TWI420589B - Plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to a glass substrate for manufacturing a flat panel display (FPD; Flat Panel Display) or a plasma processing apparatus for performing plasma treatment on a target object such as a semiconductor wafer for manufacturing a semiconductor integrated circuit (IC).

In the manufacturing process of the FPD or the IC, there is a plasma processing apparatus that performs processing such as etching on a substrate to be processed such as a glass substrate or a semiconductor wafer. For a plasma processing apparatus that performs a process such as etching, for example, a plasma dry etching apparatus is known.

A device controller for controlling process gas or high frequency output is connected to the plasma dry etching apparatus. The device controller controls the flow rate or high frequency output of the process gas, the processing time, the processing pressure, and the like in accordance with predetermined processing conditions called recipe recipes. Thereby, a predetermined process such as etching of the object to be processed is performed by the plasma processing apparatus.

When a process abnormality or the like occurs when a predetermined process is performed, for example, as described in Patent Document 1, the processing of the object to be processed is interrupted. After the interruption, the operator performs a necessary operation such as correction of the prescription, and then performs processing on the object to be processed.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] JP-A-2007-234809

As described in Patent Document 1, when a predetermined process is executed, the process is interrupted when a process abnormality or the like occurs. Therefore, there is a case where the productivity of the product is lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a plasma processing apparatus capable of suppressing a decrease in productivity even when a process abnormality or the like occurs.

In order to solve the above problems, a plasma processing apparatus according to an aspect of the present invention includes a plasma processing apparatus that processes a plasma to be processed in accordance with processing conditions, and has a control system. The control system includes a memory unit that stores a plurality of reprocessing conditions that are different from the processing conditions described above, and a monitoring function that monitors the presence or absence of an abnormality in the plasma processing, and a function of determining the type of the abnormality that occurs. When an abnormality occurs in the plasma processing, the processing object is reprocessed by selecting one of the plurality of reprocessing conditions in accordance with the type of the abnormality determined.

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

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 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 a device for performing predetermined processing on a glass substrate G for FPD production. This example is a capacitive coupling type plasma dry etching apparatus. The FPD is, for example, a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display panel (PDP), or the like.

The plasma processing apparatus 1 has a processing chamber (plasma processing chamber) 2 whose surface is, for example, alumite treated (anodized), and is made of aluminum to form a rectangular tube shape. A mounting table 3 for mounting the glass substrate G of the object to be processed is disposed at the bottom of the processing chamber 2.

The mounting table 3 is supported by the bottom of the processing chamber 2 via the insulating member 4. The mounting table 3 is constituted by a conductive substrate 5 having a convex portion 5a. The surface of the electrically conductive substrate 5 is covered with an insulating surface coating 8, such as alumina thermal spray or alumite. The periphery of the convex portion 5a is surrounded by a bezel-shaped focus ring 6. In this example, the power supply line 12 is connected to the conductive substrate 5. The feed line 12 is connected to the high frequency power source 14 via the integrator 13. The high frequency power source 14 is, for example, a high frequency power output of 13.56 MHz. The high-frequency power is supplied to the conductive substrate 5 constituting the mounting table 3 via the integrator 13 and the electric wire 12 . Thereby, the mounting table 3 has a function as a lower electrode.

The shower head 20 is disposed above the mounting table 3 so as to face the mounting table 3. The shower head 20 is supported, for example, by 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 a processing gas on a surface opposite to the mounting table 3. Thereby, the shower head 20 has a function as a processing gas discharge portion. In this example, the shower head 20 is a parallel plate electrode that is grounded and has a function as an upper electrode and a pair of mounting stages 3 having a function as a lower electrode.

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

An exhaust pipe 29 is formed at the bottom of the process chamber 2. The exhaust pipe 29 is connected to the exhaust device 30. The exhaust device 30 is a vacuum pump including a turbo molecular pump (TMP) or the like. The exhaust unit 30 regulates the amount of exhaust gas to exhaust the inside of the processing chamber 2. Thereby, the pressure in the processing chamber 2 can be depressurized to a predetermined reduced pressure environment.

A substrate carry-out port 31 is provided on the side wall of the processing chamber 2. The substrate carry-out port 31 can be opened and closed by the gate valve 32. When the gate valve 32 is opened, the glass substrate G is carried out by a transfer device (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 is connected to the integrator 13, the mass flow controller 27, the exhaust device 30, and the end point detector 51 that detects the etching end point based on the plasma luminous intensity in the processing chamber 2. And a high frequency generating device 52 that generates a high frequency output from the high frequency power source 14.

The controller 50 has a memory unit for memorizing processing conditions (process recipe), and the device controller 50 controls the mass flow controller 27 to adjust the flow rate of the processing gas in accordance with the processing conditions (process recipe) stored in the memory unit.

Similarly, the device controller 50 controls the exhaust device 30 to adjust the amount of exhaust gas in accordance with the process recipe to adjust the pressure in the process chamber 2.

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

Further, the device controller 50 is a temperature adjustment device (not shown) that controls the heat transfer medium flowing through the heat transfer medium flow path mounted in the mounting table 3, and adjusts the temperature of the glass substrate G in accordance with the process recipe.

Thus, the device controller 50 controls the plasma processing device 1 under the control mass flow controller 27, the exhaust device 30, the high frequency generating device 52, and the temperature regulating device.

Further, the device controller 50 not only has the function of controlling the plasma processing apparatus 1, but also has a monitoring function for monitoring the processing status.

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

Similarly, the device controller 50 monitors the amount of exhaust of the exhaust device 30 and monitors the pressure condition in the processing chamber 2.

Similarly, the device controller 50 monitors the output value of the high frequency generating device 52 and monitors the output state of the high frequency output.

Similarly, the device controller 50 is a monitoring temperature adjustment device that monitors the temperature of the glass substrate G or the temperature condition in the processing chamber 2.

Similarly, the device controller 50 monitors the plasma luminous intensity detected by the end point detector 51 and monitors the plasma state in the processing chamber 2. Moreover, the device controller 50 monitors the magnitude of the reflected wave of the high-frequency power returned to the high-frequency generating device 52 (hereinafter referred to as a reflected wave), and monitors the state of the plasma in the processing chamber 2.

Further, when the glass substrate G is processed, the device controller 50 selects a reprocessing condition previously stored in the memory unit when an abnormality occurs, for example, a process abnormality, and sets a necessary value so that the glass substrate G can be implemented. In the manner of reprocessing, the plasma processing apparatus 1 is controlled. FIG. 3 is a view showing an example of a substrate processing method executed by the device controller 50.

As shown in FIG. 3, the device controller 50 is a memory basic processing condition. The basic processing conditions are composed of the basic conditions of the processing conditions (process recipe) and the prescribed values for judging whether or not the process abnormality has occurred. The flow rate of the processing gas, the type of the processing gas, the pressure in the processing chamber 2, the output value of the high-frequency power, the processing time, and the like are set in the basic conditions. The predetermined value is the plasma luminous intensity obtained from each unit (the integrator 13, the mass flow controller 27, the exhaust device 30, the end point detector 51, the high frequency generating device 52, and the temperature adjusting device (not shown)). 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 predetermined value is a plasma luminous intensity observed in the glass substrate G after the normal treatment, an output value of the high-frequency power, a reflected wave, and a temperature in the substrate or the processing chamber 2 as predetermined values. When the glass substrate G is processed, the device controller 50 monitors the plasma luminous intensity, the output value of the high-frequency power, the reflected wave, and the temperature in the substrate or the processing chamber 2, and at least one of the values is deviated from the predetermined value. When the change occurs, it is judged that an abnormality has occurred. The device controller 50 also has a function of determining the type of abnormality. The determination of the type of the abnormality is, for example, a determination as to whether or not the predetermined value of the plasma luminous intensity, the output value of the high-frequency power, the reflected wave, or the temperature in the substrate or the processing chamber 2 is deviated.

For example, in the memory unit of the device controller 50, the n determination results of the judgment-1 to the judgment-n are stored in advance, and the change of the deviation from the predetermined value is determined by the determination result of which of the n determinations. .

Further, in this example, the reprocessing conditions corresponding to the plural of the n determination results are stored in the memory unit of the device controller 50. The reprocessing conditions are at least any of the flow rate of the processing gas, the type of the processing gas, the pressure in the processing chamber 2 (the amount of exhaust gas in the processing chamber 2), and the output value of the high-frequency power with respect to the processing conditions (basic conditions). One is different.

For example, as shown in FIG. 4A, when the processing time is 110 sec, the reflected wave instantaneously rises. If the judgment at this time is set to "Judge-1", "Condition-1" is selected as the reprocessing condition. Further, as shown in FIG. 4B, when the processing time was 140 sec, the plasma light emission was drastically reduced. If the judgment at this time is set to "Judge-2", "Condition-2" is selected as the reprocessing condition.

The device controller 50 changes basic conditions such as 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 in accordance with the determination result. Moreover, the device controller performs reprocessing on the glass substrate G in accordance with the selected reprocessing conditions.

As described above, according to the plasma processing apparatus of the embodiment, the device controller 50 automatically selects and executes appropriate reprocessing conditions in accordance with the processing state of the glass substrate G or the state of the device. As a result, it is possible to obtain a plasma processing apparatus capable of suppressing a decrease in productivity even when a process abnormality or the like occurs.

Next, an example of the order of specific substrate processing will be described below.

Fig. 5 is a flow chart showing an example of a procedure of substrate processing performed by the plasma processing apparatus according to the embodiment.

As shown in FIG. 5, some abnormality occurs when the processing is performed (step 1).

It is judged that the abnormality occurring in the step 1 is a severe abnormality or a slight abnormality.

The severe abnormality is, for example, a failure of a machine that cannot convey the glass substrate G, the electrode is broken, or the high-frequency power supply is broken, and is an abnormality (severe alarm) that is impossible for the continuation of the process. The process is aborted when a critical alarm is issued.

A slight abnormality is an instantaneous increase in the reflected wave, a change in the output of the high-frequency outside the predetermined period, a change in the pressure outside the predetermined range, a change in the flow rate of the predetermined processing gas, and a predetermined temperature fluctuation (in the processing chamber and/or the glass substrate, etc.) ), etc., there is an exception (usually an alert) that you want to continue processing. When a normal alarm occurs, proceed to the abnormality diagnosis step (step 2).

In step 2, the type of abnormality is determined, and the result of the determination is judged, and the continuation of the process may or may not be possible.

The type of the abnormality is determined, for example, based on the timing of the occurrence of the abnormality and the information of the unit that detected the abnormality. For example, the process information of the glass substrate G which has been normally processed normally is recorded in the memory portion of the device controller 50. For example, when the device controller 50 is processed using the B prescription, the device controller 50 becomes the luminous intensity D of the plasma after the lapse of the C time, and becomes the luminous intensity F after the lapse of the E time, and the processing at the end of the G time. That way, the process information of the elapsed time per sample is sampled. The process information sampled during each processing elapsed time includes the temperature of the processing chamber or the glass substrate G, the output value of the high-frequency power, the intensity of the plasma light emission, and the magnitude of the reflected wave in each processing when the glass substrate G is normally processed. Information on how time has changed. For example, the process information such as the elapsed time per process is set as a predetermined value of the determination, and the progress degree of the process and the possibility of reprocessing are determined.

When it is judged that the continuation of the processing is impossible, the processing is aborted (cannot be processed).

When it is judged that the continuation of the processing is possible (reprocessable), the processing proceeds to the reprocessing condition setting step (step 3).

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

The setting of the reprocessing condition is performed by selecting an optimum reprocessing condition from among a plurality of reprocessing conditions that are previously stored, in accordance with the type of the abnormality determined. For example, when the transient reflected wave is too large, and the instability of the plasma state becomes a cause of abnormality, a reprocessing condition that reduces only the high-frequency output is selected.

Then, the time during which the glass substrate G is normally processed before the abnormality detection is calculated, and the necessary reprocessing time is set by considering the change of the high frequency output. When the end point is not detected, or when the end point cannot be detected, the reprocessing time set according to this is terminated.

An example of setting specific reprocessing conditions will be described with reference to FIGS. 6A and 6B.

6A is a process information showing the elapsed time per process of the glass substrate G which is normally processed under the basic condition of a high-frequency output of 10 kW, and shows a waveform of fluctuations in processing elapsed time in accordance with the plasma luminous intensity and the reflected wave.

As shown in FIG. 6A, the glass substrate G that was normally processed was the first total processing time of 110 sec. The variation of the plasma luminous intensity and the reflected wave per treatment time is as follows.

The treatment elapsed time is 60 sec: the luminous intensity of the plasma is lowered, and the reflected wave is large.

Processing time 80sec: plasma luminous intensity is reduced again

Processing elapsed time 100 sec: plasma luminous intensity is the lower limit (just etch)

Processing time 110sec: end of processing

Fig. 6B is a process information showing the elapsed time per process of the glass substrate G in which an abnormality occurs under the basic condition of a high-frequency output of 10 kW. The example shown in Fig. 6B is that the transient reflected wave is excessively large when the processing elapsed time is 58 sec. Here, FIG. 6B shows process information until an abnormality occurs. In this example, the device controller 50 determines the continuation of the processing, and sets the reprocessing condition as follows.

Since the type of the abnormality is "the instantaneous reflected wave is too large", the device controller 50 selects a reprocessing condition that reduces the high-frequency output to only 5 kW from the basic condition from the plurality of reprocessing conditions previously memorized in the memory unit.

Also, when it is not possible to detect the end point, the reprocessing time is also set. The reprocessing time is to reduce the high-frequency output to 5 kW and set to 104 sec, that is, the total processing time (110 sec) at the time of normal processing minus the time during which the glass substrate G is normally processed before the abnormality detection ( 2 times after 58 sec).

After the reprocessing conditions are set as described above, the process proceeds to step 4, and reprocessing (addition processing) is performed. Then, as shown in step 5, if the end point of the etching is detected, the processing is terminated (endurable), and when the end point is not detected, as shown in step 6, the time control according to the set reprocessing time is not possible (not End), the end of the process.

Although an example of a specific procedure has been described above, since the execution of the reprocessing conditions is automatically performed by the device controller 50, the time from the detection of the abnormality to the start of the execution of the reprocessing condition is extremely short. Therefore, at the time of abnormality detection, the device controller 50 can control the high frequency generating device 52 to stop the high frequency output or stop it. Alternatively, as shown in FIG. 7, the high frequency generating means 52 may be controlled so that the high frequency output can be lowered to the minimum output necessary for maintaining the plasma from the time when the abnormality detection to the execution of the reprocessing condition is started. This period is a weak discharge state in which the processing such as etching does not progress.

By providing such a device controller 50 as a control system, it is possible to obtain a plasma processing apparatus capable of suppressing a decrease in productivity even when a process abnormality or the like occurs.

The present invention has been described above on the basis of an embodiment, but the present invention is not limited to the above embodiment, and various modifications are possible. For example, the reprocessing condition is set to "lower the high-frequency output value of the basic condition to 50%", and the condition based on the value of the basic condition is used. If it is such a condition, the high frequency output can be lowered even if the basic conditions are changed.

Further, the embodiment of the present invention is not the only one of the above embodiments.

For example, in the above-described embodiment, the present invention is applied to a plasma dry etching process in which a glass substrate for FPD manufacturing is applied. However, the present invention is not limited thereto, and is used for processing other substrates to be processed such as a solar cell substrate or a semiconductor wafer. The device is also applicable.

Further, although the treatment is a plasma dry etching treatment, it is not limited to the plasma dry etching treatment, and may be applied to a film formation treatment such as CVD or PVD.

Further, the above-described embodiment is a capacitive coupling type plasma device that connects the high-frequency power source 14 to the mounting table 3. However, for example, a high-frequency power source having a frequency different from the high-frequency power source 14 may be connected to the mounting table 3. The present invention can also be applied to a capacitively coupled plasma device, or to an inductively coupled plasma device or a plasma device utilizing microwaves.

2. . . Processing room

5. . . Substrate (lower electrode)

5a. . . Convex

5b. . . Flange

6. . . Focus ring

13. . . Integrator

14. . . High frequency power supply

27. . . Mass flow controller

30. . . Exhaust

50. . . Device controller

51. . . End point detector

42. . . High frequency generating device

Fig. 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 flow chart showing an example of a substrate processing method executed by a device controller included in the plasma processing apparatus according to the embodiment.

4 is a view showing an example of a change in processing conditions.

Fig. 5 is a flow chart showing an example of a procedure of substrate processing performed by the plasma processing apparatus according to the embodiment.

6A is process information showing the elapsed time per process of the glass substrate G that is normally processed, and FIG. 6B is process information showing the elapsed time per process of the glass substrate G in which the abnormality has occurred.

Figure 7 is a graph showing the relationship between discharge level and time.

2. . . Plasma processing room

3. . . Mounting table

13. . . Integrator

14. . . High frequency power supply

20. . . shower head

27. . . Mass flow controller

30. . . Exhaust

50. . . Device controller

51. . . End point detector

52. . . High frequency generating device

G. . . glass substrate

Claims (6)

A plasma processing apparatus comprising: a plasma processing apparatus that processes a plasma to be processed in accordance with processing conditions, wherein the plasma processing apparatus includes a control system, and the control system includes: memory and the processing conditions The memory function of the reprocessing condition of the plurality of complex numbers, the monitoring function for monitoring the presence or absence of the occurrence of the abnormality in the plasma processing, and the determining function for determining the type of the abnormality generated, when an abnormality occurs in the plasma processing, The control system reprocesses the object to be processed by selecting one of the plurality of reprocessing conditions in accordance with the type of the abnormality determined. The plasma processing apparatus of claim 1, wherein when the abnormality occurs in the plasma processing, the control system determines whether the continuation of the plasma processing is possible, and when it is determined that the processing may be continued, select one The reprocessing conditions are performed on the object to be processed. The plasma processing apparatus according to claim 1 or 2, wherein the temperature of the object to be processed or the processing chamber, the luminous intensity of the plasma, and the maintenance of the plasma are preliminarily stored in the memory unit. The predetermined value of the magnitude of the reflected wave of the high-frequency power is determined by the control system when the temperature of the object to be processed, the intensity of the plasma, and the magnitude of the reflected wave in the plasma processing are out of the predetermined value. abnormal. The plasma processing apparatus according to claim 3, wherein the control system selects a temperature of the object to be processed or the processing chamber from the processing time of each of the objects to be processed which is normally processed, and the value of the high frequency output. The intensity of the plasma light emission and the magnitude of the reflected wave are set to the predetermined value for each processing elapsed time, and are stored in the memory unit. The plasma processing apparatus according to claim 1 or 2, wherein the control system controls a processing gas supply system that supplies a processing gas to the processing chamber, and an exhaust system that exhausts the processing chamber, and The high-frequency power source that maintains plasma generation is supplied to the high-frequency power source system in the processing chamber, and the reprocessing condition is a flow rate of the processing gas, a type of the processing gas, and an exhaust gas in the processing chamber with respect to the processing condition. At least one of the amount and the output of the high frequency power described above is different. The plasma processing apparatus according to claim 1 or 2, wherein the control system sets a high frequency power for maintaining plasma generation from a period after determining that an abnormality has occurred to a process of reprocessing the object to be processed. The minimum output necessary for the maintenance of the plasma.