Substrate Processing Equipment

Abstract

A substrate processing apparatus according to an embodiment of the present invention includes a process chamber providing a reaction space therein and including a substrate entrance / exit through which a substrate is introduced, a susceptor disposed within the process chamber and supporting the substrate, a gas injector disposed on an opposite surface of the susceptor and injecting gas toward the substrate, a valve for opening and closing the substrate entrance / exit, and a control electrode formed on the valve. In the present invention, the control electrode can be driven vertically.

Description

[Technical Field]

[0001] The present invention relates to a plasma substrate processing apparatus, and more particularly to a substrate processing apparatus capable of providing a uniform process environment throughout the reaction space of a process chamber. [Background technology]

[0002] A typical substrate processing apparatus includes a process chamber for processing a substrate using, for example, plasma, and a transfer chamber into which a substrate before processing is loaded or into which a processed substrate is unloaded.

[0003] In the case of the process chamber, a slot is formed in one sidewall through which a substrate is loaded or unloaded, and the slot is generally opened and closed by a slot valve disposed outside the slot or outside the chamber.

[0004] When a substrate processing process is performed, the interior of the process chamber, i.e., the reaction space, must be maintained at a process environment such as a vacuum, and a uniform process environment must be applied throughout the reaction space.

[0005] Generally, the reaction space has an opening connected to a slot through which a substrate is loaded or unloaded, and the slot is opened or closed by an external slot valve. Therefore, even when the slot is closed by the external slot valve, an empty space is formed between the slot valve and the opening.

[0006] The empty space is connected to the reaction space, and as a result, the reaction space is formed asymmetrically by the empty space, which makes it difficult to form a uniform process environment overall.

[0007] When plasma is generated in the reaction space, it is difficult for the plasma to be distributed uniformly within the reaction space due to the influence of empty spaces, and it is therefore difficult for the etching or deposition to proceed uniformly over the entire surface of the substrate.

[0008] In plasma-assisted thin film deposition, thin film uniformity is affected by various factors, such as chamber structural asymmetry, substrate temperature nonuniformity, pumped gas flow patterns, and plasma nonuniformity. In particular, local plasma nonuniformity is affected by chamber structural asymmetry and electrical characteristics, as well as pumped gas flow patterns.

[0009] In plasma processing, although the structural azimuthal symmetry of the chamber is improved by employing a valve that provides the same inner surface as the chamber, local process non-uniformity still exists. For example, in a valve-free environment, the chamber interior is perfectly symmetric. However, the necessary substrate access points make it difficult to achieve perfect chamber symmetry. That is, even if the valve provides the same curved surface as the chamber interior, an O-ring is present at the interface between the valve and chamber, making it difficult to achieve 100% symmetry due to this interface. Furthermore, the electrical characteristics of the valve and the chamber are different, and the RF current does not flow azimuthal symmetrically, resulting in local process non-uniformity. Therefore, a method for controlling local non-uniformity due to differences in electrical characteristics is needed. Summary of the Invention [Problem to be solved by the invention]

[0010] The technical problem to be solved by the present invention is to control local process non-uniformity on a substrate by inserting a control electrode adjacent to an inner wall of a chamber and applying power to the control electrode.

[0011] The technical problem to be solved by the present invention is to provide a uniform process environment within a reaction space by using a chamber-integrated slot valve to prevent the reaction space from being connected to a slot when performing a plasma semiconductor process on a substrate, and to control any remaining local process non-uniformity using a control electrode formed on the opening and closing blade of the slot valve.

[0012] The technical problem to be solved by the present invention is to form a reaction space of a substrate processing apparatus symmetrically when performing a semiconductor process on a substrate, and to make a plasma process environment uniform within the reaction space, thereby allowing the process to proceed uniformly on the front surface of the substrate.

[0013] The technical problem to be solved by the present invention is to control local process non-uniformity of a substrate by inserting a valve that provides a curved surface identical to the inner surface of a chamber and connecting the valve to an impedance circuit to change its electrical characteristics. [Means for solving the problem]

[0014] A substrate processing apparatus according to an embodiment of the present invention includes a process chamber providing a reaction space therein and including a substrate entrance / exit through which a substrate enters and exits, a susceptor disposed within the process chamber and supporting the substrate, a gas injector disposed on an opposite surface of the susceptor and injecting gas toward the substrate, a valve for opening and closing the substrate entrance / exit, and a control electrode formed on the valve. In this embodiment of the present invention, the control electrode can be moved up and down.

[0015] In one embodiment of the present invention, the valve includes a blade that opens and closes the substrate entrance and has an inner surface that is the same as the inner surface of the process chamber, and a driver that raises and lowers the blade. The control electrode is formed on the blade.

[0016] In one embodiment of the invention, the blade is connected to ground or to an impedance circuit by a first switch.

[0017] In one embodiment of the present invention, the impedance circuit is a parallel-connected LC circuit or a series-connected LC circuit, and a capacitor constituting the LC circuit is variable.

[0018] In one embodiment of the present invention, the control electrode is connected to a power supply.

[0019] In one embodiment of the present invention, the power supply unit includes at least one of a positive DC power supply, a negative DC power supply, and an RF power supply.

[0020] In one embodiment of the present invention, the device further includes a second switch connecting the power supply unit or ground to the control electrode, and the second switch selects one of a positive DC power supply, a negative DC power supply, ground, and an RF power supply.

[0021] A substrate processing apparatus according to an embodiment of the present invention includes a process chamber providing a reaction space therein, a susceptor disposed within the process chamber to support a substrate, a gas injector disposed opposite the susceptor to inject gas toward the substrate, and a valve having an inner surface flush with the inner surface of the process chamber and opening and closing a substrate inlet / outlet of the process chamber. The valve includes a blade that opens and closes the substrate inlet / outlet and has an inner surface flush with the inner surface of the process chamber, and a driver that raises and lowers the blade. The blade is connected to ground or an impedance circuit by a switch. [Effects of the Invention]

[0022] The substrate processing apparatus according to the present invention provides a uniform process environment throughout the reaction space of the chamber by using a control electrode, and suppresses particle generation.

[0023] The substrate processing apparatus according to the present invention controls local process non-uniformity of the substrate by inserting a valve that provides the same curved surface as the inner wall of the chamber and connecting the valve to an impedance circuit to change electrical characteristics. DETAILED DESCRIPTION OF THE INVENTION

[0024] A substrate processing apparatus according to an embodiment of the present invention includes a process chamber, a substrate inlet / outlet formed in a sidewall of the process chamber, and a valve for opening and closing the substrate inlet / outlet. The valve includes a blade for opening and closing the substrate inlet / outlet and a driver for raising and lowering the blade. The blade provides an inner surface of the process chamber between a bottom surface of the process chamber and the substrate inlet / outlet. That is, the blade provides an inner surface that is identical to the inner surface of the process chamber. Therefore, the inner surface of the blade and the inner surface of the process chamber are continuously connected to improve structural symmetry. The structural symmetry provides symmetry in gas flow and gas exhaust, thereby improving process uniformity.

[0025] Meanwhile, contaminants are deposited on the inner surface of the blade during processing. As the blade moves up and down, the contaminants are detached and generate particles. If the particles are attached to the substrate in the processing chamber, the particles can cause device defects.

[0026] When plasma is generated in the process chamber, the process chamber is maintained at a predetermined temperature and electrically grounded. Meanwhile, the blade is not electrically connected to the process chamber but contacts it via a sealing means such as an O-ring. As a result, the blade provides different electrical characteristics from the process chamber, thereby providing locally different plasma characteristics.

[0027] Therefore, a method is needed to suppress the deposition of contaminants on the braid and control the electrical characteristics of the braid. Contaminants on the braid are removed by sputtering due to ion incidence from the plasma. A control electrode is formed on the inner surface of the braid, and DC or RF power is applied to the control electrode. When a positive DC voltage is applied to the control electrode, it repels positive ions from the plasma diffused in the reaction space, suppressing the deposition of contaminants and changing the local plasma characteristics. When a negative DC voltage is applied to the control electrode, it attracts positive ions from the plasma diffused in the reaction space, sputtering contaminants, suppressing the deposition of contaminants and changing the local plasma characteristics. When RF power is applied to the control electrode, a separate plasma is generated on the surface of the control electrode, sputtering contaminants and changing the local plasma characteristics.

[0028] When a susceptor is located at the center of the process chamber, the susceptor receiving RF power and the grounded gas injection unit face each other to form a main capacitor, and the susceptor and the wall of the process chamber form a parasitic capacitor. When a braid is disposed on the sidewall of the process chamber, azimuthal asymmetry of the parasitic capacitor occurs. That is, a deviation in parasitic impedance between the susceptor and the grounded sidewall of the process chamber occurs depending on the azimuthal angle. This deviation in parasitic impedance affects the RF current flowing through the parasitic capacitor. The RF current affects the distribution of plasma density, resulting in azimuthal non-uniformity of the plasma density. To overcome the azimuthal non-uniformity of the plasma density due to the parasitic impedance, DC power or RF power is intentionally applied to the control electrode disposed on the braid. For example, if the plasma density is locally low in the direction of the braid due to the parasitic impedance of the braid, a negative DC voltage is applied to the control electrode. When the negative voltage is sufficiently low, at the level of a few volts, the control electrode charged with a negative DC voltage controls the local plasma density non-uniformity by attracting positive ions or pushing out electrons.

[0029] On the other hand, if the plasma density is locally high in the direction of the blade due to the parasitic impedance of the blade, a positive voltage is applied to the control electrode. The control electrode, which is charged with a positive voltage, controls the local non-uniformity of the plasma density by attracting electrons or pushing out positive ions.

[0030] When RF power is applied to the control electrode, the control electrode operates as a new plasma source to control the non-uniformity of the plasma density.

[0031] According to one embodiment of the present invention, the blade is connected to ground or an impedance circuit. The impedance circuit includes LC circuits connected in parallel or in series. The capacitor of the impedance circuit blocks DC current flowing from the blade to ground. The capacitor of the impedance circuit also passes RF current. The inductor of the impedance circuit passes RF current in opposite phase to the capacitor. Thus, the impedance circuit changes the impedance between the blade and ground, thereby locally changing the characteristics of the plasma.

[0032] The present invention will now be described in more detail with reference to the accompanying drawings. The present invention will be described in more detail with reference to preferred embodiments. However, it will be apparent to those skilled in the art that these embodiments are provided to more specifically illustrate the present invention and are not intended to limit or restrict the present invention in any way by experimental conditions, types of materials, or the like. The present invention is not limited to the embodiments described herein, and may be embodied in different forms. Rather, the embodiments described herein are provided so that the disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art. In the drawings, the dimensions of elements may be exaggerated for clarity. The same reference numerals will be used throughout the specification to refer to the same elements.

[0033] FIG. 1 is a perspective view illustrating a substrate processing apparatus according to an embodiment of the present invention.

[0034] FIG. 2 is a cross-sectional view taken along line AA' in FIG.

[0035] FIG. 3 is a conceptual diagram showing the substrate processing apparatus of FIG.

[0036] As shown in Figures 1 to 3, the substrate processing apparatus 100 includes a process chamber 110 that provides a reaction space 110a therein and includes a substrate entrance / exit 112 through which a substrate 152 enters and exits, a susceptor 150 disposed inside the process chamber 110 and supporting the substrate 152, a gas injection unit 160 disposed on the opposite side of the susceptor 150 and injecting gas toward the substrate 152, a valve that opens and closes the substrate entrance / exit, and a control electrode formed on the valve.

[0037] The substrate processing apparatus 100 performs a deposition process or an etching process.

[0038] The process chamber 110 has a substrate inlet / outlet 112 on at least one sidewall to form a reaction space 110a. The process chamber 110 has a rectangular parallelepiped shape, and the reaction space 110a has a cylindrical structure. The process chamber 110 includes a bottom surface 111b and a sidewall 111a.

[0039] A gas injector 160 is disposed on the open top surface of the process chamber 110. The gas injector 160 functions as a chamber lid. The gas injector 160 receives RF power to form plasma. The process chamber 110 is evacuated by a pump 169. The process chamber 110 is electrically grounded.

[0040] The substrate entrance 112 is connected to the reaction space 110a through a sidewall of the process chamber 110. The substrate entrance 112 is connected to an opening 113 in which a blade 121 is disposed. The blade 121 moves up and down to open and close the substrate entrance 112. The substrate entrance 112 provides structural asymmetry to the process chamber 110.

[0041] The gas injector 160 includes a plurality of nozzles and injects gas from a gas supply into the reaction space 110a. The gas injector 160 receives RF power from an external source to form plasma. A first RF power source 162 supplies RF power to the gas injector 160 through a first impedance matching network (not shown).

[0042] The susceptor 150 includes a heater (not shown) that mounts the substrate 152 and heats it to a predetermined temperature. The susceptor 150 moves vertically up and down. The susceptor 150 also includes an electrostatic chuck (not shown) for fixing the substrate. The susceptor 150 receives RF power from an external source to form plasma and adjust the energy incident on the substrate. A second RF power source 166 supplies RF power to the susceptor 150 through a second impedance matching network (not shown).

[0043] The valve 120 is disposed on the inner surface of the process chamber and opens and closes the substrate entrance 112. The valve 120 suppresses the structural asymmetry of the process chamber 110.

[0044] The valve 120 includes a blade 121 that opens and closes the substrate entrance 112 and a driver 129 that raises and lowers the blade 121. The driver 129 is connected to and supported by a separate housing on the sidewall or bottom of the process chamber. The blade 121 is inserted into an opening 113 formed in the sidewall of the process chamber 110, and provides an inner surface 122a that is identical to the inner surface of the process chamber.

[0045] The blade 121 is grounded or connected to an impedance circuit 184. The impedance circuit 184 includes LC circuits connected in parallel or in series with each other.

[0046] When the impedance circuit 184 includes a capacitor and an inductor connected in series, the impedance of the impedance circuit 184 forms a resonant circuit that minimizes the impedance at the driving frequency. The impedance circuit 184 having the minimum impedance increases the RF current flowing through the braid, and the braid is stably grounded to stabilize the plasma. That is, the braid is controlled by the impedance circuit 184 to have the same electrical characteristics as the wall of the process chamber. The impedance circuit 184 is an LC series resonant circuit so that the braid provides the same electrical characteristics as the inner wall of the process chamber when it is not contaminated.

[0047] On the other hand, when the impedance circuit 184 includes a capacitor and an inductor connected in parallel, the impedance of the impedance circuit 184 forms a resonant circuit whose impedance is maximized at the driving frequency. Therefore, the impedance circuit 184 increases the impedance between the braid 121 and ground, reducing the RF current flowing through the braid 121, thereby allowing more RF current to flow through the wall of the process chamber. This locally changes the plasma characteristics. The impedance circuit 184 is an LC parallel resonant circuit so that the braid provides electrical characteristics similar to those of the heavily contaminated inner wall of the process chamber.

[0048] A first switch 182 selects between the ground and the first impedance circuit 184. The capacitor of the impedance circuit 184 is variable to adjust the RF current flowing from the blade to ground. The impedance circuit 184 changes the impedance between ground and the blade 121 to change the local plasma characteristics.

[0049] The blade 121 is not electrically connected to the process chamber 110 but contacts it via a sealing means such as an O-ring. As a result, the blade 121 provides different electrical characteristics from the process chamber 110, thereby providing locally different plasma characteristics. To control the plasma characteristics of the blade 121, the blade 121 is grounded or connected to ground through the impedance circuit 184.

[0050] The control electrode 130 is formed on the inner surface 122a of the braid 121. The control electrode 130 is disposed with an insulating layer 132 interposed between the braid 121 and the control electrode 130 for insulation. The control electrode 130 is formed in an arc-shaped band along the azimuthal direction of the inner surface 122a. The control electrode 130 is disposed adjacent to the upper surface of the opening 113 and interacts with the plasma in the reaction space. The area of ​​the control electrode is several tenths or less of the area of ​​the wall of the process chamber. In this case, the voltage applied to the control electrode has little effect on the plasma potential but changes the local plasma density distribution.

[0051] A DC power supply 174, ground, or RF power supply 176 is selectively connected to the control electrode 130 through a second switch 172. The DC power supply 174 may be a positive DC power supply or a negative DC power supply.

[0052] During the process, contaminants are deposited on the inner surface of the blade 121. As the blade 121 moves up and down, the contaminants are detached and generate particles. If the particles adhere to the substrate in the process chamber, the particles can cause device defects.

[0053] A method is required to suppress contaminant deposition on the blade 121 and control the electrical characteristics of the blade 121. DC power or RF power is applied to the control electrode 130. When a positive DC voltage is applied to the control electrode 130, it repels positive ions from the plasma diffused in the reaction space 110a, thereby suppressing contaminant deposition or changing local plasma characteristics. When a negative DC voltage is applied to the control electrode 130, it attracts positive ions from the plasma diffused in the reaction space 110a, thereby sputtering contaminants, thereby suppressing contaminant deposition or changing local plasma characteristics. When RF power is applied to the control electrode 130, a separate plasma is generated on the surface of the control electrode 130, thereby sputtering contaminants or changing local plasma characteristics. This improves the azimuthal symmetry of the plasma and increases substrate processing uniformity.

[0054] FIG. 4 is a conceptual diagram illustrating a substrate processing apparatus according to another embodiment of the present invention.

[0055] As shown in FIG. 4, the substrate processing apparatus 100a includes a process chamber 110 providing a reaction space 110a therein, a susceptor 150 disposed inside the process chamber 110 and supporting a substrate 152, a gas injection unit 160 disposed on the opposite side of the susceptor 150 and injecting gas toward the substrate 152, and a control electrode 230 locally formed on the outside of the susceptor 152 or on a curved surface that is the same as the inner surface of the process chamber 110.

[0056] The control electrode 230 is not formed on the inner surface 122a of the blade 121, but is formed on a separate control electrode support 232 and locally disposed outside the susceptor 152. The control electrode 230 has the same shape as that described in FIG. 1. The control electrode 230 is locally disposed to face the blade 121. The control electrode support 232 is rotated in the azimuth direction by a rotating means (not shown) to allow the substrate to enter and exit, and then the control electrode support 232 is rotated again to align the blade 121 to face the blade 121 for the process to proceed.

[0057] Although the present invention has been illustrated and described above with respect to specific preferred embodiments, the present invention is not limited to such embodiments and includes all of the various forms of embodiments that can be implemented by a person having ordinary skill in the art to which the invention pertains without departing from the technical concept of the present invention as claimed in the claims. [Brief explanation of the drawings]

[0058] [Figure 1] 1 is a perspective view illustrating a substrate processing apparatus according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the substrate processing apparatus taken along line AA' in FIG. [Figure 3] FIG. 2 is a conceptual diagram showing the substrate processing apparatus of FIG. [Figure 4] FIG. 10 is a conceptual diagram illustrating a substrate processing apparatus according to another embodiment of the present invention.

Claims

1. a process chamber providing a reaction space therein and including a substrate inlet / outlet through which a substrate is introduced; a susceptor disposed within the process chamber and supporting the substrate; a gas injection unit disposed on a surface of the susceptor facing the substrate and configured to inject gas toward the substrate; A valve for opening and closing the substrate entrance; a control electrode formed on the valve; The valve is a blade for opening and closing the substrate entrance and having an inner surface identical to an inner surface of the process chamber.

2. 2. The substrate processing apparatus according to claim 1, wherein the control electrode can be driven vertically.

3. The valve is A drive unit that raises and lowers the blade is included. The substrate processing apparatus according to claim 1 , wherein the control electrode is formed on the blade.

4. The substrate processing apparatus according to claim 3 , wherein the blade is connected to ground or an impedance circuit by a first switch.

5. The impedance circuit is a parallel-connected LC circuit or a series-connected LC circuit, 5. The substrate processing apparatus according to claim 4, wherein a capacitor constituting the LC circuit is variable.

6. A process chamber providing a reaction space therein and including a substrate inlet / outlet through which a substrate enters and leaves; a susceptor disposed within the process chamber and supporting the substrate; a gas injection unit disposed on a surface of the susceptor facing the substrate and configured to inject gas toward the substrate; A valve for opening and closing the substrate entrance; a control electrode formed on the valve; The substrate processing apparatus is characterized in that the control electrode is connected to a power supply unit.

7. 7. The substrate processing apparatus according to claim 6, wherein the power supply unit includes at least one of a positive DC power supply, a negative DC power supply, and an RF power supply.

8. a second switch connecting the power supply unit or ground to the control electrode; 8. The substrate processing apparatus of claim 7, wherein the second switch selects one of a positive DC power supply, a negative DC power supply, a ground, and an RF power supply.

9. The valve, a blade for opening and closing the substrate entrance and having an inner surface identical to an inner surface of the process chamber; A drive unit that raises and lowers the blade, The substrate processing apparatus according to claim 6 , wherein the control electrode is formed on the blade.

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