KR101299525B1 - Plasma process apparatus - Google Patents

Abstract

PURPOSE: A substrate processing apparatus is provided to prevent damages of internal components by preventing overload of an RF power supplying system and to prevent generation of reflected power. CONSTITUTION: A substrate processing apparatus comprises a chamber (10) forming a sealed processing space, a substrate support (40) installed in the processing space of the chamber to support a substrate (S), and a power supply (50) installed in the chamber and applying one or more RF power to generated plasma in the processing space. [Reference numerals] (AA) First RF power; (BB) Second RF power

Description

Substrate Processing Equipment {PLASMA PROCESS APPARATUS}

The present invention relates to a substrate treating apparatus for performing a substrate treating process using plasma.

In general, a substrate processing apparatus for performing a substrate treatment using a plasma on a semiconductor substrate, a glass substrate for an LCD panel, a solar cell substrate, an AMOLED panel, or the like is a process suitable for a processing space of a chamber forming a closed processing space. It is a device that performs a substrate treatment process such as deposition, etching the surface of the substrate while injecting a gas, applying a power to form a plasma.

The power applied by the power applying unit is configured in various ways according to the process conditions, and it is common to use one or more RF powers in the range of several MHZ to several tens of MHZ.

On the other hand, the substrate treating apparatus frequently generates fine arcs or hazes due to a phenomenon in which particles composed of electrons and ions accumulate inside the chamber, inside the substrate, or inside the metal pattern on the substrate. As a result, there is a problem that the substrate is damaged and the productivity is lowered.

In order to solve such a problem, in the prior art, in order to prevent an arc from occurring on the surface of the substrate or the inside of the chamber, various methods such as optimizing the hardware configuration or optimizing the plasma processing process have been attempted.

Recently, as a method of improving the convenience of use and not requiring additional configuration, the amount of charge accumulated on the inner wall or the substrate of the chamber by using a method of applying RF power in the form of a pulse using a pulse modulator. By properly adjusting, the rate of arc generation is reduced.

In this way, by using a combination of appropriate duty ratio and pulse without applying RF power continuously, RF power is applied in the form of pulse without adding additional components or hardware to the existing substrate processing apparatus. It is possible to suppress the generation of the arc generated by the plasma simply by adding a simple function. As such, recently, attempts have been made to generate stable plasma by adding a pulse modulation function to an RF source and a matching circuit.

However, the prior art as disclosed in Korean Patent Laid-Open Publication No. 10-2008-0086373 repeats the on / off of the plasma while using a pulse modulator, and the chamber of the chamber for a time when the plasma is turned off. By discharging excessively accumulated charges on the inner wall or the substrate to be processed, it has a configuration of suppressing generation of arcs by particles on the inner wall of the chamber or the substrate to be processed.

However, this configuration, as shown in Figure 1, in the process of applying the RF power in the form of a pulse, because the RF power is repeatedly performed on / off for a very short period of time, the system of supplying RF power It has the disadvantage of causing excessive damage to the overall to shorten the life of the internal drive element or increase the operation failure rate of the internal parts.

In the supply system that supplies RF power, the most demanding period is the moment of turning on the RF power, which includes the ignition process necessary for plasma generation, and reflects the reflected power back to the RF generator. The level of power is also very high, which adversely affects the system supplying RF power.

In addition, in the case of using the pulse, since the voltage driving module of the matching circuit does not correspond to the on / off pulse time of several nanoseconds to several tens of microseconds, the reflected power returned to the RF generator is inevitably generated. May have a negative effect on the quality of the product.

In particular, a substrate processing apparatus that performs processing on a large area substrate such as a flat panel display (FPD) or an organic light emitting diode (OLED) uses a high power of several tens of kW. In the case of using pulses that are repeatedly turned on and off, the RF power supply system is more likely to be overloaded, and there is a disadvantage in that an additional cost is required to construct an RF power supply system that withstands such an overload.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and does not turn off the RF power for the plasma off during the substrate processing process using the plasma, thereby modulating the RF to an amplitude such that the plasma is turned off. An object of the present invention is to provide a substrate processing apparatus capable of preventing overload of a system for supplying power, preventing damage to internal components, and preventing generation of reflected power.

Substrate processing apparatus according to the present invention for achieving the above object, the chamber forming a closed processing space; A substrate support installed in the processing space of the chamber to support the substrate; And a power applying unit installed in the chamber to apply at least one RF power to form plasma in the processing space, wherein the power applying unit has an amplitude of the RF power greater than zero when the plasma is in the off state during the substrate processing process. And a second amplitude that is larger than the minimum value of the first amplitude that forms the plasma in the processing space.

A gas supply unit installed at an upper portion of a processing space of the chamber to inject a gas for substrate processing, wherein the power applying unit includes: a lower electrode to which ground or at least one first RF power is applied to the substrate support; The gas supply unit may include an upper electrode to which ground or one or more second RF powers are applied.

The chamber is formed with an opening to open the upper side, the opening is coupled to the dielectric covering the processing space, the antenna unit for forming an induction electric field to form a plasma in the processing space is installed above the dielectric, The power applying unit may apply RF power to one end of the coil constituting the antenna unit.

A detector is installed in the chamber to detect whether the plasma is in an on state or an off state in the processing space. The sensing unit is controlled to have a second amplitude after the amplitude of the RF power is detected in the processing space. When detecting that the plasma is in the on state, the sensing unit may further reduce the amplitude of the RF power until the detection of the plasma in the off state.

The RF power may be controlled such that the first period in which the plasma is turned on in the processing space and the second period in which the plasma is off in the processing space are sequentially repeated.

And the power applying unit includes at least one RF source for generating RF power, and an RF modulator for modulating the amplitude of the RF power generated from the RF source.

A sensing unit is installed in the chamber to detect whether the plasma is in an on state or an off state in the processing space, and is further installed. When the plasma is switched off in the processing space, the power applying unit, the sensing unit, The amplitude of the RF power can be reduced until it is detected to be off.

The substrate treating apparatus according to the present invention prevents an overload of a system for supplying RF power by modulating the plasma at an amplitude such that the plasma is turned off without turning off the RF power for the plasma off during the substrate processing process using the plasma. Therefore, it is possible to prevent damage to internal parts and to prevent the generation of reflected power.

In particular, the substrate processing apparatus according to the present invention has an advantage of suppressing generation of arcs generated by plasma by repeatedly performing plasma ON / OFF, and without turning off RF power for plasma off. By modulating the amplitude of the plasma to be off, it is possible to prevent the overload of the system for supplying the RF power, thereby preventing damage to internal components.

1 is a graph showing the waveform of the RF power applied to the substrate support in the substrate processing apparatus according to the prior art.
2 is a schematic view showing a substrate processing apparatus according to the present invention.
3 is a graph illustrating a waveform and a plasma control state of RF power applied to a substrate support in the substrate processing apparatus of FIG. 2.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of a substrate processing apparatus according to the present invention.

Substrate processing apparatus according to the present invention, as shown in Figure 1, the chamber 10 to form a closed processing space; A substrate support 40 installed in the processing space of the chamber 10 to support the substrate S; And a power applying unit 50 installed in the chamber 10 to apply one or more RF powers to form plasma in the processing space.

The chamber 10 is configured to form a closed processing space for performing substrate processing, and includes a lower housing having an upper opening formed therein, and an upper housing detachably coupled with the lower housing to form a sealed processing space. Various configurations are possible, such as being made of a metal material such as aluminum, aluminum alloy, stainless steel.

The chamber 10 has a predetermined vacuum pressure in accordance with process conditions, and an exhaust port connected to a vacuum pump is formed at an appropriate position for forming a predetermined vacuum pressure and evacuating gas.

The chamber 10 may be in communication with a vacuum source (not shown). Accordingly, the inside of the chamber 10 may be in a vacuum state during the plasma processing process.

In addition, the chamber 10 may be formed with one or more gates for carrying in and out of the substrate (S).

On the other hand, the substrate processing apparatus according to the present invention can be configured in various ways, such as the arrangement of the gas supply unit, the installation of the dielectric and the antenna, depending on the type of substrate processing.

First, the substrate processing apparatus according to the first embodiment of the present invention, as shown in Figure 2, is installed in the upper portion of the processing space of the chamber 10 is connected to the gas supply device 30 installed outside to perform the substrate processing It may include a gas supply unit 20 for injecting a gas for.

As shown in FIG. 2, the gas supply unit 20 is installed at an upper portion of the processing space as a shower head, and may be configured in various ways as to inject gas into the processing space.

In addition, the substrate processing apparatus according to the second embodiment of the present invention, although not shown, is a substrate processing apparatus using ICP, with the gas supply unit for injecting the gas into the processing space in the chamber 10, the chamber having an upper side. An opening may be formed to be opened, and a dielectric coupled to the processing space may be coupled to the opening, and an antenna unit forming an induction electric field to form a plasma in the processing space may be installed above the dielectric.

On the other hand, the substrate processing apparatus according to the present invention, of course, various configurations are possible depending on the type of substrate processing, such as PECVD, LPCVD, ICP.

The power supply unit 50 is provided in the chamber 10 to apply one or more RF powers to form a plasma in the processing space, and can be variously configured according to the type and control type of RF power applied.

In the case of the substrate processing apparatus of the first embodiment, the power applying unit 50 includes a lower electrode to which ground or one or more first RF powers are applied to the substrate support 40, and the chamber 10 and the gas supply unit 20 are grounded or not. It may include an upper electrode to which at least one second RF power is applied.

In addition, the power supply unit 50, in the case of the substrate processing apparatus of the second embodiment may be configured to apply RF power to one end of the coil constituting the antenna unit and ground to the other end.

On the other hand, the power supply unit 50, the plasma is turned on in the processing space, that is, plasma on (On) and plasma off (Off), for example, as shown in FIG. The RF power may be controlled such that the first period t1 in the state and the second period t2 in the plasma off state are sequentially repeated in the processing space.

Accordingly, the power supply unit 50 of the substrate processing apparatus according to the present invention has a first amplitude of forming a plasma in the processing space when the amplitude of the RF power is greater than zero when the plasma is in the off state t2 during the substrate processing process. The second amplitude A2 is controlled to be smaller than the minimum value of the amplitude A1.

That is, the power supply unit 50 maintains the plasma power in the processing space by maintaining the amplitude of the RF power at the first amplitude A1 in the plasma on period t1 and the RF in the plasma off period t2. By maintaining the amplitude of the power at the second amplitude A2, plasma is not formed in the processing space.

Meanwhile, in controlling the amplitude of the RF power as described above, a detector (not shown) may be additionally installed in the chamber 10 to detect whether the plasma is on or off in the processing space.

Here, when the amplitude of the RF power is controlled to have a second amplitude A2 and the detector detects that the plasma is on in the processing space, the amplitude of the RF power is further increased until the detector detects that the plasma is off. Can be reduced.

Meanwhile, the detector may detect whether plasma is formed in the processing space by various methods such as concentration of radicals in the processing space and induced voltage on the substrate support surface.

In addition, when the sensing unit as described above is installed in the chamber 10, instead of reducing the amplitude of the RF power to the second amplitude during the conversion from the plasma on period t1 to the plasma off period t2, the power supply unit is configured to detect the plasma. It can be controlled to continuously reduce the amplitude of the RF power until it is detected to be off.

Meanwhile, the power supply unit 50 may include one or more RF sources for generating RF power, and an RF modulator for modulating the amplitude of the RF power generated from the RF source.

The RF source is configured to generate RF power having a frequency suitable for process conditions such as a high frequency of about 30 MHz to about 200 MHz and a low frequency of about 100 kHz to about 20 MHz by receiving a commercial power from an external source.

The RF modulator is configured to modulate the amplitude of the RF power generated from the RF source, and is configured to modulate the amplitude of the voltage or current.

Hereinafter, the operation of the substrate processing apparatus according to the embodiment as described above will be described.

First, when the substrate S to be processed is loaded into the chamber 10 and mounted on the substrate support 40, the interior of the chamber 10 is vacuumed and the process is performed from the gas supply device 30. Gas is introduced into the chamber 10 at a predetermined flow rate.

Then, at least one frequency, for example, high frequency RF power and low frequency RF power, is matched to the substrate support 40 from the power supply unit 50, and then applied.

Then, the process gas is discharged from the gas supply unit 20, the discharged process gas is plasmaized by the high frequency discharge generated between the gas supply unit 20 and the substrate support 40, radicals generated by the plasma formation and Substrate treatment such as deposition or etching is performed on the surface of the substrate S by the ions.

Here, the high frequency RF power serves to generate a high frequency discharge between the gas supply unit 20 and the substrate support 40, and further serves to generate a plasma. In addition, the low frequency RF power primarily serves to adjust the magnitude of the negative magnetic bias voltage generated in the substrate S and the substrate support 40, and further accelerates ions in the plasma toward the substrate S. Do it.

In addition, the substrate processing apparatus according to the present invention has RF power such that the first cycle t1 in which the plasma is turned on in the processing space and the second cycle t2 in which the plasma is off in the processing space are sequentially repeated. Can be controlled.

Accordingly, as shown in FIG. 3, the power applying unit 50 may have a first amplitude of forming a plasma in the processing space when the amplitude of the RF power is greater than zero when the plasma power is off (t2) during the substrate processing process. The second amplitude A2 is controlled to be smaller than the minimum value of the amplitude A1.

That is, the power applying unit 50 applies the power to the size such that the plasma is formed in the processing space and the size such that no plasma is formed in the processing space. The operation of applying the power to the size that the plasma is formed and the operation of applying the power to the size larger than zero and smaller than the size to form the plasma may be alternately repeatedly performed.

The amplitude control of the RF power may be performed through an amplitude modulation circuit for adjusting the amplitude of the current or voltage of the RF power.

On the other hand, by the above operation, the substrate processing apparatus according to the present invention, unlike the prior art that the RF power is turned on / off repeatedly is applied, the RF power applied during the plasma off cycle is greater than 0W and within the processing space In the power supply having a size such that the plasma is not formed.

Therefore, since the power is applied to the system constituting the power supply unit 50 even during the plasma off cycle, adverse effects on the system for supplying the RF power as compared to the case of repeatedly performing the on / off as in the prior art. Since it can be reduced, the substrate processing apparatus according to the present invention can prevent damage occurring in the first half of the system for supplying the RF power due to the repeated on / off operation of the RF power.

In addition, the substrate processing apparatus according to the present invention maintains the plasma off state even though power is applied to the system constituting the power applying unit 50, so that plasma is not generated inside the chamber 10 during the plasma off cycle. Therefore, the electric charge accumulated in the substrate S or the chamber 10 can be sufficiently discharged.

Therefore, the substrate processing apparatus according to the present invention, unlike the prior art, can be achieved in the prior art that repeatedly performs the on / off of the RF power, even if the operation to turn off the RF power (off) during the substrate processing process. The effect of preventing the accumulation of charge in the interior of the substrate (S) and the chamber 10 can prevent the occurrence of non-ideal arc can be achieved as it is.

The substrate treating apparatus according to the present invention includes a first RF power having a size sufficient to generate a plasma and a second RF power having a size not to generate a plasma without performing an RF power off operation during a plasma processing process. By alternately applying it periodically, it is possible to reduce the damage of internal parts by reducing the overload and fatigue of the system that supplies the RF power such as the RF generator, matching circuit and cable, and repeatedly performing the on / off operation of the RF power. The generated reflected power can be reduced.

Substrate processing apparatus using RF power may include plasma etching (PE), reactive ion etching (RIE), magnetically enhanced reactive ion etching (MERIE), electro-cyclotron resonance (ECR), and decoupled plasma (DPS) depending on the electrode configuration. Source), TCP (Transformer Coupled Plasma), Capacitive Coupled Plasma (CCP), Induced Coupled Plasma (ICP), Surface Wave Plasma (SWP), and the like can be classified in various ways, as described in the embodiments of the present invention. The first RF power having a size sufficient to generate a plasma and the second RF power having a size smaller than that of the first RF power and having a size such that no plasma is generated are alternately transferred to the substrate support 40. The configuration to apply can be applied to both substrate processing apparatus using the above RF power.

On the other hand, the substrate processing apparatus according to the present invention is characterized in that the RF power is applied to the amplitude of the plasma is turned off (off) for the plasma off during the substrate processing process using the plasma (Bar) Instead of modulating the amplitude of the same RF power from the first amplitude A1 to the second amplitude A2, the power supply unit 50 is further configured to form a plasma for the plasma on period t1 as another example. The first RF power having one amplitude A1 and the second RF power having a second amplitude A2 such that the plasma is turned off so that power can be applied so that the plasma is turned off even during the plasma off period t2 are obtained. It may be configured to apply.

The first RF power maintains the on state at the plasma on period t1 to have a first amplitude A1 for plasma formation and is changed to the off state at the plasma off period t2.

The second RF power has a second amplitude A2 such that the plasma is turned off and remains on regardless of the plasma on period t1 and the plasma off period t2 or is turned on only during the plasma off period t2. State can be changed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

20: gas supply unit 30: gas supply device
40: substrate support 50: power supply

Claims (8)

A chamber forming a closed treatment space;
A substrate support installed in the processing space of the chamber to support the substrate; And
A power supply unit installed in the chamber to apply one or more RF powers to form plasma in the processing space;
The power applying unit is controlled such that the amplitude of the RF power is greater than zero when the plasma power is off during the substrate processing process, and the second amplitude is smaller than the minimum value of the first amplitude for forming the plasma in the processing space.
A sensing unit installed in the chamber to detect whether the plasma is in an on state or an off state in the processing space;
After the amplitude of the RF power is controlled to have a second amplitude and the sensing unit detects that the plasma is on in the processing space, the amplitude of the RF power is detected until the sensing unit detects that the plasma is off. Substrate processing apparatus, characterized in that further reducing. The method of claim 1,
The power supply unit is a substrate processing apparatus characterized in that the RF power is controlled so that the first cycle of the plasma is turned on in the processing space, and the second cycle of the plasma off state in the processing space is repeated in sequence. . A chamber forming a closed treatment space;
A substrate support installed in the processing space of the chamber to support the substrate; And
A power supply unit installed in the chamber to apply one or more RF powers to form plasma in the processing space;
The power applying unit is controlled such that the amplitude of the RF power is greater than zero when the plasma power is off during the substrate processing process, and the second amplitude is smaller than the minimum value of the first amplitude for forming the plasma in the processing space.
The RF power is controlled so that the first period in which the plasma is turned on in the processing space and the second period in which the plasma is off in the processing space are sequentially repeated.
A sensing unit installed in the chamber to detect whether the plasma is in an on state or an off state in the processing space;
And when the plasma is turned off in the processing space, the power applying unit reduces the amplitude of the RF power until the detector detects that the plasma is in the off state. 4. The method according to any one of claims 1 to 3,
A gas supply unit installed at an upper portion of a processing space of the chamber to inject a gas for substrate processing;
The power supply unit includes a lower electrode to which the ground or one or more first RF powers are applied to the substrate support, and the chamber and the gas supply unit to the upper electrode to which the ground or one or more second RF powers are applied. Processing unit. 4. The method according to any one of claims 1 to 3,
The chamber has an opening so that the upper side is opened,
The opening is coupled to a dielectric covering the processing space,
An antenna unit is formed above the dielectric to form an induction field and form a plasma in the processing space.
And the power applying unit applies RF power to one end of a coil constituting the antenna unit. The method according to claim 2 or 3,
And the power applying unit includes at least one RF source for generating RF power, and an RF modulator for modulating the amplitude of the RF power generated from the RF source. 5. The method of claim 4,
And the power applying unit includes at least one RF source for generating RF power, and an RF modulator for modulating the amplitude of the RF power generated from the RF source. The method of claim 5,
And the power applying unit includes at least one RF source for generating RF power, and an RF modulator for modulating the amplitude of the RF power generated from the RF source.

Images