Wafer adsorption device

Abstract

The utility model provides a wafer adsorption device, which comprises a bearing platform and a plurality of annular flexible bosses, a plurality of annular grooves are arranged on one side of the bearing platform, which is provided with a wafer bearing surface, and the plurality of annular grooves are sequentially arranged at intervals from inside to outside, so that a plurality of adsorption areas which are sequentially arranged at intervals from inside to outside are divided in the wafer bearing surface; the multiple annular flexible bosses are arranged in the multiple annular grooves in a one-to-one correspondence mode. According to the utility model, the bearing platform is provided with the annular groove, the annular flexible boss is arranged in the annular groove, after the large-warping-degree wafer is placed on the bearing platform, the wafer, the annular flexible boss and the wafer bearing surface form the sealing cavity, and the large-warping-degree wafer can be firmly adsorbed on the bearing platform after the sealing cavity is subjected to air exhaust, so that the equipment applicability is improved; in addition, the convex points are arranged on the wafer bearing surface, so that the wafer back contact can be reduced to be within 2%, and the cross contamination of different processes to the back of the wafer is reduced; and moreover, by adopting regional and time-phased gradual adsorption, the requirements on the vacuum degree and the gas flow rate are low, and the cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductors and relates to a wafer adsorption device. Background Art

[0002] In semiconductor manufacturing, wafers, as the objects to be inspected, need to be fixed on a wafer stage for measurement, inspection, transportation and other process processing. Usually, the wafer is fixed on the wafer stage by vacuum adsorption, such as Figure 1 As shown in the figure, when the wafer 01 is flat or slightly warped, vacuum adsorption creates negative pressure between the wafer 01 and the wafer stage 02, firmly adsorbing the wafer 01 on the wafer stage 02; however, on the semiconductor production line, wafers processed by certain processes may warp and deform due to process reasons, such as Figure 2 As shown, when the warpage of the wafer 01 is large, a sealed cavity cannot be formed between the wafer back and the wafer stage 02 or the gap is too large to form sufficient adsorption force, and the wafer 01 will not be able to be adsorbed on the wafer stage 02.

[0003] For wafers with large warpage, if the upper surface of the wafer is pressed to make the wafer fit with the wafer stage, there is a problem of contamination on the upper surface of the wafer. Usually, the upper surface of the wafer cannot be touched, so the adsorption action can only be completed by adsorbing the back of the wafer. However, vacuum adsorption cannot firmly adsorb the wafer to the wafer stage, and thus the next process action cannot be carried out.

[0004] Therefore, how to provide a wafer adsorption device to achieve the adsorption of wafers with large warpage has become a technical problem that needs to be urgently solved by technical personnel in this field. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a wafer adsorption device to solve the problem that the prior art cannot adsorb and fix wafers with large warpage.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a wafer adsorption device, comprising:

[0007] A carrier, the carrier having a wafer carrying surface, the carrier having N annular grooves arranged on one side of the wafer carrying surface, the N annular grooves being arranged in sequence from the inside to the outside, so as to divide the wafer carrying surface into N adsorption areas arranged in sequence from the inside to the outside, wherein N is an integer greater than 1, the carrier having a vacuum hole in each of the adsorption areas, and the vacuum hole passing through the carrier in a vertical direction;

[0008] N annular flexible bosses are arranged in the N annular grooves in a one-to-one correspondence, and the top of the annular flexible boss is higher than the wafer carrying surface in the vertical direction.

[0009] Optionally, a portion of the annular flexible boss below the wafer supporting surface does not fill up the annular groove to provide deformation space for the annular flexible boss.

[0010] Optionally, a vacuum suction device is further included, and the vacuum suction device is connected to the vacuum hole through a suction pipeline to generate negative pressure above the adsorption area.

[0011] Optionally, N vacuum sensors are further included, wherein the i-th vacuum sensor is arranged on the exhaust pipeline of the i-th adsorption area to detect the vacuum degree above the i-th adsorption area, i is an integer, and 1≤i≤N.

[0012] Optionally, the N annular flexible bosses are arranged in concentric rings.

[0013] Optionally, an adhesive layer is provided between the annular groove and the annular flexible boss.

[0014] Optionally, the annular flexible boss comprises a rubber sealing ring.

[0015] Optionally, a plurality of protrusions are arranged on the wafer carrying surface, and the protrusions are distributed in each of the adsorption areas, wherein the top of the protrusion is lower than the top of the annular flexible boss.

[0016] As described above, in the wafer adsorption device of the present invention, a carrier table has an annular groove on one side of the wafer bearing surface, and an annular flexible boss is provided in the annular groove. After the wafer with a large warp is placed on the carrier table, the wafer, the annular flexible boss and the wafer bearing surface form a sealed cavity. After the sealed cavity is evacuated, the negative pressure generated can firmly adsorb the wafer with a large warp on the carrier table, thereby improving the applicability of the equipment; in addition, convex points are provided on the wafer bearing surface, which can reduce the wafer back contact to less than 2%, thereby reducing the cross-contamination of the wafer back by different processes; and, the gradual adsorption is carried out in different areas and time periods, which has low requirements for vacuum degree and gas flow rate, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram showing a wafer with a small warpage being placed on a wafer stage.

[0018] Figure 2 A schematic diagram showing a wafer with large warpage placed on a wafer stage.

[0019] Figure 3 Shown is a cross-sectional view of the wafer carrying device in the first embodiment of the present invention.

[0020] Figure 4 Shown is a three-dimensional diagram of the wafer carrying device in the first embodiment of the present invention.

[0021] Figure 5It is an enlarged schematic diagram of the wafer supporting device in the first embodiment of the present invention after the annular flexible boss is installed in the annular groove.

[0022] Figure 6 It is a schematic diagram showing a wafer placed on a wafer carrying device in the first embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram showing the arrangement of vacuum holes and a vacuum pumping device in a wafer carrier device in the first embodiment of the present invention.

[0024] Figure 8 Shown is a schematic diagram of the wafer carrier device in the first embodiment of the present invention adsorbing the wafer.

[0025] Fig. 9 It is a schematic diagram showing the arrangement of bumps on the wafer carrying surface in the second embodiment of the present invention.

[0026] Component number description

[0027] 01 Wafer

[0028] 02 Film table

[0029] 1 Loading platform

[0030] 10 Wafer carrying surface

[0031] 11 Annular groove

[0032] 12 Bump

[0033] 2 Annular flexible boss

[0034] 21 First boss

[0035] 22 Second boss

[0036] 23 Third boss

[0037] 24 Fourth Boss

[0038] 3 Wafer

[0039] 41 First sealed chamber

[0040] 42 Second sealed chamber

[0041] 43 Third sealed chamber

[0042] 44 Fourth sealed chamber

[0043] 51 First vacuum hole

[0044] 52 Second vacuum hole

[0045] 53 Third vacuum hole

[0046] 54 Fourth vacuum hole

[0047] 6 Vacuum pumping device

[0048] 71 First solenoid valve

[0049] 72 Second solenoid valve

[0050] 73 Third solenoid valve

[0051] 74 Fourth solenoid valve

[0052] 81 First vacuum sensor

[0053] 82 Second vacuum sensor

[0054] 83 Third vacuum sensor

[0055] 84 Fourth vacuum sensor DETAILED DESCRIPTION

[0056] The following is an explanation of the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0057] See also Figures 1 to 9 It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the utility model, and the drawings only show the components related to the utility model rather than the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0058] Embodiment 1

[0059] This embodiment provides a wafer carrying device. Figure 3 and Figure 4, respectively showing a cross-sectional view and a stereoscopic view of the wafer carrying device, the wafer carrying device includes a carrying platform 1 and a plurality of annular flexible bosses 2, the carrying platform 1 having a wafer carrying surface 10, the carrying platform 1 having a plurality of annular grooves arranged on one side of the wafer carrying surface 10, the plurality of annular grooves being arranged in sequence from the inside to the outside to divide the wafer carrying surface 10 into a plurality of adsorption areas arranged in sequence from the inside to the outside, the carrying platform 1 is provided with a vacuum hole in each of the adsorption areas, the vacuum hole passes through the carrying platform 1 in the vertical direction; the plurality of annular flexible bosses 2 are arranged one by one in the plurality of annular grooves, and the top of the annular flexible boss 2 is higher than the wafer carrying surface 10 in the vertical direction.

[0060] As an example, the number of the annular flexible bosses 2 is four, including a first boss 21, a second boss 22, a third boss 23 and a fourth boss 24, and the first boss 21, the second boss 22, the third boss 23 and the fourth boss 24 are arranged in concentric circular rings to correspond to 4-inch, 6-inch, 8-inch and 12-inch wafers respectively. In other examples, the number of the annular flexible bosses 2 may be less than four or more than four, which is not limited to this embodiment; in other examples, the annular flexible bosses 2 may also be arranged in concentric square rings, etc., which is not limited to this embodiment.

[0061] As an example, the outermost annular flexible boss 2 (fourth boss 24) can be configured as an annular flexible frame installed on the edge of the supporting platform 1, and the annular flexible frame is higher than the height of the wafer supporting surface 10 in the vertical direction and protrudes from the wafer supporting surface 10 in the horizontal direction.

[0062] As an example, Figure 5 As shown, it is an enlarged schematic diagram of the annular flexible boss 2 after being installed in the annular groove 11. After the annular flexible boss 2 is installed in the annular groove 11, there is still a deformation space, that is, the portion of the annular flexible boss 2 below the wafer bearing surface 10 does not fill the annular groove 11, and the deformation space is used to bear the deformation of the annular flexible boss 2 (see subsequent Figures 7 and 8 ).

[0063] As an example, a gluing layer (not shown) is provided between the annular flexible boss 2 and the annular groove 11 , and the annular flexible boss 2 is sealed and connected to the bearing platform 1 by gluing.

[0064] As an example, the annular flexible boss 2 comprises a rubber sealing ring.

[0065] As an example, see Figure 6, showing a schematic diagram of placing a wafer on the wafer adsorption device. After placing the wafer 3 on the wafer adsorption device, even if the wafer 3 is greatly warped due to process processing and other reasons, since the annular flexible boss 2 is flexible, the back side of the wafer 3 is completely fitted with the annular flexible boss 2, thereby forming an isolated sealing area. For example, a first sealed cavity 41 is formed between the wafer 3, the first boss 21 and the wafer bearing surface 10, and a second sealed cavity 42 is formed between the wafer 3, the second boss 22, the first boss 21 and the wafer bearing surface 10. Similarly, a third sealed cavity 43 is formed between the wafer 3, the third boss 23, the second boss 22 and the wafer bearing surface 10, and a fourth sealed cavity 44 is formed between the wafer 3, the fourth boss 24, the third boss 23 and the wafer bearing surface 10.

[0066] As an example, see Figure 7 , showing a schematic diagram of a vacuum hole and a vacuum exhaust device arranged in a wafer carrier, wherein the vacuum hole passes through the carrier 1 in a vertical direction, and the vacuum hole comprises a first vacuum hole 51, a second vacuum hole 52, a third vacuum hole 53 and a fourth vacuum hole 54, wherein the first vacuum hole 51 is connected to the first sealed cavity 41, the second vacuum hole 52 is connected to the second sealed cavity 42, the third vacuum hole 53 is connected to the third sealed cavity 43, and the fourth vacuum hole 54 is connected to the fourth sealed cavity 44.

[0067] As an example, the wafer carrying device also includes a vacuum pumping device 6, which is connected to the vacuum hole through a pumping pipeline, wherein the vacuum pumping device 6 is used to generate negative pressure on the first sealed cavity 41 through the first vacuum hole 51, the vacuum pumping device 6 is used to generate negative pressure on the second sealed cavity 42 through the second vacuum hole 52, the vacuum pumping device 6 is used to generate negative pressure on the third sealed cavity 43 through the third vacuum hole 53, and the vacuum pumping device 6 is used to generate negative pressure on the fourth sealed cavity 44 through the fourth vacuum hole 54.

[0068] As an example, the vacuum exhaust device 6 includes an air pump.

[0069] As an example, a first solenoid valve 71 and a first vacuum sensor 81 are arranged between the first vacuum hole 51 and the vacuum pumping device 6, and the first solenoid valve 71 is used to control the connection and disconnection between the first sealed cavity 41 and the vacuum pumping device 6, and the first vacuum sensor 81 is used to detect the vacuum degree of the first sealed cavity 41; similarly, a second solenoid valve 72 and a second vacuum sensor 82 are arranged between the second vacuum hole 52 and the vacuum pumping device 6, a third solenoid valve 73 and a third vacuum sensor 83 are arranged between the third vacuum hole 53 and the vacuum pumping device 6, and a fourth solenoid valve 74 and a second vacuum sensor 84 are arranged between the fourth vacuum hole 54 and the vacuum pumping device 6.

[0070] As an example, see Figure 8 , which is a schematic diagram showing the wafer carrier device adsorbing the wafer. When the vacuum exhaust device 6 is evacuating air, the first sealed cavity 41, the second sealed cavity 42, the third sealed cavity 43 and the fourth sealed cavity 43 generate negative pressure, and the negative pressure drives the wafer 3 to adhere to the wafer carrying surface 10, thereby driving the annular flexible boss 2 to deform. Since a deformation space is reserved in the annular groove 11 to bear the deformation of the annular flexible boss 2, the wafer 3 is completely adhered to the wafer carrying surface 10, and the wafer 3 is firmly adsorbed on the carrier 1.

[0071] As described above, in the wafer carrying device of the present embodiment, the carrying platform has an annular groove on one side of the wafer carrying surface, and an annular flexible boss is provided in the annular groove. After the wafer with a large warp is placed on the wafer carrying surface, the wafer, the annular flexible boss and the wafer carrying surface form a sealed sealing cavity. After the sealed cavity is evacuated to generate negative pressure, the wafer with a large warp can be firmly adsorbed on the wafer carrying surface, thereby improving the applicability of the equipment.

[0072] Embodiment 2

[0073] See also Fig. 9 This embodiment provides a wafer adsorption device, which is different from the first embodiment in that: a plurality of bump pins 12 are arranged on the wafer carrying surface 10, and the bump pins 12 are distributed in each adsorption area, wherein the top of the bump pin 12 is lower than the top of the annular flexible boss 2.

[0074] In this embodiment, by setting bumps on the wafer carrying surface, the wafer and the wafer carrying surface are not in direct contact during the wafer adsorption process, but the wafer is in contact with the bumps. This can reduce the wafer back contact to less than 2%, avoid contamination of the wafer by dirt on the wafer carrying surface, and thereby reduce cross-contamination of the wafer back by different processes.

[0075] Embodiment 3

[0076] This embodiment provides a wafer adsorption method, comprising the following steps:

[0077] S1: Provide the wafer adsorption device described in Embodiment 1 or Embodiment 2;

[0078] S2: placing the wafer 3 to be adsorbed on the carrier 1, wherein the wafer 3, the annular flexible boss 2 and the wafer carrying surface 10 form a plurality of sealed cavities which are sequentially arranged from the inside to the outside;

[0079] As an example, the wafer to be adsorbed may be a wafer with a small warp or a wafer with a large warp. This embodiment focuses on the wafer with a large warp.

[0080] S3 : sequentially evacuating the first sealed cavity 41 , the second sealed cavity 42 , the third sealed cavity 43 and the fourth sealed cavity 44 to generate negative pressure to adsorb the wafer 3 .

[0081] As an example, the step of evacuating the first sealed cavity 41, the second sealed cavity 42, the third sealed cavity 43 and the fourth sealed cavity 44 to generate negative pressure includes:

[0082] S30: evacuating the first sealed cavity 41 , wherein the first vacuum sensor 81 monitors the vacuum degree of the first sealed cavity 41 , and when the vacuum degree of the first sealed cavity 41 reaches a preset value, evacuating the second sealed cavity 42 ;

[0083] S31: the second vacuum sensor 82 monitors the vacuum degree of the second sealed cavity 42, and when the vacuum degree of the second sealed cavity 42 reaches a preset value, the third sealed cavity 43 is evacuated;

[0084] S32: the third vacuum sensor 83 monitors the vacuum degree of the third sealed cavity 43, and when the vacuum degree of the third sealed cavity 43 reaches a preset value, the fourth sealed cavity 44 is evacuated;

[0085] S33: the fourth vacuum sensor 84 monitors the vacuum degree of the fourth sealed cavity 44. When the vacuum degree of the fourth sealed cavity 44 reaches a preset value, the fourth solenoid valve 74 is closed to stop exhausting air.

[0086] As an example, for wafers with large warpage, if the wafer supporting surface 10 adsorbs the wafers at the same time, high requirements are placed on the vacuum degree and gas flow rate. However, the present embodiment adopts a method of gradual adsorption in different areas and time periods, which has low requirements on the vacuum degree and gas flow rate, reduces costs, and can firmly adsorb large warpage wafers on the supporting platform in a simple manner.

[0087] In summary, in the wafer adsorption device of the utility model, the carrier has an annular groove on one side of the wafer bearing surface, and an annular flexible boss is arranged in the annular groove. After the wafer with large warpage is placed on the wafer bearing surface, the wafer, the annular flexible boss and the wafer bearing surface form a sealed cavity. After the sealed cavity is evacuated, the negative pressure generated can firmly adsorb the wafer with large warpage on the carrier, thereby improving the applicability of the equipment; in addition, the convex points are arranged on the wafer bearing surface, which can reduce the wafer back contact to less than 2%, and reduce the cross contamination of the wafer back by different processes; and the gradual adsorption is adopted in different areas and time periods, which has low requirements for vacuum degree and gas flow rate, thereby reducing costs. Therefore, the utility model effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0088] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A wafer adsorption device, characterized in that: include: A carrier, the carrier having a wafer carrying surface, the carrier having N annular grooves arranged on one side of the wafer carrying surface, the N annular grooves being arranged in sequence from the inside to the outside, so as to divide the wafer carrying surface into N adsorption areas arranged in sequence from the inside to the outside, wherein N is an integer greater than 1, the carrier having a vacuum hole in each of the adsorption areas, and the vacuum hole passing through the carrier in a vertical direction; N annular flexible bosses are disposed in the N annular grooves in a one-to-one correspondence, and the top of each annular flexible boss is higher than the wafer carrying surface in a vertical direction; A plurality of bumps are arranged on the wafer carrying surface, the bumps are distributed in each of the adsorption areas, and the top of the bumps is lower than the top of the annular flexible boss. When the wafer is adsorbed, the wafer contacts the bumps, reducing the wafer back contact to less than 2%.

2. The wafer adsorption device according to claim 1, characterized in that: The portion of the annular flexible boss below the wafer carrying surface does not fill up the annular groove to provide deformation space for the annular flexible boss.

3. The wafer adsorption device according to claim 1, characterized in that: It also includes a vacuum pumping device, which is connected to the vacuum hole through a pumping pipeline to generate negative pressure above the adsorption area.

4. The wafer adsorption device according to claim 3, characterized in that: It also includes N vacuum sensors, wherein the i-th vacuum sensor is arranged on the exhaust pipeline of the i-th adsorption area to detect the vacuum degree above the i-th adsorption area, i is an integer, and 1≤i≤N.

5. The wafer adsorption device according to claim 1, characterized in that: The N annular flexible bosses are arranged in concentric rings.

6. The wafer adsorption device according to claim 1, characterized in that: An adhesive layer is arranged between the annular groove and the annular flexible boss.

7. The wafer adsorption device according to claim 1, characterized in that: The annular flexible boss includes a rubber sealing ring.

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