A plasma chamber equipped with a side gas feed that forms a swirl motion

Abstract

The present invention relates to a plasma chamber provided with a side gas feed for forming a swirl motion, and includes a housing provided with a placement portion on which the wafer is placed, a side gas feed provided on a side surface of the housing for injecting gas into the housing, the housing being provided with a plurality of the side gas feeds, the side gas feed including a nozzle provided with a nozzle hole through which gas is injected, and the side gas feed being characterized by injecting gas toward the wall surface of the housing.

Description

Technical Field

[0001] The present invention relates to a plasma chamber provided with a side gas feed that forms a swirl motion. More specifically, by adjusting the injection direction of the gas injected from the side gas feed so as to be directed toward the wall surface of the housing, the gas injected from the nozzle forms a swirl motion in the chamber, and the present invention relates to a plasma chamber provided with a side gas feed that can maintain a uniform etching rate inside the chamber.

Background Art

[0002] Generally, in the process of manufacturing a semiconductor, it is very important to ensure uniformity, and the uniformity of the semiconductor can be ensured or adjusted in the etching process among the semiconductor manufacturing processes.

[0003] The etching process of the semiconductor can be carried out inside the plasma chamber. The plasma chamber forms plasma in the internal reaction space and uses the plasma to perform the etching process of the semiconductor.

[0004] *A plasma source for forming plasma is provided above the plasma chamber. Representative examples of the plasma source include a capacitively coupled plasma (CCP) source and an inductively coupled plasma (ICP) source.

[0005] In the etching process, the gas distribution inside the plasma chamber can be an important factor for maintaining a uniform etching rate. Generally, to maintain a uniform etching rate, a shower head design is used in chambers with capacitively coupled plasma sources, and bottom gas feed (BGF), center gas feed (CGF), and side gas feed (SGF) are used in chambers with inductively coupled plasma.

[0006] Inductively coupled plasma (ICP) can increase the etching rate more than capacitively coupled plasma (CCP). However, in the case of inductively coupled plasma (ICP), there are problems such as low selectivity and poor process repeatability.

[0007] Also, conventional inductively coupled plasma (ICP) injects the main gas from the center gas feed and injects a small amount of gas through the side gas feed to compensate for the low etching rate at the wafer edge. By being able to adjust the etching rate at the wafer edge in such a way, an improvement in the linewidth uniformity could be expected.

[0008] However, in the side gas feed of conventional inductively coupled plasma (ICP), since the direction of the nozzle faces the wafer, there is a problem that the etching rate becomes non-uniform in the case of a gas with a large molecular weight.

[0009] Specifically, when injecting the main gas from the center gas feed and a small amount of gas from the side gas feed, there is a problem that the gas from the side gas feed leaks out into the space between the chamber and the wafer, and the effect of improving the linewidth cannot be obtained.

[0010] Conversely, increasing the amount of gas injected from the side gas feed affects the uniformity of the line width across the entire wafer, resulting in a problem where a result different from the target result is obtained.

Summary of the Invention

Problems to be Solved by the Invention

[0011] The present invention is for solving the above-described problems. More specifically, by adjusting the injection direction of the gas injected from the side gas feed to be directed toward the wall surface of the housing, the gas injected from the nozzle forms a swirl motion in the chamber, and the present invention relates to a plasma chamber provided with a side gas feed that can maintain a uniform etching rate inside the chamber by forming a swirl motion.

Means for Solving the Problems

[0012] The plasma chamber provided with a side gas feed for forming a swirl motion according to the present invention for solving the above-described problems is a plasma chamber in which plasma is formed for etching a wafer, and includes a housing provided with a mounting portion on which the wafer is placed, and a side gas feed provided on a side surface of the housing for injecting gas into the housing. The housing is provided with a plurality of the side gas feeds, and the side gas feed includes a nozzle provided with a nozzle hole through which gas is injected. The side gas feed is characterized in that it injects gas toward the wall surface of the housing.

[0013] The plurality of the side gas feeds provided in the housing of the plasma chamber provided with a side gas feed for forming a swirl motion according to the present invention for solving the above-described problems can be provided at the same height from the mounting portion.

[0014] The direction of the gas jetted from the side gas feed of the plasma chamber provided with the side gas feed forming the swirl motion of the present invention for solving the above-described problems can be a direction on a plane extending in a direction parallel to the plane formed by the mounting portion on which the wafer is mounted.

[0015] When any one of the plurality of side gas feeds provided in the housing of the plasma chamber provided with the side gas feed forming the swirl motion of the present invention for solving the above-described problems is defined as the first side gas feed, and a side gas feed adjacent to the first side gas feed is defined as the second side gas feed, the first side gas feed can jet gas in the direction of the second side gas feed.

[0016] When any one of the plurality of side gas feeds provided in the housing of the plasma chamber provided with the side gas feed forming the swirl motion of the present invention for solving the above-described problems is defined as the first side gas feed, a side gas feed adjacent to the first side gas feed is defined as the second side gas feed, and a side gas feed adjacent to the second side gas feed in the direction opposite to the direction in which the first side gas feed is adjacent is defined as the third side gas feed, the first side gas feed can jet gas in the direction between the second side gas feed and the third side gas feed.

[0017] The housing of the plasma chamber provided with the side gas feed forming the swirl motion of the present invention for solving the above-described problems can be provided with n side gas feeds. (n is a natural number of 3 or more, and n is the number of side gas feeds)

[0018] The plurality of side gas feeds provided in the housing of the plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems can be provided in the housing in the form of a regular polygon.

[0019] When the number of the side gas feeds provided at the same height from the placement portion of the plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems is n, the angle formed by one side gas feed and two side gas feeds adjacent to both sides of the side gas feed can be 180×(n - 2) / n degrees.

[0020] The plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems is provided at the upper part of the housing, and may further include a center gas feed for injecting gas into the housing.

[0021] The gas injected from the side gas feed of the plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems can be a gas having a molecular weight heavier than that of the gas injected from the center gas feed.

[0022] The plasma formed in the internal space of the housing of the plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems includes ions and radicals, and the wafer can be etched by the synergistic effect of the ions and the radicals.

[0023] The nozzle hole of the plasma chamber provided with a side gas feed for forming a swirl motion of the present invention for solving the above-described problems can be circular with a diameter of 0.1 to 1 mm.

[0024] The side gas feed provided in the housing of the plasma chamber having the swirl motion forming side gas feed for solving the above-described problems may be provided with a controller for adjusting the flow rate or velocity of the gas injected from the side gas feed.

Advantages of the Invention

[0025] The present invention relates to a plasma chamber provided with a side gas feed for forming a swirl motion. By adjusting the injection direction of the gas injected from the side gas feed to be directed toward the wall surface of the housing, the gas injected from the nozzle can form a swirl motion in the chamber and maintain a uniform etch rate inside the chamber.

[0026] Further, the present invention has an advantage that the gas injected from the nozzle can form a swirl motion in the chamber by adjusting the direction of the gas injected from one side gas feed provided in the housing to the direction of another side gas feed adjacent to the one side gas feed, thereby maintaining a uniform etch rate inside the chamber.

[0027] Further, the present invention has an advantage that it is possible to prevent the gas injected from the side gas feed from hitting the wall surface of the housing by adjusting the injection direction of the gas injected from the side gas feed to be directed toward the wall surface of the housing and forming the velocity or flow rate of the gas injected from one side gas feed to reach another adjacent side gas feed.

[0028] In addition, the present invention has an advantage that the gas injected from one side gas feed can form a swirl motion by receiving a force from another adjacent side gas feed by forming the speed or flow rate of the gas injected from one side gas feed so as to reach the other adjacent side gas feed.

[0029] At the same time, the present invention has an advantage that by simultaneously using a side gas feed and a center gas feed in a chamber and injecting a gas of heavy molecules through the side gas feed, the etching rate can be improved while improving the uniformity of the etching rate.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0031] This specification clarifies the scope of the present invention, explains the principles of the present invention, and discloses embodiments so that those with ordinary knowledge in the technical field to which the present invention pertains can practice the present invention. The disclosed embodiments can be embodied in various forms.

[0032] Expressions such as "comprising" or "capable of comprising" that may be used in various embodiments of the present invention indicate the presence of the corresponding functions, operations, or components disclosed in the invention, and do not limit one or more additional functions, operations, or components. Also, in various embodiments of the present invention, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0033] When a certain component is referred to as being "connected to" or "coupled to" another component, it may be directly connected or coupled to the other component, but it should be understood that a new separate component may also exist between the certain component and the other component. On the other hand, when a certain component is referred to as being "directly connected to" or "directly coupled to" another component, it should be understood that no new separate component exists between the certain component and the other component.

[0034] Terms such as first, second, etc. used in this specification can be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

[0035] The present invention relates to a plasma chamber provided with a side gas feed for forming a swirl motion, and by adjusting the injection direction of the gas injected from the side gas feed to be directed toward the wall surface of the housing, the gas injected from the nozzle forms a swirl motion in the chamber and a uniform etch rate can be maintained inside the chamber. The present invention relates to a plasma chamber provided with a side gas feed for forming a swirl motion.

[0036] The plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention can improve the uniformity of the etch rate in a chamber that uses heavy molecules such as metal etch or oxide etch.

[0037] However, it is not limited thereto, and of course, the plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention can be applied to a chamber that uses various molecules. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] The plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention includes a housing 110 and a side gas feed 120.

[0039] Referring to FIG. 1, the housing 110 is provided with a reaction space inside for etching the wafer 10 by plasma. The housing 110 can be the chamber outer wall of the plasma chamber according to an embodiment of the present invention and is provided with a space inside.

[0040] The housing 110 can be provided with a placement part 111 on which the wafer 10 is placed, and the wafer 10 can be loaded onto the placement part 111. When the wafer 10 is loaded inside the housing 110, the wafer 10 can be etched by plasma formed inside the housing 110.

[0041] The placement part 111 can be a plate provided inside the housing 110 on which the wafer 10 is placed, and the placement part 111 can be a wafer chuck that places and supports the wafer 10.

[0042] According to an embodiment of the present invention, a plasma source 113 for forming plasma can be provided on the upper part of the housing 110. Referring to FIG. 1, the plasma source 113 can include a coil 114 and an RF power generator 115, and the coil 114 and the RF power generator 115 can form plasma inside the housing 110.

[0043] The plasma chamber provided with a side gas feed according to an embodiment of the present invention can further include a Bias RF Source 116 that can apply a bias to the placement part 111. Referring to FIG. 1, the Bias RF Source 116 can apply a bias to the placement part 111 to apply a bias to the plasma during the etching process.

[0044] The plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention can solve the problems of the method of using a conventional Inductively Coupled Plasma (ICP) source and improve it.

[0045] Also, the plasma chamber with a side gas feed according to an embodiment of the present invention can be a Synergistic resonance ICP (SRICP) that utilizes a resonance phenomenon and a synergy effect.

[0046] Specifically, the plasma formed in the internal space of the housing 110 of the plasma chamber with a side gas feed according to an embodiment of the present invention contains ions and radicals, and the wafer 10 can be etched by the synergy effect of the ions and the radicals.

[0047] Plasma is mainly composed of electrons, ions, and radicals. Examining the conventional method of etching a wafer with plasma in detail, the dominant species in the plasma etching process is formed by either ions or radicals. Specifically, in the conventional method of etching a wafer with plasma, Metal etch mainly uses radicals, and Oxide etch mainly uses ions.

[0048] The plasma chamber with a side gas feed according to an embodiment of the present invention is not one in which the dominant species is formed by either ions or radicals in the plasma etching process, but can utilize both ions and radicals simultaneously.

[0049] That is, the plasma chamber with a side gas feed according to an embodiment of the present invention uses a process region in which ions and radicals act together to exhibit a synergy effect, rather than performing an ion-dominant reaction or a radical-dominant reaction during the etching process.

[0050] More specifically, the plasma chamber provided with the side gas feed according to the embodiment of the present invention can improve the selectivity while maintaining a high etching rate by the resonance phenomenon and the synergy effect between ions and radicals while simultaneously using ions and radicals.

[0051] Referring to FIG. 2, the side gas feed 120 is provided on the side surface of the housing 110 and injects gas into the housing 110. A plurality of the side gas feeds 120 can be provided in the housing 110.

[0052] The side gas feed 120 includes a nozzle 121 provided with a nozzle hole 122 through which gas is injected, and a plurality of the nozzles 121 can be provided in the housing 110.

[0053] Referring to FIG. 3, the plurality of side gas feeds 120 provided in the housing 110 can be provided at the same height from the mounting portion 111. Also, the direction of the gas injected from the plurality of side gas feeds 120 provided in the housing 110 can be a direction on a plane extending in a direction parallel to the plane formed by the mounting portion 111 on which the wafer 10 is placed.

[0054] The plurality of side gas feeds 120 can inject gas in one plane, and the plurality of side gas feeds 120 can be provided at the same height from the mounting portion 111 and arranged on one plane.

[0055] Specifically, the plurality of side gas feeds 120 can be arranged on a plane extending in a direction parallel to the plane formed by the mounting portion 111 at a specified height (h) away from the mounting portion 111.

[0056] Further, the plurality of the side gas feeds 120 can inject gas toward the wall surface of the housing 110 on a plane that is separated from the placement portion 111 by a specified height (h) and extends in a direction parallel to the plane formed by the placement portion 111.

[0057] Referring to FIGS. 3 and 4, the plurality of the side gas feeds 120 provided in the housing 110 can be provided in the housing 110 in the form of a regular polygon. Specifically, the plurality of the side gas feeds 120 can be provided in the housing 110 by forming a regular polygon on a plane that extends in a direction parallel to the plane formed by the placement portion 111.

[0058] Referring to FIGS. 3 and 4, the side gas feed 120 can inject gas toward the wall surface of the housing 110. The nozzle hole 122 of the side gas feed 120 faces the wall surface of the housing 110, and the plurality of the side gas feeds 120 can inject gas at a certain angle with respect to the wall surface of the housing 110.

[0059] Specifically, referring to FIG. 4, the cross section of the housing 110 can be circular. When a tangent line is formed at the point where the circular housing 110 is in contact with the side gas feed 120, the angle formed by the tangent line and the direction in which gas is injected from the side gas feed 120 can be formed at a certain angle.

[0060] According to an embodiment of the present invention, the direction of the gas injected from one side gas feed 120 provided in the housing 110 can be the direction of another side gas feed 120 adjacent to the one side gas feed 120.

[0061] Referring to FIG. 4, when one of the plurality of side gas feeds 120 provided in the housing 110 is defined as a first side gas feed 123 and the side gas feed 120 adjacent to the first side gas feed 123 is defined as a second side gas feed 124, the first side gas feed 123 can inject gas in the direction of the second side gas feed 124.

[0062] That is, the gas injected from the first side gas feed 123 can be injected so as to reach the second side gas feed 124. When the gas injected from the first side gas feed 123 is injected in the direction of the second side gas feed 124 in this way, the gas injected from the first side gas feed 123 can receive a force from the second side gas feed 124 before hitting the wall surface of the housing 110.

[0063] By the gas injected from the first side gas feed 123 receiving a force from the second side gas feed 124, the gas injected from the first side gas feed 123 can be rotated by the second side gas feed 124 instead of hitting the wall surface of the housing 110.

[0064] The gas injected from the first side gas feed 123 can be affected by gravity, and as the gas injected from the first side gas feed 123 rotates and descends in the direction of gravity, a downward swirl motion is formed.

[0065] When the gas injected from the first side gas feed 123 forms a downward swirl motion and contacts the wafer 10, even if the gas contacts the wafer 10, it will move additionally due to centrifugal force and a diffusion effect will occur.

[0066] Due to such a diffusion effect, the gas reacts with the nearby particles, enabling the uniformity of the etching rate to be improved.

[0067] Referring to FIG. 4, when the side gas feed 120 adjacent to the second side gas feed 124 is taken as the third side gas feed 125 in the direction opposite to the direction adjacent to the first side gas feed 123, the second side gas feed 124 can inject gas in the direction of the third side gas feed 125. Further, the third side gas feed 125 can inject gas into a fourth side gas feed provided in the direction opposite to the direction adjacent to the second side gas feed 124.

[0068] In such a manner, the plurality of side gas feeds 120 provided in the housing 110 can inject gas in the direction of the adjacent side gas feed 120, whereby the gas injected from the side gas feed 120 forms a downward swirl motion.

[0069] The side gas feed 120 provided in the housing 110 according to an embodiment of the present invention can be provided with a controller for adjusting the velocity or flow rate of the gas injected from the side gas feed 120.

[0070] As described above, the gas injected from one side gas feed 120 provided in the housing 110 moves to another adjacent side gas feed 120 and then receives a force from the other side gas feed 120 to form a downward swirl motion.

[0071] If the gas injected from one side gas feed 120 cannot reach the other side gas feed 120, it becomes difficult to form a downward swirl motion.

[0072] Therefore, the gas injected from one side gas feed 120 must be injected at a flow rate or velocity that allows it to move to the other adjacent side gas feed 120. The controller is capable of adjusting the velocity or flow rate of the gas injected from the side gas feed 120, and can adjust the flow rate or velocity of the gas via the controller so that the gas injected from one side gas feed 120 can move to the other adjacent side gas feed 120.

[0073] Also, according to an embodiment of the present invention, the cross-sectional area A of the nozzle hole 122 formed in one side gas feed 120 can be adjusted together with the velocity or flow rate of the gas injected from one side gas feed 120 so that the gas injected from one side gas feed 120 can move to the other adjacent side gas feed 120.

[0074] According to another embodiment of the present invention, the first side gas feed 123 can also inject gas in a direction between the second side gas feed 124 and the third side gas feed 125.

[0075] Of the plurality of the side gas feeds 120 provided in the housing 110, any one is defined as a first side gas feed 123, a side gas feed 120 adjacent to the first side gas feed 123 is defined as a second side gas feed 124, and when a side gas feed 120 adjacent to the second side gas feed 124 in a direction opposite to the direction in which the first side gas feed 123 is adjacent is defined as a third side gas feed 125, as shown in FIG. 5, the first side gas feed 123 can also inject gas in a direction between the second side gas feed 124 and the third side gas feed 125.

[0076] Even if the gas injected from the first side gas feed 123 is injected in a direction slightly deviated from the direction of the second side gas feed 124, it can receive a force from the second side gas feed 124.

[0077] However, if the gas injected from the first side gas feed 123 is deviated too much from the direction of the second side gas feed 124, the gas injected from the first side gas feed 123 cannot receive a force from the second side gas feed 124.

[0078] Therefore, it is preferable that the gas injected from the first side gas feed 123 be injected in a direction between the second side gas feed 124 and the third side gas feed 125. Also, the gas injected from the second side gas feed 124 can be injected in a direction between the third side gas feed 125 and the fourth side gas feed.

[0079] In such a manner, the plurality of the side gas feeds 120 provided in the housing 110 can inject gas in the vicinity of the direction of the adjacent side gas feed 120, whereby the gas injected from the side gas feed 120 comes to form a downward swirl motion.

[0080] Of course, also in this case, the velocity or flow rate of the gas injected from the first side gas feed 123 can be adjusted so that the gas reaches between the second side gas feed 124 and the third side gas feed 125, and the cross-sectional area of the nozzle hole 122 can also be adjusted.

[0081] According to an embodiment of the present invention, the housing 110 can be provided with n side gas feeds 120. Here, n is a natural number of n ≧ 3 or more, and n can be the number of side gas feeds.

[0082] According to an embodiment of the present invention, it is preferable that three or more side gas feeds 120 are provided. Specifically, the housing 110 can be provided with three or more side gas feeds 120, and the three side gas feeds 120 can be arranged on one plane.

[0083] When there are two side gas feeds 120, it is difficult to form a swirl motion. Therefore, it is preferable that three or more side gas feeds 120 are provided.

[0084] More specifically, in order to form a swirl motion through the side gas feed 120, it is preferable that the housing 110 is provided with 3 to 8 side gas feeds 120.

[0085] However, the number of the side gas feeds 120 provided in the housing 110 is not limited to eight, and the number of the side gas feeds 120 provided in the housing 110 may be more than eight.

[0086] According to an embodiment of the present invention, the plurality of side gas feeds 120 can be provided in the housing 110 in the form of a regular polygon. When the number of the side gas feeds 120 provided at the same height from the placement portion 111 according to an embodiment of the present invention is n, the angle formed by one side gas feed and two side gas feeds adjacent to both sides of the side gas feed can be 180×(n - 2) / n degrees. (Here, since the number of the side gas feeds 120 provided in the housing 110 is three or more, n in the formula 180×(n - 2) / n can be greater than 3.)

[0087] As shown in FIG. 6, when the number of the side gas feeds 120 provided at the same height from the placement portion 111 is six, the angle formed by one side gas feed and two side gas feeds adjacent to both sides of the side gas feed can be 120 degrees.

[0088] As shown in FIG. 7, when the number of the side gas feeds 120 provided at the same height from the placement portion 111 is four, the angle formed by one side gas feed and two side gas feeds adjacent to both sides of the side gas feed can be 90 degrees.

[0089] Specifically, as shown in FIG. 6, when the number of the side gas feeds 120 is six, the angle formed by the line connecting the first side gas feed 123 from the second side gas feed 124 and the line connecting the third side gas feed 125 from the second side gas feed 124 can be 120 degrees.

[0090] Also, as shown in FIG. 7, when the number of the side gas feeds 120 is four, the angle formed by the line connecting the first side gas feed 123 from the second side gas feed 124 and the line connecting the third side gas feed 125 from the second side gas feed 124 can be 90 degrees.

[0091] According to an embodiment of the present invention, when a tangent line is formed at the point where the circular housing 110 and the side gas feed 120 are in contact, the angle formed by the tangent line and the direction in which gas is injected from the side gas feed 120 can be 20 degrees to 60 degrees.

[0092] As described above, it is preferable that the housing 110 is provided with 3 to 8 side gas feeds 120. Referring to FIG. 8, when the housing 110 is provided with 8 side gas feeds 120, the angle formed by the line connecting the first side gas feed 123 from the second side gas feed 124 and the line connecting the third side gas feed 125 from the second side gas feed 124 can be 135 degrees.

[0093] According to an embodiment of the present invention, the second side gas feed 124 can inject gas in the direction of the third side gas feed 125. At this time, when a tangent line is formed at the point where the circular housing 110 and the second side gas feed 124 are in contact, the angle formed by the tangent line and the direction in which gas is injected from the second side gas feed 124 can be 22.5 degrees.

[0094] In order for the gas injected from the second side gas feed 124 to receive a force from the third side gas feed 125, it is preferable that the angle formed by the tangent line and the direction in which gas is injected from the second side gas feed 124 is 22.5 degrees larger.

[0095] Since the number of the side gas feeds 120 provided in the housing 110 is preferably 8 or less, when a tangent line is formed at the point where the circular housing 110 and the side gas feed 120 are in contact, it is preferable that the angle formed by the tangent line and the direction in which gas is injected from the side gas feed 120 is 22.5 degrees larger and preferably larger than 20 degrees.

[0096] Also, when the housing 110 is provided with three of the side gas feeds 120, the angle formed by the line connecting the first side gas feed 123 from the second side gas feed 124 and the line connecting the third side gas feed 125 from the second side gas feed 124 can be 60 degrees.

[0097] At this time, when a tangent line is formed at the point where the circular housing 110 and the second side gas feed 124 are in contact, the angle formed by the tangent line and the direction in which gas is injected from the second side gas feed 124 can be 60 degrees.

[0098] The number of the side gas feeds 120 provided in the housing 110 is preferably three or more. Therefore, when a tangent line is formed at the point where the circular housing 110 and the side gas feed 120 are in contact, the angle formed by the tangent line and the direction in which gas is injected from the side gas feed 120 is preferably less than 60 degrees.

[0099] The plasma chamber provided with the side gas feed for forming the swirl motion according to an embodiment of the present invention is provided above the housing 110 and may further include a center gas feed 130 for injecting gas into the housing 110.

[0100] When the gas injected into the plasma chamber consists of heavy molecules, if only the center gas feed is used, there is a problem that the uniformity of the etching rate deteriorates because the velocity in the z - direction (the direction of the lower part of the housing) increases due to the heavy molecules.

[0101] The plasma chamber provided with the side gas feed according to an embodiment of the present invention can prevent the deterioration of the uniformity of the etching rate by adjusting the design of the side gas feed 120 while using the side gas feed 120 together with the center gas feed 130.

[0102] When the center gas feed 130 and the side gas feed 120 are used simultaneously, the side gas feed 120 is preferably provided between the placement portion 111 of the housing 110 and the center gas feed 130 provided at the upper part of the housing 110.

[0103] According to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 contains ions and radicals, and the wafer 10 can be etched by the synergistic effect of the ions and the radicals.

[0104] According to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 contains electrons, and the electron energy relaxation length (EERL) of the electrons can be smaller than the diameter of the housing.

[0105] The plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention can be carried out in the process region of Local Electron Kinetics. The conventional etching process was carried out in the process region of Nonlocal electron kinetics where the electron energy relaxation length (EERL) was always larger than the diameter of the process chamber.

[0106] However, the plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention can be carried out in the process region of Local Electron Kinetics where the electron energy relaxation length (EERL) is smaller than the diameter of the process chamber (the diameter of the housing 110).

[0107] As a result, the plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention can make the plasma density at the end of the housing 110 higher than that at the center of the housing 110, and the etching rate can also be higher at the end of the housing 110 than at the center of the housing 110.

[0108] In the conventional etching process, a problem (low edge yield problem) may occur in which etching is weakly performed at the edge of the wafer. However, the plasma chamber provided with the side gas feed according to the embodiment of the present invention can prevent the occurrence of the above problem by forming the etching rate at the end of the housing 110 to be higher than that at the center of the housing 110.

[0109] Also, in the conventional etching process, in order to solve the problem (low edge yield problem) that etching is weakly performed at the edge of the wafer, independent RF power is applied, or a heater, a lift device for preventing erosion by plasma of the edge ring, etc. are used.

[0110] However, the plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention can form the etching rate at the end of the housing 110 to be higher than that at the center of the housing 110, so that it is not necessary to use a separate device, and thus there is an advantage that the yield can be improved while reducing the manufacturing cost.

[0111] The plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention is advanced in the process region of Local Electron Kinetics, and the plasma density inside the housing 110 can be made higher from the inside to the outside of the housing 110.

[0112] As a result, a concave etch rate profile can be obtained such that the etch rate is low inside the housing 110 but increases towards the outside of the housing 110. The concave etch rate profile can solve the low edge yield problem where the etch rate decreases at the edge of the housing 110.

[0113] However, if a gas of heavy molecules is injected only through the center gas feed 130, a concave etch rate profile cannot be obtained. That is, when a gas of heavy molecules is present and a gas of heavy molecules is injected from the center gas feed 130, the process region of Local Electron Kinetics can become ineffective.

[0114] The plasma chamber provided with the side gas feed for forming the swirl motion according to an embodiment of the present invention can inject a gas of heavy molecules from the side gas feed 120 in order to solve such problems.

[0115] According to an embodiment of the present invention, the gas injected from the side gas feed 120 can have a molecular weight heavier than the gas injected from the center gas feed 130. Since injecting a gas of heavy molecules from the center gas feed 130 cannot improve the uniformity of the etch rate, it is preferable to inject the gas of heavy molecules through the side gas feed 120.

[0116] Specifically, the gas of the heavy molecule can be injected from the side gas feed 120 to form a downward swirl motion, thereby improving the uniformity of the etch rate.

[0117] Here, the gas injected from the side gas feed 120 can have a molecular weight heavier than that of the gas injected from the center gas feed 130. However, a part of the gas injected from the side gas feed 120 may not be heavier than the gas injected from the center gas feed 130 or may be the same gas as the gas injected from the center gas feed 130.

[0118] That is, the gas of the heavy molecule is injected only through the side gas feed 120, and the general gas that is not the gas of the heavy molecule can be injected from both the side gas feed 120 and the center gas feed 130.

[0119] According to an embodiment of the present invention, the side gas feed 120 includes a nozzle 121 provided with nozzle holes 122 through which the gas is injected, and a plurality of the side gas feeds 120 can be provided in the housing 110.

[0120] According to an embodiment of the present invention, by adjusting the radius of the swirl motion formed by the gas injected from the side gas feed 120 in consideration of the gas injected from the center gas feed 130, it is also possible to affect the plasma density distribution.

[0121] Specifically, by adjusting the radius of the swirl motion formed by the gas injected from the side gas feed 120, the plasma density distribution of the concave etch rate profile can also be adjusted.

[0122] As described above, the plasma chamber provided with the side gas feed for forming the swirl motion according to the embodiment of the present invention has a concave etch rate profile in which the etch rate is low inside the housing 110 but increases toward the outside of the housing 110.

[0123] The concave etch rate profile can be obtained by adjusting the pressure inside the housing 110. According to the embodiment of the present invention, by adjusting the radius of the swirl motion formed by the gas injected from the side gas feed 120 in addition to the factors related to the pressure, the plasma density distribution can also be adjusted with the concave etch rate profile.

[0124] According to the embodiment of the present invention, the side gas feed 120 includes a nozzle 121 provided with a nozzle hole 122 through which gas is injected, and the housing 110 can be provided with a plurality of the side gas feeds 120.

[0125] The plurality of the side gas feeds 120 can be provided at the upper, middle, and lower parts of the housing 110, and the plurality of the side gas feeds 120 can also be provided at one or more of the upper, middle, and lower parts of the housing 110.

[0126] According to an embodiment of the present invention, when the side gas feed 120 is provided at the lower part of the housing 110, the uniformity of the etching rate can be improved. However, when the side gas feed 120 is provided at the lower part of the housing 110, the etching rate may not be effectively improved. Therefore, a plurality of the side gas feeds 120 according to the embodiment of the present invention are preferably arranged at appropriate positions in the upper, middle, and lower parts of the housing 110.

[0127] Referring to FIG. 3, each nozzle 121 of the side gas feed 120 may be provided with a plurality of the nozzle holes 122. The plurality of the nozzle holes 122 provided in the nozzle 121 may have the same size or different sizes.

[0128] According to an embodiment of the present invention, the nozzle hole 122 preferably has a circular shape with a diameter of 0.1 to 1 mm. When the diameter of the nozzle hole 122 is larger than 1 mm, an arcking phenomenon may occur. Therefore, in order to prevent this, the diameter of the nozzle hole 122 is preferably smaller than 1 mm. Also, in order to efficiently inject gas through the nozzle hole 122, the diameter of the nozzle hole 122 is preferably larger than 0.1 mm.

[0129] According to an embodiment of the present invention, the gas injected from the side gas feed 120 can be injected onto the wafer 10 while forming a downward swirl motion in the housing 110. At this time, the gas injected from the side gas feed 120 can form a downward swirl motion while rotating in the clockwise or counterclockwise direction.

[0130] The plasma chamber equipped with a side gas feed according to an embodiment of the present invention uses the side gas feed 120 with inductively coupled plasma (ICP), and the gas injected from the side gas feed 120 can form a downward swirl motion.

[0131] The plasma chamber equipped with a side gas feed according to an embodiment of the present invention, in which the gas injected from the side gas feed 120 forms a downward swirl motion, can be applied to metal etch, oxide etch, and poly etch to improve the etch rate.

[0132] In addition, the side gas feed 120 that injects gas to form a downward swirl motion can also be applied to plasma processes such as plasma deposition, PR stripping, and plasma doping.

[0133] The plasma chamber equipped with a side gas feed that forms a swirl motion according to an embodiment of the present invention described above has the following effects.

[0134] The plasma chamber equipped with a side gas feed that forms a swirl motion according to an embodiment of the present invention described above has the advantage that by adjusting the injection direction of the gas injected from the side gas feed toward the wall surface of the housing, the gas injected from the nozzle can form a swirl motion in the chamber to maintain a uniform etch rate inside the chamber.

[0135] In addition, a plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention has an advantage that the gas ejected from a nozzle can form a swirl motion in the chamber by adjusting the direction of the gas ejected from one side gas feed provided in the housing to the direction of another side gas feed adjacent to the one side gas feed, whereby a uniform etching rate can be maintained inside the chamber.

[0136] In addition, a plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention has an advantage that it can prevent the gas ejected from the side gas feed from hitting the wall surface of the housing by adjusting the ejection direction of the gas ejected from the side gas feed so as to face the wall surface of the housing and forming the velocity or flow rate of the gas ejected from one side gas feed to reach another adjacent side gas feed.

[0137] In addition, a plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention has an advantage that the gas ejected from one side gas feed can form a swirl motion by receiving a force from another side gas feed by forming the velocity or flow rate of the gas ejected from one side gas feed to reach another adjacent side gas feed.

[0138] At the same time, a plasma chamber provided with a side gas feed for forming a swirl motion according to an embodiment of the present invention has an advantage that it can improve the etching rate while improving the uniformity of the etching rate by simultaneously using a side gas feed and a center gas feed in the chamber and ejecting a gas of heavy molecules through the side gas feed.

[0139] The plasma chamber equipped with a side gas feed that forms a swirl motion according to an embodiment of the present invention can obtain an effect similar to that of using a Confinement Ring or an electromagnet by forming a swirl motion. The process of using a Confinement Ring can also be expected to enhance Plasma density and Edge etch rate by directly controlling the space where the process occurs.

[0140] The process of using an electromagnet can control the escape of electrons from the wall surface of the housing by arranging electromagnets around the chamber.

[0141] The plasma chamber equipped with a side gas feed that forms a swirl motion according to an embodiment of the present invention has the advantage of being able to obtain an effect similar to that of using a Confinement Ring or an electromagnet by forming a swirl motion.

[0142] In addition, the plasma chamber equipped with a side gas feed that forms a swirl motion according to an embodiment of the present invention can effectively improve the uniformity of the etching rate when performing metal etch or oxide etch, and can also contribute to the density of radicals and ions by increasing the number of side gas feeds.

[0143] As described above, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and those with ordinary knowledge in the art will understand that various modifications and variations of the embodiments are possible from now on. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the appended claims.

Claims

1. In a plasma chamber in which plasma is formed to etch a wafer, a housing provided with a mounting portion on which the wafer is mounted, a side gas feed provided on a side surface of the housing and injecting gas into the housing, the housing is provided with a plurality of the side gas feeds, the side gas feed includes a nozzle provided with a nozzle hole through which gas is injected, the side gas feed is provided with a side gas feed that forms a swirl motion by injecting gas toward the wall surface of the housing. A plasma chamber having a side gas feed for forming a swirl motion, characterized in that.

2. The plurality of side gas feeds provided in the housing are provided at the same height from the mounting portion, and a plasma chamber having a side gas feed for forming a swirl motion according to claim 1, characterized in that.

3. The direction of the gas injected from the side gas feed is a direction on a plane extending in a direction parallel to a plane formed by the mounting portion on which the wafer is mounted, and a plasma chamber having a side gas feed for forming a swirl motion according to claim 2, characterized in that.

4. When any one of the plurality of side gas feeds provided in the housing is a first side gas feed and a side gas feed adjacent to the first side gas feed is a second side gas feed, the first side gas feed injects gas in the direction of the second side gas feed, and a plasma chamber having a side gas feed for forming a swirl motion according to claim 2, characterized in that.

5. Of the plurality of the side gas feeds provided in the housing, any one is defined as the first side gas feed, the side gas feed adjacent to the first side gas feed is defined as the second side gas feed, and when a side gas feed adjacent to the second side gas feed in the direction opposite to the direction in which the first side gas feed is adjacent is defined as the third side gas feed, The plasma chamber provided with the side gas feed for forming a swirl motion according to claim 2, wherein the first side gas feed injects gas in a direction between the second side gas feed and the third side gas feed.

6. The plasma chamber provided with the side gas feed for forming a swirl motion according to claim 2, wherein the housing is provided with n side gas feeds (n is a natural number of 3 or more, and n is the number of side gas feeds).

7. The plasma chamber provided with the side gas feed for forming a swirl motion according to claim 2, wherein the plurality of the side gas feeds provided in the housing are provided in the form of a regular polygon in the housing.

8. When the number of the side gas feeds provided at the same height from the placement portion is n, The plasma chamber provided with the side gas feed for forming a swirl motion according to claim 2, wherein an angle formed by one side gas feed and two side gas feeds adjacent to both sides of the side gas feed is 180×(n−2) / n degrees (n≧3).

9. The plasma chamber provided with the side gas feed for forming a swirl motion according to claim 1, further including a center gas feed provided at an upper portion of the housing and injecting gas into the housing.

10. The gas injected from the side gas feed The plasma chamber provided with a side gas feed that forms a swirl motion according to claim 9, characterized in that the gas is a gas having a molecular weight heavier than the gas injected from the center gas feed.

11. The plasma formed in the internal space of the housing contains ions and radicals, The plasma chamber provided with a side gas feed that forms a swirl motion according to claim 1, characterized in that the wafer is etched by the synergistic effect of the ions and the radicals.

12. The plasma chamber provided with a side gas feed that forms a swirl motion according to claim 1, characterized in that the nozzle hole has a circular shape with a diameter of 0.1 to 1 mm.

13. The side gas feed provided in the housing includes The plasma chamber provided with a side gas feed that forms a swirl motion according to claim 1, characterized in that a controller for adjusting the flow rate or velocity of the gas injected from the side gas feed is provided.

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