A high-precision intelligent etching system

Abstract

The present invention relates to a high-precision intelligent etching system applied to the technical field related to wafer etching. By setting a gas velocity monitoring disk in a reaction chamber, the uniformity of the gas flow velocity in the reaction chamber can be monitored during etching, so that the problem of uneven plasma distribution caused by uneven gas flow velocity in various places in the reaction chamber can be discovered in time before etching. Compared with the prior art, the uniformity of wafer etching can be improved, the etching accuracy can be guaranteed, and the waste of resources can be effectively reduced. In addition, with the setting of a direction finding unit, the gas flow direction at the target position can also be detected. According to the data, it is convenient for subsequent staff to analyze the gas distribution characteristics in the reaction chamber. When uneven flow velocity occurs, it is convenient for staff to make targeted adjustments according to the data, thereby reducing the maintenance difficulty of staff when the gas distribution is uneven.

Description

Technical Field

[0001] The present invention relates to a high-precision intelligent etching system, and in particular to a high-precision intelligent etching system applied to the technical field related to wafer etching. Background Art

[0002] There are two main types of etching processes: dry etching and wet etching. Dry etching removes surface materials by physical or chemical reaction (or a combination of physical and chemical reactions) between plasma gas and the etched part; wet etching removes surface materials of the etched part by chemical reagents.

[0003] The specification of Chinese patent CN110544615B discloses a plasma etching system. In the plasma etching method, it is necessary to continuously fill the reaction gas or auxiliary etching gas during etching, and at the same time remove the product and excess gas generated in the reaction process through the vacuum unit to maintain the appropriate pressure and cleanliness in the reaction chamber, so as to ensure the quality and efficiency of etching and keep the gas in the reaction chamber in a flowing state. When the gas flow rate in different areas is very different, it will cause uneven plasma distribution, resulting in differences in the surface of the wafer during etching, affecting the etching accuracy and quality. The surface etching uniformity of the same batch of wafers is often passively monitored after etching. In this case, it is easy to cause the etching of the same batch of wafers to be unqualified, affecting product quality. However, the above patent does not have the function of monitoring the gas flow rate.

[0004] Therefore, it is urgently necessary to provide an etching system that can monitor the uniformity of the gas flow rate in the reaction chamber during etching, so that the problem of uneven plasma distribution caused by uneven gas flow rate in various places in the reaction chamber can be detected in time before etching, thereby improving the uniformity of wafer etching. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the prior art generally lacks equipment for monitoring the flow uniformity of the gas in the reaction chamber, which leads to uneven etching of batch wafers when the gas flow rate is uneven, thus affecting product quality.

[0006] In order to solve the above problems, the present invention provides a high-precision intelligent etching system, including a reaction chamber, an outer cover shell is fixedly connected to the upper end of the reaction chamber, a bottom cover head is fixedly connected to the lower end of the reaction chamber, an air inlet pipe is fixedly connected to the left end of the outer cover shell, a gas flow control unit is externally connected to the air inlet pipe of the outer cover shell, a vacuum suction pipe is fixedly connected to the bottom of the bottom cover head, the reaction chamber is externally connected to a vacuum unit through the vacuum suction pipe, a dielectric window is also fixedly connected between the reaction chamber and the outer cover shell, an excitation electrode is arranged above the dielectric window, an air inlet is arranged in the middle of the dielectric window, a base is fixedly connected to the inside of the reaction chamber, and a bias electrode is installed at the upper end of the base;

[0007] The left and right ends of the base are fixedly connected with a gas velocity monitoring plate, which includes an annular plate and multiple gas velocity measuring columns distributed in an annular array on the upper end of the annular plate. The gas velocity measuring column includes a base plate, two connecting columns fixedly connected to the upper end of the base plate, and an air sensing plate located above the base plate. Multiple support rods are connected between the air sensing plate and the base plate, and the two connecting columns are respectively located on both sides of the air sensing plate. A controller is connected to the outer end of the reaction chamber, and the gas velocity measuring column is connected to the controller signal.

[0008] In the above-mentioned high-precision intelligent etching system, by setting up a gas velocity monitoring disk, the uniformity of the gas flow rate in the reaction chamber can be monitored during etching, so that the problem of uneven plasma distribution caused by uneven gas flow rates in various places in the reaction chamber can be detected in time before etching. Compared with the existing technology, it can not only improve the uniformity of wafer etching and ensure etching accuracy, but also effectively reduce the waste of resources.

[0009] As a further improvement of the present application, the two gas velocity monitoring disks located on the left and right sides of the base are symmetrical to each other and both are lower than the bias electrode.

[0010] As a further improvement of the present application, the gas sensing sheet is an S-shaped structure, and the two connecting sheet posts are respectively located in the semicircles at both ends of the S shape, the semicircles and the connecting sheet posts are coaxially arranged, and the two do not contact each other.

[0011] As a further improvement of the present application, a monitoring strip is installed at the outer end of the connecting column close to the gas sensing piece. The monitoring strip includes a plurality of evenly distributed pressure sensors and an outer protective layer located outside the pressure sensors. Both the outer protective layer and the pressure sensors are fixedly connected to the connecting column.

[0012] As a further improvement of the present application, the outer protective layer is made of high temperature resistant elastic material, the distribution range of multiple pressure sensors on the connecting column is not lower than the lateral center line of the connecting column, the support rod is a hard structure, and the gas sensing sheet is an elastic structure.

[0013] As another improvement of the present application, the connecting column includes a fixed half-column fixedly connected to the base plate, a movable half-column slidably connected to the base plate, and multiple pairs of elastic connecting rods fixedly connected between the fixed half-column and the movable half-column. A pressure sensor is fixedly installed on the fixed half-column toward the middle of the movable half-column. The pressure sensor is in contact with the movable half-column, and the movable half-column is located on the side of the semicircle adjacent to the gas sensing plate.

[0014] As another improvement of the present application, a direction finding unit is fixedly embedded on the connecting column, and the direction finding unit is close to the upper end of the connecting column. The direction finding unit includes a central shaft installed at the axis center of the connecting column through an electric rotating shaft, a distance meter installed at the outer end of the central shaft, and an outer protective ring fixedly connected to the edge of the connecting column, and the distance meter is connected to the controller signal.

[0015] As a supplement to another improvement of the present application, the outer protective ring is a hard transparent structure, the outer protective layer is also a transparent structure, and the transmitting end of the rangefinder is misaligned with the pressure sensor.

[0016] In summary, in the above-mentioned high-precision intelligent etching system, through the setting of the gas velocity monitoring disk, the uniformity of the gas flow rate in the reaction chamber can be monitored during etching, so that the problem of uneven plasma distribution caused by uneven gas flow rate in various places in the reaction chamber can be discovered in time before etching. Compared with the existing technology, it can not only improve the uniformity of wafer etching and ensure etching accuracy, but also effectively reduce the waste of resources; in addition, with the setting of the direction finding unit, the gas flow direction at the target position can also be detected. According to the data, it is convenient for subsequent staff to analyze the gas distribution characteristics in the reaction chamber. When uneven flow rate occurs, it is convenient for staff to make targeted adjustments based on the data, thereby reducing the maintenance difficulty of staff when the gas distribution is uneven. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a front cross-sectional view of the first embodiment of the present application;

[0018] Figure 2 A three-dimensional diagram of a gas velocity monitoring panel according to a first embodiment of the present application;

[0019] Figure 3 A top view of a gas velocity monitoring panel according to a first embodiment of the present application;

[0020] Figure 4 A three-dimensional diagram of a gas velocity measuring column according to a first embodiment of the present application;

[0021] Figure 5 This is a front view of the gas sensing sheet according to the first embodiment of the present application;

[0022] Figure 6 This is a top view of the change of the gas velocity measuring column before and after the gas push in the first embodiment of the present application;

[0023] Figure 7 A front view of a tab column according to a first embodiment of the present application;

[0024] Figure 8 This is a schematic diagram of the process when the gas pushes the gas-sensitive sheet to deform according to the first embodiment of the present application;

[0025] Fig. 9 A top view of a gas velocity measuring column according to a second embodiment of the present application;

[0026] Fig.10 This is a top cross-sectional view of a tab column according to a second embodiment of the present application;

[0027] Fig.11A cross-sectional view of the upper half of the tab column of the third embodiment of the present application;

[0028] Fig.12 This is a comparison diagram of the laser beam emitted by the direction-finding unit of the third embodiment of the present application before and after the gas-sensing sheet is deformed.

[0029] Description of the numbers in the figure:

[0030] 1-reaction chamber, 11-base, 12-outer cover, 2-bottom head, 31-bias electrode, 32-medium window, 33-excitation electrode, 41-inlet pipe, 401-inlet, 42-vacuum suction pipe, 5-gas velocity monitoring disk, 51-annular disk, 521-bottom plate, 522-connecting column, 523-gas sensing plate, 501-support rod, 61-outer protective layer, 62-pressure sensor, 71-fixed semi-column, 72-moving semi-column, 73-elastic connecting rod, 81-outer protective ring, 82-central axis, 83-range finder. DETAILED DESCRIPTION

[0031] Three implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0032] The first implementation method:

[0033] Figure 1 A high-precision intelligent etching system is shown, in which a represents a wafer, including a reaction chamber 1, an outer cover shell 12 is fixedly connected to the upper end of the reaction chamber 1, a bottom end 2 is fixedly connected to the lower end of the reaction chamber 1, an air inlet pipe 41 is fixedly connected to the left end of the outer cover shell 12, a gas flow control unit is externally connected to the air inlet pipe 41 of the outer cover shell 12, a vacuum suction pipe 42 is fixedly connected to the bottom of the bottom end 2, the reaction chamber 1 is externally connected to a vacuum unit through the vacuum suction pipe 42, and a dielectric window 32 is fixedly connected between the reaction chamber 1 and the outer cover shell 12. When etching, the wafer is placed An excitation electrode 33 is arranged above the dielectric window 32, and an air inlet 401 is arranged in the middle of the dielectric window 32. A base 11 is fixedly connected to the inside of the reaction chamber 1, and a bias electrode 31 is installed on the upper end of the base 11. Gas velocity monitoring disks 5 are fixedly connected to the left and right ends of the base 11. The two gas velocity monitoring disks 5 located on the left and right sides of the base 11 are symmetrical to each other, and both are lower than the bias electrode 31, so that the setting of the two gas velocity monitoring disks 5 is not easy to block or affect the etching of the wafer above 3, thereby effectively ensuring the stable etching.

[0034] like Figure 2-Figure 4 The gas velocity monitoring disk 5 includes an annular disk 51 and a plurality of gas velocity measuring columns distributed in an annular array on the upper end of the annular disk 51. The gas velocity measuring columns include a bottom plate 521, two connecting columns 522 fixedly connected to the upper end of the bottom plate 521, and a gas sensing sheet 523 located above the bottom plate 521. Figure 5A plurality of supporting rods 501 are connected between the gas sensing piece 523 and the bottom plate 521, two connecting pieces 522 are respectively located on both sides of the gas sensing piece 523, a controller is connected to the outer end of the reaction chamber 1, and the gas velocity measuring column is connected to the controller signal. The gas sensing piece 523 is an S-shaped structure, and the two connecting pieces 522 are respectively located in the semicircles at both ends of the S shape, the semicircles and the connecting pieces 522 are coaxially arranged, and the two do not contact each other, so that for the same gas velocity measuring column, no matter whether the gas flows from the front toward the gas sensing piece 523 or from the guard toward the gas sensing piece 523, the gas sensing piece 523 gathers energy and deforms under force and approaches the corresponding connecting piece 522, and squeezes each other, so that the corresponding monitoring strip generates force data, and the size of the gas flow rate at this location can be effectively judged according to the size of the data.

[0035] At the same time, since multiple gas velocity measuring columns are distributed in a circular array, the gas flow rate in each direction can be monitored during monitoring. Since the relative direction of each gas velocity measuring column is different, the force data generated by the pressure sensor 62 thereon may be different in size. For the same gas velocity monitoring disk 5, the force data with the largest data among the multiple pressure sensors 62 thereon is used as the standard for judging the gas flow rate at that location, and based on the pressure sensor 62 that generates the largest force data, the overall direction of the gas at the gas velocity monitoring disk 5 can be roughly judged.

[0036] When the force data of multiple pressure sensors 62 at symmetrical positions on the two gas velocity monitoring disks 5 differ greatly, it means that the gas flow rates in the reaction chamber 1 are quite different, which may affect the distribution uniformity of the plasma and the etching uniformity of the wafer. Based on this, the staff can make corresponding maintenance adjustments in time to effectively avoid the situation where the etching uniformity of batches of wafers does not meet the standards, thereby reducing the defective rate and waste of materials.

[0037] like Figure 7 A monitoring strip is installed at the outer end of the connecting column 522 near the gas sensing piece 523. The monitoring strip includes a plurality of evenly distributed pressure sensors 62 and an outer protective layer 61 located outside the pressure sensor 62. The outer protective layer 61 and the pressure sensor 62 are fixedly connected to the connecting column 522. The outer protective layer 61 is made of a high temperature resistant elastic material. The distribution range of the plurality of pressure sensors 62 on the connecting column 522 is not lower than the transverse center line of the connecting column 522. The support rod 501 is a hard structure, and the gas sensing piece 523 is an elastic structure. The support rod 501 is used to support the gas sensing piece 523 so that it is not easy to automatically deviate to one side, such as Figure 6 and Figure 8Under the thrust of the flowing reaction gas, the gas sensing piece 523 is deformed toward the connecting piece column 522, and is squeezed with the connecting piece column 522, so that the pressure sensor 62 generates force data, wherein the force data generated by multiple pressure sensors 62 on the same gas velocity measuring column can be recorded as a group of force data; as the connecting piece column 522 is deformed, multiple pressure sensors 62 on the same gas velocity measuring column are gradually squeezed from top to bottom, so that in the same group of data, the number of data increases, from which the staff can conclude that the greater the gas flow rate, the greater the deformation amplitude of the connecting piece column 522, the larger the force data generated by the pressure sensor 62, and the greater the number of data.

[0038] It is worth noting that the vertical center line of the monitoring strip intersects with the center line of the connecting column 522 and the connecting line between the centers of the semicircles of the adjacent gas sensing sheets 523, so that the deformation of the gas sensing sheets 523 will cause the corresponding pressure sensor 62 to generate force data only when the gas thrust is directly facing the gas sensing sheets 523. When the force direction deviation is large, the pressure sensor 62 on the gas velocity measuring column only generates very small or no force data. However, since the multiple gas velocity measuring columns have different directions, there is always a pressure sensor 62 on the gas velocity measuring column that can generate larger force data. Based on this, some gas velocity measuring columns can be made not to generate force data, so that the controller obtains relatively few signals of force data, which is convenient for judging the gas flow rate and the general direction of the gas.

[0039] In the above-mentioned high-precision intelligent etching system, by setting the gas velocity monitoring disk 5, the uniformity of the gas flow rate in the reaction chamber 1 can be monitored during etching, so that the problem of uneven plasma distribution caused by uneven gas flow rates in various places in the reaction chamber 1 can be detected in time before etching. Compared with the existing technology, it can not only improve the uniformity of wafer etching and ensure etching accuracy, but also effectively reduce the waste of resources.

[0040] The second implementation method:

[0041] This embodiment is based on the first embodiment, and changes the connecting column 522 and the method of monitoring the local flow rate of the gas, while the rest is consistent with the first embodiment.

[0042] Figure 9-10As shown, the connecting column 522 includes a fixed semi-column 71 fixedly connected to the bottom plate 521, a movable semi-column 72 slidably connected to the bottom plate 521, and a plurality of pairs of elastic connecting rods 73 fixedly connected between the fixed semi-column 71 and the movable semi-column 72. A pressure sensor 62 is fixedly installed on the fixed semi-column 71 toward the middle of the movable semi-column 72. The pressure sensor 62 and the movable semi-column 72 are in contact with each other, and the movable semi-column 72 is located on the side of the semicircle adjacent to the gas sensing piece 523. In this embodiment, under the action of the gas flow rate, when the gas sensing piece 523 is deformed toward the connecting column 522, it will push the movable semi-column 72, so that the movable semi-column 72 moves toward the fixed semi-column 71, and squeezes the pressure sensor 62 to generate force data. Based on the size of the force data, the flow rate of the gas in the reaction chamber 1 can be judged.

[0043] Different from the first embodiment, in this embodiment, as long as the air sensing piece 523 is deformed and contacts the moving semi-column 72, the pressure sensor 62 can generate force data. Compared with the first embodiment, in this embodiment, only one pressure sensor 62 is required for one monitoring strip, which can effectively save costs. However, for the controller, each air velocity measuring column may generate force data, causing the controller to receive multiple sets of invalid data. Therefore, in the specific implementation, a suitable implementation method can be selected according to actual needs.

[0044] The third implementation method:

[0045] This implementation is based on the first implementation, and a direction finding unit is added, and the rest of the parts are consistent with the first implementation.

[0046] like Figure 11-Figure 12 A direction-finding unit is fixedly embedded on the connecting column 522, and the direction-finding unit is close to the upper end of the connecting column 522. The direction-finding unit includes a central shaft 82 installed at the axis of the connecting column 522 through an electric rotating shaft, a distance meter 83 installed at the outer end of the central shaft 82, and an outer protective ring 81 fixedly connected to the edge of the connecting column 522. The distance meter 83 is connected to the controller signal, such as Fig.12 In the figure, b represents the laser beam. When the etching process is not carried out, the gas sensing piece 523 is in the original vertical state. At this time, if the central axis 82 rotates under the control of the electric shaft, when the rangefinder 83 rotates with it, when the light emitted by the rangefinder falls on the gas sensing piece 523, there will be a part of the data with the same size, and the data measured by multiple rangefinders 83 on multiple gas speed monitoring disks 5 tend to be consistent. When it rotates to the part away from the gas sensing piece 523, the data will become larger.

[0047] During the etching process, under the action of gas, the gas-sensing sheet 523 moves toward the connecting column 522 and deforms. At this time, the controller can control the central axis 82 to rotate. Due to the deformation of the gas-sensing sheet 523, some of the data that should have been consistent will change, and some will become smaller. The position corresponding to the minimum data is the contact point between the gas-sensing sheet 523 and the connecting column 522. According to the contact point, the flow direction of the gas can be further effectively judged. Compared with the first embodiment, the monitoring of the flow direction of the gas is more accurate, which is convenient for subsequent staff to perform adaptive maintenance and adjustment according to the characteristics of the gas flow, so that the flow rate of the reaction gas flowing in the reaction chamber 1 tends to be consistent and the flow direction tends to be stable, which helps to further improve the uniformity of wafer etching and achieve the effect of improving etching accuracy.

[0048] The outer protective ring 81 is a hard transparent structure, the outer protective layer 61 is also a transparent structure, and the transmitting end of the rangefinder 83 is offset from the pressure sensor 62, so that the two are not easy to block the laser beam emitted outward by the rangefinder 83, effectively ensuring the smooth progress of the direction finding process.

[0049] In summary, in the above-mentioned high-precision intelligent etching system, through the setting of the gas velocity monitoring disk 5, the uniformity of the gas flow rate in the reaction chamber 1 can be monitored during etching, so that the problem of uneven plasma distribution caused by uneven gas flow rates in various places in the reaction chamber 1 can be discovered in time before etching. Compared with the existing technology, it can not only improve the uniformity of wafer etching and ensure etching accuracy, but also effectively reduce the waste of resources; in addition, with the setting of the direction finding unit, the gas flow direction at the target position can also be detected. According to the data, it is convenient for subsequent staff to analyze the gas distribution characteristics in the reaction chamber 1. When the flow rate is uneven, it is convenient for the staff to make targeted adjustments according to the data, thereby reducing the maintenance difficulty of the staff when the gas distribution is uneven.

[0050] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A high-precision intelligent etching system, comprising a reaction chamber (1), characterized in that: The upper end of the reaction chamber (1) is fixedly connected to an outer cover shell (12), the lower end of the reaction chamber (1) is fixedly connected to a bottom cover head (2), the left end of the outer cover shell (12) is fixedly connected to an air inlet pipe (41), the air inlet pipe (41) of the outer cover shell (12) is externally connected to a gas flow control unit, the bottom of the bottom cover head (2) is fixedly connected to a vacuum suction pipe (42), the reaction chamber (1) is externally connected to a vacuum unit via the vacuum suction pipe (42), a dielectric window (32) is also fixedly connected between the reaction chamber (1) and the outer cover shell (12), an excitation electrode (33) is arranged above the dielectric window (32), an air inlet (401) is arranged in the middle of the dielectric window (32), the interior of the reaction chamber (1) is fixedly connected to a base (11), and a bias electrode (31) is installed at the upper end of the base (11); The left and right ends of the base (11) are both fixedly connected with a gas velocity monitoring disk (5), the gas velocity monitoring disk (5) comprising an annular disk (51) and a plurality of gas velocity measuring columns distributed in an annular array on the upper end of the annular disk (51), the gas velocity measuring columns comprising a bottom plate (521), two connecting columns (522) fixedly connected to the upper end of the bottom plate (521), and a gas sensing plate (523) located above the bottom plate (521), a plurality of supporting rods (501) being connected between the gas sensing plate (523) and the bottom plate (521), the two connecting columns (522) being respectively located on both sides of the gas sensing plate (523), the outer end of the reaction chamber (1) being connected with a controller, and the gas velocity measuring columns being connected to the controller signal; The gas sensing sheet (523) is an S-shaped structure, and the two sheet connecting columns (522) are respectively located in the semicircles at both ends of the S shape, and the semicircles and the sheet connecting columns (522) are coaxially arranged, and the two do not contact each other.

2. A high-precision intelligent etching system according to claim 1, characterized in that: The two gas velocity monitoring disks (5) located on the left and right sides of the base (11) are symmetrical to each other and are lower than the bias electrode (31).

3. A high-precision intelligent etching system according to claim 1, characterized in that: A monitoring strip is installed at the outer end of the connecting column (522) close to the gas sensing sheet (523), and the monitoring strip includes a plurality of evenly distributed pressure sensors (62) and an outer protective layer (61) located outside the pressure sensors (62), and the outer protective layer (61) and the pressure sensors (62) are both fixedly connected to the connecting column (522).

4. A high-precision intelligent etching system according to claim 3, characterized in that: The outer protective layer (61) is made of a high temperature resistant elastic material, the distribution range of the plurality of pressure sensors (62) on the connecting column (522) is not less than the transverse center line of the connecting column (522), the support rod (501) is a hard structure, and the gas sensing sheet (523) is an elastic structure.

5. The high-precision intelligent etching system according to claim 1, characterized in that: The connecting column (522) comprises a fixed semi-column (71) fixedly connected to the bottom plate (521), a movable semi-column (72) slidably connected to the bottom plate (521), and a plurality of pairs of elastic connecting rods (73) fixedly connected between the fixed semi-column (71) and the movable semi-column (72). A pressure sensor (62) is also fixedly mounted on the middle of the fixed semi-column (71) facing the movable semi-column (72). The pressure sensor (62) and the movable semi-column (72) are in contact with each other, and the movable semi-column (72) is located on the side of the semicircle close to the gas sensing sheet (523).

6. A high-precision intelligent etching system according to claim 3, characterized in that: A direction-finding unit is fixedly embedded on the connecting column (522), the direction-finding unit being close to the upper end of the connecting column (522), the direction-finding unit comprising a central shaft (82) mounted at the axis of the connecting column (522) via an electric rotating shaft, a distance meter (83) mounted at the outer end of the central shaft (82), and an outer protective ring (81) fixedly connected to the edge of the connecting column (522), the distance meter (83) being connected to a controller signal.

7. A high-precision intelligent etching system according to claim 6, characterized in that: The outer protective ring (81) is a hard transparent structure, the outer protective layer (61) is also a transparent structure, and the transmitting end of the rangefinder (83) is misaligned with the pressure sensor (62).

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