TW202031941A - Electroplating apparatus for depositing metal on the entire substrate with high electroplating rate and uniform plated film - Google Patents

Abstract

Disclosed is an electroplating apparatus for depositing metal on a substrate, which comprises a membrane frame, a catholyte inlet pipe and a center cap. The membrane frame has a center passage which passes through the center of the membrane frame. The catholyte inlet pipe is connected to the center passage of the membrane frame. The center cap is fixed at the center of the membrane frame and covers the center passage of the membrane frame. The top of the center cap has a plurality of first holes. The catholyte inlet pipe supplies catholyte to the center cap through the center passage of the membrane frame, and the catholyte is supplied to a center area of the substrate through the first holes of the center cap.

Description

Electroplating device

The present invention relates to a semiconductor integrated circuit manufacturing equipment, and more specifically, to an electroplating device for metal deposition.

In the field of semiconductor manufacturing, electroplating is a common method of depositing metal films on substrates. Especially in advanced packaging technology, since electroplating has the advantages of simple process, low cost, easy mass production, etc., copper pillars and solder bumps are generally formed on the substrate by electroplating to realize wafer substrate interconnection. Unfortunately, the current electroplating equipment on the market generally has the defect of low electroplating rate. Low plating rate means low production efficiency, which is unacceptable for semiconductor companies. For semiconductor companies, the biggest investment cost comes from a large number of manufacturing equipment. Therefore, how to optimize equipment productivity is the most effective way to reduce costs.

In order to increase the plating rate, quality transmission needs to be enhanced. Figure 23 shows a copper pillar with an abnormal shape. Figure 24 shows a copper pillar with a normal shape. When the quality transmission is insufficient, the deposition rate is limited and the shape of the copper pillar is abnormal. In the electroplating process, when the quality transmission is insufficient, for the copper pillars formed in the columnar through holes, the area where the electrolyte flows stronger, the higher the plating rate, while the other areas are relatively low. Finally, the shape of the copper pillar is abnormal after the electroplating. It can be seen that in order to obtain a copper pillar with a normal shape on the entire substrate, The mass transfer should be large enough, and on the entire substrate, the mass transfer should also be large enough to ensure that the shape of each copper pillar is normal and all the copper pillars on the substrate have good consistency.

Generally speaking, there are many methods for enhancing quality transmission, such as optimizing the chemical formula of the plating solution, increasing the temperature of the plating solution, and enhancing the agitation of the plating solution. Among them, a common way to enhance the agitation of the electroplating solution includes: increasing the rotation speed of the substrate, using a stirrer in the electrolyte, and increasing the flow rate of the electrolyte. However, due to the centrifugal force, the increase in the rotation speed of the substrate will result in an increase in the coating on the edge of the substrate and a decrease in the coating on the center of the substrate. So simply increasing the speed of the substrate will result in uneven plating. The agitator is usually a movable paddle. The stirrer moves back and forth at a high frequency, which easily traps bubbles in the electrolyte. The bubbles on the substrate prevent the electrolyte from entering the device structure or columnar through holes. Regarding increasing the flow rate of the electrolyte, since the increase in flow rate is provided to the entire substrate, the flow rate will be distributed in a central manner and the flow rate will rotate from the center of the substrate to the edge of the substrate. Therefore, there will be less fresh electrolyte supplement in the center of the substrate.

In order to provide fresh electrolyte and additives in time to meet the requirements of high current density, more electrolyte needs to be provided to the center of the substrate. Otherwise, the shape of the column in the center of the substrate is abnormal or the height of the column will be low. In fact, it is impossible to increase the plating rate simply by increasing the current density, because the current density through the entire substrate is not uniform. Due to a phenomenon called "terminal effect", the current density at the outer edge of the substrate is higher. This non-uniformity of current density leads to a higher plating rate at the edge of the substrate and a lower plating rate at the center of the substrate, which further leads to uneven plating. Due to the uneven current density through the entire substrate, if there is no structural improvement, Simply increasing the electroplating rate by increasing the electrolyte flow rate will make the unevenness of the coating more serious.

For electroplating equipment, although the chemical substance is a factor that affects the electroplating rate, the electroplating rate is mainly related to the flow of the electrolyte on the entire substrate. In order to achieve a high plating rate, a large and stable electrolyte flow must be supplied to the substrate. However, once the electrolyte flow rate increases, it is difficult to control the uniformity of the electric field and electrolyte flow across the entire substrate.

The purpose of the present invention is to disclose an electroplating device for depositing metal on the entire substrate with a higher electroplating rate and a uniform coating.

According to an embodiment of the present invention, an electroplating device is provided, which includes a membrane holder, a catholyte inlet pipe and a center cap. The membrane frame has a central channel passing through the center of the membrane frame. The catholyte inlet pipe is connected with the central channel of the membrane frame. The center cap is fixed at the center of the film frame and covers the center channel of the film frame. The top of the center cap is provided with a plurality of first holes. The catholyte inlet pipe supplies the catholyte to the central cap through the central channel of the membrane frame, and the catholyte is supplied to the central area of the substrate through the first hole of the central cap.

In summary, the electroplating device of the present invention uses the center cap to improve the electrolyte flow rate and the uniformity of the electric field in the center area of the substrate, thereby improving the uniformity of the coating on the entire substrate. Therefore, during the electroplating process, the flow rate of the catholyte in the catholyte inlet pipe can be increased, thereby increasing the electroplating rate.

10‧‧‧Craft cavity

11‧‧‧Anode cavity

12‧‧‧Cathode cavity

13‧‧‧membrane

14‧‧‧Film frame

15‧‧‧Fixed plate

16‧‧‧First sealing ring

17‧‧‧Second sealing ring

18‧‧‧Fixture

19‧‧‧Third sealing ring

20‧‧‧Base

30‧‧‧Catholyte inlet pipe

31‧‧‧Fourth sealing ring

32‧‧‧Fifth seal ring

40‧‧‧Center cap

41‧‧‧Through hole

42‧‧‧First hole

43‧‧‧Second hole

44‧‧‧Mounting hole

45‧‧‧O-ring seal

50‧‧‧Adjustable component

51‧‧‧Matrix

52‧‧‧Blocking Department

53‧‧‧Slot opening

60‧‧‧First diffuser

61‧‧‧Hole

62‧‧‧Seal ring

70‧‧‧Second diffuser

71‧‧‧Hole

72‧‧‧Seal ring

80‧‧‧Intermediate plate

80’‧‧‧Intermediate plate

80"‧‧‧Intermediate plate

801‧‧‧Protrusion

802‧‧‧Recess

82‧‧‧Seal ring

90‧‧‧Positioning piece

100‧‧‧Chuck

101‧‧‧Annular base

111‧‧‧Anode area

112‧‧‧Partition wall

113‧‧‧Annular anode

114‧‧‧Power Channel

115‧‧‧Protection Cover

116‧‧‧Anolyte inlet

117‧‧‧Anolyte outlet

118‧‧‧Drain hole

119‧‧‧Exhaust Channel

120‧‧‧Column

121‧‧‧Inner Wall

122‧‧‧Outer Wall

123‧‧‧ groove

124‧‧‧notch

125‧‧‧Electrolyte outlet

126‧‧‧Substrate cleaning nozzle

141‧‧‧Catholyte inlet

142‧‧‧Branch

143‧‧‧Spray hole

144‧‧‧Central Channel

145‧‧‧Containing cavity

146‧‧‧fixing hole

147‧‧‧Gap

1010‧‧‧Shield

1011‧‧‧Collection tank

1012‧‧‧Drain channel

1013‧‧‧Cleaning fluid inlet

1020‧‧‧Chuck Qingxi Nozzle

1030‧‧‧Exhaust port

1040‧‧‧Liquid level sensor

1115‧‧‧Lip seal

1161‧‧‧Anolyte inlet pipe

1162‧‧‧The third valve

1171‧‧‧Anolyte Outlet Pipe

1172‧‧‧Fourth valve

1173‧‧‧Deionized water outlet pipe

1174‧‧‧Fifth valve

1191‧‧‧Exhaust pipe

1192‧‧‧Second valve

1193‧‧‧Deionized water inlet pipe

1194‧‧‧First valve

2011‧‧‧Finger Shape

Figure 1 discloses a perspective view of the electroplating device of the present invention.

Fig. 2 discloses a cross-sectional view of the electroplating device shown in Fig. 1.

Fig. 3 discloses another cross-sectional view of the electroplating device shown in Fig. 1.

Fig. 4 discloses another cross-sectional view of the electroplating device shown in Fig. 1.

Fig. 5 discloses a cross-sectional view of part of the elements of the electroplating device shown in Fig. 1.

Fig. 6 discloses an exploded view of some elements of the electroplating device shown in Fig. 5.

FIG. 7 discloses a partial enlarged view of some elements of the electroplating device shown in FIG. 5.

Figure 8 discloses a perspective view of the film frame of the electroplating device of the present invention.

FIG. 9 discloses a cross-sectional view of the film holder of the electroplating device shown in FIG. 8.

Figure 10 shows a perspective view of the central cap of the electroplating device of the present invention.

Figure 11 shows another perspective view of the center cap of the electroplating device of the present invention.

Figure 12 discloses a perspective view of the adjustable component of the electroplating device of the present invention

Fig. 13 discloses a perspective view of the first diffuser plate of the electroplating device of the present invention.

Fig. 14 discloses a perspective view of the second diffuser plate of the electroplating device of the present invention.

Figure 15 shows a perspective view of the middle plate of the electroplating device of the present invention.

Fig. 16 discloses a perspective view of the chuck of the electroplating device of the present invention.

Fig. 17 discloses a perspective view of a chuck cleaning nozzle for cleaning the chuck.

Figure 18 discloses a cross-sectional view of the chuck.

Fig. 19 discloses a partial enlarged view of the chuck shown in Fig. 18.

Figure 20 discloses a simplified schematic diagram of the electroplating apparatus of the present invention.

Figure 21 reveals the relationship between the gap change and the height of the plating column.

Figure 22 reveals the edge plating material when using the middle plate.

Figure 23 reveals an abnormally shaped copper pillar.

Figure 24 reveals a copper pillar with a normal shape.

Referring to FIG. 1 to FIG. 7, an electroplating apparatus according to an exemplary embodiment of the present invention is disclosed. The electroplating device includes a process chamber 10. The process chamber 10 is supported by a base 20. The process chamber 10 is divided into an anode chamber 11 and a cathode chamber 12. The anode cavity 11 and the cathode cavity 12 are separated by a membrane 13 fixed on a membrane frame 14.

The anode cavity 11 is divided into a plurality of anode regions 111 and every two adjacent anode regions 111 are separated by a partition wall 112 arranged vertically. The material of the partition wall 112 can be selected from non-conductive and chemical-resistant plastics. The partition wall 112 separates the electric field and limits the electrolyte fluid field. In one embodiment, for example, and not limiting the present invention, the anode cavity 11 is divided into two anode regions 111. Each anode area 111 contains an annular anode 113 which is connected to an independently controlled power supply channel 114. The electroplating current or voltage is independently applied to each annular anode 113 by the power supply channel 114. Each power channel 114 is connected to a power source, which can be a DC power source or a pulse power source. The power channel 114 is located in the protective cover 115. The ring anode 113 is made of a soluble material, such as copper, nickel, and tin. The ring anode 113 can also be made of inert materials. Each anode area 111 has an independent anolyte inlet 116, and the anolyte inlet 116 is connected to an electrolyte flow control device to provide anolyte to the anode area 111. At the same time, every yang The pole region 111 has an independent anolyte outlet 117 to discharge old electrolyte, decomposition products and particles in the anode region 111.

The film 13 is a cationic film used for copper, nickel, and tin electroplating. In addition, the membrane 13 may also be a proton exchange membrane or a common membrane covered with a fabric structure suitable for alloy plating. The membrane 13 is fixed on the membrane holder 14. The annular fixing plate 15 is used to fix the outer edge of the film 13 on the film holder 14. The first sealing ring 16 is arranged between the outer edge of the membrane 13 and the membrane holder 14. The second sealing ring 17 is provided between the outer edge of the membrane 13 and the annular fixing plate 15. A plurality of fixing members 18, such as screws, fix the membrane frame 14, the first sealing ring 16, the membrane 13, the second sealing ring 17, and the annular fixing plate 15 on the process chamber 10 to connect the anode cavity 11 and the cathode cavity 12 Separate. The third sealing ring 19 is arranged between the annular fixed plate 15 and the process chamber 10.

The catholyte inlet pipe 30 is installed in the center of the membrane frame 14 to supply catholyte to the cathode cavity 12. The fourth sealing ring 31 is arranged between the inner edge of the membrane 13 and the catholyte inlet pipe 30. The fifth sealing ring 32 is arranged between the inner edge of the membrane 13 and the membrane holder 14.

As shown in FIG. 4, the anode regions 111 are not completely isolated. There is a certain distance between the top of the partition wall 112 and the membrane 13 for air bubbles to pass through. The side wall of the anode cavity 11 is provided with a plurality of discharge holes 118 close to the membrane 13. Each discharge hole 118 is connected to a discharge channel 119. The air bubbles in the anode region 111 are collected by the membrane 13 and guided to the discharge hole 118, and then discharged from the discharge channel 119.

Referring to the simplified schematic diagram of the electroplating device shown in FIG. 20, the circulation of the anolyte and the automatic cleaning of the ring anode 113 are mainly illustrated. During the electroplating process, open the third valve set on the anolyte inlet pipe 1161 1162. The anolyte inlet pipe 1161 is connected to the anolyte inlet 116. At the same time, the second valve 1192 provided on the discharge pipe 1191 is opened. The discharge pipe 1191 is connected to the discharge passage 119. The anolyte is supplied to the anode region 111 through the anolyte inlet pipe 1161 and the anolyte inlet 116, and then discharged through the discharge hole 118, the discharge channel 119 and the discharge pipe 1191 to realize the circulation of the anolyte. When the electroplating process reaches a preset condition, for example, the process time exceeds 200 hours, the ring anode 113 needs to be cleaned. In order to clean the annular anode 113, first, the third valve 1162 and the second valve 1192 are closed to stop the circulation of the anolyte. Then, the fourth valve 1172 provided on the anolyte outlet pipe 1171 is opened. The anolyte outlet pipe 1171 is connected to the anolyte outlet 117. The anolyte in the anode region 111 is discharged through the anolyte outlet 117 and the anolyte outlet pipe 1171. After that, the fourth valve 1172 is closed. The first valve 1194 provided on the deionized water inlet pipe 1193 and the fifth valve 1174 provided on the deionized water outlet pipe 1173 are opened. The deionized water inlet pipe 1193 is connected to the discharge channel 119. The deionized water outlet pipe 1173 is connected to the anolyte outlet 117. Deionized water (DIW) is supplied to the anode region 111 of the anode cavity 11 through the deionized water inlet pipe 1193, the discharge channel 119 and the discharge hole 118 to flush the annular anode 113, and then passes through the anolyte outlet 117 and deionized The water outlet pipe 1173 is discharged to remove the anode mud. The flow rate of deionized water is controlled within the range of 0.5 lpm to 10 lpm. There are other methods to clean the ring anode 113, including the following steps: open the first valve 1194 to supply a certain amount of deionized water to the anode cavity 11; close the first valve 1194; open the fifth valve 1174 to discharge the deionized water and Remove anode slime; close the Five valves 1174; these steps are repeated until the annular anode 113 is cleaned. In Fig. 20, only one anode region 111 is shown. It should be recognized that the circulation of the anolyte in the other anode regions 111 and the automatic cleaning of the annular anode 113 are the same as in the described example.

The membrane frame 14 with the membrane 13 is arranged laterally to separate the anode cavity 11 and the cathode cavity 12. Referring to Figures 8 and 9, the film frame 14 is a rigid perforated or mesh frame. The membrane frame 14 is substantially dish-shaped and has a catholyte inlet 141 in the middle. The catholyte inlet 141 is connected to the catholyte inlet pipe 30. The film frame 14 is also provided with a plurality of branch pipes 142 extending from the center of the film frame 14 to the edge of the film frame 14. Each branch pipe 142 is connected to the catholyte inlet 141. Each branch pipe 142 is provided with a plurality of injection holes 143. The diameter of the multiple injection holes 143 on each branch pipe 142 may be the same or different. As on the substrate, as the radius increases, the area increases, and more flow is needed to meet the electroplating mass transfer requirements. Therefore, the diameter of the injection hole 143 gradually increases from the center to the edge of the film holder 14. For example, corresponding to a radius of 50 mm, the diameter of the injection hole 143 is 2 mm, and corresponding to a radius of 100 mm, the diameter of the injection hole 143 is 4 mm, and corresponding to a radius of 150 mm, the diameter of the injection hole 143 is 6 mm, and so on. In another way, the density of the injection holes 143 on each branch pipe 142 may be the same or different. The density of the injection holes 143 gradually increases from the center to the edge of the film holder 14. According to an embodiment, the opening direction of each injection hole 143 is inclined with respect to the vertical plane to prevent the catholyte from being sprayed to the same place and causing impact. The plurality of spray holes 143 on each branch pipe 142 may be divided into two groups. The opening directions of the two groups of injection holes 143 are opposite. Or, every branch on each branch 142 The opening directions of two adjacent injection holes 143 are opposite. In one embodiment, the membrane frame 14 has 6 branch pipes 142 for uniform flow distribution.

The film frame 14 has a central channel 144 passing through the center of the film frame 14. The accommodating cavity 145 is provided in the center of the film frame 14. The bottom end of the central channel 144 is connected to the catholyte inlet 141, and the top end of the central channel 144 is connected to the containing cavity 145. The film frame 14 is further provided with a plurality of fixing holes 146 in the containing cavity 145.

Because it is difficult to control electroplating in the central area of the substrate with a diameter of about 0-60 mm, especially the electrolyte flow rate and the uniformity of the electric field in the central area of the substrate are difficult to control. For the limitation of the entire electroplating, the electroplating device of the present invention further includes a center cap 40 and an adjustable member 50. The central cap 40 is fixed in the containing cavity 145 of the film frame 14. 10 and 11, the center of the center cap 40 is provided with a through hole 41. The top of the center cap 40 is provided with a plurality of first holes 42 arranged in a radial manner for uniform flow distribution. The diameters of the plurality of first holes 42 may be uniform or inconsistent. As on the substrate, as the radius increases, the area increases, and more flow is needed to meet the electroplating mass transfer requirements. Therefore, the diameter of the first hole 42 gradually increases from the center of the center cap 40 to the edge. In another way, the density of the first holes 42 on the center cap 40 can also be the same or different. The density of the first holes 42 gradually increases from the center of the center cap 40 to the edge. Preferably, the side wall of the center cap 40 is provided with a plurality of second holes 43. The opening direction of each second hole 43 is diagonally upward. During the electroplating process, if only the top of the center cap 40 is provided with the first hole 42, when the catholyte is sprayed from the first hole 42 to the cathode cavity 12, air pockets may be formed in the area around the center cap 40 and the center The electrolyte flow around the cap 40 is insufficient. Through the side of the center cap 40 The second hole 43 in the wall can solve this problem. The diameter and density of the second holes 43 distributed on the sidewall of the central cap 40 may be different from the diameter and density of the first holes 42 distributed on the top of the central cap 40.

The top of the center cap 40 is provided with a plurality of mounting holes 44. A plurality of screws are used to fix the central cap 40 in the accommodating cavity 145 of the film frame 14. The screws are inserted into the mounting hole 44 of the center cap 40 and the fixing hole 146 of the film frame 14 respectively. An O-shaped sealing ring 45 is provided between the center cap 40 and the film frame 14. The catholyte is supplied to each branch pipe 142 and the central cap 40 through the catholyte inlet pipe 30, the catholyte inlet 141 and the central channel 144. The catholyte is sprayed into the cathode cavity 12 through the spray holes 143 on each branch pipe 142 and the first hole 42 and the second hole 43 on the center cap 40. The flow rate of the catholyte in the catholyte inlet pipe 30 can reach more than 30 LPM (liters per minute), usually in the range of 2 LPM to 60 LPM. Although the flow rate of the catholyte is increased, due to the novel design of the central cap 40 and the branches 142 of the film frame 14, the electrolyte flow rate and the uniformity of the electric field of the entire substrate are improved, and the coating uniformity of the entire substrate is further improved. In addition, since a large and stable electrolyte flow rate can be obtained, the electroplating rate is improved compared to the traditional electroplating device. If there is no center cap 40, since the catholyte is directly flushed upwards from the catholyte inlet pipe 30 and the catholyte inlet 141, the flow speed is fast and the impact force is large, causing the ejection phenomenon in the central area of the substrate, which further leads to the phenomenon of the central area of the substrate. The shape of the plated column is abnormal. By providing the center cap 40 and increasing the number of the first holes 42 and the second holes 43, the flow rate will be slowed down and the impact force will be reduced. On the other hand, the distribution of the first holes 42 and the second holes 43 can adjust the flow rate of the catholyte, which further improves the uniformity of the catholyte in the central area of the substrate.

Referring to FIG. 12, the adjustable member 50 is configured to adjust the flow rate of the catholyte provided to the center cap 40, and further adjust the flow rate of the catholyte provided to the central area of the substrate. The adjustable member 50 is inserted into the through hole 41 of the center cap 40 and is located at the top of the center channel 144 of the membrane holder 14 to control the center flow. The adjustable member 50 can completely block the top end of the central channel 144 of the membrane holder 14, so the catholyte cannot be supplied to the central cap 40. By gradually lifting the adjustable member 50 upward, the top opening of the center channel 144 is gradually opened, so the catholyte is supplied to the center cap 40 through the gap 147 formed between the adjustable member 50 and the center channel 144. Therefore, the flow rate of the catholyte provided to the central area of the substrate can be adjusted by changing the size of the gap 147. The size of the gap 147 can be changed by raising or lowering the adjustable member 50. According to one embodiment, the adjustable member 50 includes a base 51 and a blocking portion 52 formed at the bottom of the base 51. The base 51 is cylindrical. The blocking portion 52 has an inverted cone shape. The top of the base 51 is provided with a slot-shaped opening 53 to facilitate the use of tools such as a screwdriver to rotate the adjustable member 50. Therefore, the adjustable member 50 moves up or down in the through hole 41 of the center cap 40 to adjust the size of the gap 147, thereby The flow rate of the catholyte provided to the center cap 40 is adjusted, and the flow rate of the catholyte provided to the central area of the substrate is adjusted. It can be seen that the flow rate of the catholyte provided to the center cap 40 is independently controlled by the adjustable member 50. The adjustable member 50 may be a fixing screw. In addition, when the flow rate of the catholyte in the catholyte inlet pipe 30 is given, if the flow rate of the catholyte supplied to the center cap 40 is small, the flow rate of the catholyte supplied to the branches 142 of the membrane frame 14 is Big. Conversely, if the flow rate of the catholyte supplied to the center cap 40 is large, the flow rate of the catholyte supplied to the branches 142 of the membrane frame 14 is small. therefore, The flow rate of the catholyte provided to the center cap 40 and the flow rate of the catholyte provided to the branches 142 of the membrane frame 14 can be adjusted.

By adjusting the size of the gap, the flow rate in the central area of the substrate can be controlled. If the gap is small, the flow rate in the center area of the substrate is small. Conversely, if the gap is large, the flow rate in the center area of the substrate is large. The size of the gap can be adjusted by rotating the adjustable member 50. Each time the adjustable member 50 rotates upward or downward, correspondingly, the size of the gap increases or decreases by 1 mm. Referring to Figure 21, it can be seen from Figure 21 that in the central area of the substrate, the larger the gap, the higher the average height of the plated pillars in a wafer, which means that the height of the plated pillars can be adjusted by adjusting the size of the gap. To control. In the center area of the substrate, the larger the gap, the larger the flow rate, and the higher the plating column height, which solves the plating problem in the center area of the substrate.

For more uniform control, including the uniformity control of the electric field and the uniformity control of the electrolyte flow, the electroplating device of the present invention includes at least one diffuser plate provided with many small holes. In one embodiment, the electroplating device includes two diffusion plates fixed on the top of the film frame 14. Please refer to Figure 5, Figure 6, Figure 13, and Figure 14. The first diffusion plate 60 is provided with a plurality of holes 61. In one embodiment, the sizes of the holes 61 of the first diffusion plate 60 are the same, and the density of the holes 61 distributed on the first diffusion plate 60 is also uniform. The diameter of the hole 61 of the first diffusion plate 60 is 0.5 mm to 5 mm. In another embodiment, the density of the holes 61 distributed in the first diffusion plate 60 is uniform, but the diameter of the holes 61 is different. The diameter of the holes 61 distributed in the central area of the first diffuser plate 60 is larger than the diameter of the holes 61 distributed in the edge area of the first diffuser plate 60, which can enhance the electric field intensity in the central area, thereby increasing the plating rate in the central area of the substrate. First diffuser The material of 60 can be polyvinyl chloride, polypropylene, polyether ether ketone, polyvinylidene fluoride, soluble polytetrafluoroethylene, Teflon, etc. The thickness of the first diffusion plate 60 is 2 mm to 20 mm. The second diffusion plate 70 is provided with a plurality of holes 71. In one embodiment, the size of the holes 71 of the second diffusion plate 70 is the same, and the density of the holes 71 distributed in the second diffusion plate 70 is uniform. The diameter of the hole 71 of the second diffusion plate 70 is 0.5 mm to 5 mm. In another embodiment, the density of the holes 71 distributed in the second diffusion plate 70 is uniform, but the diameter of the holes 71 may be different. The diameter of the holes 71 distributed in the central area of the second diffuser plate 70 is larger than the diameter of the holes 71 distributed in the edge area of the second diffuser plate 70, which can enhance the electric field intensity in the central area, thereby increasing the plating rate in the central area of the substrate. The material of the second diffusion plate 70 may be polyvinyl chloride, polypropylene, polyether ether ketone, polyvinylidene fluoride, soluble polytetrafluoroethylene, Teflon and the like. The thickness of the second diffusion plate 70 is 2 mm to 20 mm. The first diffuser 60 and the second diffuser 70 may be the same or different. Preferably, the density of the holes 61 distributed on the first diffusion plate 60 is greater than the density of the holes 71 distributed on the second diffusion plate 70, and the first diffusion plate 60 is arranged above the second diffusion plate 70. Since the second diffusion plate 70 is close to the membrane 13 and the annular anode 113, which can control the electric field distribution, the redistribution of the electric field can be realized and the problem of edge effect can be solved. Due to the resistance of the photoresist and the seed layer on the substrate, the resistance in the central area of the substrate is larger, and the closer to the edge of the substrate, the smaller the resistance. Therefore, the second diffuser 70 is mainly used to adjust the electric field in the circuit. The diameter of the holes 71 distributed in the central area of the second diffusion plate 70 is relatively large, and the size is 4 mm. The diameter of the hole 71 gradually decreases from the center to the edge of the second diffusion plate 70. The diameter of the holes 71 distributed on the edge of the second diffusion plate 70 is 2.5 mm. In this way, the electric field in the center will be enhanced And the electric field at the edge will be weakened, solving the problem of edge effect. The first diffuser 60 is closer to the substrate and is mainly for achieving smooth flow and fluid distribution. However, considering the influence of the distance of the electric field distribution, the distance between the first diffusion plate 60 and the second diffusion plate 70 cannot be too large. If the distance between the first diffusion plate 60 and the second diffusion plate 70 is too large, the electric field distribution effect of the second diffusion plate 70 is significantly weakened. The distance between the first diffusion plate 60 and the second diffusion plate 70 is 1 mm to 20 mm.

As shown in FIG. 5 and FIG. 6, the annular intermediate plate 80 is arranged between the first diffusion plate 60 and the second diffusion plate 70 to control the height of the plating column in the edge area of the substrate. The sealing ring 62 is provided between the first diffusion plate 60 and the intermediate plate 80. The other sealing ring 82 is provided between the intermediate plate 80 and the second diffusion plate 70. Another sealing ring 72 is provided between the second diffusion plate 70 and the top of the film frame 14. The multiple positioning members 90 are used to fix the first diffuser plate 60, the sealing ring 62, the intermediate plate 80, the sealing ring 82, the second diffuser plate 70 and the sealing ring 72 on the top of the film frame 14.

As shown in FIG. 15A, preferably, the inner edge of the intermediate plate 80 is provided with a plurality of convex portions 801 and a plurality of concave portions 802, which are used to improve the uniformity of the plating pillars at the edge of the substrate. The convex parts 801 and the concave parts 802 are arranged alternately. The intermediate plate 80 is provided between the first diffusion plate 60 and the second diffusion plate 70. The protrusion 801 blocks the corresponding holes 61 distributed on the edge of the first diffusion plate 60 to prevent the electrolyte from passing through the holes 61. The other holes 61 distributed on the edge of the first diffusion plate 60 correspond to the recesses 802 and are not blocked, so the electrolyte can pass through these holes 61 that are not blocked by the intermediate plate 80. Preferably, the holes 61 distributed on one half of the edge of the first diffuser plate 60 are blocked by the convex portion 801 of the middle plate 80, and the holes 61 distributed on the remaining half of the edge of the first diffuser plate 60 are not blocked.

15A shows the middle plate 80 with a plurality of convex parts 801 and a plurality of concave parts 802. The holes 61 distributed in half of the edge of the first diffuser plate 60 are blocked by the convex parts 801 of the middle plate 80 and are distributed on the first diffuser plate 60 The remaining half of the hole 61 of the edge is not blocked. FIG. 15B shows the intermediate plate 80', which cannot block the holes 61 distributed on the edge of the first diffuser 60 at all, so the electrolyte can pass through all the holes 61 distributed on the edge of the first diffuser 60. 15C illustrates the intermediate plate 80", which can block all the holes 61 distributed on the edge of the first diffusion plate 60, so the electrolyte cannot pass through these holes 61. It can be seen from Figure 22 that the intermediate plate mainly affects the coating thickness at the edge of the substrate. When all the holes 61 on the edge of the first diffusion plate 60 are blocked, the coating thickness on the edge of the substrate is lower than the coating thickness of other areas of the substrate due to the reduction of the edge power lines. On the contrary, when all the holes 61 on the edge of the first diffusion plate 60 are not blocked, the thickness of the coating on the edge of the substrate is higher than that of other areas of the substrate. In the above two cases, the height of the plating column at the edge of the substrate is not within the range required by the process, which will result in a loss of yield. The present invention uses an intermediate plate 80 including a plurality of protrusions 801 and a plurality of recesses 802 to selectively block some of the holes 61 distributed on the edge of the first diffusion plate 60, so that the thickness of the coating on the entire substrate is substantially uniform and within the range of process requirements within. Therefore, the coating thickness on the edge of the substrate can be well controlled.

Referring to FIG. 4, the cathode cavity 12 includes an inner wall 121 and an outer wall 122. A groove 123 is formed between the inner wall 121 and the outer wall 122. A notch 124 is provided on the top of the inner wall 121. A catholyte outlet 125 is provided at the bottom of the groove 123. The electrolyte in the cathode cavity 12 flows out through the slot 124 and is collected In the groove 123, it is discharged through the catholyte outlet 125. The substrate cleaning nozzle 126 is arranged in the cathode chamber 12 for cleaning the coating film of the substrate.

Referring to FIG. 2, a shield 1010 is fixed on the top of the cathode cavity 12 to avoid splashing of electrolyte during the electroplating process. The shield 1010 includes a collection tank 1011. The drainage channel 1012 is connected with the collection tank 1011. The liquid in the collection tank 1011 is discharged through the drain channel 1012. The side wall of the shield 1010 is provided with a cleaning liquid inlet 1013 for cleaning the collection tank 1011. The exhaust port 1030 is connected to the cathode chamber 12 for exhausting gas. The electroplating device can also include a liquid level sensor 1040 for monitoring the liquid level in the cathode cavity 12.

The chuck cleaning nozzle 1020 is located above the shield 1010, and is used to spray a cleaning liquid to clean the chuck 100, which is used to hold the substrate for electroplating processing. When the chuck 100 is cleaned, the cleaning liquid sprayed from the chuck cleaning nozzle 1020 is collected in the collecting tank 1011 of the shield 1010 and discharged through the drain channel 1012. The chuck 100 is described in detail in the PCT application number PCT/CN2015/096402 filed on December 4, 2015, and is quoted here in full.

16 to 19, the chuck 100 includes a cup-shaped base 101, three pillars 120 located on the top of the cup-shaped base 101 for support and power transmission, a conductive ring, the conductive ring has a plurality of contact with the front edge of the substrate The finger portion 2011 and the seal, the seal has a lip seal 1115 for sealing the front edge of the substrate, so when the substrate is immersed in the electrolyte for electroplating, the electrolyte cannot reach the front edge of the substrate and the back of the substrate. The chuck cleaning nozzle 1020 sprays cleaning liquid to clean the finger portion 2011 of the conductive ring and the lip seal portion 1115 of the seal. After the substrate plating is completed, the finger part of the conductive ring 2011 And there may be residual plating solution on the lip-shaped seal 1115 of the seal. If the remaining plating solution is not cleaned up in time, the remaining plating solution will form crystals. The crystallization at the lip-shaped seal portion 1115 of the seal will affect the sealing performance between the lip-shaped seal portion 1115 and the front edge of the substrate, causing the plating solution to contact the conductive ring, causing problems in electroplating. Therefore, after each substrate is electroplated, it is necessary to clean the finger portion 2011 of the conductive ring and the lip seal portion 1115 of the seal.

However, since the chuck 100 keeps rotating during the cleaning process, the cleaning liquid sprayed from the chuck cleaning nozzle 1020 will hit the three pillars 120, causing the cleaning liquid to splash. In order to solve this problem, a controller includes a timer for controlling an on-off valve provided on the supply pipe. The supply pipe is connected to the chuck cleaning nozzle 1020 and is used to supply the chuck cleaning nozzle 1020 with cleaning liquid. The controller is configured to control the on-off valve based on a timer: close the on-off valve when each column 120 passes through the chuck cleaning nozzle 1020 to stop spraying cleaning liquid; open the on-off valve after the column 120 passes through the chuck cleaning nozzle 1020 , To spray cleaning fluid. For example, the rotation speed of the chuck 100 is 20 rpm and the time for one revolution of the chuck 100 is 3 seconds. The chuck 100 includes three uprights 120 and the time for each upright 120 to pass through the chuck cleaning nozzle 1020 is 0.1 second. When the first column passes through the chuck cleaning nozzle 1020, the on-off valve is closed for 0.1 second. Then open the on-off valve for 0.9 seconds. After that, when the second column passes through the chuck cleaning nozzle 1020, the on-off valve is closed again for 0.1 second. Then open the switch valve for 0.9 seconds. After that, when the third column passes through the chuck cleaning nozzle 1020, the on-off valve is closed again for 0.1 second. Repeat this method to prevent the cleaning fluid from hitting the column 120.

In summary, the present invention has been described in detail through the above-mentioned embodiments and related drawings, and the related technology has been disclosed in detail, so that those skilled in the art can implement it accordingly. The above-mentioned embodiments are only used to illustrate the present invention, not to limit the present invention. The scope of rights of the present invention should be defined by the scope of the patent application of the present invention. As for the change in the number of elements described herein or the replacement of equivalent elements, all should still belong to the scope of the present invention.

10‧‧‧Craft cavity

11‧‧‧Anode cavity

12‧‧‧Cathode cavity

13‧‧‧membrane

14‧‧‧Film frame

19‧‧‧Third sealing ring

20‧‧‧Base

111‧‧‧Anode area

112‧‧‧Partition wall

113‧‧‧Annular anode

116‧‧‧Anolyte inlet

117‧‧‧Anolyte outlet

1010‧‧‧Shield

1011‧‧‧Collection tank

1012‧‧‧Drain channel

1020‧‧‧Chuck Qingxi Nozzle

Claims (40)

An electroplating device for depositing metal on a substrate, comprising: a film frame with a central channel passing through the center of the film frame; a catholyte liquid inlet pipe connected with the central channel of the film frame; a center cap fixed at the center of the film frame And covering the central channel of the membrane frame, the top of the central cap is provided with a plurality of first holes; wherein the catholyte inlet pipe supplies catholyte to the central cap through the central channel of the membrane frame, and the catholyte passes through the first hole of the central cap. A hole is supplied to the central area of the substrate. The electroplating apparatus according to claim 1, wherein the flow rate of the cathodic electrode liquid supplied to the center cap is adjustable and independently controlled. The electroplating device according to claim 1, wherein the center of the center cap is provided with a through hole, the adjustable member is inserted into the through hole of the center cap and is located at the top end of the center channel of the film holder, and the adjustable member is configured to adjust Provides the flow of catholyte to the center cap. The electroplating apparatus according to claim 3, wherein the adjustable member includes a base and a blocking part formed at the bottom of the base. The electroplating device according to claim 4, wherein the top of the base body is provided with a slot-shaped opening to facilitate the rotation of the adjustable member, and the adjustable member moves up or down in the through hole of the center cap to adjust the blocking portion and in The size of the gap between the heart channels through which the catholyte is supplied to the center cap. The electroplating apparatus according to claim 3, wherein the adjustable member is a fixing screw. The electroplating apparatus according to claim 1, wherein the diameter of the first holes is the same or the density of the first holes is the same. The electroplating apparatus according to claim 1, wherein the diameter of the first hole is different or the density of the first hole is different. The electroplating apparatus according to claim 1, wherein the diameter of the first hole gradually increases from the center to the edge of the center cap, or the density of the first hole gradually increases from the center to the edge of the center cap. The electroplating device according to claim 1, wherein the central cap has a side wall, a plurality of second holes are provided on the side wall of the central cap, and the opening direction of each second hole is diagonally upward. The electroplating device according to claim 1, wherein the membrane frame has a catholyte inlet, the catholyte inlet is connected with the catholyte inlet pipe and the central channel, and the membrane frame is provided with a plurality of membrane frames extending from the center of the membrane frame The branch pipes to the edge of the membrane frame are connected with the catholyte inlet, and each branch pipe is provided with a plurality of spray holes. The electroplating apparatus according to claim 11, wherein the diameter or density of the plurality of injection holes on each branch pipe is the same. The electroplating apparatus according to claim 11, wherein the diameters or densities of the plurality of injection holes on each branch pipe are different. The electroplating apparatus according to claim 11, wherein the diameter or density of the injection hole gradually increases from the center to the edge of the film holder. The electroplating apparatus according to claim 11, wherein the opening direction of each injection hole is inclined with respect to a vertical plane. The electroplating apparatus according to claim 15, wherein the plurality of spray holes on each branch pipe are divided into two groups, and the opening directions of the two groups of spray holes are opposite. The electroplating device according to claim 1, further comprising at least one diffuser plate provided with a plurality of holes, and the diffuser plate is fixed on the film frame. The electroplating device according to claim 17, wherein the size of the holes on the diffusion plate is uniform and the density of holes distributed on the diffusion plate is uniform. The electroplating device according to claim 17, wherein the density of the holes distributed on the diffuser plate is uniform, but the diameter of the holes distributed on the central area of the diffuser plate is larger than the diameter of the holes distributed on the edge of the diffuser plate. The electroplating apparatus according to claim 17, wherein the number of the diffusion plates is two, the two diffusion plates are divided into a first diffusion plate and a second diffusion plate, and the first diffusion plate is arranged on the second diffusion plate Above, a certain distance is formed between the two diffuser plates. The electroplating apparatus according to claim 20, wherein the density of the holes distributed on the first diffusion plate is greater than the density of the holes distributed on the second diffusion plate. The electroplating apparatus according to claim 20, further comprising an annular intermediate plate arranged between the two diffuser plates, and the inner edge of the intermediate plate is provided with a plurality of convex parts and a plurality of concave parts. The electroplating apparatus according to claim 22, wherein the convex portions and the concave portions are alternately arranged. The electroplating device according to claim 22, wherein half of the holes distributed on the edge of the first diffuser plate are blocked by the convex part of the middle plate, and the other half of the holes distributed on the edge of the first diffuser plate are not blocked. The electroplating device according to claim 1, further comprising an anode cavity and a cathode cavity, and the anode cavity and the cathode cavity are separated by a film fixed on the film frame. The electroplating device according to claim 25, wherein the anode cavity has a side wall, and the side wall of the anode cavity is provided with a plurality of discharge holes, and each discharge hole is connected to a discharge channel. The electroplating device according to claim 26, wherein the anode cavity is divided into a plurality of anode regions and every two adjacent anode regions are separated by a partition wall arranged vertically, each anode region contains a ring anode, and An anode area has independent anolyte inlet and anolyte outlet. The electroplating device according to claim 27, wherein there is a certain distance between the top of the partition wall and the membrane for air bubbles to pass through, and the air bubbles in the anode region are collected by the membrane and guided to the discharge hole, and then discharged from the discharge channel. The electroplating device according to claim 28, further comprising a third valve provided on the anolyte inlet pipe connected to the anolyte inlet, and a second valve provided on the On the discharge pipe connected to the discharge channel, the anolyte is supplied to the anode area through the anolyte inlet pipe and the anolyte inlet, and then discharged through the discharge hole, the discharge channel and the discharge pipe. The electroplating device according to claim 27, further comprising a fourth valve disposed on the anolyte outlet pipe connected to the anolyte outlet, wherein the anolyte in the anode region passes through the anolyte electrolysis The liquid outlet and the anode electrolyte outlet pipe are discharged. The electroplating device according to claim 28, further comprising a first valve arranged on the deionized water inlet pipe and a fifth valve arranged on the deionized water outlet pipe, wherein the deionized water inlet pipe is connected to the discharge pipe Channel, the deionized water outlet pipe is connected to the anolyte outlet, wherein the deionized water is supplied to the anode area of the anode cavity through the deionized water inlet pipe, the discharge channel and the discharge hole to flush the annular anode, and then passes through the anolyte outlet And the deionized water outlet pipe is discharged. The electroplating device according to claim 25, wherein the cathode cavity includes an inner wall and an outer wall, a groove is formed between the inner wall and the outer wall, a notch is provided at the top of the inner wall, and a groove is provided at the bottom of the groove. Catholyte out The electrolyte in the cathode cavity flows out through the slot, is collected in the groove, and is discharged through the catholyte outlet. The electroplating apparatus according to claim 25, further comprising a substrate cleaning nozzle, which is arranged in the cathode cavity for cleaning the plating film of the substrate. The electroplating device according to claim 25, further comprising a shield fixed on the top of the cathode chamber. The electroplating device according to claim 34, wherein the shield includes a collection tank, and a drain channel connected to the collection tank, and the liquid in the collection tank is discharged through the drain channel. The electroplating device according to claim 35, wherein the side wall of the shield is provided with a cleaning liquid inlet for cleaning the collection tank. The electroplating device according to claim 25, further comprising an exhaust port connected to the cathode chamber for exhausting gas. The electroplating device according to claim 34, further comprising a chuck cleaning nozzle located above the shield for cleaning the chuck. The electroplating apparatus according to claim 38, wherein the chuck includes a plurality of uprights. The electroplating device according to claim 39, further comprising a controller with a timer, and the on-off valve is provided on a supply pipe connected to the chuck cleaning nozzle for supplying cleaning liquid to the chuck cleaning nozzle, wherein the control The device is configured to control the on-off valve based on a timer: close the on-off valve when each column passes through the chuck cleaning nozzle to stop spraying the cleaning liquid; after the column passes the chuck cleaning nozzle, open the on-off valve to spray the cleaning liquid .

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