Wafer processing device and wafer processing method

Abstract

The invention relates to a wafer processing device and a wafer processing method. The wafer processing device comprises a shell and a reaction cavity formed by wrapping the shell. The reaction cavity is divided into an upper cavity body and a lower cavity body by a filtering device; the filtering device comprises a filtering baffle, and one or more filtering holes penetrating through the filtering baffle are formed in the filtering baffle; and the reaction rate control system is used for controlling the opening and partial closing of the filtering holes, so that the throughput of charged particles in the plasma and the reaction rate are adjusted. The machining device is adopted in the machining method. The problem that ion damage and processing efficiency are difficult to consider at the same time in the prior art is effectively solved by optimizing the filtering and control mechanism of the plasma, and the method has important application value.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer processing device and a wafer processing method. Background Art

[0002] Plasma, also known as plasma, is an ionized gaseous substance composed of positive and negative ions, electrons, free radicals, central particles, etc. generated by the ionization of atoms and atomic groups; it is a macroscopic electrically neutral ionized gas with a scale greater than the Debye length, its movement is mainly dominated by electromagnetic forces, and it exhibits significant collective behavior. Plasma has important applications in the semiconductor industry, especially in the wafer processing process, involving a variety of equipment and processes, such as semiconductor plasma degumming equipment, plasma etching equipment, and plasma thin film deposition equipment. However, when using plasma, existing equipment is often prone to ion damage to the wafer substrate due to process limitations. If the ion damage is reduced, the reaction rate will decrease. Therefore, how to achieve a balance between low ion damage and high reaction rate has become a technical problem that needs to be solved urgently for existing equipment. In addition, as semiconductor manufacturing processes develop towards higher precision and smaller sizes, the performance requirements for plasma equipment are also increasing, further exacerbating the complexity of this problem. Summary of the invention

[0003] Based on this, in order to solve the above problems, the present invention provides a wafer processing device and a wafer processing method, which effectively reduce ion damage by optimizing the filtering and control mechanism of plasma while maintaining a high processing efficiency.

[0004] The present invention provides a wafer processing device, comprising: a shell and a reaction chamber formed by wrapping the shell; The reaction chamber is divided into an upper chamber and a lower chamber by a filtering device; The filter device comprises a filter baffle, and the filter baffle is provided with one or more filter holes penetrating the filter baffle; A reaction rate control system is also included, which controls the opening and partial closing of the filter holes to adjust the charged particle throughput and reaction rate in the plasma.

[0005] In some embodiments, a first groove is provided on a hole wall on one side of each filter hole, and a second groove is provided on a hole wall on the other side opposite to the filter hole; A first slider is arranged in the first groove, the first slider comprises a first extension part and a first connection part, the first connection part is slidably connected with the filter baffle, and the first extension part extends out of the first groove into the filter hole by sliding in the first groove; A second slider is arranged in the second groove, the second slider comprises a second extension part and a second connection part, the second connection part is slidably connected with the filter baffle, and the second extension part extends out of the second groove into the filter hole by sliding in the second groove; The reaction rate control system controls the sliding of the first slider and the second slider, and controls the opening and partial closing of the filter hole through the intersection and separation of the first protrusion and the second protrusion in the filter hole.

[0006] In some embodiments, the first extension portion includes an upper blocking block and a lower blocking block, and the horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter hole; the second extension portion is a protrusion, and the distance between the upper blocking block and the lower blocking block is greater than the thickness of the protrusion.

[0007] In some other embodiments, the first protruding portion is an upper blocking block, the second protruding portion is a lower blocking block, the horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter hole, and the bottom of the upper blocking block is higher in the vertical direction than the top of the lower blocking block.

[0008] In some other embodiments, each filter hole further includes a blocking sheet, which is rotatably connected to the filter baffle; The reaction rate control system controls the rotation of the blocking plate, and controls the opening and partial closing of the filter holes through the rotation of the blocking plate. In some embodiments, the filter baffle is a cylinder, and the filter baffle is in contact with the inner wall of the housing.

[0009] In some embodiments, the filtering device further includes a gas distribution plate disposed below the filtering baffle, for evenly distributing the plasma passing through the filtering baffle to facilitate better operation.

[0010] In some embodiments, an ion density analysis system is also included for real-time monitoring of the density of charged particles in the plasma reaching the lower chamber, such as ion or electron density, which can provide real-time feedback of ion density information to adjust the state of the baffle.

[0011] In some embodiments, the ion density analysis system is provided with a detection probe, which extends into the lower cavity to detect the ion density; preferably, a Langmuir probe is used.

[0012] In some embodiments, a process gas source is also provided and connected to the upper cavity through a pipeline, and the process gas includes but is not limited to CxFy, O2, Ar, N2, H2, He, etc.

[0013] In some embodiments, a plasma excitation device is also provided to excite the process gas into plasma to enter the upper cavity and reach the lower cavity for operation after passing through the baffle.

[0014] In some embodiments, the material of the filter baffle is a conductor, and the baffle includes an aluminum baffle, or an aluminum baffle with a surface coated with aluminum nitride or aluminum oxide.

[0015] In some embodiments, a wafer stage is further provided in the lower chamber, and the wafer to be processed is provided on the wafer stage. During the wafer processing, by controlling the filtering state of the filtering device, the damage of ions to the wafer substrate can be effectively reduced while maintaining a high processing efficiency.

[0016] In some embodiments, a gas extraction pipeline is further provided inside the reaction chamber for exhausting the gas in the chamber. The gas extraction pipeline is connected to a pump to ensure that the pressure and gas composition in the chamber meet the process requirements.

[0017] The present application also provides a wafer processing method, which adopts the above-mentioned wafer processing device.

[0018] The processing method includes: Confirm the operations that need to be performed on the wafer to be processed and the wafer products that need to be obtained; Design the closing range of the filter holes at different time periods when processing wafers; The closing amplitude is adjusted through a reaction rate control system, and the wafer to be processed is processed to obtain a wafer product.

[0019] Methods for designing the closing amplitude include: S1: Establish the relationship curve between D, R, P and closing amplitude; S2: Set the target value D at different time t t , R t , P t , and determine the selection range of D, R, and P at time t; for example, confirm the target value D at time t0 t0 , R t0 , P t0 , and determine D <D t0 、R>R t0 , P <P t0 ; S3: Substitute the selected range of D, R, and P at time t in S2 into the relationship curve obtained in S1, and design the closing amplitude required at time t; Wherein, D is the ion density, R is the reaction rate, P is the ion damage under unit reaction rate, P=D / R; the closing range is less than 100%, of which opening is 0%, 0%<partial closing<100%.

[0020] In some embodiments, the processing method includes growing a thin film on a wafer or removing a thin film on a wafer.

[0021] In some embodiments, you can choose to fix the closing amplitude at different time periods, for example: When removing the film on the wafer, the first slider and the second slider are controlled to slide so that the first extension part and the second extension part enter the groove, so that the filter hole is fully opened; when approaching the termination interface, the first slider and the second slider are controlled to slide so that the first extension part and the second extension part enter the filter hole, so that the filter hole is partially closed; When a thin film is grown on the wafer, the sliding of the first slider and the second slider is controlled so that the first extension part and the second extension part enter the filter hole, so that the filter hole is partially closed; after a thin film of a certain thickness is grown, the control device controls the sliding of the first slider and the second slider so that the first extension part and the second extension part enter the groove, so that the filter hole is fully opened; when the growth is close to completion, the sliding of the first slider and the second slider is controlled so that the first extension part and the second extension part enter the filter hole, so that the filter hole is partially closed.

[0022] In other embodiments, the closing amplitude may also be adjusted continuously, but it is necessary to satisfy the selection ranges of D, R, and P at different times.

[0023] In the above wafer processing device, when low ion damage and low reaction rate are required, the filter holes are partially closed; when a high reaction rate is required, the filter holes are opened. Ion damage can be monitored in real time by an ion density analysis system, and the opening and closing of the filter holes can be adjusted in real time. The effect of controlling the reaction rate and ion damage is achieved. The present invention effectively solves the problem of the difficulty in balancing ion damage and processing efficiency in the prior art by optimizing the filtering and control mechanism of plasma, and has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a wafer processing device of the present invention; Figure 2 A schematic diagram of the structure of a filter baffle in one embodiment of the present invention; Figure 3 It is a schematic diagram of the structure when the first slider and the second slider partially close the filter hole in one embodiment of the present invention; Figure 4 In one embodiment of the present invention, the first slider and the second slider connect the filter hole to the filter hole. Figure 3 Structural diagram of the parts in the figure with different closing amplitudes; Figure 5 It is a schematic diagram of the structure when the first slider and the second slider open the filter hole in one embodiment of the present invention; Figure 6 It is a schematic structural diagram of another embodiment of the present invention when the first slider and the second slider partially close the filter hole; Figure 7 It is a schematic structural diagram of another embodiment of the present invention when the first slider and the second slider partially close the filter hole; Figure 8 This is a schematic structural diagram of another embodiment of the present invention when the blocking plate partially closes the filter holes to different degrees.

[0025] Reference numerals: 1-shell; 2-upper cavity; 3-lower cavity; 4-filter baffle; 5-gas distribution plate; 6-process gas source; 7-plasma excitation device; 8-ion density analysis system; 9-detection probe; 10-wafer to be processed; 11-wafer stage; 12-exhaust pipeline; 41 - first slider; 42 - second slider; 43 - blocking piece; 44 - rotating shaft. DETAILED DESCRIPTION

[0026] 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.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. 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 of the related listed items.

[0028] 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.

[0029] 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.

[0030] The present invention provides a wafer processing device, such as Figure 1 As shown, it includes a shell 1 and a reaction chamber wrapped by the shell 1; The reaction chamber is divided into an upper chamber 2 and a lower chamber 3 by a filtering device; The filter device includes a filter baffle 4, such as Figure 2 The filter baffle 4 shown is provided with a plurality of filter holes penetrating the filter baffle 4; A reaction rate control system is also included, which controls the opening and partial closing of the filter holes to adjust the charged particle throughput and reaction rate in the plasma.

[0031] In some embodiments, a first groove is provided on a hole wall on one side of each filter hole, and a second groove is provided on a hole wall on the other side opposite to the filter hole; A first slider 41 is disposed in the first groove. The first slider 41 includes a first extension portion and a first connection portion. The first connection portion is slidably connected to the filter baffle 4. The first extension portion extends out of the first groove and enters the filter hole by sliding in the first groove. A second slider 42 is disposed in the second groove. The second slider 42 includes a second extension portion and a second connection portion. The second connection portion is slidably connected to the filter baffle 4. The second extension portion extends out of the second groove and enters the filter hole by sliding in the second groove. The reaction rate control system controls the sliding of the first slider 41 and the second slider 42 , and controls the opening and partial closing of the filter hole by the intersection and separation of the first extension and the second extension in the filter hole.

[0032] In some embodiments, the first slider 41 and the second slider 42 are integrally formed.

[0033] like Figure 3-Figure 5 As shown, in some embodiments, the first protruding portion includes an upper blocking block and a lower blocking block, and the horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter hole; the second protruding portion is a protrusion, and the distance between the upper blocking block and the lower blocking block is greater than the thickness of the protrusion.

[0034] like Figure 6 and Figure 7 As shown, in some other embodiments, the first protruding portion is an upper blocking block, the second protruding portion is a lower blocking block, the horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter holes, and the bottom of the upper blocking block is higher in the vertical direction than the top of the lower blocking block.

[0035] like Figure 8 As shown, in some other embodiments, each filter hole further includes a blocking sheet 43, and a rotating shaft 44 is provided on the blocking sheet 43 and penetrates the blocking sheet 43 in the diameter direction, and the blocking sheet 43 is rotatably connected to the filter baffle 4 through the rotating shaft 44; The reaction rate control system controls the rotation of the blocking plate 43 , and controls the opening and partial closing of the filter holes through the rotation of the blocking plate 43 . Figure 8 (A) and (B) show different partial closing conditions of the filter holes when the blocking plate 43 rotates to different degrees.

[0036] In some embodiments, the filter baffle 4 is a cylinder, and the filter baffle 4 fits the inner wall of the housing 1. In some embodiments, the filter device further comprises a gas distribution plate 5 disposed below the filter baffle 4, for evenly distributing the plasma passing through the filter baffle 4, so as to facilitate better operation.

[0037] In some embodiments, an ion density analysis system 8 is also included for real-time monitoring of the density of charged particles in the plasma reaching the lower chamber 3, such as ion or electron density, which can provide real-time feedback of ion density information to adjust the state of the filter baffle 4.

[0038] In some embodiments, the ion density analysis system 8 is provided with a detection probe 9, which extends into the lower cavity 3 to detect the ion density; preferably, a Langmuir probe is used.

[0039] In some embodiments, a process gas source 6 is also provided and connected to the upper cavity 2 through a pipeline, and the process gas includes but is not limited to CxFy, O2, Ar, N2, H2, He, etc.

[0040] In some embodiments, a plasma excitation device 7 is further provided to excite the process gas into plasma to enter the upper cavity 2 and reach the lower cavity 3 after passing through the filter baffle 4 for operation.

[0041] In some embodiments, the material of the filtering baffle 4 is a conductor, and the baffle includes an aluminum baffle, or an aluminum baffle with a surface coated with aluminum nitride or aluminum oxide.

[0042] In some embodiments, a wafer stage 11 is further provided in the lower cavity 3, and the wafer 10 to be processed is provided on the wafer stage 11. During the processing of the wafer 10 to be processed, by controlling the filtering state of the filtering device, the damage of ions to the wafer substrate can be effectively reduced while maintaining a high processing efficiency.

[0043] In some embodiments, a gas extraction pipeline 12 is further provided at the bottom of the lower cavity 3 for exhausting the gas in the cavity. The gas extraction pipeline 12 is connected to a pump to ensure that the pressure and gas composition in the cavity meet the process requirements.

[0044] The present application also provides a wafer processing method, which adopts the above-mentioned wafer processing device.

[0045] The processing method includes: Confirming the operations to be performed on the wafer 10 to be processed and the wafer products to be obtained; Designing the closing range of the filter holes in different time periods when processing the wafer 10 to be processed; The closing amplitude is adjusted by a reaction rate control system, and the wafer 10 to be processed is processed to obtain a wafer product.

[0046] Methods for designing the closing amplitude include: S1: Establish the relationship curve between D, R, P and closing amplitude; S2: Set the target value D at different time t t , R t , P t , and determine the selection range of D, R, and P at time t; for example, confirm the target value D at time t0 t0 , R t0 , P t0 , and determine D <D t0 、R>R t0 , P <P t0 ; S3: Substitute the selected range of D, R, and P at time t in S2 into the relationship curve obtained in S1, and design the closing amplitude required at time t; Where D is the ion density, R is the reaction rate, P is the ion damage per unit reaction rate, P=D / R; the closing range is less than 100%, where opening is 0%, 0%<partial closing<100%. Figure 3 As shown in , when the filter hole is partially closed, almost all ions have no direct path from top to bottom, and the probability and number of contact with the slider wall are the highest, the ion filtering ability is extremely strong, and the reaction rate is the slowest; Figure 4 As shown, the filter hole is also partially closed, but the degree of closure is smaller than Figure 3 , almost all ions have no direct path from top to bottom, the probability and number of contact with the slider wall are moderate, the ion filtering capacity is moderate, and the reaction rate is moderate; Figure 5 As shown, when the filter hole is opened, a large number of ions have a direct path from top to bottom, the ion filtering ability is weak, and the reaction rate is fast. At the same time, the reaction rate can be further controlled by adjusting the space in which the filter hole is opened.

[0047] In some embodiments, the processing method includes growing a thin film on a wafer or removing a thin film on a wafer.

[0048] In some embodiments, you can choose to fix the closing amplitude at different time periods, for example: When removing the film on the wafer 10 to be processed, the first slider 41 and the second slider 42 are controlled to slide, so that the first extension part and the second extension part enter the groove, so that the filter hole is fully opened; when approaching the termination interface, the first slider 41 and the second slider 42 are controlled to slide, so that the first extension part and the second extension part enter the filter hole, so that the filter hole is partially closed; When a thin film is grown on the wafer 10 to be processed, the sliding of the first slider 41 and the second slider 42 is controlled so that the first extension part and the second extension part enter the filter hole, thereby closing the filter hole; after a thin film of a certain thickness is grown, the control device controls the sliding of the first slider 41 and the second slider 42 so that the first extension part and the second extension part enter the groove, thereby fully opening the filter hole; when the growth is close to completion, the sliding of the first slider 41 and the second slider 42 is controlled so that the first extension part and the second extension part enter the filter hole, thereby partially closing the filter hole.

[0049] In other embodiments, the closing amplitude may also be adjusted continuously, but it is necessary to satisfy the selection ranges of D, R, and P at different times.

[0050] The processing method includes growing a thin film on a wafer 10 to be processed or removing a thin film on the wafer 10 to be processed.

[0051] In some embodiments, when removing a thin film on the wafer 10 to be processed, the first slider 41 and the second slider 42 are controlled to slide so that the first extension part and the second extension part enter the groove, so that the filter hole is fully opened; when approaching the termination interface, the first slider 41 and the second slider 42 are controlled to slide so that the first extension part and the second extension part enter the filter hole, so that the filter hole is partially closed; When a thin film is grown on the wafer 10 to be processed, the sliding of the first slider 41 and the second slider 42 is controlled so that the first extension part and the second extension part enter the filter hole, thereby closing the filter hole. After a thin film of a certain thickness is grown, the control device controls the sliding of the first slider 41 and the second slider 42 so that the first extension part and the second extension part enter the groove, thereby fully opening the filter hole. When the growth is close to completion, the sliding of the first slider 41 and the second slider 42 is controlled so that the first extension part and the second extension part enter the filter hole, thereby partially closing the filter hole. This can reduce the damage of ions to the substrate while ensuring a high reaction rate.

[0052] 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.

[0053] 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 wafer processing device, characterized in that: It comprises: a shell and a reaction chamber formed by wrapping the shell; The reaction chamber is divided into an upper chamber and a lower chamber by a filtering device; The filtering device comprises a filtering baffle, wherein the filtering baffle is provided with one or more filtering holes penetrating the filtering baffle; Also included is a reaction rate control system, which controls the opening and partial closing of the filter holes to adjust the reaction rate; A first groove is arranged on one side wall of each of the filter holes, and a second groove is arranged on the other side wall of the filter hole; a first slider is arranged in the first groove, the first slider comprises a first extension part and a first connecting part, the first connecting part is slidably connected with the filter baffle, and the first extension part extends out of the first groove and enters the filter hole by sliding in the first groove; a second slider is arranged in the second groove, the second slider comprises a second extension part and a second connecting part, the second connecting part is slidably connected with the filter baffle, and the second extension part extends out of the second groove and enters the filter hole by sliding in the second groove; Alternatively, each of the filter holes further includes a blocking piece, and the blocking piece is rotatably connected to the filter baffle.

2. The wafer processing device according to claim 1, characterized in that: When a first groove is provided on one side hole wall of each of the filter holes, and a second groove is provided on the other side hole wall of the filter hole; a first slider is provided in the first groove, the first slider comprises a first protruding portion and a first connecting portion, the first connecting portion is slidably connected to the filter baffle, and the first protruding portion is extended out of the first groove and enters the filter hole by sliding in the first groove; a second slider is provided in the second groove, the second slider comprises a second protruding portion and a second connecting portion, the second connecting portion is slidably connected to the filter baffle, and the second protruding portion is extended out of the second groove and enters the filter hole by sliding in the second groove; The reaction rate control system controls the sliding of the first slider and the second slider, and controls the opening and partial closing of the filter hole through the intersection and separation of the first protrusion and the second protrusion in the filter hole, thereby adjusting the ion reaction rate.

3. The wafer processing device according to claim 2, characterized in that: The first extension portion includes an upper blocking block and a lower blocking block, and the horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter hole; the second extension portion is a convex block, and the distance between the upper blocking block and the lower blocking block is greater than the thickness of the convex block.

4. The wafer processing device according to claim 3, characterized in that: The first protruding portion is an upper blocking block, and the second protruding portion is a lower blocking block. The horizontal side lengths of the upper blocking block and the lower blocking block are not less than the side lengths of the filter holes, and the bottom of the upper blocking block is higher in the vertical direction than the top of the lower blocking block.

5. The wafer processing device according to claim 1, characterized in that: When each of the filter holes further includes a blocking sheet, and the blocking sheet is rotatably connected to the filter baffle; The reaction rate control system controls the rotation of the blocking plate, and controls the opening and partial closing of the filter holes through the rotation of the blocking plate.

6. The wafer processing device according to claim 1, characterized in that: The filtering device also includes a gas distribution plate arranged below the filtering baffle.

7. The wafer processing device according to claim 6, characterized in that: Also included is an ion density analysis system for real-time monitoring of the density of plasma arriving at the lower chamber; The ion density analysis system is provided with a detection probe, and the detection probe extends into the lower cavity to detect the ion density; It also includes a process gas source and a plasma excitation device, wherein the process gas source and the upper cavity are connected via a pipeline; The plasma excitation device is used to excite the process gas into plasma and let it enter the upper cavity; A wafer stage is also provided in the lower chamber, and the wafer to be processed is provided on the wafer stage; The cavity is also provided with an exhaust pipe for exhausting the gas in the cavity.

8. A wafer processing method, using the wafer processing device described in claims 1-7.

9. The processing method according to claim 8, characterized in that: The processing method comprises: Confirm the operations that need to be performed on the wafer to be processed and the wafer products that need to be obtained; Designing the closing range of the filter holes at different time periods when processing the wafer; The closing amplitude is adjusted by a reaction rate control system, and the wafer to be processed is processed to obtain the wafer product.

10. The processing method according to claim 9, characterized in that: The design method of the closing range includes: S1: Establish the relationship curve between D, R, P and closing amplitude; S2: Set the target value D at different time t t , R t , P t , and determine the selection range of D, R, and P at time t; S3: Substitute the selected range of D, R, and P at time t in S2 into the relationship curve obtained in S1, and design the closing amplitude required at time t; Wherein, D is ion density, R is reaction rate, P is ion damage under unit reaction rate, P=D / R; the closing range is less than 100%, wherein opening is 0%, 0%<partial closing<100%.

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