a preset offset value based on the determination point.
In claim 1,
The arc detection unit,
It further includes; an average power value calculation unit that calculates the average power value in the corresponding section at each preset period with respect to the power value measured by the power measurement unit.
The standard size value derivation step is,
A first reference size value deriving step of calculating a first reference size value by adding up the most recently calculated average power value and a preset offset value based on the judgment time;
The second standard size value is calculated by adding the first standard size value and the offset value multiplied by the first weight, wherein the second standard size value is a second value smaller than the first standard size value. Reference size value derivation step; and
The third standard size value is calculated by adding the first standard size value and the offset value multiplied by the second weight, wherein the third standard size value is a third value that is smaller than the second standard size value. Including a reference size value derivation step,
The first weight and the second weight correspond to a value greater than 0 and less than 1, and the first weight corresponds to a value greater than the second weight.
In claim 3,
The reference time value derivation step is,
A first reference time value deriving step of determining a reference time value received from the outside as a first reference time value;
A second reference time value deriving step of determining a time shorter than the first reference time value as a second reference time value by a preset ratio; and
A third reference time value deriving step of determining a time shorter by a preset ratio of the second reference time value as the third reference time value. An RF generator comprising a.
In claim 4,
The RF generator is,
It further includes a predictive maintenance unit that performs predictive maintenance of the device on which the RF sputtering is performed based on a score counted by applying a preset rule to the measured power value,
The predictive maintenance department said,
A magnitude score is counted whenever the measured power value exceeds any one of the first standard magnitude value, the second standard magnitude value, and the third standard magnitude value, and the power value is greater than the first standard magnitude value. The first size score counted when the power value exceeds the second standard size value is greater than the second size score counted when the power value exceeds the second standard size value, and the second size score is greater than the power value when the power value exceeds the third standard size value. A size score calculation step greater than the third size score counted when the value is exceeded;
A time score is calculated according to the time when a power value greater than the third reference size value is continuously measured. However, if the continuously measured time is more than the first reference time value, the first time score is counted, and the continuous If the time measured is less than the first reference time value or more than the second reference time value, a second time score smaller than the first time score is counted, and the continuously measured time is less than the second reference time value. A time score calculation step of counting a third time score smaller than the second time score when the third reference time value is greater than the third reference time value; and
An RF generator that performs a notification generation step of generating a notification to be delivered to the user when the sum score of the size score and the time score is greater than or equal to a preset reference value.
In claim 1,
When the power cut command step is performed,
The RF power supply unit blocks the RF power for a first time and then re-supplies the RF power to the matching box,
The arc detection unit is an RF generator that determines whether an arc occurs after a second time has elapsed from the time the RF power is resupplied.

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