KR100683253B1 - Matching device and plasma processing apparatus - Google Patents

Abstract

A matching device and a plasma processing apparatus are provided to transfer effectively an RF power to an upper electrode portion by controlling an inductor of the matching device using a fixing part capable of fixing both end portions of the inductor to a support body. A matching device is installed at a predetermined portion between upper or lower electrode portions(112,116) and an RF power source. The matching device includes a pair of support bodies, an inductor, and a fixing part. The pair of support bodies are arranged corresponding to an inductor installing position. The inductor is fixed to the support bodies through both end portions. The fixing part is used for fixing the both end portions of the inductor to the support bodies.

Description

MATCHING DEVICE AND PLASMA PROCESSING APPARATUS}

1 is a schematic cross-sectional view showing a general semiconductor plasma processing apparatus.

2 is an internal configuration diagram showing a conventional matching device.

3 is a schematic cross-sectional view showing a plasma processing apparatus according to the present invention.

4 is an internal configuration diagram showing a matcher equipped with an inductor according to the present invention.

5 is a view showing the fastening of the inductor and the inductor according to the present invention.

6 is a view showing a fastening means of the inductor according to the present invention.

Figure 7 is another embodiment showing the fastening of the inductor according to the present invention.

FIG. 8 is a cross-sectional view illustrating the A-A cross section of FIG. 7.

              <Description of the code | symbol about the principal part of drawings>

10, 100: vacuum chamber 12, 112: upper electrode portion

14, 114: substrate 16, 116: lower electrode portion

18a, 18b: high frequency power supply 24a, 24b: matching device

30, 130: load capacitor 32, 132: tuning capacitor

34, 134: inductors 36, 38, 136, 138: DC motor

40, 140: RF sensor 178: fastening hole

182: fastening member 186: fastener

The present invention relates to a matcher, and more particularly, to a matcher and a plasma processing apparatus for improving efficiency of high frequency power by providing an inductor having a specific shape and configured to adjust an inductance value.

As the semiconductor and display industries develop, processing of substrates such as wafers and glass is also progressing toward minimizing and integrating desired patterns in a limited area.

Generally, a semiconductor device is manufactured by forming an insulating film or a metal film on the surface of a semiconductor substrate such as a wafer, and then forming a pattern according to the characteristics of the semiconductor device on the film.

At this time, the pattern that can be formed on the surface of the substrate can be formed by completely removing or selectively removing the film formed on the substrate, which is mainly performed in the etching process.

In general, the initial etching process of semiconductors has been performed by wet etching using chemical solutions. However, as the degree of integration of circuits increases, the isotropic etching of wet etching reaches a limit, and dry etching using plasma is a technique to replace the etching process. The process is being applied.

The solution used for wet etching is mainly acid (ACID) and the activated acid chemically reacts with the film to be etched to vaporize and remove it. Although the effect of cleaning the surface is great, the role of the isotropic etching is limited to the cleaning process, while the etching process is being replaced by dry etching (dry etching) process using plasma. In addition, recently, it has been developed into a reactive ion etching process that further improves the efficiency of plasma.

1 is a schematic cross-sectional view showing a general semiconductor plasma device, and FIG. 2 is an internal configuration diagram showing a conventional matching device.

Referring to FIG. 1, the plasma processing apparatus includes an upper electrode 12 and a lower electrode 16 positioned opposite to the upper electrode 12 in the reaction chamber 10 and on which a semiconductor substrate 14 to be processed is seated. .

The upper electrode 10 includes an upper high frequency power source 18a for generating a high frequency, a high frequency output line 20 for applying a high frequency generated from the high frequency power source 18a to the reaction chamber 10, and the reaction chamber 10. ) Is formed in the upper electrode 12 for generating a plasma, and is connected between the upper high frequency power source 18a for applying high frequency power to the upper electrode 12 and the reaction chamber 10 to form a plasma forming apparatus. The upper matcher 24a which matches an impedance inside is comprised.

The lower high frequency power source 18b is connected to the lower electrode 16 when the lower high frequency power source 18b is connected to the lower electrode 16 through the lower matching unit 28b to the lower electrode 16. By the high frequency power is supplied. As a result, ions in the plasma are introduced to the lower electrode 16, whereby the anisotropy of etching is increased by ion assist. The lower high frequency power source 18b and the reaction chamber 10 are constituted by a lower matcher 24b for matching impedance.

Referring to FIG. 2, the matcher 24 includes the variable capacitors 30 and 32 and the inductor 34 for supplying the high frequency power supplied from the high frequency power source 18 to the reaction chamber 10, and the variable capacitor 30. And a match detection sensor 40 and a match detection sensor 40 for detecting whether or not the motors 36 and 38 for adjusting the capacity of the control unit 32 are matched with the high frequency power source 18 and the reaction chamber 10. And a control device 42 for driving and controlling the motors 36 and 38 to adjust the capacities of the variable capacitors 30 and 32 according to the sensed and inputted detection signals.

The variable capacitors 30 and 32 are mechanically variable in capacity by the motors 36 and 38, and the inductor 34 has a fixed inductor value.

The matcher 24 configured as described above, when the match detection sensor 40 inputs a detection signal for detecting whether the high frequency power source 18 and the reaction chamber 10 are matched to the control device 42, the control device ( 42 reacts with the high frequency power source 18 by adjusting the capacitance of the variable capacitors 30 and 32 by controlling the driving of the motors 36 and 38 according to the sensing signal input and detected by the matching sensor 40. The chamber 10 is matched to produce a plasma.

Conventional matcher 24 typically uses a vacuum variable condenser or variable coil, and drives the vacuum variable condenser or variable coil with a motor.

The vacuum variable capacitor or the variable coil as described above has a limitation in the variable range because resonance is generated by generating a necessary impedance for varying capacitance, and in particular, in order to match the impedance that varies widely according to the types and processes of various reaction chambers, There was a difficult problem such as enlarging the registration area or changing the location of the registration area.

In addition, the inductor value of the inductor can be taken as a variable, such a method of varying the inductance of the inductor is difficult, there is also the hassle of having to replace the variable inductor according to the input power.

Accordingly, the present invention has been made to solve the above problems, and provides a matching device having an inductor having a specific shape, and a matching device and a plasma processing apparatus capable of efficiently transferring power of the high frequency power supply to the upper electrode. It aims to provide.

In order to achieve the above object, the present invention provides a matching device connected between an upper or lower electrode portion of a plasma processing apparatus for plasma processing a substrate and a high frequency power supply, a pair provided at a position where an inductor is installed in the matching device. It is composed of a spaced apart support of the, an inductor which is formed in an open loop shape with both ends extending side by side and fixed to the support at any position on both sides of the side, and a fixture for fixing both ends of the inductor to the support.

Fastening holes are formed parallel to each other at both ends of the inductor, and the inductor is fixed to the support through the fastening holes. The fastening holes formed at both ends of each of the inductors may be one long hole extending in the extending direction of both ends.

The fastening holes formed at both ends of each of the inductors may include a plurality of holes spaced apart in the extending direction. The inductor is characterized in that the shape of any one of the open "U", "V", planar open loop, polygon.

3 is a schematic cross-sectional view showing a plasma processing apparatus according to the present invention.

Referring to the drawings, the plasma processing apparatus includes a reaction chamber 100, an upper electrode portion 112 disposed above the reaction chamber 100, and a lower electrode portion 116 facing the upper electrode portion 112. It consists of).

The reaction chamber 100 has a cylindrical shape whose surface is made of anodized aluminum, and the reaction chamber 100 is safety-grounded. Of course, the shape of the reaction chamber 100 is not limited to a cylindrical shape, and may be a cube shape.

An exhaust pipe 177 is connected to the side surface of the reaction chamber 100, and an exhaust device 176 is connected to the exhaust pipe 177. The exhaust device 176 is provided with a vacuum pump such as a turbo-molecular pump, and thus the inside of the reaction chamber 100 to a predetermined pressure reduction atmosphere, for example, to a predetermined pressure of 0.1 mTorr or less. It is configured to allow vacuum suction.

In addition, a gate valve 144 is provided on the side wall of the reaction chamber 100, and the substrate 114 is conveyed between adjacent load lock chambers while the substrate 114 is opened while the gate valve 144 is opened. It is.

The upper electrode portion 112 positioned above the reaction chamber 100 is supported on the upper portion of the reaction chamber 100 through an insulating material, and is disposed to face the lower electrode portion 116. The upper electrode portion 112 has a plurality of discharge holes 146 in the lower portion, for example, the upper electrode plate 148 made of aluminum, the upper electrode plate 148 is supported, and the surface is anodized aluminum and An electrode support 150 made of the same conductive material is provided.

The gas inlet 152 is provided in the electrode support 150 in the upper electrode part 112, and the gas supply source 152 is connected to this gas inlet 152. The gas source 152 is provided with a valve 154 and a mass flow controller 156, which is connected to the gas source 158. Reaction gas for plasma treatment is supplied from the gas source 158.

As the reaction gas, various ones conventionally used can be adopted. For example, a gas containing a halogen element such as a fluorocarbon gas or a hydrofluorocarbon gas may be appropriately used. In addition there may be added a rare gas (gas Rate) or N _2, such as Ar, He.

The upper high frequency power supply 118a is connected to the upper electrode portion 112 via the upper matcher 124a. The high frequency power of the upper high frequency power source 118a dissociates the reaction gas introduced into the upper electrode part 112 to form a plasma.

The lower electrode portion 116 facing the upper electrode portion 112 is positioned below the reaction chamber 100. The lower electrode unit 116 includes a substrate lift 160 positioned at the bottom of the reaction chamber 100, an electrostatic force for electrostatic adsorption of the lower electrode 162 and the substrate 114 on the upper surface of the substrate lift 160. It consists of a chuck 164.

A cooling passage is installed in the lower electrode 162, which is connected to the chiller 166.

The coolant is introduced into the lower electrode 162 through the coolant introduction pipe 168 and is discharged from the coolant discharge pipe 170 to circulate. The cold heat is transferred to the substrate 114 through the lower electrode 162, whereby the temperature of the processing surface of the substrate 114 is controlled to a desired temperature.

An electrostatic chuck 164 having substantially the same shape as the substrate 114 is provided on the upper surface of the lower electrode 162. The electrostatic chuck 164 has a lower electrode plate (not shown) provided between the insulating materials, and a DC voltage is applied from the high voltage DC power supply 172 connected to the lower electrode plate. In this case, the electrostatic chuck 164 may maintain the substrate 114 by a mechanical force in addition to the electrostatic force.

An outer circumferential surface of the lower electrode 162 and the electrostatic chuck 164 is provided with an annular focus ring 174 so as to surround the substrate 114 placed on the electrostatic chuck 164. The focus ring 174 is made of a conductive material such as silicon, thereby improving the uniformity of etching.

A lower high frequency power supply 118b is connected to the lower electrode 162, and a lower matcher 124b is provided between the lower high frequency power supply 118b and the lower electrode 162.

The upper and lower matchers 124a and 124b detect the impedance of the reaction chamber 100 and generate an impedance imaginary component of a phase opposite to the imaginary component of the impedance so that the impedance is equal to the pure resistance of the real component so that the reaction chamber 100 ) To supply the maximum power to generate an optimal plasma.

If the impedance for plasma generation is Z, Z is

It can be expressed as a complex number. In this equation, the R component is the real part, that is, the active component, and the X component represents the imaginary part, that is, the inactive component.

4 is an internal configuration diagram showing a matcher equipped with an inductor according to the present invention.

Referring to the drawings, the matching unit 124 provided between the high frequency power source 118 and the reaction chamber 100 includes an RF sensor 140, a load capacitor 130, a tuning capacitor 132, and an inductor 134. And the DC motors 136 and 138 and the control device 142.

The load capacitor 130 is used to match the active components, and the tuning capacitor 132 is used to match the reactive components. In addition, the inductor according to the present invention is also used for reactive component matching. The inductor will be described later.

The RF sensor 140 detects a high frequency current applied from the high frequency power source 118 or reflected from the reaction chamber 100 and transmits a signal to the control device 142.

Although the matching device is connected to the upper electrode part of the chamber, it may be connected to the lower electrode part.

The operation description of the matching unit 124 will be described with reference to FIG. 3. When power is applied from the high frequency power source 118, the RF sensor 140 operates to operate from the high frequency power and the load introduced from the high frequency power source 118. The return wave is sensed and a constant signal is transmitted to the control device 142.

When the control device 142 converts a signal received from the RF sensor 140 into an electric value and transmits the signal to the DC motors 136 and 138, the DC motors 136 and 138 are electrically connected to the control device 142. The capacitors 130 and 132 are adjusted according to the value of the signal.

In general, the impedance of a semiconductor device that generates a plasma using a parallel plate type electrode is not limited to a C value, but R, L, and C may be present at the same time in consideration of an atmosphere inside a process chamber and a line connected to the electrode.

Therefore, there is a phase difference between voltage and current due to L and C, and reflected waves are generated due to the phase difference, which makes it difficult to efficiently transmit power. Therefore, the capacitor inside the matching device and the inductor according to the present invention are effectively configured to attenuate the values of L and C which are ineffective components.

5 and 6 are diagrams illustrating an inductor of a matcher according to the present invention.

Referring to FIG. 5, the inductor 134 has an “U” shape in which one side is opened, and a plurality of screw fastening holes 178 to be electrically connected are formed in a straight line in the inductor 134 along the length direction. It is. As described above, by forming the fastening hole 178, the fastening position can be moved, and the magnitude of the inductance can be changed by changing the length of the inductor 134. In FIG. 5, only a plurality of circular holes are formed, and the number and spacing between them may be variously formed. In addition, the inductor may be implemented in various shapes such as a planar open loop shape, a “V” shape, and a polygonal shape instead of the “U” shape.

In order to fix the inductor 134 to the line 181, a pair of supports 180 spaced apart from each other by a predetermined distance is positioned on the line. The support 180 is fixed in the matching unit 124, and a fastening hole having a female thread is formed in the fastening hole 178 formed in the inductor 134 so that a fastener such as a screw or a bolt can be inserted therethrough. It is. The inductor 134 may be fixed at a predetermined position of the fastening hole 178 to adjust the value of the inductance.

As shown in FIG. 6, the fastening holes 179 may be two long holes spaced apart from each other, and these fastening holes may be formed of one fastening hole 179 connected to each other. This has the advantage that the fastening position can be arbitrarily set without separating the inductor 134 from the support 180 during fastening.

In addition, since the thickness and width of the inductor 134 can be adjusted according to the characteristics of the semiconductor device or the power supply, it is more effective than controlling the number of windings of the conventional coil or changing the inductor.

As described above, in the case of changing the impedance value according to the characteristics of the circuit and the values of the capacitors 30 and 32 and the value of the inductor 34 according to the related art, the values of the capacitors 30 and 32 are DC motors 36. It is possible to control by using the capacitor (30, 32) using, 38, it was difficult to change the value of the inductor (34).

However, by using the inductor 134 according to the present invention, it is possible to easily change the value of the inductor according to the impedance change not only the capacitors 130 and 132, but also the inductor 134.

Meanwhile, although the fastening holes 178 and 179 are formed inside the inductor 134 in the above-described embodiment, a structure for fastening the inductor to the support 180 without the same as the fastening hole is illustrated in FIGS. 7 and 8. It is.

Figure 7 is another embodiment showing the fastening of the inductor according to the present invention, Figure 8 is a cross-sectional view taken along the line A-A of FIG.

As shown in FIGS. 7 and 8, a support 180 is formed below the inductor 134, and a fastening member 182 is positioned above the inductor 134. The fastening member 172 is spaced apart from the inductor 134 by a predetermined distance so as not to interfere with the hole 184, and the fastening member 186, such as a screw, can be fastened after being inserted through the fastening member 182. have. Here, the inductance value can be adjusted while adjusting the position of the inductor 134 in the vertical direction.

Next, a process of the plasma processing apparatus will be described with reference to FIG. 3.

When the substrate 114 having completed the preceding process is loaded into the reaction chamber 100 from the gate valve 144 and seated on the electrostatic chuck 164 located in the reaction chamber 100, the substrate 114 from the high voltage direct current power source 172. ) Is electrostatically adsorbed. Thereafter, the lower electrode portion 116 on which the substrate 114 is seated is lifted from the substrate lift 160 in the direction of the upper electrode portion 112.

At this time, when the distance between the substrate 114 and the upper electrode portion 112 is several tens of mm, the substrate lift 160 stops the rise of the substrate 114, and the gas supply source 158 to the upper electrode portion 112. Start supplying reaction gas.

The reaction gas introduced into the upper electrode part 112 is uniformly sprayed toward the substrate 114 through the injection hole 146 of the upper electrode plate 148.

Thereafter, a high frequency current is applied to the upper electrode portion 112 from the upper high frequency power supply 118a through the upper matcher 124a. As a result, a high frequency electric field is generated between the upper electrode portion 112 and the lower electrode portion 116, and the reaction gas dissociates to become plasma.

On the other hand, when power is applied from the high frequency power source 118 in the matching unit 124, the RF sensor 140 operates to detect a high frequency power introduced from the high frequency power source 118 and the reflected wave coming back from the load to provide a constant signal. It transmits to the control apparatus 142.

When the control device 142 converts a signal received from the RF sensor 140 into an electric value and transmits the signal to the DC motors 136 and 138, the DC motors 136 and 138 are electrically connected to the control device 142. By adjusting the capacitors 130 and 132 and the inductor 134 according to the present invention according to the value of the signal, high frequency power is transmitted to the upper electrode portion 112 more efficiently.

Accordingly, ions are attracted to the substrate 114 side, and the reaction gas in the plasma state by the ion assist reacts with the film formed on the surface of the substrate 114 to selectively perform the plasma treatment such as dry etching selectively.

Thereafter, when the plasma processing is completed, the power supply is stopped from the high-voltage DC power supply 172 and the high frequency power supply 118a and 118b, and the substrate 114 is taken out of the reaction chamber 100 through the gate valve 144 to perform the process. It is finished.

As described above, the matching device according to the present invention includes an inductor, and the inductor includes a fastening means capable of adjusting a position.

Therefore, the present invention can change the value of the inductor of the matcher, which has the effect of effectively impedance matching.

Claims (5)

In the matching device connected between the upper or lower electrode portion and the high frequency power supply of the plasma processing apparatus for plasma processing the substrate, A pair of spaced support provided at a position where the inductor is to be installed in the matching unit; An inductor formed in an open loop shape with both ends extending side by side and fixed to the support at an arbitrary position on both sides of the side, Fixtures for fixing both ends of the inductor to the support Matching apparatus comprising a. 2. The fastening hole is formed at both ends of the inductor in parallel to each other, the inductor is fixed to the support through the fastening hole, and the fastening holes formed at both ends of each of the inductors extend in the extending direction of both ends. A matching device, characterized in that one long hole. The method of claim 1, wherein fastening holes are formed at both ends of the inductor in parallel to each other, and the inductor is fixed to the support through the fastening holes, and the fastening holes formed at both ends of each of the inductors are spaced apart in the extending direction. A matching device comprising a hole. The matcher according to any one of claims 1 to 3, wherein the inductor has a shape of any one of "U", "V", planar open loop, and polygon with one open. A plasma processing apparatus for plasma processing a substrate, Chamber, An upper electrode portion and a lower electrode portion located opposite to the chamber; A high frequency power source to which high frequency power is applied to the upper electrode part and the lower electrode part; Claims 1 to 3 between the upper or lower electrode portion and the high frequency power supply comprises a matching device according to any one of claims 1 to 3.

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