Substrate processing device and method equipped with focusing ring

Abstract

The substrate processing device of the present invention may include: a chamber for performing a processing process; a chuck installed inside the chamber for supporting the wafer; and a focus ring facing the edge of the chuck. The substrate processing method of the present invention may include: a first process for performing a process on the wafer; and a second process for performing a process on the focus ring.

Description

Technical Field

[0001] The invention relates to a substrate processing device and method for preventing a focusing ring used in semiconductor engineering from being corroded. Background Art

[0002] The overall semiconductor process generally includes exposure, etching, purification and deposition processes for forming circuit patterns. Etching is the process of engraving thin films deposited by exposure. Recently, with the refinement of circuit patterns, the requirements for etching accuracy have become higher and higher. Therefore, atomic layer etching (ALE: Atomic Layer Etching) and atomic layer deposition (ALD: Atomic Layer Deposition) have attracted much attention as semiconductor production-related technologies with good development prospects. Summary of the invention

[0003] Technical issues

[0004] A focus ring (or edge ring) may be provided to focus the source gas or the reaction gas on the wafer after etching or etching and cleaning process. However, the chemical substances contained in the etching gas of the etching process may corrode the focus ring and thus reduce its durability, which may further lead to problems such as time-dependent changes in the process and reduced equipment operation rate.

[0005] Therefore, the present invention relates to a substrate processing apparatus and method that can improve the durability of the focus ring.

[0006] Technical Solution

[0007] The substrate processing device of the present invention may include: a chamber for performing a processing process; a chuck installed inside the chamber for supporting the wafer; and a focusing ring facing the edge of the chuck.

[0008] The processing process may include: a first process for performing a process on the wafer; and a second process for performing a process on the focus ring.

[0009] The substrate processing method of the present invention may include: a first process for performing a process on a wafer; and a second process for performing a process on a focus ring.

[0010] The second process may be performed after the first process, and a purification process for removing byproducts of the first process or polymer particles may be additionally performed between the first process and the second process.

[0011] Effects of the Invention

[0012] When a wafer is placed on a chuck for processing, a focus ring shaped to surround the edge of the wafer can protect the upper surface of the chuck, a portion of the side surface, and the upper side surface of the joint forming the focus ring from the plasma environment inside the chamber.

[0013] A first process for performing a process on a wafer and a second process for performing a process on a focus ring may be performed, the second process may be performed after the first process, and a purification process for removing byproducts of the first process or polymer particles may be additionally performed between the first process and the second process.

[0014] As an embodiment of the second process, the first process may be an etching process, the first process may include an etching gas, and the etching gas may include a first chemical substance. In the second process, a second chemical substance may be supplied to the focusing ring to prevent corrosion of the focusing ring caused by the first chemical substance. When the second chemical substance reacts with the first chemical substance to generate a third chemical substance, the first chemical substance may be fluorine (F) and the second chemical substance may be silicon (Si).

[0015] As another embodiment of the second process, when the deposited film of the wafer is formed by atomic layer deposition (ALD), the second chemical substance supplied to the focusing ring in the second process can be the same as the atomic layer deposition (ALD) precursor, and after the supply of the second chemical substance, an additional process of supplying at least one of a reaction gas or a purge gas for forming an additional film in the focusing ring that is the same as the deposited film of the wafer can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a plan view of the focusing ring and the chuck of the present invention, Figure 1 (a) is a plan view of the state before the focus ring is combined with the chuck, and (b) is a plan view of the state after the focus ring is combined with the chuck.

[0017] Figure 2 It is a sequence diagram of the substrate processing method of the present invention.

[0018] Figure 3 This is a schematic diagram for explaining the substrate processing apparatus of the present invention.

[0019] Figure 4 This is an embodiment of a focusing ring and a chuck according to the present invention.

[0020] Explanation of symbols

[0021] 10: chamber, 100: chuck, 120: placement part, 140: lower electrode, 200: focusing ring, 300: bonding part, S100: first process, S200: second process, S300: purification process. DETAILED DESCRIPTION

[0022] As a part of the semiconductor manufacturing process, the present invention may include at least one of etching, cleaning and deposition processes.

[0023] The method of depositing a film in the wafer of the present invention may include atomic layer deposition (ALD) or plasma enhanced atomic layer deposition (PEALD). Since plasma enhanced atomic layer deposition (PEALD) can form a thin film at a lower temperature, it has recently been widely used in semiconductor engineering.

[0024] As an embodiment of the present invention, in plasma enhanced atomic layer deposition (PEALD), the plasma generation method in the chamber 10 for performing the process can be an inductively coupled plasma (ICP) method or a capacitively coupled plasma (CCP) method.

[0025] Plasma can be composed of charged particles, and plasma can easily control the electrons, ions, protons and active substances in the plasma by adjusting variables such as electric and magnetic fields, and greatly improve the reactivity of plasma-formed source gases or reaction gases. In the following content, plasma can mean a group of ions with increased reactivity or a plasma-formed gas.

[0026] The present invention may include a chamber 10 for performing a processing process on a wafer and a chuck 100 that may support the wafer during the process.

[0027] The chuck 100 may be provided with a placement portion 120 for placing a wafer, and may be provided with a coupling portion 300 for coupling a focus ring 200 (Focus ring).

[0028] The chuck 100 may be an electrostatic chuck 100 (ESC) that uses electrostatic force to fix the wafer. The electrostatic chuck 100 can fix the wafer by means of uniform electrostatic force on the entire contact surface with the wafer, and can maintain the flatness of the wafer surface. It can also effectively release the heat of the wafer and easily achieve temperature regulation by making the wafer and the surface of the electrostatic chuck ESC in close contact as a whole.

[0029] A lower electrode 140 for generating static electricity may be provided in the electrostatic chuck 100. When a voltage is applied to the lower electrode 140, a charge opposite to that of the lower electrode 140 is induced on the wafer, thereby fixing the wafer to the chuck 100 even without a mechanical fixing device such as a clamp.

[0030] When the wafer is placed in the placement part 120, the focus ring 200 can be located outside the wafer, thereby limiting the movement of the wafer during the process, thereby allowing the ions in the plasma state in the chamber 10 to collide with the upper side of the wafer, and making the dry etching in the etching process more effective.

[0031] The focus ring 200 may be in the shape of an edge ring surrounding the edge of the wafer, and any component that can play the role of plasma concentration and corrosion protection of the electrostatic chuck 100 described in this specification may be used without limitation.

[0032] The deposition process of the present invention may include atomic layer deposition (ALD) or plasma enhanced atomic layer deposition (PE-ALD), and the etching process may include atomic layer etching (ALE).

[0033] The focus ring 200 may be disposed on the edge of the electrostatic chuck 100 to help condense plasma and protect the surface of the electrostatic chuck 100 .

[0034] The first process S10 of the present invention may be a process of spraying etching gas into the chamber 10, which may separate a part of the components of the deposited film from the deposited film by reacting a part of the film deposited on the wafer with the etching gas, and may generate a first chemical substance during the reaction with the deposited film.

[0035] As an embodiment, the first process S100 may be an etching process, and the etching gas may include fluorine (F), and the first chemical substance, namely fluorine, may be dissociated when the etching process is performed. The etching gas may enhance reactivity through gas discharge, and may accelerate particles to cause collision with the wafer, and may include NF3, CF4, ClF3, SiF4, C3F8, C2F6, CHF3, CClF3, C3F8, CHF3, CClF3, etc.

[0036] The deposition film formation of the present invention can be completed by an atomic layer deposition (ALD) process, which can be a process of alternately exposing the wafer surface to an organic metal precursor (precursor) and a reactant (reactant) in a gaseous state. The precursor can be referred to as a source gas, and the reactant can be referred to as a reactive gas. After the source gas and the reactive gas are injected into the chamber 10, a purge gas can be supplied. The purge gas is an inert gas and has a low reactivity with other chemical substances, so that it can purge the byproducts remaining after the atomic layer is formed by the meta-titious and reactive gases.

[0037] Therefore, one cycle of atomic layer deposition (ALD) can be a series of processes of supplying source gas, purge gas, reaction gas and purge gas, and the case where the gas of each process is enhanced by plasma can be a plasma enhanced atomic layer deposition (PE-ALD) process. Similar to the atomic layer stacking based on the self-limiting reaction of atomic layer deposition (ALD), the process of etching the atomic layer film by the reverse process is called atomic layer etching (ALE), and the case where the process is enhanced by plasma can be plasma enhanced atomic layer etching (PE-ALE).

[0038] The deposition of the present invention can be performed by an atomic layer deposition (ALD) process, and as an embodiment, the precursor can be trimethylaluminum (TMA, TriMethyl Aluminum, Al(CH3)3), the reactant can be H2O, and the deposited film can be Al2O3.

[0039] The first chemical substance dissociated or generated in the first process S100 of the present invention can not only etch a portion of the film deposited on the wafer, but also react with the components of the focus ring 200. For example, the first process S100 can be an etching process, the first chemical substance can be fluorine F, the focus ring 200 can contain Al2O3 or Y2O3, and F can react and etch for a long time because of its high affinity with Al or Y.

[0040] The raw material of the focus ring 200 may include aluminum oxide (Al2O3), yttrium oxide (Y2O3) and sapphire. The focus ring 200 is continuously exposed to plasma during the semiconductor manufacturing process for each wafer due to its structure, and the focus ring 200 may be corroded due to the reaction between the first chemical substance and the raw material of the focus ring 200.

[0041] Therefore, the corroded focus ring 200 needs to be replaced, and when replacing the focus ring 200, a series of processes need to be performed, including stopping all processes and replacing the focus ring 200 while cleaning the etching chamber 10. This will lead to a loss of the overall semiconductor manufacturing process, and not only involves a cost issue, but also involves the issue of discarding the focus ring 200.

[0042] Therefore, the second process S200 for further extending the life time of the focus ring 200 may be additionally performed.

[0043] The second process S200 may be a process for processing the focus ring 200, and the focus ring 200 may be installed continuously for processing multiple substrates. For example, a first wafer and a second wafer to be processed may be provided, and each wafer may perform semiconductor process in the chamber 10. The semiconductor process may be composed of multiple processes, and the first process S100 or the second process S200 may be at least one of the multiple processes.

[0044] The semiconductor process of the second wafer may be performed after the semiconductor process of the first wafer, and in the continuous process, the focus ring 200 may be continuously installed in the bonding part 300. That is, the second process S200 on the first wafer may be the semiconductor process in the second wafer.

[0045] The second process S200 may be a process of treating the focus ring 200 with a second chemical substance.

[0046] As an embodiment of the second process S200, when the deposition film process for processing the wafer in the second process S200 is an atomic layer deposition (ALD) process, the second chemical substance may be a precursor of the atomic layer deposition (ALD). That is, when the second chemical substance used to process the focus ring 200 is a precursor of the atomic layer deposition (ALD) process, a subsequent process for forming a deposition film in the focus ring 200 by the atomic layer deposition (ALD) process may be added to the second process S200. The subsequent process may include at least one of a reactant supply process or a purge process.

[0047] Therefore, one embodiment may be to apply an additional film on the focus ring 200, and the additional film may be used to prevent the focus ring 200 from being corroded by the first chemical substance in the first process S100, and the composition of the additional film may be the same as that of the film deposited on the wafer of the present invention.

[0048] When an additional film is formed on the focus ring 200, the additional film may be corroded at the same time as the wafer deposited film is corroded by the first chemical substance. However, the focus ring 200 itself can be protected from being corroded by the first chemical substance.

[0049] In addition, when the film deposited on the wafer is the same as the additional film deposited on the focusing ring 200, since the by-products generated in processes such as atomic layer deposition (ALD) and atomic layer etching (ALE) are the same, there is no need to consider additional gas components such as purification for removing process by-products.

[0050] As another embodiment of the second process S200 , the second chemical substance may be a Si precursor.

[0051] The first process S100 may be an etching process for forming a circuit pattern, and the etching gas may be a gas containing F as the first chemical substance. Therefore, in order to prevent the corrosion of the focus ring 200 due to the etching gas, SiF4 contained in the third chemical substance may be formed by supplying a Si precursor having a high chemical affinity with F to the focus ring 200 after the first process S100 is transferred. As described above, by combining the first chemical substance with the second chemical substance and converting it into the third chemical substance, the focus ring 200 may be prevented from being corroded by the first chemical substance.

[0052] In order to prevent the generation of byproducts and polymer particles generated after the first process S100, a purification process S300 may be added between the first process S100 and the second process S200. When the first process S100 is an etching process, the purification process S300 may be a purification process.

[0053] The wafer can be placed on the upper side of the chuck 100. The plane constituting the upper side of the chuck 100 may include a first direction (x-axis direction) and a second direction (y-axis direction) that intersect vertically, and a third direction (z-axis direction) may be perpendicular to the first direction and the second direction.

[0054] For the convenience of description, the relationship between the seating portion 120 and the focus ring 200 may be described based on a cross section cut along the first direction (x-axis direction).

[0055] When the wafer is placed in the placement portion 120 , the height of the upper side of the wafer in the vertical direction (third direction, z-axis direction) is referred to as a first height h1 , and the height of the upper side of the focus ring 200 is referred to as a second height h2 .

[0056] When the second height is greater than the first height, the plasma sprayed onto the wafer can be condensed, thereby improving the etching rate or etching spread. The above situation belongs to the situation where the height of the upper surface of the focus ring 200, i.e., the second height, is greater than the height of the placed wafer, i.e., the first height. The condensation or concentration of plasma can refer to the phenomenon that the plasma sprayed onto the wafer collides with a part of the focus ring 200 corresponding to the difference between the second height and the first height and returns to the wafer.

[0057] When the second height is the same as the first height, the upper side of the placed wafer and the upper side of the focus ring 200 on the outer contour can be at the same height, thereby preventing the etching from being concentrated at the edge due to the sprayed plasma being concentrated at the edge of the wafer. In addition, in the above case, by using a raw material that is the same as or similar to the material of the wafer in the focus ring 200, the processing area of ​​the wafer can be expanded.

[0058] Therefore, according to the composition of plasma engineering, when it is necessary to concentrate plasma to the edge of the wafer, the second height can be designed to be greater than the first height, and when it is necessary to prevent concentration at the edge by alleviating the concentration of plasma at the edge of the wafer, the second height can be designed to be similar to or the same as the first height.

[0059] When observed based on the cross section along the first direction, based on a specific straight line parallel to the third direction (such as the z-axis passing through the center point of the wafer), the length of the wafer protruding in the first direction can be called the first length, and the length of the placement portion 120 can be called the second length.

[0060] In order to prevent the seating portion 120 or the bonding portion 300 from being exposed to plasma when an etching process is performed, the first length may be equal to or greater than the second length.

[0061] In the case where the first length is the same as the second length, when the focus ring 200 is formed in such a way that the height of the upper side surface of the seating portion 120 is the same as the height of the upper side surface of the coupling portion 300 and surrounds the upper side surface of the coupling portion 300, the seating portion 120 and the coupling portion 300 can be prevented from being corroded by the outside. In addition, in the case where the height of the upper side surface of the seating portion 120 is greater than the height of the upper side surface of the coupling portion 300, a break can be formed between the coupling portion 300 and the seating portion 120, and when the focus ring 200 is installed in such a way that the side surface equivalent to the break and the upper side surface of the coupling portion 300 are surrounded, the upper side surface of the seating portion 120, the side surface and the upper side surface of the coupling portion 300 can be protected from external corrosion.

[0062] In the case where the first length is greater than the second length, a placement surface for placing a wafer may be provided on the focus ring 200, and an intermediate surface facing the side surface of the wafer may be provided between the upper surface and the placement surface, and the intermediate surface may be in a vertical or inclined state parallel to the third direction. In the above case, when the focus ring 200 is installed, the upper side surface and the side surface of the placement portion 120 and the upper side surface of the coupling portion 300 may be protected from being corroded due to being exposed to the outside.

[0063] Thus, when the wafer is mounted in the seating portion 120 , the focus ring 200 can minimize the exposure of the seating portion 120 and the coupling portion 300 to plasma, thereby reducing the area in contact with plasma during the etching process and thereby reducing corrosion.

[0064] The coupling part 300 to which the focus ring 200 can be coupled can be provided in a manner facing the placement part 120. The coupling part 300 can be made of a ceramic material, and can include alumina (Alumina, Al2O3). That is, by coupling the focus ring 200 to the coupling part 300, when the wafer is placed on the placement part 120, the placement part 120 and the coupling part 300 can be prevented from being corroded by plasma during the process.

[0065] By adjusting the first height, the second height, the first length and the second length, a variety of wafer, placement portion 120 and focus ring 200 structures can be realized. However, as long as a smaller portion of the coupling portion 300 or the placement portion 120 is exposed to plasma when the wafer is placed after the focusing ring 200 is coupled to the coupling portion 300, it is sufficient to reflect the characteristics of the present invention.

Claims

1. A substrate processing device, characterized in that: include: a chamber for carrying out the processing works; A chuck, installed inside the chamber, for supporting the wafer; as well as, a focusing ring facing an edge of the chuck; The processing engineering comprises: a first engineering for performing engineering on the wafer; and, a second process for performing a process on the focus ring, In a first process, an etching gas is supplied to the wafer, the etching gas comprising a first chemical substance, In the second process, a second chemical substance is supplied into the chamber to prevent the focusing ring from being corroded by the etching gas. The second chemical substance reacts with the first chemical substance to generate a third chemical substance. The third chemical substance has a lower corrosive effect on the focusing ring than the first chemical substance.

2. The substrate processing device according to claim 1, characterized in that: The height of the upper side surface of the wafer is defined as a first height, and the height of the upper side surface of the focus ring is defined as a second height, and the second height is greater than or equal to the first height.

3. The substrate processing device according to claim 1, characterized in that: Between the first step and the second step, a purification step for removing byproducts of the first step or polymer particles is additionally performed.

4. The substrate processing device according to claim 1, characterized in that: The first chemical substance is fluorine, the second chemical substance is a silicon precursor, and the third chemical substance is SiF4.

5. The substrate processing apparatus according to claim 1, wherein: Through atomic layer deposition, films are deposited on the wafer in layers. In the first step, an etching gas for etching the deposited film is sprayed toward the wafer. In the second step, a second chemical substance for preventing the focus ring from being corroded by the etching gas is supplied to the focus ring. The second chemical substance is an atomic layer deposition precursor for the atomic layer deposition process of the wafer, After supplying the atomic layer deposition precursor to the focus ring, additionally performing a process of supplying at least one of a reaction gas or a purge gas to form an additional film on the focus ring, The additional film has the same component as that of the deposited film formed on the wafer.

6. The substrate processing apparatus according to claim 1, wherein: The chuck comprises a placement portion and a coupling portion, The wafer is placed on the placement part, and the focus ring is combined with the combination part. The back side of the focus ring is closely attached to the joint portion and thereby prevented from being exposed to the outside.

7. A substrate processing method, characterized in that: Equipped with a chamber for carrying out the processing works, A chuck is installed inside the chamber for supporting the wafer. equipped with a focusing ring facing the edge of the chuck, include: A first process for performing a process on a wafer; and A second process is used to perform a process on the focus ring; performing the second process after the first process, Between the first step and the second step, a purification step for removing byproducts of the first step or polymer particles is additionally performed. In a first process, an etching gas is supplied to the wafer, the etching gas comprising a first chemical substance, In the second process, a second chemical substance is supplied into the chamber to prevent the focusing ring from being corroded by the etching gas. The second chemical substance reacts with the first chemical substance to generate a third chemical substance. The third chemical substance has a lower corrosive effect on the focusing ring than the first chemical substance.

8. The substrate processing method according to claim 7, characterized in that: The first chemical substance is fluorine, the second chemical substance is a silicon precursor, and the third chemical substance is SiF4.

9. The substrate processing method according to claim 7, characterized in that: Through atomic layer deposition, films are deposited on the wafer in layers. In the first step, an etching gas for etching the deposited film is sprayed toward the wafer. In the second step, a second chemical substance for preventing the focus ring from being corroded by the etching gas is supplied to the focus ring. The second chemical substance is an atomic layer deposition precursor for the atomic layer deposition process of the wafer, After supplying the atomic layer deposition precursor to the focus ring, additionally performing a process of supplying at least one of a reaction gas or a purge gas to form an additional film on the focus ring, The additional film has the same component as that of the deposited film formed on the wafer.

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