Plasma filtering device and filtering method

Abstract

The invention relates to a plasma filtering device and a filtering method, the plasma filtering device comprises a first passage and a second passage located in a plasma filtering device body, a baffle is arranged between the first passage and the second passage, the baffle is provided with an opening capable of adjusting the opening degree, and when the opening is closed, the second passage is closed. The plasma is firstly diffused upwards in the first channel after being formed, crosses the top of the baffle plate and then flows downwards in the second channel, and when the plasma is diffused upwards in the first channel, part of the plasma collides with the side wall of the first channel and is filtered and removed, so that the plasma density is reduced, and the damage to the substrate can be reduced; when the opening is opened, at least part of plasma is formed in the first channel and then can directly enter the second channel through the opening, the plasma density can be increased, and the reaction rate is increased.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing, and in particular to a plasma filtering device and a filtering method. Background Art

[0002] In the chip manufacturing process, plasma is used in many processes, such as plasma etching, plasma stripping, plasma thin film deposition, etc. Some process steps have strict requirements on ion damage. Too high plasma density will lead to severe ion bombardment on the substrate and accumulation of too much charge on the substrate, causing substrate breakdown damage. Some process steps require high reaction rate, and the thin film on the substrate surface is stable and hard enough, and ion bombardment will not damage the substrate. At this time, increasing the plasma density can improve the reaction activity and increase the reaction rate. The existing equipment cannot take into account the different plasma density requirements of different process steps. Summary of the invention

[0003] Based on this, in order to solve the above problems, the present invention provides a plasma filtering device and a filtering method.

[0004] The present invention provides a plasma filter device, comprising: a first passage and a second passage located in a body of the plasma filter device, a baffle plate is arranged between the first passage and the second passage, and an opening with adjustable opening is arranged on the baffle plate. When the opening is closed, plasma diffuses upward in the first passage and passes over the top of the baffle plate before flowing downward in the second passage after being formed, so that the degree of ion damage is reduced and the reaction rate is reduced; when the opening is opened, at least part of the plasma directly enters the second passage through the opening after being formed in the first passage, so that the degree of ion damage is increased and the reaction rate is increased. The baffle plate comprises an upper baffle plate and a lower baffle plate, and a gap between the upper baffle plate and the lower baffle plate constitutes the opening. The baffle plate also comprises a lifting device, which is connected to the upper baffle plate through a lifting component, and the relative position between the upper baffle plate and the lower baffle plate is adjusted by lifting / lowering the lifting component by the lifting device to adjust the opening. When the upper baffle plate and the lower baffle plate are closed, the opening is closed; when the upper baffle plate and the lower baffle plate are separated, the opening is opened.

[0005] The plasma filtering device can switch between high plasma density and low plasma density. When the opening is closed, after the plasma is formed, it diffuses upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage. When the plasma diffuses upward in the first passage, part of the plasma collides with the side wall of the first passage and is filtered and removed, thereby reducing the plasma density and reducing damage to the substrate. When the opening is opened, at least part of the plasma can directly enter the second passage through the opening after being formed in the first passage, thereby increasing the plasma density and improving the reaction rate.

[0006] In one embodiment, a control module is further included to control the opening degree of the opening. When the opening is closed, the ion damage degree is reduced and the reaction rate is reduced; when the opening is opened, the ion damage degree is increased and the reaction rate is increased. The opening degree of the opening can be controlled in real time according to demand, and the low substrate damage and high reaction rate can be switched at any time according to demand.

[0007] In one embodiment, a plasma density detection module is further included, which is used to detect the plasma density signal in the reaction chamber of the plasma filter device. The control module includes a signal receiving unit, a signal processing unit, and an execution unit. The signal receiving unit is used to receive the plasma density signal and transmit it to the signal processing unit. The signal processing unit judges and processes the plasma density signal. When the plasma density signal is greater than a preset value, an opening closing instruction is issued to the execution unit; when the plasma density signal is less than a preset value, an opening opening instruction is issued to the execution unit. The execution unit is used to receive and execute the opening closing instruction / opening instruction issued by the signal processing unit. The opening opening can be automatically adjusted according to the preset value, and a trade-off between low substrate damage and high reaction rate can be automatically made to achieve the expected comprehensive effect.

[0008] In one embodiment, the first passage is located outside the second passage, and the plasma filter device body is located above the wafer.

[0009] In one embodiment, when the opening is closed, after the plasma is formed, it first swirls and diffuses upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage. The swirl of the plasma in the first passage can increase the probability of the plasma colliding with the side wall of the first passage, and can further remove part of the plasma.

[0010] In one embodiment, the cross-sectional area of ​​the upper portion of the second passage is smaller than the cross-sectional area of ​​the lower portion of the second passage, the shape of the plasma filter body includes a truncated cone, and the shape of the first passage includes a hollow truncated cone. The smaller cross-sectional area of ​​the upper portion of the second passage can reduce the probability of plasma entering the first passage when the opening is closed.

[0011] In one embodiment, the baffle includes an inclined surface, and when the opening is closed, after the plasma is formed, it diffuses obliquely upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage. The baffle including an inclined surface can increase the probability of extinguishing the plasma and the baffle, and can further remove part of the plasma.

[0012] In one embodiment, the baffle is grounded, the baffle comprises a conductor baffle, and the baffle comprises one or a combination of aluminum baffles, aluminum nitride baffles, and aluminum oxide baffles. The baffle is grounded to extinguish charged ions in contact with it and to guide the generated charge.

[0013] In one embodiment, the second passage is provided with a filter plate, the filter plate has at least one layer, the filter plate is provided with a through hole, the through hole includes a straight through hole or a curved through hole. The filter plate can further filter and remove part of the plasma, and the curved through hole can further filter and remove part of the plasma.

[0014] In one embodiment, an upper filter plate is disposed at the top of the second passage, and a lower filter plate is disposed at the bottom of the second passage, so as to further filter and remove part of the plasma.

[0015] In one embodiment, an air inlet is provided at the lower end of the first passage, and the gas entering from the air inlet is excited to form plasma in the first passage. The number of the air inlets includes several, and the several air inlets are centrally symmetrically distributed on the periphery of the second passage. The direction of the air inlet points horizontally to the central axis of the second passage, or the angle between the direction of the air inlet and the direction from the position of the air inlet to the central axis of the second passage is greater than 0 degrees and less than or equal to 90 degrees. The air inlet is provided at the lower end to further increase the probability of plasma colliding with the baffle when the opening is closed. The angle between the direction of the air inlet and the direction from the position of the air inlet to the central axis of the second passage is greater than 0 degrees and less than or equal to 90 degrees, which can make the plasma vortex in the first passage when the opening is closed, and can further increase the probability of plasma colliding with the side wall of the first passage.

[0016] In one embodiment, a coupling coil is disposed outside the lower end of the first passage, and the gas entering from the gas inlet is excited at the coupling coil in the first passage to form plasma. The coupling coil is disposed outside the lower end of the first passage to further increase the probability of plasma extinguishing with the side wall of the first passage when the opening is closed.

[0017] In one embodiment, the top of the opening is lower than the top of the coupling coil. The top of the opening is lower than the top of the coupling coil, so that when the opening is opened, more plasma can directly enter the second passage through the opening after being formed, thereby increasing the plasma density and improving the reaction rate.

[0018] The present invention also provides a plasma filtering method, comprising: using the above-mentioned plasma filtering device to filter plasma.

[0019] In the above plasma filtering method, when the opening is closed, after the plasma is formed, it diffuses upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage. When the plasma diffuses upward in the first passage, part of the plasma collides with the side wall of the first passage and is filtered and removed, thereby reducing the plasma density and reducing damage to the substrate. When the opening is opened, at least part of the plasma can directly enter the second passage through the opening after being formed in the first passage, thereby increasing the plasma density and improving the reaction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of the plasma filter device of the present invention when the opening is closed;

[0021] Figure 2 It is a cross-sectional view of the plasma filter device of the present invention when the opening is opened;

[0022] Figure 3 A top view of a baffle in a first embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the opening closing in the first embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the opening in the first embodiment of the present invention;

[0025] Figure 6 A top view of a baffle in a second embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the opening closing in the second embodiment of the present invention;

[0027] Figure 8This is a schematic diagram of the opening in the second embodiment of the present invention;

[0028] Figure 9a A side view of the baffle when the opening is opened in the second embodiment of the present invention;

[0029] Figure 9b A side view of the baffle when the opening is closed in the second embodiment of the present invention;

[0030] Fig.10a The second embodiment of the present invention Figure 8 A magnified view of part A;

[0031] Fig.10b The second embodiment of the present invention Figure 7 A magnified view of part A;

[0032] Fig.11a The second embodiment of the present invention Figure 8 A magnified view of part A;

[0033] Fig.11b The second embodiment of the present invention Figure 7 A magnified view of part A;

[0034] Fig.12 is a cross-sectional view of a filter plate in a plasma filter device of the present invention;

[0035] In the figure: 10, plasma filter body; 101, baffle; 1011, opening; 1012, upper baffle; 1013, lower baffle; 1014, slide; 1015, first side; 10151, first convex strip; 10152, first concave strip; 1016, second side; 10161, second convex strip; 10162, second concave strip; 1017, joint; 102, filter plate; 1021, upper filter plate; 1022, lower filter plate; 1023, through hole; 20, first passage; 30, second passage; 40, wafer; 50, air inlet; 60, coupling coil; 70, lifting wire; 80 lifting device. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0038] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the method or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In the plasma etching and plasma stripping processes, some process steps have strict requirements on ion damage. Too high plasma density will lead to severe ion bombardment on the substrate and accumulation of too much charge on the substrate, causing substrate breakdown damage. However, some process steps require a high reaction rate. The thin film on the substrate surface is stable and hard enough, and ion bombardment will not damage the substrate. At this time, increasing the ion density can improve the reaction activity and increase the reaction rate.

[0040] An embodiment, such as Figures 1 to 12 As shown, a plasma filter device is provided, comprising: a first passage 20 and a second passage 30 located in a plasma filter device body 10, a baffle 101 is arranged between the first passage 20 and the second passage 30, and an opening 1011 with an adjustable opening is arranged on the baffle 101, as shown in FIG. Figure 1 As shown, when the opening 1011 is closed, after the plasma is formed, it diffuses upward in the first passage 20, passes over the top of the baffle 101, and then flows downward in the second passage 30; Figure 2 As shown, when the opening 1011 is opened, at least a portion of the plasma formed in the first passage 20 directly enters the second passage 30 through the opening 1011 .

[0041] In the present embodiment, in the above-mentioned plasma filtering device, when the opening 1011 is closed, after the plasma is formed, it diffuses upward in the first passage 20, passes over the top of the baffle 101, and then flows downward in the second passage 30. When the plasma diffuses upward in the first passage 20, part of the plasma collides with the side wall of the first passage 20 and is filtered and removed, thereby reducing the plasma density and reducing the damage to the substrate; when the opening 1011 is opened, at least part of the plasma can directly enter the second passage 30 through the opening 1011 after being formed in the first passage 20, thereby increasing the plasma density and improving the reaction rate.

[0042] In one embodiment, a control module is further included to control the opening of the opening 1011. When the opening 1011 is closed, the ion damage degree is reduced and the reaction rate is reduced; when the opening 1011 is opened, the ion damage degree is increased and the reaction rate is increased. The opening of the opening 1011 can be controlled in real time according to demand, and the low substrate damage and high reaction rate can be switched at any time according to demand.

[0043] The position of the control module is not limited, and the control module can be located inside the reaction chamber or outside the reaction chamber.

[0044] In one embodiment, a plasma density detection module is further included, which is used to detect the plasma density signal in the reaction chamber of the plasma filter device. The control module receives the plasma density signal and controls the opening of the opening 1011 according to the plasma density signal. When the plasma density signal is greater than a preset value, the control module controls the opening 1011 to be closed; when the plasma density signal is less than the preset value, the control module controls the opening 1011 to be opened. The opening of the opening 1011 can be automatically adjusted according to the preset value, and a trade-off between low substrate damage and high reaction rate can be automatically made to achieve the expected comprehensive effect.

[0045] The control module includes a signal receiving unit, a signal processing unit, and an execution unit. The signal receiving unit is used to receive a plasma density signal and transmit it to the signal processing unit. The signal processing unit judges and processes the plasma density signal. When the plasma density signal is greater than a preset value, an opening 1011 closing instruction is sent to the execution unit; when the plasma density signal is less than the preset value, an opening 1011 opening instruction is sent to the execution unit. The execution unit is used to receive and execute the opening 1011 closing instruction / opening 1011 opening instruction issued by the signal processing unit.

[0046] In one embodiment, the plasma density detection module includes an ion density analysis system, which can characterize the degree of substrate ion damage.

[0047] In one embodiment, the plasma density detection module includes a Langmuir probe.

[0048] In one embodiment, the opening degree of the opening 1011 can also be adjusted manually.

[0049] The first embodiment, as Figure 3 to Figure 5As shown, the baffle 101 includes an upper baffle 1012 and a lower baffle 1013, and the gap between the upper baffle 1012 and the lower baffle 1013 constitutes an opening 1011. The baffle 101 also includes a lifting device 80, and the lifting device 80 is connected to the upper baffle 1012 through a lifting component. The lifting device 80 lifts / lowers the lifting component to adjust the relative position between the upper baffle 1012 and the lower baffle 1013 to adjust the opening 1011. When the upper baffle 1012 and the lower baffle 1013 are closed, the opening 1011 is closed; when the upper baffle 1012 and the lower baffle 1013 are separated, the opening 1011 is opened.

[0050] In one embodiment, the lifting member comprises a lifting wire.

[0051] The lifting member may also be a rigid structure.

[0052] The upper baffle 1012 is connected to the lifting device 80 through the pulling line 70. When the opening 1011 needs to be opened, the lifting device 80 retracts the pulling line 70, the corresponding upper baffle 1012 will be lifted, the distance between the upper baffle 1012 and the lower baffle 1013 will be increased, and the opening 1011 will be opened; when the opening 1011 needs to be closed, the lifting device 80 relaxes the pulling line 70, the corresponding upper baffle 1012 will be lowered, the distance between the upper baffle 1012 and the lower baffle 1013 will be closed, and the opening 1011 will be closed.

[0053] The opening degree of the opening 1011 can also be adjusted by manually pulling the lower pulling wire 70 .

[0054] The second embodiment, as Figures 7-8 , Figure 9a-9b As shown, a slide 1014 is provided at a position corresponding to the opening 1011 on the baffle 101, and also includes a driving device, which is connected to the slide 1014. The opening of the opening 1011 is adjusted by adjusting the position of the slide 1014 by the driving device. When the slide 1014 completely covers the opening 1011, the opening 1011 is closed; when the slide 1014 does not completely cover the opening 1011, the opening 1011 is opened.

[0055] In one embodiment, the driving device includes a cylinder, which is connected to the slide 1014 and drives the slide 1014 to move. When the slide 1014 moves to completely cover the opening 1011, the opening 1011 is closed; when the slide 1014 moves to not completely cover the opening 1011, the opening 1011 is opened.

[0056] The position of the slide 1014 can also be manually adjusted to adjust the opening degree of the opening 1011 , for example, the slide 1014 can be pushed up to close the opening 1011 , and the slide 1014 can be pulled down to open the opening 1011 .

[0057] In one embodiment, the opening 1011 may be opened / closed along a horizontal direction or a vertical direction.

[0058] In one embodiment, Figure 6 As shown, the number of openings 1011 is greater than or equal to 3. For example, the number of openings 1011 can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, or 20.

[0059] In the second embodiment, if Figure 10a to Figure 11b As shown, when the opening 1011 is closed, the first side 1015 of the joint 1017 includes at least one first convex strip 10151 and at least one first concave strip 10152. For example, the number of the first convex strips 10151 can be 1, 2, 3, 4, 5, 6, 8, or 10, and the number of the first concave strips 10152 can be 1, 2, 3, 4, 5, 6, 8, or 10. The second side 1016 joined to the first side 1015 includes a second concave strip 10162 joined to the first convex strip 10151 and a second convex strip 10161 joined to the first concave strip 10152. When the opening 1011 is closed, plasma cannot enter the second passage 30 through the joint 1017 of the opening 1011.

[0060] In one embodiment, directions of the first convex strip 10151 , the first concave strip 10152 , the second convex strip 10161 , and the second concave strip 10162 are all perpendicular to the direction in which the opening 1011 enters the plasma.

[0061] In one embodiment, Figures 10a to 10b As shown, when the opening 1011 is closed, the first side edge 1015 of the joint 1017 includes a first concave strip 10152 located in the middle and first convex strips 10151 located on both sides of the first concave strip 10152, and the second side edge 1016 joined to the first side edge 1015 includes a second convex strip 10161 located in the middle and joined to the first concave strip 10152 and second concave strips 10162 located on both sides and joined to the first convex strip 10151. When the opening 1011 is closed, plasma cannot enter the second passage 30 through the joint 1017 of the opening 1011.

[0062] In one embodiment, Figure 11a to Figure 11bAs shown, when the opening 1011 is closed, the first side edge 1015 of the joint 1017 includes a first convex strip 10151 located on one side and a first concave strip 10152 located on the other side and adjacent to the first convex strip 10151, and the second side edge 1016 joined to the first side edge 1015 includes a second concave strip 10162 joined to the first convex strip 10151 and a second convex strip 10161 joined to the first concave strip 10152. When the opening 1011 is closed, plasma cannot enter the second passage 30 through the joint 1017 of the opening 1011.

[0063] In one embodiment, the first passage 20 is located outside the second passage 30 .

[0064] In one embodiment, the plasma filter body 10 is located above the wafer 40 .

[0065] In one embodiment, when the opening 1011 is closed, after the plasma is formed, it first swirls and diffuses upward in the first passage 20, passes over the top of the baffle 101, and then flows downward in the second passage 30. The swirl of the plasma in the first passage 20 can increase the probability of the plasma colliding with the side wall of the first passage 20, and can further remove part of the plasma.

[0066] In one embodiment, the cross-sectional area of ​​the upper portion of the second passage 30 is smaller than the cross-sectional area of ​​the lower portion of the second passage 30. The smaller cross-sectional area of ​​the upper portion of the second passage 30 can reduce the probability of plasma entering the first passage 20 when the opening 1011 is closed.

[0067] In one embodiment, the shape of the plasma filter body 10 includes a truncated cone.

[0068] In one embodiment, the shape of the first passage 20 comprises a hollow truncated cone.

[0069] In one embodiment, the baffle 101 includes an inclined surface, and when the opening 1011 is closed, the plasma, after being formed, diffuses upward in the first passage 20, passes over the top of the baffle 101, and then flows downward in the second passage 30. The baffle 101 is grounded to extinguish charged ions in contact with it and conduct the generated charges.

[0070] In one embodiment, the baffle 101 is grounded. The grounding of the baffle 101 increases the probability of plasma extinguishing with the baffle 101 and conducts away the charges generated by the extinguishing.

[0071] In one embodiment, the baffle 101 includes a conductor baffle 101 , and the baffle 101 includes one or a combination of an aluminum baffle 101 , an aluminum nitride baffle 101 , and an aluminum oxide baffle 101 .

[0072] In one embodiment, the second passage 30 is provided with a filter plate 102, and the number of layers of the filter plate 102 includes at least 1. The filter plate 102 can further filter and remove part of the plasma.

[0073] In one embodiment, the filter plate 102 is provided with a through hole 1023, and the through hole 1023 includes a straight through hole 1023 or a curved through hole 1023. The curved through hole 1023 can further filter and remove part of the plasma, such as Fig.12 shown.

[0074] In one embodiment, an upper filter plate 1021 is disposed at the top of the second passage 30, and a lower filter plate 1022 is disposed at the bottom of the second passage 30. Part of the plasma can be further filtered and removed.

[0075] In one embodiment, the lower end of the first passage 20 is provided with an air inlet 50, and the gas entering from the air inlet 50 is excited to form plasma in the first passage 20. The lower end is provided with an air inlet 50 to further increase the probability of plasma extinguishing with the baffle 101 when the opening 1011 is closed.

[0076] In one embodiment, the number of the air inlets 50 includes a plurality.

[0077] In one embodiment, a plurality of air inlets 50 are centrally symmetrically distributed around the outer periphery of the second passage 30 .

[0078] In one embodiment, the air inlet 50 is directed horizontally toward the central axis of the second passage 30 .

[0079] In one embodiment, the angle between the direction of the air inlet 50 and the direction horizontally pointing from the position of the air inlet 50 to the central axis of the second passage 30 is greater than 0 degrees and less than or equal to 90 degrees. For example, the angle between the direction of the air inlet 50 and the direction horizontally pointing from the position of the air inlet 50 to the central axis of the second passage 30 can be 10 degrees, 20 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. The angle between the direction of the air inlet 50 and the direction horizontally pointing from the position of the air inlet 50 to the central axis of the second passage 30 is greater than 0 degrees and less than or equal to 90 degrees, which can make the plasma vortex in the first passage 20 when the opening 1011 is closed, and can further increase the probability of plasma colliding with the side wall of the first passage 20.

[0080] In one embodiment, a coupling coil 60 is disposed outside the lower end of the first passage 20, and the gas entering from the gas inlet 50 is excited to form plasma at the coupling coil 60 in the first passage 20. The coupling coil 60 disposed outside the lower end of the first passage 20 can further increase the probability of plasma extinguishing with the side wall of the first passage 20 when the opening 1011 is closed.

[0081] In one embodiment, the top of the opening 1011 is lower than the top of the coupling coil 60. The top of the opening 1011 is lower than the top of the coupling coil 60, so that when the opening 1011 is opened, more plasma can directly enter the second passage 30 through the opening 1011 after being formed, thereby increasing the plasma density and improving the reaction rate.

[0082] In one embodiment, the sidewall of the first via 20 is grounded. The sidewall grounding will increase the probability of plasma extinguishing with the sidewall and lead out the charge generated by the extinguishing.

[0083] In one embodiment, the generatrix of the baffle 101 includes a straight line, a curve, or a combination thereof. The curve can further increase the probability of extinguishing the plasma and the baffle 101 .

[0084] In one embodiment, the filter plate 102 may also be a curved surface, and the cross section of the filter plate 102 may be an arc, a curve, etc.

[0085] In one embodiment, the number of layers of the filter plate 102 includes at least 1 layer, for example, the number of layers of the filter plate 102 may be 1 layer, 2 layers, 3 layers, 4 layers, 5 layers, or 6 layers, so as to further filter and remove part of the plasma.

[0086] In one embodiment, the filter plate 102 is provided with through holes 1023, and the shape of the through holes 1023 includes one or a combination of circular, rectangular, and polygonal. The through holes 1023 can be evenly distributed or non-evenly distributed, for example, the distribution density of the central area of ​​the filter plate 102 is greater than the distribution density of the edge area, or the distribution density of the central area of ​​the filter plate 102 is less than the distribution density of the edge area.

[0087] In one embodiment, the diameter of the through hole 1023 is between 0.1 mm and 10 mm. For example, the diameter of the through hole 1023 can be 0.1 mm, 1 mm, 2 mm, 4 mm, 5 mm, 8 mm, or 10 mm.

[0088] In one embodiment, the width of the opening 1011 is between 1 mm and 100 mm. For example, the width of the opening 1011 may be 1 mm, 10 mm, 20 mm, 30 mm, 50 mm, 70 mm, 80 mm, or 100 mm.

[0089] In one embodiment, the number of the air inlets 50 is at least four. For example, the number of the air inlets 50 may be four, five, six, seven, eight, ten, or twelve.

[0090] One embodiment provides a plasma filtering method, comprising: filtering plasma using the above-mentioned plasma filtering device.

[0091] In the present embodiment, in the above-mentioned plasma filtering method, when the opening 1011 is closed, after the plasma is formed, it diffuses upward in the first passage 20, passes over the top of the baffle 101, and then flows downward in the second passage 30. When the plasma diffuses upward in the first passage 20, part of the plasma collides with the side wall of the first passage 20 and is filtered and removed, thereby reducing the plasma density and reducing the damage to the substrate. When the opening 1011 is opened, at least part of the plasma can directly enter the second passage 30 through the opening 1011 after being formed in the first passage 20, thereby increasing the plasma density and improving the reaction rate.

[0092] In one embodiment, when low substrate damage and low reaction rate are required, the opening 1011 is closed; when a high reaction rate is required, the opening 1011 is opened; when moderate substrate damage and reaction rate are required, the opening 1011 is partially opened.

[0093] The plasma filtering device and filtering method can be applied to processes such as plasma etching and plasma stripping.

[0094] Plasma etching: In a typical plasma etching process, different process gas combinations (such as CxFy, O2, Ar, etc.) are excited by radio frequency to form plasma in a radio frequency environment. The formed plasma physically bombards and chemically reacts with the surface of the wafer 40 under the action of the electric field of the upper and lower electrodes in the etching chamber, completing the etching process of the designed pattern on the surface of the wafer 40. Typical etching chambers include capacitively coupled chambers (CCP) and inductively coupled chambers (ICP).

[0095] Plasma stripping: A plasma stripper is a device that uses plasma technology to remove surface materials. Stripping is a surface treatment technology used to remove residual photoresist on the surface of the wafer 40 to provide a clean surface of the wafer 40 for subsequent processes. The principle of the plasma stripper is to generate plasma through discharge and introduce it into the stripping area. The organic matter on the surface of the material reacts with the activated plasma and is oxidized and decomposed into gas, thereby achieving the purpose of removing the photoresist on the surface of the wafer 40.

[0096] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A plasma filtering device, characterized in that: include: a first passage and a second passage located in a plasma filter body, a baffle is provided between the first passage and the second passage, an opening with an adjustable opening is provided on the baffle, when the opening is closed, plasma diffuses upward in the first passage first and passes over the top of the baffle before flowing downward in the second passage after being formed, the degree of ion damage is reduced and the reaction rate is reduced; when the opening is opened, at least part of the plasma directly enters the second passage through the opening after being formed in the first passage, the degree of ion damage is increased and the reaction rate is increased, the baffle comprises an upper baffle and a lower baffle, the gap between the upper baffle and the lower baffle constitutes the opening, and further comprises a lifting device, the lifting device is connected to the upper baffle through a lifting component, the lifting device lifts / lowers the lifting component to adjust the relative position between the upper baffle and the lower baffle to adjust the opening, and when the upper baffle and the lower baffle are closed, the opening is closed; When the upper baffle plate and the lower baffle plate are separated, the opening is opened.

2. A plasma filtering device according to claim 1, characterized in that: The invention also includes a control module for controlling the opening of the opening, and a plasma density detection module for detecting a plasma density signal in a reaction chamber of the plasma filtering device. The control module includes a signal receiving unit, a signal processing unit, and an execution unit. The signal receiving unit is used to receive the plasma density signal and transmit it to the signal processing unit. The signal processing unit performs judgment processing on the plasma density signal. When the plasma density signal is greater than a preset value, an opening closing instruction is issued to the execution unit; when the plasma density signal is less than a preset value, an opening opening instruction is issued to the execution unit. The execution unit is used to receive and execute the opening closing instruction / opening instruction issued by the signal processing unit.

3. A plasma filtering device according to claim 1, characterized in that: The first passage is located outside the second passage, the plasma filter device body is located above the wafer, the cross-sectional area of ​​the upper part of the second passage is smaller than the cross-sectional area of ​​the lower part of the second passage, the shape of the plasma filter device body includes a truncated cone, the shape of the first passage includes a hollow truncated cone, the baffle is grounded, the baffle includes a conductor baffle, the baffle includes one or a combination of aluminum baffles, aluminum nitride baffles, and aluminum oxide baffles, the second passage is provided with a filter plate, the number of layers of the filter plate includes at least 1 layer, the filter plate is provided with a through hole, the through hole includes a straight through hole or a curved through hole, the top of the second passage is provided with an upper filter plate, and the bottom of the second passage is provided with a lower filter plate.

4. A plasma filtering device according to claim 1, characterized in that: When the opening is closed, after being formed, plasma first swirls and diffuses upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage.

5. The plasma filtering device according to claim 1, characterized in that: The baffle includes an inclined surface. When the opening is closed, after being formed, the plasma diffuses obliquely upward in the first passage, passes over the top of the baffle, and then flows downward in the second passage.

6. The plasma filtering device according to claim 1, characterized in that: An air inlet is provided at the lower end of the first passage, and the gas entering from the air inlet is excited to form plasma in the first passage. The number of the air inlets includes several, and the several air inlets are centrally symmetrically distributed on the periphery of the second passage. A coupling coil is provided on the outer side of the lower end of the first passage, and the gas entering from the air inlet is excited to form plasma at the coupling coil in the first passage, and the top of the opening is lower than the top of the coupling coil.

7. A plasma filtering method, characterized in that: The plasma is filtered using a plasma filtering device as claimed in any one of claims 1 to 6.

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