Plasma modulation apparatus for substrate processing system

Abstract

To provide a plasma modulation apparatus for use in a substrate processing system.SOLUTION: The apparatus comprises a plurality of radio frequency (RF) paths connected to N different meshes, where a susceptor of the substrate processing system is divided into the N different meshes and N is an integer equal to or greater than 2. Each of the RF paths comprises: an RF rod connected to a mesh and configured to transmit an RF signal from the meshes; a Voltage-Current (VI) sensor connected to the RF rod and configured to measure a current from the RF rod; and a variable impedance circuit connected to the VI sensor and configured to change an impedance of the RF path and further configured to be grounded. Each of the RF paths are grounded separately and corresponds to a respective different mesh.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing system, and more particularly to an apparatus for adjusting a plasma environment inside a reaction chamber of a substrate processing system. [Background technology]

[0002] The deposition and sputter uniformity on the wafer is closely related to the plasma profile, such as density, in the reaction chamber. Any non-uniformity in the plasma profile directly affects the deposition and sputter uniformity on the wafer in the plasma-enhanced atomic layer deposition (PEALD) process.

[0003] The present disclosure provides plasma conditioning hardware that can solve the problem of non-uniformity across the wafer during PEALD or sputtering processes.

[0004] The present disclosure provides an apparatus for achieving across-wafer uniformity for deposition and sputtering by adjusting the impedance of a radio frequency (RF) return path to the ground surface. Summary of the Invention

[0005] This Summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in more detail in the Detailed Description of the exemplary embodiments of the disclosure below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] According to one embodiment, a plasma conditioning apparatus for use in a substrate processing system may be provided, the apparatus comprising a plurality of radio frequency (RF) paths connected to N different meshes, a susceptor of the substrate processing system being divided into N different meshes, N being an integer equal to or greater than 2, each of the RF paths comprising an RF rod connected to the mesh and configured to transmit an RF signal from the mesh, a voltage-current (VI) sensor connected to the RF rod and configured to measure a current from the RF rod, and a variable impedance circuit connected to the VI sensor and configured to change an impedance of the RF path and further configured to be grounded, each of the RF paths being separately grounded, each of the RF paths respectively corresponding to a different mesh.

[0007] According to another embodiment, an apparatus may be provided that further comprises an RF filter configured to filter out noise from the RF rod.

[0008] According to another embodiment, an apparatus may be provided that further includes a controller coupled to each of the RF paths and configured to monitor a current in each of the VI sensors and alter the impedance of each of the RF paths based on the monitored current.

[0009] In at least one embodiment, the controller is configured to vary the impedance of each of the RF paths to be equal.

[0010] According to another embodiment, a substrate processing system includes a reaction chamber having a showerhead and a susceptor for supporting a wafer, the reaction chamber having the susceptor divided into N different meshes, N being an integer equal to or greater than 1; and a plasma conditioning device including a plurality of radio frequency (RF) paths connected to the N different meshes, each of the RF paths including an RF rod connected to the mesh and configured to transmit an RF signal from the mesh, a voltage-current (VI) sensor connected to the RF rod and configured to measure a current from the RF rod, and a variable impedance circuit connected to the VI sensor and configured to change an impedance of the RF path, the variable impedance circuit further configured to be grounded, each of the RF paths being separately grounded, each of the RF paths corresponding to a different mesh.

[0011] According to another embodiment, a system may be provided that further comprises an RF filter configured to filter out noise from the RF rod.

[0012] According to another embodiment, a system may be provided that further includes a controller connected to each of the RF paths and configured to monitor a current in each of the VI sensors and alter the impedance of each of the RF paths based on the monitored current.

[0013] In at least one embodiment, the controller of the system is configured to vary the impedance of each of the RF paths to be equal.

[0014] According to another embodiment, a method for adjusting a plasma in a substrate processing system may be provided, the system comprising: a reaction chamber having a susceptor disposed therein, the susceptor being divided into N different meshes, N being an integer equal to or greater than 1; and a plasma adjusting apparatus including a plurality of radio frequency (RF) paths connected to the N different meshes, each of the RF paths being disposed with an RF rod, a voltage and current (VI) sensor, and a variable impedance circuit, the method including: monitoring currents of all the VI sensors from each of the RF paths; determining whether it is true that the monitored currents have the same value; if it is determined to be false, changing the impedances of the variable impedance circuits from each of the RF paths to be equal; and if it is determined to be true, repeating the determination.

[0015] In at least one embodiment, the method further comprises filtering noise from each of the RF rods. [Brief description of the drawings]

[0016] It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale, for example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure.

[0017] [Figure 1] FIG. 1 is a top-down schematic diagram of a susceptor (heater) having three meshes according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating a system overview of a substrate processing system according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 is a detailed view of the plasma profile in the reaction chamber and three meshes of the susceptor according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a detailed view of a plasma conditioning apparatus according to one embodiment of the present disclosure. [Diagram 5]FIG. 5 is a flow chart of a method of plasma regulation according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious modifications and equivalents thereof, and therefore it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0019] As used herein, the term "substrate" may refer to any underlying material or materials, including any underlying material or materials, on which a device, circuit, or film may be formed, that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous, rigid or flexible, solid or porous, and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. Substrates in the form of plates may include wafers of various shapes and sizes. Substrates may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0020] As an example, the substrate in powder form may have applications for pharmaceutical manufacturing. The porous substrate may include a polymer. Examples of workpieces may include medical devices (e.g., stents and syringes), jewelry, tooling devices, components for battery manufacturing (e.g., anodes, cathodes, or separators), or components of photovoltaic cells, etc.

[0021] The continuous substrate may extend beyond the boundaries of the process chamber in which the deposition process occurs. In some processes, the continuous substrate may move through the process chamber so that the process continues until the edge of the substrate is reached. The continuous substrate may be supplied from a continuous substrate supply system to enable the production and output of the continuous substrate in any suitable form.

[0022] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, webs, flexible materials, bundles of continuous filaments or fibers (e.g., ceramic or polymeric fibers). Continuous substrates may also include carriers or sheets onto which a non-continuous substrate is placed.

[0023] The illustrations presented herein are not meant to be actual representations of any particular materials, structures, or devices, but merely idealized representations used to describe embodiments of the present disclosure.

[0024] The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, association, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in an actual system and / or may not be present in some embodiments.

[0025] It should be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be taken in a limiting sense, as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Thus, the various illustrated operations may be performed in the order illustrated, in other orders, or omitted in some cases.

[0026] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations and / or properties disclosed herein, as well as all equivalents thereof.

[0027] 1, the susceptor 100 may be illustrated in detail. The susceptor 100 may be divided into three regions (meshes), such as a background mesh (mesh #1) 110, a left mesh (mesh #2) 120, and a right mesh (mesh #3) 130. Alternatively, the heater may be subject to mesh division depending on the system requirements.

[0028] FIG. 2 shows an overview of the present disclosure.

[0029] The substrate processing system 200 may include a reaction chamber 201 having a showerhead 213, a susceptor 216, a heater coil 217, an RF generator 210, and a matching unit 211, a plasma conditioner 224, and a controller 225. Between the showerhead 213 and the susceptor 216, a space 214 for the generated plasma may be formed, and a wafer 215 may be placed on the susceptor 216 so that the wafer 215 can be processed with the plasma and reactive gases (not shown).

[0030] The top of the susceptor 216 may be divided into several different meshes, and for simplicity three meshes may be used in the description of this disclosure.

[0031] The susceptor 216 may be divided into three meshes 221, 222, 223, like the susceptor 100 of Figure 1. Each of the meshes 221, 222, 223 is connected to a plasma conditioning device 224 by three RF rods 231, 232, 233.

[0032] 3 and 4 explain different aspects of the system and device in more detail.

[0033] 3 shows a detailed view of a reaction chamber 300 and a space 314 containing a plasma profile therein, as well as three meshes 321, 322, 323 of a susceptor 316. In this reaction chamber 300 of a substrate processing system, a plasma in the space 314 may be generated between an upper electrode (showerhead) 313 and a lower electrode (susceptor) 316. A wafer 315 may be placed on the susceptor 316.

[0034] In order to adjust the plasma profile in the space 314, the susceptor 316 may be divided into several regions. As shown in FIG. 3, the number of divided regions of the susceptor 316 is three. However, there may be more than three regions based on the needs. The susceptor 316 may be equipped with different meshes 321, 322, 323. The three meshes 321, 322, 323 may be installed just under the surface of the susceptor 316. Alternatively, the meshes can be installed on the surface of the susceptor 316 based on the system requirements.

[0035] The left mesh (mesh #2) 322 may be mainly affected by the plasma profile at its upper right, i.e. (P2), while the right mesh (mesh #3) 323 is affected by the plasma profile (P3). Also, the background mesh (mesh #1) 321 may be affected by the plasma profile (P1). Each mesh 321, 322, 323 may be connected to an RF rod 331, 332, 333, respectively.

[0036] FIG. 4 illustrates a plasma conditioning apparatus according to one embodiment of the present disclosure.

[0037] A number of RF rods 401, 402, 403 are attached to meshes #1, #2, #3, respectively. Each of the RF rods may be connected to a VI sensor (voltage and current sensor) 451, 452, 453 that can measure the plasma voltage and current traveling from the mesh.

[0038] The VI sensor 451 may be connected to a variable impedance circuit 441 that can change the impedance of the electrical path established from the RF rod 401 to the surface 461, and the variable impedance circuit 441 may include at least one of a coil, a capacitance, or a variable capacitance for changing the impedance. The variable impedance circuit 441 is to be grounded to the surface 461. In the VI sensor 451, a current is measured (i1), which reflects the plasma profile (P1).

[0039] The VI sensor 452 may be connected to a variable impedance circuit 442 that can change the impedance of the electrical path established from the RF rod 402 to the surface 462, and the variable impedance circuit 442 may include at least one of a coil, a capacitance, or a variable capacitance for modifying the impedance. The variable impedance circuit 442 is to be grounded to the surface 462. In the VI sensor 452, a current is measured (i2), which reflects the plasma profile (P2).

[0040] The VI sensor 453 may be connected to a variable impedance circuit 443 that can change the impedance of the electrical path established from the RF rod 403 to the surface 463, and the variable impedance circuit 443 may include at least one of a coil, a capacitance, or a variable capacitance for changing the impedance. The variable impedance circuit 443 is to be grounded to the surface 463. In the VI sensor 453, a current is measured (i3), which reflects the plasma profile (P3).

[0041] The plasma uniformity in the reaction chamber 300 may be expressed as "P1=P2=P3" (Condition 1).

[0042] To make the plasma profile in the chamber uniform (i.e., P1=P2=P3), the currents measured by the VI sensors 451, 452, 453 shall be the same. Therefore, the currents i1, i2, i3 can be adjusted to be the same between them by changing the impedance of the variable impedance circuits 441, 442, 443.

[0043] This same current of i1, i2, i3 may be expressed as "i1=i2=i3" (condition 2), and if "condition 1" (P1=P2=P3) is satisfied, then "condition 2" (i1=i2=i3) is satisfied.

[0044] There may be multiple paths (as shown in FIG. 4) from the mesh to the surface of the Earth, and each path may be referred to as an RF path. Thus, the number of RF paths may be equal to the number of meshes. As an example, there are three RF paths in FIG. 4. RF path #1 may include RF rod 401, VI sensor 451, and variable impedance circuit 441. RF path #2 may include RF rod 402, VI sensor 452, and variable impedance circuit 442. RF path #3 may include RF rod 403, VI sensor 453, and variable impedance circuit 443. RF path #1 may eventually lead to the surface of the Earth 461. RF path #2 may eventually lead to the surface of the Earth 462. RF path #3 may eventually lead to the surface of the Earth 463.

[0045] The plasma conditioning apparatus 400 may include N RF paths, where N is the number of meshes, and N is equal to or greater than 2. The apparatus 400 may further include an RF filter 450 and a controller 425.

[0046] Changing the impedance of the variable impedance circuits 441, 442, 443 can be done manually or automatically.

[0047] For automatic impedance change, the currents of the VI sensors 451, 452, 453 should be constantly monitored. This can be achieved by having the controller 425 connected to each of the RF paths, specifically the VI sensors and the variable impedance circuits. The controller 425 can monitor the VI sensors 451, 452, 453. If the measured currents i1, i2, i3 differ among themselves, the controller 425 can adjust the impedances of the circuits 441, 442, 443. The controller 425 can adjust the circuits 441, 442, 443 to satisfy "Condition 2" (i1=i2=i3).

[0048] An RF filter 450 may be disposed in the RF rods 401, 402, and 403. The RF filter 450 may remove noise from the signals in the RF rods 401, 402, and 403 so that each of the signals entering the VI sensors 451, 452, and 453 may be clear for better current measurement in each of the VI sensors.

[0049] The number of meshes and the number of RF paths in this disclosure may be three, but the number may vary depending on the system conditions and requirements.

[0050] FIG. 5 illustrates a method for regulating a plasma according to another embodiment of the present disclosure.

[0051] The controller 425 may constantly monitor each of the RF rods 401, 402, 403. That means the controller 425 may monitor (512) the currents (i1, i2, i3) of the VI sensors (451, 452, 453), respectively. Given the monitored current values, the controller 425 may compare the current values ​​and may determine (513) whether it is true that the monitored currents are the same.

[0052] If the determination may be false, the controller 425 may change the impedances of the variable impedance circuits to be equal among themselves, and if true, the controller 425 continues to monitor the current of the VI sensor (514).

[0053] Before monitoring, an RF filter 450 will be used to remove noise from each RF rod for better signal measurement in the VI sensor (511).

[0054] The above-described arrangements of the device are merely illustrative of the application of the principles of the present invention, and numerous other embodiments and modifications may be made without departing from the spirit and scope of the invention as defined in the claims. The scope of the invention should therefore not be determined with reference to the above description, but should instead be determined with reference to the appended claims along with their full scope of equivalents. [Explanation of symbols]

[0055] 100 Susceptor 110 Background Mesh (Mesh #1) 120 mesh (mesh #2) 130 mesh (mesh #3) 200 Substrate Processing System 201 Reaction chamber 210 RF Generator 211 Integrity Unit 213 Shower Head 214 Space 215 Wafer 216 Susceptor 217 Heater coil 221 Mesh 222 Mesh 223 Mesh 224 Plasma Control Device 225 Controller 231 RF Rod 232 RF Rod 233 RF Rod 300 Reaction Chamber 313 Upper electrode (shower head) 314 Space 315 Wafer 316 Lower electrode (susceptor) 321 Background Mesh 322 mesh 323 Mesh 331 RF Rod 332 RF Rod 333 RF Rod 400 Plasma Regulator 401 RF Rod 402 RF Rod 403 RF Rod 425 Controller 441 Variable Impedance Circuit 442 Variable Impedance Circuit 443 Variable Impedance Circuit 450 RF Filter 451 VI Sensor 452 VI Sensor 453 VI Sensor 461 Ground surface 462 Ground surface 463 Ground surface

Claims

1. 1. A plasma conditioning apparatus for use in a substrate processing system, comprising: a plurality of radio frequency (RF) paths connected to N different meshes, wherein a susceptor of the substrate processing system is divided into the N different meshes, and N is an integer equal to or greater than 1; Each of the RF paths comprises: an RF rod connected to one of the N different meshes and configured to transmit an RF signal from the connected mesh; a voltage and current (VI) sensor connected to the RF rod and configured to measure a current from the RF rod; a variable impedance circuit connected to the VI sensor and configured to vary the impedance of the RF path, and further configured to be grounded; A plasma conditioning apparatus, wherein each of the RF paths is separately grounded, and each of the RF paths corresponds to a different mesh.

2. 10. The apparatus of claim 1, further comprising an RF filter configured to filter out noise from the RF rod.

3. 3. The plasma regulating apparatus of claim 1, further comprising a controller coupled to each of the RF paths and configured to monitor the current in each of the VI sensors and modify an impedance of each of the RF paths based on the monitored current.

4. The plasma conditioning apparatus of claim 3 , wherein the controller is configured to vary the impedances of the multiple RF paths to be equal among themselves.

5. 1. A substrate processing system, comprising: A reaction chamber in which a showerhead and a susceptor for supporting a wafer are disposed, the susceptor being divided into N different meshes, N being an integer of 2 or more; 1. A plasma regulating device, comprising: a plasma conditioning device including a plurality of radio frequency (RF) paths connected to the N different meshes; Each of the RF paths comprises: an RF rod connected to one of the N different meshes and configured to transmit an RF signal from the connected mesh; a voltage and current (VI) sensor connected to the RF rod and configured to measure a current from the RF rod; a variable impedance circuit connected to the VI sensor and configured to vary the impedance of the RF path, and further configured to be grounded; A substrate processing system, wherein each of the RF paths is separately grounded, and each of the RF paths corresponds to a different mesh.

6. The substrate processing system of claim 5 , further comprising an RF filter configured to filter out noise from the RF rod.

7. 7. The substrate processing system of claim 5, further comprising a controller connected to each of the RF paths and configured to monitor the current in each of the VI sensors and alter the impedance of each of the RF paths based on the monitored current.

8. The substrate processing system of claim 7 , wherein the controller is configured to vary the impedances of the multiple RF paths to be equal among themselves.

9. 1. A method of regulating a plasma in a substrate processing system, the system comprising: a reaction chamber having a susceptor disposed therein, the susceptor being divided into N different meshes, N being an integer equal to or greater than 1; and a plasma conditioning apparatus including a plurality of radio frequency (RF) paths connected to the N different meshes, each of the RF paths being disposed with an RF rod, a voltage and current (VI) sensor, and a variable impedance circuit, the method comprising: monitoring current flow through each of the VI sensors; determining whether it is true that the monitored currents have the same value; if determined to be false, varying the impedance of the variable impedance circuits from each RF path to be equal, and repeating the determination if determined to be true.

10. The method of regulating a plasma of claim 9 further comprising filtering noise from each of the RF rods.

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