WO2024046345A1

WO2024046345A1 - Chuck structure of semiconductor cleaning device, and semiconductor cleaning device and method

Info

Publication number: WO2024046345A1
Application number: PCT/CN2023/115692
Authority: WO
Inventors: 杨慧毓; 王海阔; 宋爱军; 刘本锋; 张敬博; 卢夕生; 谢志勇
Original assignee: 北京北方华创微电子装备有限公司
Priority date: 2022-08-31
Filing date: 2023-08-30
Publication date: 2024-03-07
Also published as: CN115424974B; CN115424974A

Abstract

Provided in the present invention are a chuck structure of a semiconductor cleaning device, and a semiconductor cleaning device. The chuck structure comprises a chuck base body configured to bear a wafer, and a plurality of avoidance recesses are formed at an edge of a first surface of the chuck base body that is opposite the wafer; the plurality of avoidance recesses are arranged in one-to-one correspondence with contact positions between a manipulator and the wafer when the manipulator takes and places the wafer, so as to prevent the manipulator from being in contact with the chuck base body when the manipulator takes and places the wafer; a first gas channel is arranged in the chuck base body, the first gas channel is provided with a plurality of first air outlets in the first surface, and the plurality of first air outlets are distributed at intervals in a circumferential direction of the first surface; and an air injection direction of each first air outlet inclines towards the outer side of the surface of the wafer that is opposite the chuck base body. By means of the embodiments of the present invention, the position calibration difficulty of the manipulator can be reduced, and particle pollution and corrosion generated at the edge of the wafer are avoided.

Description

Chuck structure of semiconductor cleaning equipment, semiconductor cleaning equipment and method

Technical field

The present invention relates to the field of semiconductor processing technology, and specifically to a chuck structure of semiconductor cleaning equipment, semiconductor cleaning equipment and methods.

Background technique

With the development of integrated circuit manufacturing technology, back-end copper interconnect technology has been widely used in the chip manufacturing process. Copper connections on semiconductor devices are generally generated by electroplating. During electroplating, the front and back sides of the silicon wafer are immersed in a plating solution containing copper ions at the same time. At this time, the copper ion concentration on the back side of the silicon wafer is very high, and the copper ions need to be reduced. concentration to avoid copper contamination of the silicon wafer clamping and transfer mechanisms of subsequent semiconductor processing equipment. The existing method is to use a single-wafer backside cleaning machine to clean the backside of the silicon wafer to reduce the copper ion concentration on the backside of the silicon wafer.

The typical wafer transfer process of a single-wafer backside cleaning machine is as follows: the wafer is flipped from front-side up to back-side by the flipping mechanism located in the transfer area, and under the clamping action of the robot hand, the wafer enters the process chamber while maintaining the front-side down state. And it is suspended above the chuck structure under the action of the air flow ejected from the chuck structure. However, since the distance between the chuck structure and the suspended wafer is very small (generally 0.2mm-0.8mm), this will make it difficult to calibrate the position of the manipulator, and it is easy for interference to occur between the manipulator and the chuck structure. , and the repeatability and reliability of the calibrated position are difficult to maintain mass production requirements.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. It proposes a chuck structure of a semiconductor cleaning equipment, a semiconductor cleaning equipment and a method, which can not only reduce the difficulty of position calibration of the robot hand, but also improve the repeatability of the calibration position. performance and reliability, thereby meeting mass production requirements and avoiding particle contamination on the front side of the wafer.

In order to achieve the above object, the present invention provides a chuck structure of a semiconductor cleaning equipment, including a chuck base for carrying a wafer, and multiple holes are formed at the edge of the first surface of the chuck base opposite to the wafer. A plurality of avoidance recesses, the plurality of avoidance recesses are provided in one-to-one correspondence with the contact positions of the manipulator and the wafer when picking up and placing the wafer, so as to prevent the manipulator from contacting the chuck base when picking up and placing the wafer;

A first gas channel is provided in the chuck base. The first gas channel has a plurality of first gas outlets on the first surface. The plurality of first gas outlets are along the first surface. Circumferentially spaced distribution; the jet direction of each first air outlet is inclined toward the outside of the surface of the wafer opposite to the chuck base.

Optionally, a second gas channel is also provided in the chuck base, the second gas channel has a plurality of second gas outlets on the first surface, and each of the avoidance recesses is connected to a plurality of second gas outlets. At least one second air outlet is provided correspondingly between the circumferences of the first air outlets, and the jet direction of each second air outlet is inclined toward the outside of the surface of the wafer opposite to the chuck base body. .

Optionally, there are a plurality of second air outlets located between each of the avoidance recesses and the circumference of the plurality of first air outlets, and are arranged in an arc shape.

Optionally, a plurality of the second air outlets are arranged in an arc shape along the circumferential direction of the first surface;

The extension direction of the first side of each escape recess adjacent to the plurality of second air outlets is consistent with the arrangement direction of the plurality of second air outlets.

Optionally, the chuck base includes a bearing base and a cover plate disposed on the bearing base. The upper surface of the cover plate is used as the first surface, and there is a gap between the cover plate and the bearing base. An air cavity is formed;

The first gas channel includes a plurality of first oblique holes provided in the cover plate, one end of each first oblique hole is located on the first surface and serves as the first gas outlet; each The other end of the first inclined hole is connected with the air chamber;

The second gas channel includes a plurality of second inclined holes provided in the cover plate, each of the first One end of the two oblique holes is located on the first surface and serves as the second air outlet; the other end of each second oblique hole is connected with the air chamber.

Optionally, the plurality of escape recesses are divided into multiple escape groups, and the number of the escape recesses in each escape group is the same as the number of contact positions between the manipulator and the wafer; The avoidance groups are symmetrically distributed relative to the center of the first surface.

Optionally, the opening area enclosed by the inner peripheral surface of the escape recess increases gradually in a direction away from the bottom surface of the escape recess.

Optionally, a first fillet is formed between the inner peripheral surface of the escape recess and the bottom surface of the escape recess.

Optionally, the orthographic projection shape of the inner circumferential surface of the escape recess on the first surface is a polygon, and each corner of the polygon is formed with a second rounded corner.

Optionally, the distance between the second air outlet and the first side is greater than or equal to 10 mm and less than or equal to 20 mm.

Optionally, there are three escape recesses, namely a first escape recess and two second escape recesses located on both sides of the first escape recess, and the first escape recess is located around the first surface. The upward length is greater than or equal to 20 mm and less than or equal to 40 mm; the length of the second escape recess in the circumferential direction of the first surface is greater than or equal to 30 mm and less than or equal to 60 mm.

Optionally, the number of the second air outlets located between each of the avoidance recesses and the circumference of the plurality of first air outlets is greater than or equal to 5 and less than or equal to 15.

Optionally, the angle between the air jet direction of each second air outlet and the first surface is greater than or equal to 30° and less than or equal to 45°.

As another technical solution, the present invention also provides a semiconductor cleaning equipment, including a process chamber, a manipulator and a spray device. A rotatable and lifting chuck structure is provided in the process chamber for carrying wafers. ; The spray device includes a first swing arm for spraying chemical liquid, a second swing arm for spraying deionized water, and a third swing arm for spraying dry gas. The chuck structure adopts this invention The above chuck structure is provided.

As another technical solution, the present invention also provides a semiconductor cleaning method, which uses the above-mentioned semiconductor cleaning equipment provided by the present invention to clean the wafer. The semiconductor cleaning method includes:

Pass inert gas into the first gas channel;

Control the manipulator to transfer the wafer into the process chamber, so that the wafer is suspended in the transfer position above the first surface under the action of air flow;

Control the chuck structure to drop to the first process position and rotate;

Control the nozzle of the first swing arm to swing above the wafer while spraying chemical liquid onto the wafer;

After the spraying is completed, control the first swing arm to return to the initial position and keep the chuck structure to continue rotating;

Control the chuck structure to rise to the second process position while maintaining rotation;

Control the nozzle of the second swing arm to swing above the wafer while spraying deionized water onto the wafer;

After the spraying is completed, control the second swing arm to return to the initial position and keep the chuck structure to continue rotating;

Control the nozzle of the third swing arm to swing above the wafer while spraying purge gas toward the wafer;

After the purging is completed, the chuck structure is controlled to return to the wafer transfer position, and the manipulator is controlled to take out the wafer.

Optionally, while the inert gas is introduced into the first gas channel, the inert gas is introduced into the second gas channel.

Optionally, the flow rate of the inert gas is greater than or equal to 10L/min and less than or equal to 600L/min.

Optionally, when the chuck structure is lowered to the first process position, the vertical distance between the nozzle of the first swing arm and the wafer is greater than or equal to 20 mm and less than or equal to 60 mm.

Optionally, the swing distance of the nozzle of the first swing arm above the wafer surface is 80% of the maximum swing distance; the maximum swing distance is the distance from the center of the wafer surface to the edge;

The swing speed of the first swing arm is greater than or equal to 10°/s and less than or equal to 25°/s.

Optionally, after the spraying is completed, control the first swing arm to return to the initial position and keep the chuck structure to continue rotating, including:

Keep the chuck structure to continue to rotate at the same first rotation speed as when the first swing arm is spraying;

After a preset period of time, the chuck structure is controlled to rotate at a second rotational speed, and the second rotational speed is higher than the first rotational speed.

Optionally, the first rotational speed is greater than or equal to 300R/min and less than or equal to 900R/min; the second rotational speed is greater than or equal to 1000R/min and less than or equal to 2000R/min.

Beneficial effects of the present invention:

The chuck structure of the semiconductor cleaning equipment provided by the present invention is formed by forming a plurality of avoidance recesses at the edge of the first surface of the chuck base opposite to the wafer. The plurality of avoidance recesses interact with the robot when picking up and placing the wafer. The contact positions of the circles are set in one-to-one correspondence, which can prevent the robot from contacting the chuck base when picking up and placing wafers, thereby reducing the difficulty of position calibration of the robot, improving the repeatability and reliability of the calibration position, and thus meeting mass production requirements; On this basis, by combining the use of the first gas channel with multiple first gas outlets on the first surface to blow air obliquely toward the wafer surface, the wafer can be suspended above the chuck base without the need for vertical jet air flow. This way, the height of the wafer suspended above the chuck structure can be increased to avoid particle contamination on the front side of the wafer.

The semiconductor cleaning equipment provided by the present invention, by adopting the above-mentioned chuck structure provided by the present invention, can not only reduce the difficulty of position calibration of the manipulator, improve the repeatability and reliability of the calibration position, thereby meeting mass production requirements, but also avoid Particle contamination on the front side of the wafer.

The semiconductor cleaning method provided by the present invention, by using the above-mentioned semiconductor cleaning equipment provided by the present invention, can not only reduce the difficulty of position calibration of the robot hand, but also improve the repeatability and reliability of the calibration position. reliability, thereby meeting mass production requirements, and also avoiding particle contamination on the front side of the wafer.

Description of drawings

Figure 1 is a top view of the chuck structure of the semiconductor cleaning equipment provided by the first embodiment of the present invention;

Figure 2A is a structural diagram of the manipulator used in the first embodiment of the present invention;

Figure 2B is a process diagram of a robot picking up and placing a wafer according to the first embodiment of the present invention;

3A is a top view of the chuck structure of the semiconductor cleaning equipment provided by the second embodiment of the present invention;

3B is a partial cross-sectional view of the chuck structure of the semiconductor cleaning equipment provided by the second embodiment of the present invention;

3C is a cross-sectional view of the chuck structure of the semiconductor cleaning equipment provided by the second embodiment of the present invention;

Figure 4 is another top view of the chuck structure of the semiconductor cleaning equipment provided by the second embodiment of the present invention;

Figure 5A is an enlarged view of one of the avoidance recesses used in various embodiments of the present invention;

Figure 5B is an enlarged view of another avoidance recess used in various embodiments of the present invention;

Figure 6 is a structural diagram of a semiconductor cleaning equipment provided by a third embodiment of the present invention;

FIG. 7 is a flow chart of a semiconductor cleaning method provided by the fourth embodiment of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the chuck structure of the semiconductor cleaning equipment and the semiconductor cleaning equipment provided by the present invention will be described in detail below with reference to the accompanying drawings.

In the related technology, on the basis that the wafer is suspended above the chuck structure under the action of the air flow ejected from the chuck structure, in order to increase the distance between the chuck structure and the suspended wafer, the position calibration belt for the robot is reduced. To overcome the difficulty, the method of vertically ejecting airflow is used to increase the height of the wafer suspended above the chuck structure. However, the inventor found through research that this method of vertically ejecting airflow requires a larger amount of time. Gas flow rate (about 200-400LPM), vertical jet will blow particles towards the front of the wafer, causing contamination to the front of the wafer and causing defect problems.

First embodiment

Please refer to FIGS. 1 to 2B together. In order to solve the above problems, a first embodiment of the present invention provides a chuck structure of a semiconductor cleaning equipment, which includes a chuck base 1 for carrying a wafer 3. A plurality of escape recesses 12 are formed at the edge of the first surface 11 of the base 1 opposite to the wafer 3. The plurality of escape recesses 12 are arranged in one-to-one correspondence with the contact positions of the robot 4 and the wafer 3 when picking up and placing the wafer 3. , to prevent the robot 4 from contacting the chuck base 1 when picking up and placing the wafer 3 . Taking the robot hand 4 shown in FIG. 2A as an example, the robot hand 4 includes two mechanical fingers 41 and a movable hook part 42. One end of the two mechanical fingers 41 is provided with a fixed hook part 411; the movable hook part 42 is located on the two mechanical fingers 41 Between the other end away from the fixed hook part 411, the movable hook part 42 can expand and contract in the direction closer to or away from the fixed hook part 411 along the A direction shown in Figure 2A. As shown in Figure 2B, when the movable hook part 42 moves toward When extending in the direction close to the fixed hook part 411, it will clamp the edge of the wafer 3 together with the two fixed hook parts 411; when the movable hook part 42 retracts in the direction away from the fixed hook part 411, it will work with the two fixed hook parts 411. The two fixing hooks 411 release the clamping of the edge of the wafer 3 . The three contact positions of the movable hook part 42 and the two fixed hook parts 411 with the wafer 3 when clamping the wafer 3 are the position B1, the position B2 and the position B3 in FIG. 2B. In this case, there are three escape recesses 12 , and the three escape recesses 12 are provided in one-to-one correspondence with the positions B1 , B2 , and B3 , so that the movable hook 42 and the two fixed hooks 411 can respectively One of the three escape recesses 12 is in contact with the edge of the wafer 3 . In this way, interference between the movable hook part 42 and the two fixed hook parts 411 and the chuck base 1 can be avoided, thereby ensuring that the robot 4 can normally perform the operation of picking up and placing wafers, which is especially suitable for use between the chuck base 1 and the suspension. When the distance between the wafers 3 is very small (generally 0.2mm-0.8mm), by setting the avoidance recess 12, the movable hook 42 and the two fixed hooks 411 can be prepared when the robot 4 picks and places the wafer. Leave a certain space to prevent the three from contacting the chuck base 1, thereby reducing the difficulty of position calibration of the manipulator 4, improving the repeatability and reliability of the calibration position, and thus meeting mass production requirements. And, because on wafer 3 the When the floating height is small, with the help of the above-mentioned avoidance recess 12, the robot 4 can normally perform the pick-and-place operation, so there is no need to use a vertical airflow method (that is, blowing air toward the wafer in a direction perpendicular to the back of the wafer). Gas ejected from the back side) increases the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front side of the wafer.

It should be noted that there are three contact positions between the robot 4 and the wafer shown in FIG. 2A , and correspondingly, the number of avoidance recesses 12 is three. However, the embodiment of the present invention is not limited to this. In practice, In application, the number of contact positions between the manipulator and the wafer can also be other numbers, and the number of avoidance recesses 12 can also be adjusted accordingly. In addition, the embodiment of the present invention is not limited to the structure of the manipulator shown in FIG. 2A , and may also adopt any other structure. The embodiment of the present invention has no particular limitation on this.

Referring to FIG. 1 , a first gas channel is provided in the chuck base 1 . The first gas channel has a plurality of first gas outlets 131 on the first surface 11 , and the plurality of first gas outlets 131 are along the first surface 11 . circumferentially spaced distribution; the jet direction of each first air outlet 131 is inclined toward the outside of the surface of the wafer opposite to the chuck base 1 .

For example, the jet direction of the first gas channel is the arrow direction A shown in FIG. 3B , and this direction forms an included angle of less than 90° with the first surface 11 . By slanting the jet direction of the first gas outlet 131 along the arrow direction A shown in FIG. 3B , the gas flow rate on the surface of the wafer opposite to the chuck base 1 can be increased to be greater than that of the wafer and the chuck. According to Bernoulli's principle, the faster the gas flow rate is, the smaller the pressure is; conversely, the slower the gas flow rate is, the greater the pressure is. Therefore, the wafer is deviating from the chuck substrate 1. The pressure on the surface is less than the pressure on the surface of the wafer opposite to the chuck base 1, so that the wafer is subject to an attraction force toward the first surface 11 until the forces on the two surfaces of the wafer reach a balance. , the wafer will be stably suspended at a certain height above the chuck base 1 to enable the cleaning process, and at the same time, the wafer 3 will not be in contact with the chuck base 1 . In addition, by distributing the plurality of first gas outlets 131 at intervals along the circumferential direction of the first surface 11 , the gas can be ejected evenly along the circumferential direction of the wafer 3 , thereby ensuring that the wafer can be stably supported by the gas. rise.

In practical applications, the angle between the jet direction of the first air outlet 131 (ie, the arrow direction A shown in FIG. 3B ) and the first surface 11 can be set according to specific needs, so as to increase the relationship between the wafer and the wafer. The gas flow rate on the opposite surface of the chuck base 1 enables the wafer 3 to receive an attraction force until the wafer is stably suspended at a certain height above the chuck base 1 . Optionally, the value range of the angle between the air jet direction of the first air outlet 131 (ie, arrow direction A shown in FIG. 3B ) and the first surface 11 is greater than or equal to 30° and less than or equal to 45°. Within this angle range, it can be ensured that the wafer 3 can receive the attraction force until the wafer is stably suspended at a certain height position above the chuck base 1 .

The chuck structure of the semiconductor cleaning equipment provided in this embodiment is formed by forming a plurality of escape recesses 12 at the edge of the first surface 11 of the chuck base 1 opposite to the wafer. When placing the wafer, the contact positions of the wafer are set in one-to-one correspondence, which can prevent the robot arm 4 from contacting the chuck base 1 when picking up and placing the wafer, thereby reducing the difficulty of position calibration of the robot arm 4 and improving the repeatability and reliability of the calibration position. performance, and thus can meet mass production requirements; on this basis, by combining the use of the first gas channel with multiple first gas outlets 141 on the first surface 11 to blow air obliquely toward the wafer surface, the wafer can be suspended on the card. Above the disc base, there is no need to use vertical airflow to increase the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front of the wafer.

Second embodiment

Please refer to FIG. 3A , FIG. 3B and FIG. 3C together. The chuck structure of the semiconductor cleaning equipment provided by the second embodiment of the present invention is an improvement based on the above-mentioned first embodiment. Specifically, in this embodiment, in addition to the above-mentioned first gas channel, a second gas channel is also provided in the chuck base 1 . The second gas channel has a plurality of second gas channels on the first surface 11 . The air outlet 141 is provided with at least one second air outlet 141 correspondingly between each avoidance recess 12 and the circumference of the plurality of first air outlets 131. The air injection direction of each first air outlet 131 and each second air outlet 141 is All dynasties It is inclined toward the outside of the surface of the wafer 3 that faces the chuck base 1 . Specifically, the diameter of the circumference of the inner circumferential edge of each escape recess 12 is larger than the diameter of the circumference of the plurality of first air outlets 131 , and at least one second air outlet 141 is provided between the inner circumferential edge of each escape recess 12 and the plurality of first air outlets 131 . The first air outlet 131 is located in the area between the circles.

The chuck structure of the semiconductor cleaning equipment provided by the embodiment of the present invention uses a plurality of avoidance recesses 12 to prevent the robot from contacting the chuck base when picking up and placing wafers, and uses a plurality of first air outlets 131 and a plurality of third air outlets in combination. The two air outlets 141 eject air obliquely toward the wafer surface, and use the first gas channel to provide multiple first air outlets 141 on the first surface 11 to eject air obliquely toward the wafer surface, so that the wafer can be suspended above the chuck base. , and at the same time, there is no need to use vertical airflow to increase the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front of the wafer; using the above-mentioned second gas channel to install multiple second gas channels on the first surface 11 The air outlet 141 blows air obliquely toward the wafer surface, which can protect the edge of the wafer, especially the location of the avoidance recess 12, thereby not only avoiding the unstable air flow field generated at the edge of the wafer due to the influence of the avoidance recess 12. Particle contamination; and during the cleaning process, it can also avoid chemical liquid splashing back at the avoidance recess 12, causing wafer edge corrosion.

In some optional embodiments, as shown in FIG. 3A , there are multiple second air outlets 141 located between each avoidance recess 12 and the circumference of the plurality of first air outlets 131 , and are arranged in an arc shape. In this way, the protective effect of the gas ejected from the plurality of second air outlets 141 on the location of each avoidance recess 12 can be enhanced.

In some optional embodiments, as shown in FIG. 3A , a plurality of second air outlets 141 are arranged in an arc shape along the circumferential direction of the first surface 11 ; each avoidance recess 12 is connected to the plurality of second air outlets 141 The extending direction of the adjacent first sides 121 is consistent with the arrangement direction of the plurality of second air outlets 141 . In this way, particle contamination at the edge of the wafer due to the unstable air flow field generated by the avoidance recess 12 can be more effectively avoided. In addition, in practical applications, in order to avoid particle contamination at the edge of the wafer due to the unstable air flow field generated by the avoidance recess 12, the first air outlet can be appropriately increased. For example, the number of first air outlets 131 used when the escape recess 12 is provided may be 1.2 to 1.6 times the number of the first air outlets 131 used when the escape recess 12 is not provided.

In some optional embodiments, as shown in FIG. 3A , the distance D between the second air outlet 141 and the first side 121 is greater than or equal to 10 mm and less than or equal to 20 mm. In this way, it can be ensured that the gas ejected from the plurality of second air outlets 141 can protect the location of each avoidance recess 12 .

In some optional embodiments, in order to enhance the protective effect of the gas ejected from the plurality of second air outlets 141 on the location of each avoidance recess 12, the gas is located on the circumference of each avoidance recess 12 and the plurality of first air outlets 131. The number of second air outlets 141 therebetween is greater than or equal to 5 and less than or equal to 15. However, the embodiment of the present invention is not limited to this. In practical applications, the number of second air outlets 141 corresponding to each escape recess 12 can be set according to the length of the escape recess 12 in the circumferential direction of the first surface 11 . For example, as shown in FIG. 3A , there are three escape recesses 12 , which are a first escape recess (top) and two second escape recesses located on both sides of the first escape recess. The first escape recess is located on the first escape recess. The circumferential length of the surface 11 is greater than or equal to 20 mm and less than or equal to 40 mm; the length of the second escape recess in the circumferential direction of the first surface 11 is greater than or equal to 30 mm and less than or equal to 60 mm. Preferably, the length of the first escape recess in the circumferential direction of the first surface 11 is greater than the length of each second escape recess in the circumferential direction of the first surface 11. This arrangement is for the two fixed hooks 411 and 411 of the robot hand 4 respectively. The size of the movable hook 42 is designed such that the movable hook 42 contacts the edge of the wafer 3 in the first escape recess, and each fixed hook 411 contacts the edge of the wafer 3 in each second escape recess. In addition, the length range of the first and second escape recesses in the circumferential direction of the first surface 11 may be applicable to: the second air outlet 141 located between each escape recess 12 and the circumference of the plurality of first air outlets 131 The quantity is greater than or equal to 5 and less than or equal to 15.

In some optional embodiments, the ejection direction of each second air outlet 141 may be the same as or different from the ejection direction of the first air outlet 131 . Optionally, the angle between the air jet direction of each second air outlet 141 (ie, arrow direction B shown in FIG. 3B ) and the first surface 11 is greater than or equal to 30° and less than or equal to 45°.

In some optional embodiments, as shown in Figures 3B and 3C, the chuck base 1 includes a bearing base 1a and a cover plate 1b disposed on the bearing base 1a, and the two can be fixedly connected using screws, for example. The upper surface of the cover plate 1b serves as the first surface 11, and an air cavity 1c is formed between the cover plate 1b and the carrier base 1a. Optionally, a concave portion is provided on the carrier base 1a on the surface opposite to the wafer, and a convex portion is formed on the bottom of the cover plate 1b, and the convex portion is disposed in the concave portion, and between the inner surface of the concave portion and the convex portion The outer surfaces of the chuck base 1a and the cover plate 1b are nested together to form an air cavity 1c, which can reduce the overall size of the chuck base 1 and reduce the difficulty of processing.

The above-mentioned first gas channel includes a plurality of first oblique holes 13 provided in the cover plate 1b. One end of each first oblique hole 13 is located on the first surface 11 and serves as the above-mentioned first gas outlet 131; The other end of the hole 13 is connected with the air chamber 1c; the above-mentioned second gas channel includes a plurality of second oblique holes 14 provided in the cover plate 1b, and one end of each second oblique hole 14 is located on the first surface 11, serving as The above-mentioned second air outlet 141; the other end of each second inclined hole 14 is connected with the air chamber 1c. In this way, the gas provided by the gas source can first flow into the air chamber 1c, and then after diffusing in the air chamber 1c, pass through the first air outlet 131 of each first inclined hole 13 and the second air outlet of each second inclined hole 14. 141 is ejected, and the gas flow direction is shown by the arrow in Figure 3C. The gas chamber 1c can both equalize the gas and hold the gas. This function can control the height of the wafer suspended above the chuck base by controlling the gas flow and gas pressure, and at the same time ensure that the gas can be stable. Continuously ejected from each first air outlet 131 and each second air outlet 141 . In addition, by providing the air chamber 1c, air can be introduced from the middle position of the chuck base 1, and then diffused toward the chuck base 1 through the air chamber 1c.

It should be noted that in practical applications, other air inlet methods can also be used, for example, gas can be separately introduced into the plurality of first inclined holes 13 and the plurality of second inclined holes 14 through two gas sources. The gas is, for example, an inert gas such as nitrogen. In addition, the solution that the above-mentioned first gas channel includes a plurality of first inclined holes 13 can also be applied to the above-mentioned first embodiment.

In some other optional embodiments, the plurality of escape recesses 12 can be divided into multiple escape groups, and the number of escape recesses 12 in each escape group is equal to the number of contact positions between the robot and the wafer. The same; the plurality of avoidance groups are symmetrically distributed with respect to the center of the first surface 11 . Taking the robot 4 shown in Figure 2A as an example. As shown in Figure 4, there are three contact positions between the robot 4 and the wafer, and there are two avoidance groups, namely the first avoidance group and the second avoidance group. Among them, the first avoidance group The avoidance group includes three avoidance recesses 12a, the second avoidance group includes three avoidance recesses 12b, and the first avoidance group and the second avoidance group are symmetrically distributed with respect to the center of the first surface 11. In this way, the wafer can be processed in different directions. When the angle is located above the chuck base 1, the contact positions of the robot 4 and the wafer can all correspond to the position of the escape recess 12. In other words, the wafer can be allowed to be positioned in a variety of ways on the premise that the escape recess 12 can correspond to the contact position. Different angles are provided above the chuck base 1 .

In some optional embodiments, as shown in Figures 1 and 2B, the three avoidance recesses 12 corresponding to the contact positions of the movable hook portion 42 and the two fixed hook portions 411 with the wafer are structurally different, Specifically, the length of the escape recess 12 (shown in FIG. 5A ) corresponding to the movable hook part 42 in the circumferential direction is greater than the length of the escape recess 12 (shown in FIG. 5B ) corresponding to each fixed hook part 411 in the circumferential direction. length to ensure that the space of each escape recess 12 is enough to accommodate the movable hook 42 and the two fixed hooks 411, and the opening surrounded by the inner peripheral surface of the escape recess 12 corresponding to each fixed hook 411, in the circumferential direction The width on the hook is larger closer to the edge of the first surface 11 , so that each fixing hook 411 can enter the avoidance recess 12 more easily.

In some optional embodiments, in order to avoid the impact of the avoidance recess 12 on the local airflow field, a vortex is formed at the avoidance recess 12. As shown in Figure 5A and Figure 5B, the opening surrounded by the inner peripheral surface of the avoidance recess 12 The area increases in the direction away from the bottom surface of the escape recess 12 , that is, the inner peripheral surface 122 of the escape recess 12 is a slope, so as to play a transitional role in mitigating sudden changes in the gas flow field. Optionally, a first rounded corner 122a is formed between the inner peripheral surface 122 of the escape recess 12 and the bottom surface of the escape recess 12, which can also play a role in easing the transition of sudden changes in the gas flow field. In addition, optionally, the orthographic projection shape of the inner peripheral surface of the relief recess 12 on the first surface 11 is a polygon, such as a rectangle, a trapezoid, a square, etc. Each corner of the polygon is formed with a second rounded corner 122b, which can also play a role in easing the transition of sudden changes in the gas flow field.

In some optional embodiments, the depth of the relief recess 12 is greater than or equal to 0.5 mm and less than or equal to 2 mm; the angle between the inner peripheral surface 122 of the relief recess 12 and the first surface 11 is greater than or equal to 5° and less than or equal to 5°. 85°; the radius of the above-mentioned first fillet is greater than or equal to 0.2mm and less than or equal to 2mm.

To sum up, the chuck structure of the semiconductor cleaning equipment provided by the embodiment of the present invention is formed by forming a plurality of avoidance recesses at the edge of the first surface of the chuck base opposite to the wafer. The plurality of avoidance recesses are in contact with the robot arm. The contact positions of the wafers when picking up and placing the wafers are set in one-to-one correspondence, which can prevent the robot from contacting the chuck base when picking up and placing the wafers, thereby reducing the difficulty of position calibration of the robot and improving the repeatability and reliability of the calibration position. Then mass production requirements can be met; on this basis, the first gas channel is combined with a plurality of first air outlets on the first surface to blow air obliquely toward the wafer surface, so that the wafer can be suspended above the chuck base. At the same time, there is no need to use vertical air jets to increase the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front side of the wafer. Optionally, the second gas channel is used in combination with multiple second gas outlets on the first surface to eject gas obliquely toward the wafer surface, so that the edge of the wafer, especially the location of the avoidance recess, can be protected, thereby not only avoiding The unstable air flow field generated by the avoidance recess will cause particle contamination at the edge of the wafer; it can also avoid chemical liquid splashing at the avoidance recess during the cleaning process, causing corrosion on the wafer edge.

Third embodiment

As another technical solution, please refer to Figure 6. The third embodiment of the present invention also provides a semiconductor cleaning equipment 100, including a process chamber 7, a robot (such as the robot 4 shown in Figure 4) and a spray device, wherein , the process chamber 7 is defined by the cavity 71, and a chuck structure (including the chuck body 1) is provided in the process chamber 7 for carrying the wafer 3 in a gas suspension manner; the chuck structure and The driving device 5 is connected. Under the driving of the driving device 5, the chuck structure can rotate around its axis and can also perform lifting and lowering movements. The spray device includes a first swing arm 61 for spraying chemical liquid (such as a mixed chemical liquid of HF and HNO3), a second swing arm 62 for spraying deionized water, and a second swing arm 62 for spraying deionized water. The third swing arm 63 of dry gas (such as nitrogen), and the chuck structure adopts the above-mentioned chuck structure provided by the embodiment of the present invention.

The above-mentioned semiconductor cleaning equipment 100 is, for example, a single-wafer backside cleaning equipment, which is used to perform a cleaning process on the backside of the wafer. During the process, the front side of the wafer faces the first surface of the chuck body 1 and passes through the plurality of first air outlets 131 Spraying a certain flow of inert gas (such as nitrogen) on the wafer in an oblique direction can not only suspend the wafer above the chuck base, but also protect the front of the wafer to ensure that the chemical liquid will not splash back to the front of the wafer.

The semiconductor cleaning equipment provided by the embodiments of the present invention, by adopting the above-mentioned chuck structure provided by the embodiments of the present invention, can not only reduce the difficulty of position calibration of the manipulator, but also improve the repeatability and reliability of the calibration position, thereby meeting mass production requirements. Moreover, there is no need to use vertical air jets to increase the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front side of the wafer.

Fourth embodiment

When using semiconductor cleaning equipment to clean wafers, when the chemical solution is sprayed onto the surface of the wafer (ie, the upward facing back side) through the spray device, it is affected by components located at the edge of the wafer (such as wafer clamping components). , chuck structure, etc.), part of the chemical solution often splashes back to the front edge of the wafer, resulting in particle contamination and corrosion at the front edge of the wafer. In order to solve this problem, as another technical solution, please refer to Figures 6 and 7 together. The fourth embodiment of the present invention also provides a semiconductor cleaning method, which uses the above-mentioned semiconductor cleaning equipment provided by the embodiment of the present invention to clean the crystal. For cleaning, taking the chuck structure of a semiconductor cleaning equipment provided by the first embodiment of the present invention as an example, the semiconductor cleaning method includes the following steps:

S1. Inject inert gas (such as nitrogen) into the first gas channel;

In step S1 , the flow rate of the inert gas is switched from the flow rate in the idle state to the wafer unloading flow rate. The wafer unloading flow rate is set to allow the wafer to float above the chuck body 1 .

S2. Control the robot 4 to transfer the wafer 3 into the process chamber 7, so that the wafer 3 is suspended in the transfer position C1 above the first surface 11 under the action of the air flow;

After the wafer 3 is completely separated from the robot 4, the robot 4 immediately moves out of the process chamber 7 to complete the wafer loading process.

S3. Control the chuck structure to drop to the first process position C2 and rotate;

In step S3, the vertical distance between the nozzle 61a of the first swing arm 61 and the wafer 3 can be appropriately reduced when the chuck structure is lowered to the first process position C2, which will help reduce the probability of liquid backsplash. Especially for liquids with low viscosity or no viscosity. Optionally, the vertical distance is greater than or equal to 20 mm and less than or equal to 60 mm.

Optional, the rotation speed of the chuck structure is greater than or equal to 500R/min and less than or equal to 800R/min.

S4. Control the nozzle 61a of the first swing arm 61 to swing above the wafer 3 while spraying the chemical liquid onto the wafer 3;

The maximum swing range of the nozzle 61a of the first swing arm 61 is: from one edge of the wafer surface, through the center of the wafer surface to the other edge.

In step S4, in order to prevent the nozzle 61a of the first swing arm 61 from overshooting due to inertia, causing the liquid column to spray toward the edge of the wafer, causing the liquid to flow toward the front edge of the wafer, causing particle contamination and pollution at the edge of the wafer. Corrosion can be achieved by controlling the swing range of the nozzle 61a of the first swing arm 61 and/or the swing speed of the first swing arm 61. Optionally, the swing distance of the nozzle 61a of the first swing arm 61 above the wafer surface is 80% of the maximum swing distance; the maximum swing distance is the distance from the center of the wafer surface to the edge; optionally, The swing speed of a swing arm 61 is greater than or equal to 10°/s and less than or equal to 25°/s.

In addition, optionally, in step S4, the flow rate range of the medical solution is less than or equal to 4000ml/min; the process duration is less than or equal to 300s.

S5. After the spraying is completed, control the first swing arm 61 to return to the initial position (a position outside the chuck structure), and keep the chuck structure to continue rotating;

In step S5, the chuck structure is in an idling state without spraying, so as to be able to throw off the remaining chemical liquid on the wafer surface. In this idling state, since the rotation speed is increased compared to step S4, the rotation speed is higher than that in step S4. Changes can easily cause chemical liquid to backsplash and flow back to the front edge of the wafer, resulting in particle contamination and corrosion at the front edge of the wafer. In order to solve this problem, optional step S5 further includes:

S51. Keep the chuck structure to continue rotating at the same first rotation speed as when the first swing arm 61 is spraying;

S52. After the preset time period, the chuck structure is controlled to rotate at a second rotational speed, and the second rotational speed is higher than the first rotational speed.

By dividing the above-mentioned idling process into two stages, the first stage uses a lower first rotation speed to throw off most of the remaining chemical solution on the wafer surface, and the lower rotation speed can avoid the back splash of the solution And flow back to the front edge of the wafer, and then use a higher second rotation speed in the second stage to ensure that all the remaining chemical liquid on the wafer surface can be thrown out through high-speed rotation. Optionally, the above-mentioned first rotational speed is greater than or equal to 300R/min and less than or equal to 900R/min; the above-mentioned second rotational speed is greater than or equal to 1000R/min and less than or equal to 2000R/min. Optionally, the above preset time is greater than or equal to 3s and less than or equal to 10s.

S6. Control the chuck structure to rise to the second process position C3 while maintaining rotation;

S7. Control the nozzle 62a of the second swing arm 62 to swing above the wafer while spraying deionized water onto the wafer;

In step S7, residual chemical solution and reactants can be taken away from the wafer surface by spraying deionized water.

Optionally, in step S7, the rotation speed of the chuck structure is greater than or equal to 400 R/min and less than or equal to 700 R/min; when the chuck structure drops to the second process position C3, the nozzle 62a of the second swing arm 62 and the crystal The vertical distance between circles 3 is greater than or equal to 20 mm and less than or equal to 70 mm; the swing distance of the nozzle 61a of the first swing arm 61 above the wafer surface is 50% of the maximum swing distance; the swing speed of the second swing arm 62 is greater than or equal to 10°/s, and less than or equal to 30°/s. The flow range of the medical solution is greater than or equal to 800ml/min and less than or equal to 2000ml/min.

S8. After the spraying is completed, control the second swing arm 62 to return to the initial position (a position outside the chuck structure), and keep the chuck structure to continue rotating;

S9. Control the nozzle 63a of the third swing arm 63 to swing above the wafer while spraying the purge gas toward the wafer;

Purge gas (such as nitrogen) can be used to dry the wafer. Optional, the flow rate of the purge gas is greater than or equal to 5L/min and less than or equal to 20L/min; the rotation speed of the chuck structure is greater than or equal to 1000R/min and less than Equal to 2000R/min; the process time of step S9 is greater than or equal to 15s and less than or equal to 45s.

S10. After the purging is completed, control the chuck structure to return to the wafer transfer position C1, and control the manipulator to take out the wafer.

In some other optional embodiments, taking the second embodiment of the present invention to provide a chuck structure of a semiconductor cleaning equipment as an example, in the above step S1, while inert gas is introduced into the first gas channel, Pour inert gas into the second gas channel. By combining the use of a second gas channel with a plurality of second air outlets on the first surface to eject gas obliquely toward the wafer surface, the edge of the wafer, especially the location of the avoidance recess, can be protected, thereby not only avoiding the risk of being hit by the avoidance recess It affects the unstable air flow field and causes particle contamination at the edge of the wafer; it can also avoid back-splashing of chemical liquid at the avoidance recesses during the cleaning process, causing corrosion on the edge of the wafer.

In some optional embodiments, in the above-mentioned step S1, the above-mentioned wafer unloading flow rate can be appropriately increased to meet the need for the flow to be divided into the first gas channel and the second gas channel to ensure that the gas flow rate can satisfy the gas pressure on the wafer edge. , especially the location of the avoidance recess 12 is protected, thereby not only avoiding particle contamination at the edge of the wafer due to the unstable air flow field affected by the avoidance recess. Optionally, the flow rate of the inert gas (ie, the above-mentioned discharge flow rate) is greater than or equal to 10L/min and less than or equal to 600L/min.

The semiconductor cleaning method provided by the embodiment of the present invention, by using the above-mentioned semiconductor cleaning equipment provided by the embodiment of the present invention, can not only reduce the difficulty of position calibration of the robot, improve the repeatability and reliability of the calibration position, and thereby meet mass production requirements, Moreover, there is no need to use vertical airflow to increase the height of the wafer suspended above the chuck structure, so there is no need to use vertical airflow. This method increases the height of the wafer suspended above the chuck structure, thereby avoiding particle contamination on the front side of the wafer.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

A chuck structure of a semiconductor cleaning equipment, including a chuck base for carrying a wafer, characterized in that a plurality of avoidance recesses are formed at the edge of the first surface of the chuck base opposite to the wafer. The avoidance recesses are provided in one-to-one correspondence with the contact positions of the robot hand and the wafer when picking up and placing the wafer, so as to prevent the robot hand from contacting the chuck base when picking up and placing the wafer;

A first gas channel is provided in the chuck base. The first gas channel has a plurality of first gas outlets on the first surface. The plurality of first gas outlets are along the first surface. Circumferentially spaced distribution; the jet direction of each first air outlet is inclined toward the outside of the surface of the wafer opposite to the chuck base.
The chuck structure according to claim 1, wherein a second gas channel is further provided in the chuck base, and the second gas channel has a plurality of second gas outlets on the first surface. , at least one second air outlet is provided between each avoidance recess and the circumference of the plurality of first air outlets, and the jet direction of each second air outlet is toward the wafer. The outer side of the surface opposite to the chuck base is inclined.
The chuck structure according to claim 2, characterized in that there are a plurality of second air outlets located between each of the avoidance recesses and the circumference of the plurality of first air outlets, and are in the shape of an arc. arranged like.
The chuck structure according to claim 3, wherein a plurality of the second air outlets are arranged in an arc shape along the circumferential direction of the first surface;

The extension direction of the first side of each escape recess adjacent to the plurality of second air outlets is consistent with the arrangement direction of the plurality of second air outlets.
The chuck structure according to claim 2, wherein the chuck base body includes A load-bearing base body and a cover plate provided on the load-bearing base body, the upper surface of the cover plate is used as the first surface, and an air cavity is formed between the cover plate and the load-bearing base body;

The first gas channel includes a plurality of first oblique holes provided in the cover plate, one end of each first oblique hole is located on the first surface and serves as the first gas outlet; each The other end of the first inclined hole is connected with the air chamber;

The second gas channel includes a plurality of second oblique holes provided in the cover plate, one end of each second oblique hole is located on the first surface and serves as the second air outlet; each The other end of the second inclined hole is connected with the air chamber.
The chuck structure according to claim 1, wherein a plurality of the escape recesses are divided into a plurality of escape groups, and the number of the escape recesses in each escape group is related to the distance between the manipulator and the wafer. The number of contact positions is the same; a plurality of avoidance groups are symmetrically distributed with respect to the center of the first surface.
The chuck structure according to claim 1, wherein the opening area enclosed by the inner peripheral surface of the escape recess increases gradually in a direction away from the bottom surface of the escape recess.
The chuck structure according to claim 1, wherein a first rounded corner is formed between the inner peripheral surface of the escape recess and the bottom surface of the escape recess.
The chuck structure according to claim 1, wherein the orthographic projection shape of the inner circumferential surface of the escape recess on the first surface is a polygon, and each corner of the polygon is formed with a second rounded corner. .
The chuck structure according to claim 4, wherein the distance between the second air outlet and the first side is greater than or equal to 10 mm and less than or equal to 20 mm.
The chuck structure according to claim 2, characterized in that there are three escape recesses, namely a first escape recess and two second escape recesses located on both sides of the first escape recess, and the third escape recess is The length of an escape recess in the circumferential direction of the first surface is greater than or equal to 20 mm and less than or equal to 40 mm; the length of the second escape recess in the circumferential direction of the first surface is greater than or equal to 30 mm and less than or equal to 60 mm.
The chuck structure according to claim 2 or 11, characterized in that the number of the second air outlets located between each of the avoidance recesses and the circumference of the plurality of first air outlets is greater than or equal to 5. , and less than or equal to 15.
The chuck structure according to claim 2, wherein the angle between the air jet direction of each second air outlet and the first surface is greater than or equal to 30° and less than or equal to 45°.
A semiconductor cleaning equipment includes a process chamber, a manipulator and a spray device. A rotatable and lifting chuck structure is provided in the process chamber for carrying wafers; the spray device includes a spray device for spraying wafers. The first swing arm for spraying chemical liquid, the second swing arm for spraying deionized water, and the third swing arm for spraying dry gas are characterized in that the chuck structure adopts any of claims 1-13. The chuck structure described in one item.
A semiconductor cleaning method, characterized in that the semiconductor cleaning equipment of claim 14 is used to clean the wafer, the semiconductor cleaning method includes:

Pass inert gas into the first gas channel;

Control the manipulator to transfer the wafer into the process chamber, so that the wafer is suspended in the transfer position above the first surface under the action of air flow;

Control the chuck structure to drop to the first process position and rotate;

The nozzle of the first swing arm is controlled to swing above the wafer while spraying chemicals onto the wafer. liquid;

After the spraying is completed, control the first swing arm to return to the initial position and keep the chuck structure to continue rotating;

Control the chuck structure to rise to the second process position while maintaining rotation;

Control the nozzle of the second swing arm to swing above the wafer while spraying deionized water onto the wafer;

After the spraying is completed, control the second swing arm to return to the initial position and keep the chuck structure to continue rotating;

Control the nozzle of the third swing arm to swing above the wafer while spraying purge gas toward the wafer;

After the purging is completed, the chuck structure is controlled to return to the wafer transfer position, and the manipulator is controlled to take out the wafer.
The semiconductor cleaning method according to claim 15, wherein while an inert gas is introduced into the first gas channel, an inert gas is introduced into the second gas channel.
The semiconductor cleaning method according to claim 15 or 16, characterized in that the flow rate of the inert gas is greater than or equal to 10L/min and less than or equal to 600L/min.
The semiconductor cleaning method according to claim 15, wherein when the chuck structure is lowered to the first process position, the vertical distance between the nozzle of the first swing arm and the wafer is greater than Equal to 20mm, and less than or equal to 60mm.
The semiconductor cleaning method according to claim 15, characterized in that the swing distance of the nozzle of the first swing arm above the wafer surface is 80% of the maximum swing distance; the maximum swing distance is from the The distance from the center of the wafer surface to the edge;

The swing speed of the first swing arm is greater than or equal to 10°/s and less than or equal to 25°/s.
The semiconductor cleaning method according to claim 15, characterized in that, after the spraying is completed, controlling the first swing arm to return to the initial position and keeping the chuck structure to continue rotating includes:

Keep the chuck structure to continue to rotate at the same first rotation speed as when the first swing arm is spraying;

After a preset period of time, the chuck structure is controlled to rotate at a second rotational speed, and the second rotational speed is higher than the first rotational speed.
The semiconductor cleaning method according to claim 20, wherein the first rotational speed is greater than or equal to 300R/min and less than or equal to 900R/min; the second rotational speed is greater than or equal to 1000R/min and less than or equal to 2000R/min. .