KR102225605B1 - Apparatus and method for treating substrate and method for detecting leakage of processing chamber - Google Patents

Abstract

The present invention provides a substrate processing device using plasma. The substrate processing device capable of efficiently procesisng a substrate may comprise: a chamber having a processing space for processing a substrate; an upper electrode disposed above the processing space; a lower electrode disposed under the processing space and provided to face the upper electrode; and an impedance adjusting unit connected to any one of the upper electrode and the lower electrode, wherein the impedance adjusting unit includes an inductor, a capacitor, and at least one switch selectively connecting the inductor and the capacitor in series or parallel.

Description

Substrate processing apparatus and substrate processing method {APPARATUS AND METHOD FOR TREATING SUBSTRATE AND METHOD FOR DETECTING LEAKAGE OF PROCESSING CHAMBER}

The present invention relates to a substrate processing apparatus and a substrate processing method, and more particularly, to a substrate processing apparatus and a substrate processing method for processing a substrate using plasma.

Plasma refers to an ionized gaseous state composed of ions, radicals, and electrons. Plasma is generated by very high temperatures, strong electric fields, or RF electromagnetic fields. The semiconductor device manufacturing process includes an ashing or etching process in which a thin film on a substrate (eg, a wafer) is removed using plasma. The ashing or etching process is performed by colliding or reacting with ions and radical particles contained in the plasma with the film on the substrate.

FIG. 1 is a diagram showing a general substrate processing apparatus for processing a substrate using plasma, and FIG. 2 is an equivalent circuit diagram schematically representing the substrate processing apparatus of FIG. 1. 1 and 2, a general substrate processing apparatus 10 for processing a substrate using plasma P includes a chamber 11, an upper electrode 12, a power supply 13, and a lower electrode 14. Includes. The substrate processing apparatus 10 shown in FIGS. 1 and 2 may be a capacitively coupled plasma apparatus.

The chamber 11 provides a processing space in which a substrate W such as a wafer is processed. An upper electrode 12 is provided above the processing space of the chamber 11. The upper electrode 12 is connected to the power supply 13. The lower electrode 14 is grounded. The lower electrode 14 is provided under the processing space of the chamber 11, and its upper surface is provided so as to face each other with the lower surface of the upper electrode 12. The substrate W is mounted on the lower electrode 14. Further, the power supply 13 is an RF power supply. In addition, a process gas that is excited in a plasma (P) state is injected into the chamber 11. When the power source 13 applies power, plasma P is generated in the space between the upper electrode 12 and the lower electrode 14. The generated plasma P is transferred to the substrate W to process the substrate W.

3 is a graph showing voltage and current formed in the lower electrode of FIG. 1. Referring to FIG. 3, although the lower electrode 14 is physically grounded, a non-zero voltage V is applied to the lower electrode 14. This is because there is _{a parasitic impedance L SR} formed between the lower electrode 14 and the physical ground point. In this way, _{the voltage V applied to the lower electrode 14 by the parasitic impedance L SR} affects the processing result of the substrate W in a manner that affects the voltage or current of the substrate W.

An object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of efficiently processing a substrate.

In addition, an object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of providing an additional factor for processing a substrate.

Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of controlling the ion energy of plasma transmitted to a substrate.

Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of controlling the density of plasma generated between an upper electrode and a lower electrode.

The problem to be solved by the present invention is not limited to the above-described problems, and the tasks that are not mentioned can be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings. There will be.

The present invention provides an apparatus for processing a substrate using plasma. A substrate processing apparatus includes: a chamber having a processing space for processing the substrate; An upper electrode disposed above the processing space; A lower electrode disposed below the processing space and provided to face the upper electrode; An impedance adjusting unit connected to one of the upper electrode and the lower electrode, the impedance adjusting unit comprising: an inductor; Capacitors; And at least one switch selectively connecting the inductor and the capacitor in series or in parallel.

According to an embodiment, the capacitor may be a variable capacitor whose capacitance value is variable.

According to an embodiment, the device further includes a controller, and the controller may change the capacitance value of the capacitor so that a circuit including the inductor, the capacitor, and the switch becomes a resonant circuit.

According to an embodiment, the device further includes a controller, wherein the controller is intended to increase ion energy of the plasma transmitted to the upper electrode and the substrate disposed between the lower electrode, or the lower electrode When it is desired to keep the level of the voltage applied to a constant, the switch may be controlled so that the inductor and the capacitor are connected in parallel.

According to an embodiment, the controller may change the capacitance value of the capacitor so that the circuit including the inductor, the capacitor, and the switch becomes a parallel resonance circuit.

According to an embodiment, the device further includes a controller, wherein the controller is configured to increase the density of the plasma generated between the upper electrode and the lower electrode, wherein the inductor and the capacitor are in series. The switch can be controlled to be connected.

According to an embodiment, the controller may change the capacitance value of the capacitor so that a circuit including the inductor, the capacitor, and the switch becomes a series resonant circuit.

According to an embodiment, the switch includes a first switch, a second switch, and a third switch, the first switch and the third switch are turned on, and the second switch is turned off ( Off), the inductor and the capacitor are connected in parallel, the first switch and the third switch are turned off, and the second switch is turned on, the inductor and the capacitor are connected in series. I can.

According to an embodiment, the impedance adjusting unit may further include a sensor unit measuring voltage and/or current formed on the upper electrode or the lower electrode.

In addition, the present invention provides a method of treating a substrate using plasma. In the substrate processing method, the substrate is disposed between an upper electrode and a lower electrode disposed in a processing space of a chamber, and the plasma is generated between the upper electrode and the lower electrode to process the substrate. An inductor and a variable capacitor having an electrode and an impedance adjusting part connected to one of the lower electrodes may be selectively connected in series or parallel.

According to an embodiment, the inductor and the variable capacitor may be connected in parallel, and the capacitance value of the capacitor may be changed.

According to an embodiment, the capacitance value of the variable capacitor may be changed so that the inductor and the variable capacitor connected in parallel form a parallel resonance circuit.

According to an embodiment, the inductor and the variable capacitor are connected in series, and the capacitance value of the variable capacitor may be changed.

According to an embodiment, the capacitance value of the variable capacitor may be changed so that the inductor and the variable capacitor connected in series form a series resonance circuit.

According to an embodiment of the present invention, it is possible to efficiently process a substrate.

In addition, according to an embodiment of the present invention, it is possible to provide an additional factor for processing the substrate.

In addition, according to an embodiment of the present invention, ion energy of plasma transmitted to the substrate may be controlled.

In addition, according to an embodiment of the present invention, it is possible to control the density of plasma generated between the upper electrode and the lower electrode.

The effects of the present invention are not limited to the above-described effects, and effects that are not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.

1 is a diagram showing a general substrate processing apparatus for processing a substrate using plasma.
FIG. 2 is an equivalent circuit diagram schematically illustrating the substrate processing apparatus of FIG. 1.
3 is a graph showing voltage and current formed in the lower electrode of FIG. 1.
4 is a diagram illustrating a substrate processing apparatus according to an embodiment of the present invention.
5 is an equivalent circuit diagram schematically illustrating the substrate processing apparatus of FIG. 4.
6 is a diagram illustrating a state in which an inductor and a capacitor are connected in parallel according to on/off of the switches of FIG. 5.
FIG. 7 is a graph showing a change in the magnitude of a current flowing through a lower electrode according to a change in a capacitance value of the capacitor when the inductor and the capacitor of FIG. 5 are connected in parallel.
8 is a diagram illustrating a state in which an inductor and a capacitor are connected in series according to on/off of the switches of FIG. 5.
FIG. 9 is a graph showing a change in a voltage applied to a lower electrode according to a change in a capacitance value of the capacitor when the inductor and the capacitor of FIG. 5 are connected in series.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in describing a preferred embodiment of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions.

"Including" a certain component means that other components may be further included rather than excluding other components unless specifically stated to the contrary. Specifically, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features or It is to be understood that the presence or addition of numbers, steps, actions, components, parts, or combinations thereof does not preclude the possibility of preliminary exclusion.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In addition, shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 4 to 9.

4 is a diagram illustrating a substrate processing apparatus according to an exemplary embodiment of the present invention, and FIG. 5 is an equivalent circuit diagram schematically illustrating the substrate processing apparatus of FIG. 4. 4 and 5, the substrate processing apparatus 100 according to an embodiment of the present invention may process a substrate W using plasma P. The substrate processing apparatus 100 may be a capacitively coupled plasma apparatus. The substrate processing apparatus 100 may include a chamber 110, an upper electrode 130, a lower electrode 150, an impedance adjustment unit 170, and a controller 200.

The chamber 110 may have a processing space 112 for processing the substrate W. The chamber 110 may have a processing space 112 in which the substrate W is processed by the plasma P. An opening (not shown) through which the substrate W is carried or carried out may be formed at one side of the chamber 110. The opening formed in the chamber 110 may be selectively opened and closed by a gate valve (not shown). An opening formed in the chamber 110 may form a path for carrying in and/or carrying out the substrate W.

Also, the chamber 110 may be a vacuum chamber. For example, on the bottom surface of the chamber 110, there is an exhaust hole 114 that exhausts the processing space 112 of the chamber 110 so that the atmosphere of the processing space 112 becomes a vacuum atmosphere while processing the substrate W. Can be formed. The exhaust hole 114 may be connected to a pressure reducing member (not shown) such as a pump. The pressure reducing member is not limited to a pump, and may be variously modified into a known device capable of providing a reduced pressure to the processing space 112.

The upper electrode 130 may be disposed above the processing space 112. Also, the upper electrode 130 may be connected to the power line 134. The power line 134 may be connected to the power source 132. The power source 132 may be an RF power source.

The lower electrode 150 may be disposed under the processing space 112. A substrate W may be mounted on the lower electrode 150. For example, the upper surface of the lower electrode 150 may be a seating surface on which the substrate W is mounted. In addition, the lower electrode 150 may be provided to face the upper electrode 130. For example, an upper surface of the lower electrode 150 and a lower surface of the upper electrode 130 may be provided to face each other. The lower electrode 150 may be connected to the ground line 154. That is, the lower electrode 150 may be grounded.

The upper electrode 130 and the lower electrode 150 may be a pair of opposite electrodes that excite the process gas injected into the processing space 112 into a plasma (P) state. Plasma P may be generated in a region between the upper electrode 130 and the lower electrode 150 based on the RF power applied from the power source 132. The generated plasma P may process the substrate W.

In the above-described example, the power source 132 is connected to the upper electrode 130 and the lower electrode 150 is grounded. However, the present invention is not limited thereto. For example, the upper electrode 130 may be grounded, and the power 132 may be connected to the lower electrode 150.

The impedance adjusting unit 170 may be connected to one of the upper electrode 130 and the lower electrode 150. For example, the impedance adjusting unit 170 may be provided to be connected to the lower electrode 150. In addition, the impedance adjusting unit 170 may be installed on the ground line 154. The impedance adjusting unit 170 may include a sensor unit 172 and a circuit unit 174. The sensor unit 172 may be installed on the ground line 154. The sensor unit 172 may measure voltage and/or current formed on the lower electrode 150. However, it is not limited thereto. For example, as described above, when the upper electrode 130 is grounded and the power source 132 is connected to the lower electrode 150, the sensor unit 172 measures the voltage and/or current formed in the upper electrode 130. You can also measure it. The magnitude of the voltage and/or current measured by the sensor unit 172 may be transmitted to the controller 200.

The circuit unit 174 may include an inductor (L ₁ ), a capacitor (C ₁ ), and switches (SW ₁ , SW ₂ , SW ₃ ). The inductor L ₁ may be _{a fixed inductor L 1} having a fixed capacitance value. A capacitor (C ₁₎ may be capable of changing the capacitance variable capacitor (C _1). In addition, the switches SW ₁ , SW ₂ , and SW ₃ may connect the inductor L ₁ and the capacitor C ₁ in series or in parallel. For example, the switches SW ₁ , SW ₂ , and SW ₃ may include a first switch SW ₁ , a second switch SW ₂ , and a third switch SW ₃ . When connecting the inductor (L ₁ ) and the capacitor (C ₁ ) in parallel, the first switch (SW ₁ ) and the third switch (SW ₃ ) are turned on, and the second switch (SW ₂ ) is turned off. Can be (Off). In contrast, in _{the case of connecting the inductor (L 1} ) and the capacitor (C ₁ ) in series, the first switch (SW ₁ ) and the third switch (SW ₃ ) are off, and the second switch (SW _{2 ).} ) Can be turned on.

The capacitance value of the inductor L ₁ may be set according to the impedance Zc of the chamber 110. For example, the inductor capacitance of the inductor (L ₁₎ so as to have an impedance of a value of 50% ~ 150% of the impedance (Zc) of the chamber (110) according to (L ₁₎ may be set. In addition, the capacitance range of the _{variable capacitor C 1} may be set with reference to the _{inductor L 1} and the parasitic impedance L _SR. For example, the impedance according to the _{capacitor C 1} may be set to cover 50 to 150% of the impedance value according to _{“L 1} + L _{SR ”.} The following is a table showing examples of capacitance values of the inductor (L ₁ ), and the capacitor (C ₁ ) according to the chamber 110 impedance, the parasitic impedance (L _{SR ).}

Value Impedance (imaginary part, 13.56MHz) Cc 600pF -j19.5 L _One 200nH +j17 C _One 0 to 1000 pF ∞ to -j11.7 L _SR 20nH +j1.7

The controller 200 may control the substrate processing apparatus 100. The controller 200 may control the substrate processing apparatus 100 so that the substrate processing apparatus 100 processes the substrate W using the plasma P. In addition, the controller 200 may control the switches SW ₁ , SW ₂ , and SW ₃ to selectively connect the capacitor C ₁ and the inductor L ₁ in series or parallel. In addition, the controller 200 may change the capacitance value of the _{capacitor C 1.} In addition, the controller 200 may control the substrate processing apparatus 100 to perform the substrate processing method described below. Hereinafter, a substrate processing method according to an embodiment of the present invention will be described in detail. 6 is a view showing a state in which an inductor and a capacitor are connected in parallel according to the on/off of the switches of FIG. 5, and FIG. 7 is a diagram showing a change in the capacitance value of the capacitor when the inductor and the capacitor having the circuit of FIG. 5 are connected in parallel. This is a graph showing the change in the magnitude of the current flowing through the lower electrode. 6 and 7, as described above, the controller 200 may control the switches SW ₁ , SW ₂ , and SW ₃ to connect the inductor L ₁ and the capacitor C ₁ in parallel. . For example, the first switch (SW ₁ ) and the third switch (SW ₃ ) are turned on, and the second switch (SW ₂ ) is turned off, so that the inductor (L ₁ ) and the capacitor (C ₁ ) are Can be connected in parallel. At this time, when the controller 200 _{adjusts the capacitance value of the capacitor C 1} , the magnitude of the current I flowing through the lower electrode 150 can be finely adjusted. In addition, the controller 200 may adjust the capacitance value of _{the capacitor C 1} so that the circuit unit 172 forms a parallel resonance circuit. When the circuit unit 172 forms a parallel resonance circuit, the current I flowing through the lower electrode 150 becomes 0, and at this time, the voltage V applied to the lower electrode 150 becomes maximum. Accordingly, it is possible to minimize the effect of the above-described parasitic impedance L _{SR on the processing of the substrate W.} In addition, when the circuit unit 172 forms a parallel resonance circuit, the potential difference between the upper electrode 130 and the lower electrode 150 increases, thereby increasing the ionic energy of the plasma P transmitted to the substrate W. I can. That is, in the substrate processing method according to the exemplary embodiment of the present invention, when the ion energy transmitted to the plasma P transmitted to the substrate W is to be increased, the circuit unit 172 forms a parallel resonance circuit. The adjustment unit 170 can be controlled.

FIG. 8 is a view showing a state in which an inductor and a capacitor are connected in series according to the on/off of the switches of FIG. 5, and FIG. 9 is a diagram showing a change in the capacitance value of the capacitor when the inductor and the capacitor having the circuit of FIG. 5 are connected in series. This is a graph showing the change in the magnitude of the voltage applied to the lower electrode. 8 and 9, the controller 200 may connect the inductor L ₁ and the capacitor C ₁ in series _{by controlling the switches SW 1} , SW ₂ and SW _{3 as described above.} . For example, the first switch (SW ₁ ) and the third switch (SW ₃ ) are off, and the second switch (SW ₂ ) is on, so that the inductor (L ₁ ) and the capacitor (C ₁ ) are Can be connected in series. At this time, when the controller 200 _{adjusts the capacitance value of the capacitor C 1} , the magnitude of the voltage V flowing through the lower electrode 150 can be finely adjusted. In addition, the controller 200 may adjust the capacitance value of _{the capacitor C 1} so that the circuit unit 172 forms a series resonance circuit. When the circuit unit 172 forms a series resonance circuit, the voltage V applied to the lower electrode 150 becomes 0, and at this time, the current I applied to the lower electrode 150 becomes maximum. Accordingly, the change in the process result can be minimized by keeping the voltage V of the lower electrode 150 equal to 0 at all times. In addition, the density of the plasma P generated between the upper electrode 130 and the lower electrode 150 may be further increased. That is, in the substrate processing method according to an embodiment of the present invention, in the case of increasing the density of the plasma P generated between the upper electrode 130 and the lower electrode 150, the circuit unit 172 is in series. The impedance adjusting unit 170 may be controlled to form a resonance circuit.

In general, in an apparatus for processing a substrate using plasma, although the lower electrode is physically grounded, a non-zero voltage is applied to the lower electrode and a non-zero current flows. This is because there is a parasitic impedance formed between the lower electrode and the physical ground point. In this way, the parasitic impedance affects the substrate processing result. However, according to an embodiment of the present invention, the controller 200 minimizes the current I flowing through the lower electrode 150 by allowing the circuit unit 174 of the impedance control unit 170 to form a parallel resonance circuit. Alternatively, the magnitude of the current I can be adjusted. In addition, the maximum voltage may be applied to the lower electrode 150. In addition, the controller 200 prevents voltage from being applied to the lower electrode 150 by allowing the circuit unit 174 of the impedance control unit 170 to form a series resonance circuit, and the maximum current to the lower electrode 150 is I can make it flow. Accordingly, it is possible to minimize the problem that the above-described parasitic impedance affects the substrate processing result. In addition, as described above, by _{adjusting the capacitance value of the capacitor C 1} , the magnitude of the current flowing through the lower electrode 150 or the applied voltage may be finely adjusted. That is, an embodiment of the present invention provides an additional factor for processing the substrate W by adjusting the capacitance value of the _{capacitor C 1.} In addition, the present invention _{selectively connects the inductor (L 1} ) and the capacitor (C ₁ ) in series or parallel, and by adjusting the capacitance value of the _{capacitor (C 1 ),} It is possible to control the ion energy or the density of the plasma P generated on the substrate W.

The detailed description above is illustrative of the present invention. In addition, the above description shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications may be made within the scope of the concept of the invention disclosed in the present specification, the scope equivalent to the disclosed contents, and/or the skill or knowledge of the art. The above-described embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in the specific application fields and uses of the present invention are also possible. Therefore, the detailed description of the invention is not intended to limit the invention to the disclosed embodiment. In addition, the appended claims should be construed as including other embodiments.

Substrate processing equipment: 10
Vacuum Chamber: 11
Upper electrode: 12
Lower electrode: 13
Substrate processing equipment: 100
Vacuum Chamber: 110
Processing space: 112
Exhaust hole: 114
Upper electrode: 130
RF Power: 132
Power line: 134
Lower electrode: 150
Ground line: 154
Impedance control unit: 170
Sensor part: 172
Circuit Department: 174
Inductor: L ₁
Capacitor: C ₁
1st switch: SW ₁
2nd switch: SW ₂
3rd switch: SW ₃

Claims (14)

In the apparatus for processing a substrate using plasma,
A chamber having a processing space for processing the substrate;
An upper electrode disposed above the processing space;
A lower electrode disposed below the processing space and provided to face the upper electrode;
Includes an impedance adjusting unit connected to any one of the upper electrode and the lower electrode,
The impedance control unit,
Inductor;
Capacitors; And
Including at least one switch for selectively connecting the inductor and the capacitor in series or in parallel,
The switch,
Including a first switch, a second switch, and a third switch,
When the first switch and the third switch are turned on and the second switch is turned off, the inductor and the capacitor are connected in parallel,
When the first switch and the third switch are turned off and the second switch is turned on, the inductor and the capacitor are connected in series. The method of claim 1,
The capacitor,
A substrate processing device that is a variable capacitor whose capacitance value can be changed. The method of claim 2,
The device,
Further comprising a controller,
The controller,
A substrate processing apparatus for changing a capacitance value of the capacitor so that a circuit including the inductor, the capacitor, and the switch becomes a resonant circuit. The method of claim 2,
The device,
Further comprising a controller,
The controller,
The substrate processing apparatus for controlling the switch so that the inductor and the capacitor are connected in parallel. The method of claim 4,
The controller,
A substrate processing apparatus for changing a capacitance value of the capacitor so that a circuit including the inductor, the capacitor, and the switch becomes a parallel resonance circuit. The method of claim 2,
The device,
Further comprising a controller,
The controller,
The substrate processing apparatus for controlling the switch so that the inductor and the capacitor are connected in series. The method of claim 6,
The controller,
A substrate processing apparatus for changing a capacitance value of the capacitor such that a circuit including the inductor, the capacitor, and the switch becomes a series resonant circuit. delete The method according to any one of claims 3 to 7,
The impedance control unit,
A substrate processing apparatus further comprising a sensor unit for measuring voltage and/or current formed on the upper electrode or the lower electrode. In the method of processing a substrate using plasma with the substrate processing apparatus of claim 1,
Disposing the substrate between the upper electrode and the lower electrode, and processing the substrate by generating the plasma between the upper electrode and the lower electrode,
A substrate processing method for selectively connecting the inductor and the capacitor in series or in parallel. The method of claim 10,
The capacitor is a variable capacitor whose capacity value is variable,
The substrate processing method of connecting the inductor and the variable capacitor in parallel and changing a capacitance value of the capacitor. The method of claim 11,
A substrate processing method of changing a capacitance value of the variable capacitor so that the inductor and the variable capacitor connected in parallel form a parallel resonance circuit. The method of claim 10,
The capacitor is a variable capacitor whose capacity value is variable,
A substrate processing method for connecting the inductor and the variable capacitor in series and changing a capacitance value of the variable capacitor. The method of claim 13,
A substrate processing method of changing a capacitance value of the variable capacitor so that the inductor and the variable capacitor connected in series form a series resonance circuit.

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