KR101148605B1 - Plasma processing apparatus - Google Patents

Abstract

The present invention provides a plasma processing apparatus capable of suppressing a decrease in productivity even when a process abnormality or the like occurs. The present invention provides a plasma processing apparatus including a processing chamber that performs plasma processing on a processing target G according to processing conditions. And a control unit 50 having a storage unit for storing a plurality of reprocessing conditions different from the conditions, a monitoring function for monitoring the presence or absence of abnormality occurrence during plasma processing, and a determination function for determining the type of abnormality occurring. When an abnormality occurs during the plasma processing, the control system 50 selects one reprocessing condition from among the plurality of reprocessing conditions according to the determined kind of abnormality, and reprocesses the object G.

Description

PLASMA PROCESSING APPARATUS

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for performing plasma processing on a target substrate such as a glass substrate for manufacturing a flat panel display (FPD) or a semiconductor wafer for manufacturing a semiconductor integrated circuit (IC).

In the manufacturing process of FPD and IC, the plasma processing apparatus which processes a process, such as an etching, to a to-be-processed object, such as a glass substrate and a semiconductor wafer, is used. As a plasma processing apparatus which performs a process such as etching, for example, a plasma dry etching apparatus is well known.

An apparatus controller for controlling the process gas and the high frequency output is connected to the plasma dry etching apparatus. The device controller controls the flow rate of the process gas, the high frequency output, the processing time, the processing pressure, and the like according to a predetermined processing condition called a process recipe. Thereby, predetermined | prescribed processes, such as an etching with respect to a to-be-processed object by a plasma processing apparatus, are performed.

If a process abnormality or the like occurs when the predetermined processing is executed, the processing on the processing target object is interrupted, for example, as described in Patent Document 1. After the interruption, the operator performs necessary operations such as correcting a recipe, and then executes the processing for the target object again.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2007-234809

As described in Patent Literature 1, when a predetermined process is executed, the process is stopped when a process abnormality or the like occurs. For this reason, there exists a situation that productivity of a product falls.

This invention is made | formed in view of such a situation, and an object of this invention is to provide the plasma processing apparatus which can suppress the fall of productivity also when a process abnormality etc. generate | occur | produce.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the plasma processing apparatus which concerns on one form of this invention is a plasma processing apparatus provided with the processing chamber which performs a plasma process with respect to a to-be-processed object in accordance with a process condition, Comprising: A plurality of material which differs from the said process conditions A storage unit that stores processing conditions, a monitoring function for monitoring the presence or absence of an abnormal occurrence during the plasma processing, and a determining function for determining the type of abnormality that has occurred, wherein the abnormality determined when the abnormality occurs during the plasma processing According to this, a control system for selecting one reprocessing condition from among the plurality of reprocessing conditions and reprocessing the target object is provided.

According to the present invention, even when a process abnormality or the like occurs, it is possible to provide a plasma processing apparatus capable of suppressing a decrease in productivity.

1 is a cross-sectional view schematically showing an example of a plasma processing apparatus according to an embodiment of the present invention;
FIG. 2 is a block diagram schematically showing a control system for controlling the plasma processing apparatus 1 shown in FIG. 1;
3 is a flowchart illustrating an example of a substrate processing method executed by an apparatus controller included in a plasma processing apparatus according to one embodiment;
4 is a diagram showing an example of processing condition change;
5 is a flowchart showing an example of a sequence of substrate processing performed by a plasma processing apparatus according to one embodiment;
FIG. 6: (a) is a figure which shows the process information for every processing elapsed time of the glass substrate G processed normally, and FIG. 6 (b) shows the process information for every processing elapsed time of the glass substrate G in which abnormality occurred. drawing,
7 is a diagram illustrating a relationship between discharge level and time.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to an accompanying drawing.

1 is a cross-sectional view schematically showing an example of a plasma processing apparatus according to an embodiment of the present invention.

The plasma processing apparatus 1 shown in FIG. 1 is an example of the apparatus which performs predetermined | prescribed process with respect to the glass substrate G for FPD manufacture, and is comprised as a capacitively coupled plasma dry etching apparatus in this example. Examples of FPDs include liquid crystal displays (LCDs), electroluminescent (EL) displays, plasma display panels (PDPs), and the like.

The plasma processing apparatus 1 has, for example, a processing chamber (plasma processing chamber) 2 whose surface is formed into a square tube shape made of aluminum subjected to anodization (anodic oxidation treatment). In the bottom part of the process chamber 2, the mounting table 3 for mounting the glass substrate G which is a to-be-processed object is arrange | positioned.

The mounting table 3 is supported by the bottom of the processing chamber 2 via the insulating member 4. The mounting table 3 is comprised by the electroconductive base material 5 which has the convex part 5a. The surface of the conductive base material 5 is covered with an insulating coating 8, for example, alumina spray or alumite. The periphery of the convex part 5a is surrounded by the frame-shaped focus ring 6. In this example, the feed line 12 is connected to the conductive base material 5. The feed line 12 is connected to the high frequency power supply 14 via the matcher 13. The high frequency power supply 14 outputs high frequency power of 13.56 MHz, for example. The high frequency power is supplied to the conductive base 5 constituting the mounting table 3 via the matching unit 13 and the feed line 12. Thereby, the mounting table 3 functions as a lower electrode.

Above the mounting table 3, the shower head 20 is disposed facing the mounting table 3. The shower head 20 is supported at, for example, the upper portion of the processing chamber 2. The shower head 20 has an internal space 21 therein and has a plurality of discharge holes 22 for discharging the processing gas on a surface opposite to the mounting table 3. Thereby, the shower head 20 functions as a process gas discharge part. In addition, in this example, the shower head 20 is grounded, functions as an upper electrode, and comprises a pair of parallel flat electrodes with the mounting table 3 which functions as a lower electrode.

The gas introduction port 24 is provided in the upper surface of the shower head 20. The process gas supply pipe 25 is connected to the gas inlet 24. The process gas supply pipe 25 is connected to the process gas supply source 28 via an on / off valve 26 and a mass flow controller (MFC) 27. The process gas supply source 28 is a process gas used for plasma processing, for example, plasma dry etching, and the mass flow controller 27, an opening / closing valve 26, a process gas supply pipe 25, and a shower head 20. It feeds into the process chamber 2 through. As the processing gas, a gas usually used in this field, such as a halogen-based gas, O ₂ gas, or Ar gas, can be used.

An exhaust pipe 29 is formed at the bottom of the processing chamber 2. The exhaust pipe 29 is connected to the exhaust device 30. The exhaust device 30 includes a vacuum pump such as a turbomolecular pump (TMP). The exhaust device 30 exhausts the inside of the processing chamber 2 by adjusting the exhaust amount. As a result, the pressure in the processing chamber 2 can be reduced to a predetermined pressure-reducing atmosphere.

The board | substrate carrying in / out port 31 is provided in the side wall of the process chamber 2. The substrate loading / exiting opening 31 can be opened and closed by the gate valve 32. In the state which opened the gate valve 32, the glass substrate G is carried in and out by a conveyer (not shown).

FIG. 2 is a block diagram schematically showing a control system for controlling the plasma processing apparatus 1 shown in FIG. 1.

As shown in FIG. 2, the device controller 50 sets the end point of the matcher 13, the mass flow controller 27, the exhaust device 30, and the etching based on the plasma emission intensity in the processing chamber 2. It is connected to the end-point detector 51 to detect, and the high frequency generator 52 which generate | occur | produces a high frequency output in the high frequency power supply 14.

The device controller 50 has a storage unit that stores processing conditions (process recipes), and the device controller 50 controls the massflow controller 27 to respond to the processing conditions (process recipes) stored in the storage unit. Adjust the flow rate of the process gas.

Similarly, the device controller 50 controls the exhaust device 30 to adjust the displacement according to the process recipe, thereby adjusting the pressure in the process chamber 2.

In addition, the device controller 50 controls the high frequency generator 52 to adjust the output value of the high frequency power supplied to the mounting table 3 in accordance with the process recipe.

In addition, although not shown, the apparatus controller 50 controls the temperature control apparatus of the heat transfer medium supplied to the heat transfer medium flow path built into the mounting table 3, and according to the process recipe, the temperature of the glass substrate G Adjust

Thus, the apparatus controller 50 controls the plasma processing apparatus 1 by controlling the massflow controller 27, the exhaust apparatus 30, the high frequency generator 52, and the temperature control apparatus.

In addition, the device controller 50 has a function of controlling the plasma processing apparatus 1 as well as a monitoring function of monitoring the status of the processing.

Specifically, the device controller 50 monitors the flow rate of the processing gas in the mass flow controller 27 and monitors the supply status of the processing gas.

Similarly, the device controller 50 monitors the displacement in the exhaust device 30 and monitors the pressure situation in the processing chamber 2.

Similarly, the device controller 50 monitors the output value of the high frequency generator 52 to monitor the output state of the high frequency output.

Similarly, the device controller 50 monitors the temperature regulating device and monitors the temperature of the glass substrate G and the temperature situation in the processing chamber 2.

Similarly, the device controller 50 monitors the plasma emission intensity detected by the endpoint detector 51 and monitors the state of the plasma in the processing chamber 2. In addition, the device controller 50 monitors the magnitude (hereinafter, simply referred to as a reflected wave) of the high frequency power reflected wave returned to the high frequency generator 52 to monitor the state of the plasma in the processing chamber 2.

In addition, the device controller 50 selects reprocessing conditions stored in advance in the storage unit when an abnormality, for example, a process abnormality occurs when the glass substrate G is being processed, sets a necessary value, The plasma processing apparatus 1 is controlled to perform reprocessing with respect to this glass substrate G. FIG. 3 shows an example of a substrate processing method executed by the device controller 50.

As shown in Fig. 3, the device controller 50 stores basic processing conditions. The basic processing condition is composed of a basic condition which is a processing condition (process recipe) and a prescribed value for determining whether or not a process abnormality has occurred. In basic conditions, the flow volume of a process gas, the kind of process gas, the pressure in the process chamber 2, the output value of high frequency electric power, a process time, etc. are set. The prescribed value is obtained from each unit (matching device 13, mass flow controller 27, exhaust device 30, end point detector 51, high frequency generator 52, temperature control device (not shown)). The plasma emission intensity, the output value of the high frequency power, the reflected wave, and the temperature in the substrate or the processing chamber 2 are set.

An example of the prescribed value is to set the plasma emission intensity, the output value of the high frequency power, the reflected wave, the temperature in the substrate or the processing chamber 2 observed in the glass substrate G which has normally been processed, as the prescribed value. When the device controller 50 is processing the glass substrate G, the device controller 50 monitors the plasma emission intensity, the output value of the high frequency power, the reflected wave, the temperature in the substrate or the processing chamber 2, and at least one of these values is defined in the above. When a change deviates from the value, it is determined that an abnormality has occurred. The device controller 50 also has a determination function for determining the above kind. The above kind of determination may be made based on, for example, what specific value is out of the plasma emission intensity, the output value of the high frequency power, the reflected wave, the temperature in the substrate or the processing chamber 2.

For example, by storing the n judgment results from the judgment-1 to the judgment-n in the storage unit of the device controller 50, and searching for which of the n judgments the change that deviates from the prescribed value matches the judgment result. Determine the type.

In this example, a plurality of reprocessing conditions corresponding to each of the n determination results are stored in the storage unit of the device controller 50. The reprocessing condition differs from the processing conditions (basic conditions) at least one of the flow rate of the processing gas, the type of processing gas, the pressure in the processing chamber 2 (the amount of exhaust in the processing chamber 2), and the output value of the high frequency power.

For example, as shown in Fig. 4A, when the processing time is 110 sec, the reflected wave is said to rise momentarily. If the judgment at this time is "decision-1", "condition-1" is selected as the reprocessing condition. In addition, as shown in Fig. 4B, when the processing time is 140 sec, the plasma light emission is said to decrease rapidly. If the judgment at this time is "decision-2", "condition-2" is selected as the reprocessing condition.

The apparatus controller 50 changes the basic conditions, for example, the flow rate of the processing gas, the pressure in the processing chamber 2, the output value of the high frequency power, and the processing time to the reprocessing conditions selected according to the determination result. The device controller then performs reprocessing on the glass substrate G under the selected reprocessing conditions.

As described above, according to the plasma processing apparatus according to the embodiment, the device controller 50 automatically selects and executes an appropriate reprocessing condition according to the processing situation of the glass substrate G or the state of the apparatus. Thereby, the plasma processing apparatus which can suppress the fall of productivity also when a process abnormality etc. generate | occur | produces can be obtained.

Next, an example of the sequence of a specific substrate processing is demonstrated below.

5 is a flowchart illustrating an example of a sequence of substrate processing performed by the plasma processing apparatus according to one embodiment.

As shown in Fig. 5, it is assumed that any abnormality has occurred when the process is being executed (step 1).

In step 1, it is determined whether the abnormality occurred is a serious abnormality or a minor abnormality.

A serious abnormality is an abnormality in which the processing cannot be continued, including a failure of the apparatus, for example, the glass substrate G cannot be conveyed, an electrode is broken, or a high frequency power supply is broken (a fatal alarm). ). If a fatal alarm occurs, stop processing.

Minor abnormalities include an instantaneous increase in reflected waves, fluctuations in output from high frequencies, fluctuations in pressure outside the specification, fluctuations in the flow rate of out-of-spec process gas, or fluctuations in unspecified temperature (in-process and / or process chambers). It is an abnormality with the possibility of continuing a process, such as having a glass substrate) (normally an alert). When an alarm normally occurs, it goes to the abnormality diagnosis step (step 2).

In step 2, the above-described kind is determined, and the result of the determination determines whether the processing can be continued or not.

The above kind is determined based on, for example, the timing at which the abnormality occurred and the information of the unit which detected the abnormality. For example, the process information of the glass substrate G recently processed normally is recorded in the storage unit of the device controller 50. For example, in the device controller 50, when processed using the B recipe, if it is A variety, the emission intensity D of the plasma becomes C after the elapse of C time, and becomes the emission intensity F after the E time elapses, and the processing ends in G time. As described above, process information for each elapsed processing time is sampled. The process information sampled every processing elapsed time includes, for example, when the glass substrate G is normally processed, for example, the temperature of the processing chamber or the glass substrate G, the output value of the high frequency power, the intensity of plasma emission, and the magnitude of the reflected wave for each processing elapsed time. It contains information about how it changes. For example, the process information for each elapsed processing time is defined as a determination value, and the progress of the process and the reprocessing are determined.

If it is determined that the processing cannot be continued, the processing is stopped (reprocessing impossible).

If it is determined that the processing can be continued (reprocessing possible), the processing proceeds to the reprocessing condition setting step (step 3).

In step 3, reprocessing conditions are set for the glass substrate G from which abnormality of the process was detected.

The reprocessing condition is set by selecting an appropriate reprocessing condition among a plurality of reprocessing conditions stored in advance according to the determined abnormality. For example, when the instability of the plasma state becomes an abnormal factor such as excessively reflected waves, a reprocessing condition for lowering only the high frequency output is selected.

Moreover, the time which glass substrate G processed normally before abnormality detection is calculated, and the necessary reprocessing time is set in consideration of the said high frequency output change. When the end point detection is not used, or when the end point detection cannot be performed, the processing ends by this set reprocessing time.

An example of setting specific reprocessing conditions will be described with reference to Figs. 6 (a) and 6 (b).

FIG. 6 (a) shows process information for each elapsed processing time of the glass substrate G processed normally under the basic condition of the high frequency output of 10 kW, and a variation waveform corresponding to the elapsed processing time of the plasma emission intensity and the reflected wave is shown. .

As shown to Fig.6 (a), the normal processing time of the glass substrate G processed normally is 110 sec. The variation of the plasma emission intensity and the reflected wave for each elapsed processing time is as follows.

Elapsed processing time 60sec: Plasma emission intensity decreases, reflected wave increases

Elapsed processing time 80sec: Plasma emission intensity decreases again

Processing elapsed time 100sec: Plasma emission intensity is lower limit (just etching)

Processing elapsed time 110sec: Processing end

FIG.6 (b) shows the process information for every processing elapsed time of the glass substrate G which the abnormality generate | occur | produced on the basic conditions of a high frequency output of 10 kW. In the example shown in Fig. 6B, when the processing elapsed time is 58 sec, the reflected wave is excessively instantaneously. 6 (b) shows the process information up to the occurrence of abnormality. In this example, the device controller 50 determines that the processing can be continued, and sets the reprocessing conditions as follows.

Since the above kind is "in an instant, the reflected wave becomes excessive," the device controller 50 selects the reprocessing condition which reduces only the high frequency output to 5 kW from the basic condition among the plurality of reprocessing conditions previously stored in the storage unit. .

In addition, the reprocessing time is also set in case the end point cannot be detected. Regarding the reprocessing time, since the high frequency output was reduced to 5 kW, the total processing time (110 sec) in the case of normal processing was doubled by subtracting the time (58 sec) in which the glass substrate G was normally processed before the abnormality detection. , 104sec.

After the reprocessing conditions are set in this way, the process proceeds to step 4, where the reprocessing (additional processing) is executed. Subsequently, as shown in step 5, when the end point of etching is detected, the process is terminated (can be terminated). When the end point is not detected, as shown in step 6, time control by the set reprocessing time The process ends by (no termination).

As mentioned above, although an example of a specific sequence was demonstrated, since all of the execution of a reprocessing condition is performed automatically by the apparatus controller 50, the time from abnormality detection to execution of reprocessing conditions is very short. Therefore, at the time of abnormality detection, the device controller 50 may control the high frequency generator 52 to stop the high frequency output once, and may not stop it. Alternatively, as shown in FIG. 7, the high frequency generator 52 is controlled so as to lower the high frequency output to the minimum output required for maintaining the plasma from the abnormality detection to the start of execution of the reprocessing condition. It is good also as a weak discharge state in which the process of is not advanced.

By providing such an apparatus controller 50 as a control system, the plasma processing apparatus which can suppress the fall of productivity also in the case of process abnormality etc. can be obtained.

As mentioned above, although one Example demonstrated this invention, this invention is not limited to the said Example, A various deformation | transformation is possible for it. For example, the reprocessing condition may be a condition based on the value of the basic condition, such as "reducing the high frequency output value of the basic condition to 50%". Under these conditions, the high frequency output can be lowered even if the basic conditions change.

In addition, the embodiment of the present invention is not the only one described above.

For example, in the said Example, although this invention was shown about the case where this invention was applied to the plasma dry etching process of the glass substrate for FPD manufacture, it is not limited to this, Comprising: It processes other to-be-processed objects, such as a solar cell substrate or a semiconductor wafer, It is also applicable to the device.

In addition, although the plasma dry etching process was shown as a process, it is not limited to a plasma dry etching process and can also apply to film-forming processes, such as CVD and PVD.

In addition, in the above embodiment, a capacitively coupled plasma apparatus in which the high frequency power source 14 is connected to the mounting table 3 is shown. For example, the high frequency power source 14 is different from the high frequency power source 14 in the mounting table 3. The present invention can be applied to a capacitively coupled plasma device connected to a power source, or to an inductively coupled plasma device or a plasma device using microwaves.

2: process chamber 5: base material (lower electrode)
5a: convex portion 5b: flange portion
6: focus ring 13: matcher
14: high frequency power supply 27: mass flow controller
30: exhaust device 50: device controller
51: end point detector 42: high frequency generator

Claims (6)

A plasma processing apparatus comprising a processing chamber for performing plasma processing on a target object in accordance with processing conditions,
And a control unit including a storage unit for storing a plurality of reprocessing conditions different from the processing conditions, a monitoring function for monitoring the presence or absence of abnormality occurrence during the plasma processing, and a determination function for determining the type of abnormality occurring.
When an abnormality occurs during the plasma processing, the control system selects one reprocessing condition from the plurality of reprocessing conditions according to the determined abnormality type, and performs reprocessing on the target object.
Plasma processing apparatus, characterized in that.
The method of claim 1,
When an abnormality occurs during the plasma processing, the control system determines whether the plasma processing can be continued, selects one reprocessing condition when determining that the processing can be continued, and reprocesses the object to be processed. Plasma processing apparatus comprising the.

The method according to claim 1 or 2,
In the storage section, predetermined values relating to the temperature in the target object or the processing chamber, the light emission intensity of the plasma, and the magnitude of the reflected wave of the high frequency power for generating and maintaining the plasma are stored in advance. And the control system determines that an abnormality has occurred when the light emission intensity of the plasma and the magnitude of the reflected wave deviate from the prescribed value.
The method of claim 3, wherein
The control system is defined according to the temperature in the target object or the processing chamber, the value of the high frequency output, the intensity of the plasma emission, and the magnitude of the reflected wave at each processing elapsed time in the target object that is normally finished processing. A value is set for each elapsed processing time and stored in the storage unit.
The method according to claim 1 or 2,
The control system controls a processing gas supply system for supplying a processing gas into the processing chamber, an exhaust system for exhausting the interior of the processing chamber, and a high frequency power supply system for supplying high frequency power for generating and maintaining plasma to the processing chamber,
The reprocessing condition is different from at least one of the flow rate of the processing gas, the type of the processing gas, the displacement in the processing chamber, and the output of the high frequency power with respect to the processing condition.
Plasma processing apparatus, characterized in that.
The method according to claim 1 or 2,
The control system sets the high frequency power for generating and maintaining the plasma to the minimum output required for the plasma maintenance until the control system judges that an abnormality has occurred and until reprocessing is performed on the object to be processed. Device.

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