Electrostatic chuck with back blowing holes

Abstract

The utility model particularly relates to an electrostatic chuck with back blowing holes, which comprises a base, and a first dielectric layer, an adsorption electrode layer, a second dielectric layer, a heater layer and a third dielectric layer which are sequentially arranged from top to bottom, and the lower surface of the third dielectric layer is arranged on the upper surface of the base; the first dielectric layer, the second dielectric layer and the third dielectric layer are ceramic dielectric layers; the bottom of the base is provided with an air channel and an air inlet hole communicated with the air channel, the electrostatic chuck is further provided with a plurality of through air holes, the through air holes comprise first hole channels and second hole channels communicated with upper end openings of the first hole channels, and the first hole channels are located above an inner cavity of the air channel and communicated with the inner cavity of the air channel. The second hole channel extends upwards and penetrates through the first dielectric layer, and the aperture of the first hole channel is larger than that of the second hole channel. When the electrostatic chuck is used, the blockage of the helium channel can be reduced, so that the temperatures of the electrostatic chuck and the wafer are more uniform, and later maintenance and cleaning are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, and particularly relates to an electrostatic chuck provided with back blowing air holes. Background Art

[0002] An electrostatic chuck, also known as an electrostatic chuck (abbreviation: ESC), is a new adsorption technology based on principles such as Coulomb's law, Lorentz's law, J-R effect, and electric potential gradient. According to the characteristics of the material of the adsorbed object, one or more adsorption methods are adopted to effectively adsorb the object. During the processing of a wafer, the electrostatic chuck can firmly adsorb the wafer on its surface by using the electrostatic adsorption principle. Currently, helium air holes often need to be provided in the electrostatic chuck. The helium air holes are provided to introduce helium gas into the front from the air holes to cool down the wafer. However, during the processing of the electrostatic chuck, it is easy to generate tiny particles that block the air holes, affecting the performance of the electrostatic chuck and being unfavorable for later maintenance and cleaning. Therefore, it is of great significance to design the electrostatic chuck to facilitate maintenance and cleaning, ensure the smoothness of the helium air hole channel, and thus effectively play its cooling and heat transfer roles. Summary of the Invention

[0003] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the utility model is to provide an electrostatic chuck provided with back blowing air holes. When the electrostatic chuck is used, the blockage of the helium gas channel can be reduced, the temperature of the electrostatic chuck and the wafer can be made more uniform, and it is convenient for later maintenance and cleaning.

[0004] To achieve the above purpose, the utility model adopts the following technical scheme: An electrostatic chuck provided with back blowing air holes, comprising a base and a first dielectric layer, an adsorption electrode layer, a second dielectric layer, a heater layer, and a third dielectric layer which are sequentially arranged from top to bottom. The lower surface of the third dielectric layer is arranged on the upper surface of the base; the first dielectric layer, the second dielectric layer, and the third dielectric layer are all ceramic dielectric layers; the adsorption electrode layer and the heater layer are respectively provided with an adsorption electrode lead-out end and a heating electrode lead-out end;

[0005] An air channel and a gas inlet hole communicated with the air channel are arranged at the bottom of the base. The electrostatic chuck is further provided with a plurality of through air holes. The through air holes comprise a first hole channel and a second hole channel communicated with the upper end opening of the first hole channel. The first hole channel is located above the inner cavity of the air channel and communicated with the inner cavity of the air channel. The second hole channel extends upward and penetrates through the first dielectric layer. The aperture of the first hole channel is larger than that of the second hole channel.

[0006] Further, the air passage includes a first gas passage and a second gas passage; the first gas passage is annular and surrounds the gas inlet hole, both ends of the second gas passage are respectively communicated with the gas inlet hole and the first gas passage, and the first pore is located above the inner cavity of the first gas passage and is communicated with the first gas passage.

[0007] Further, the second gas passage is linear, and a first notch and a second notch are respectively formed in the side wall of the gas inlet hole and the inner ring wall of the first gas passage; one end of the second gas passage is communicated with the gas inlet hole via the first notch, and the other end of the second gas passage is communicated with the first gas passage via the second notch.

[0008] Further, a plurality of the through pores are annularly and arrayedly distributed above the first gas passage.

[0009] Further, the first pore extends upward along the axial direction of the base from above the air passage and penetrates through the upper end of the base, and the second pore extends upward along the axial direction of the base and sequentially penetrates through the third dielectric layer, the heater layer, the second dielectric layer, the adsorption electrode layer, and the first dielectric layer.

[0010] Further, the first pore and the second pore are coaxially arranged.

[0011] Further, the first pore includes a plurality of pore segments that are sequentially communicated from bottom to top, and the plurality of pore segments respectively penetrate through the third dielectric layer, the heater layer, the second dielectric layer, the adsorption electrode layer, and the first dielectric layer. The aperture of the pore segment located below is not less than the aperture of the adjacent pore segment above.

[0012] Further, the first gas passage is arranged in a region of the base close to the edge of the base.

[0013] Further, the adsorption electrode lead extends downward from the adsorption electrode layer to the lower end of the base.

[0014] Further, the heating electrode lead extends downward from the heater electrode layer to the lower end of the base.

[0015] The beneficial effects of the present utility model are as follows: When the electrostatic chuck of the present utility model is in use, the gas inlet hole, the air duct and the through-hole form a closed-loop helium source channel. Helium can enter through the gas inlet hole and enter the inside of the base along the air duct, and sequentially pass through the first hole and the second hole of the through-hole from the inside of the base to penetrate the entire ceramic dielectric layer. The heat of the heater layer can quickly be transferred to the wafer, making the temperature of the electrostatic chuck and the wafer more uniform; the through-hole is set such that the aperture of the first hole is larger than that of the second hole. If particles generated during the operation of the electrostatic chuck block the through-hole, only the second hole at one end of the through-hole is blocked, and the first hole at the other end of the through-hole is not easily blocked, which helps to keep the helium channel unobstructed, facilitates later maintenance and cleaning, and is beneficial to cost savings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a perspective structural view of the electrostatic chuck of the present utility model.

[0017] Figure 2 is a top view of the electrostatic chuck of the present utility model.

[0018] Figure 3 is a bottom sectional view of the electrostatic chuck of the present utility model.

[0019] Figure 4 is a sectional view of the electrostatic chuck of the present utility model.

[0020] Figure 5 is another sectional view of the electrostatic chuck of the present utility model from another perspective.

[0021] The reference numerals are: 11, base; 12, first dielectric layer; 13, second dielectric layer; 14, third dielectric layer; 15, adsorption electrode layer; 16, heater layer; 17, adsorption electrode lead-out end; 18, heating electrode lead-out end; 19, gas inlet hole; 20, air duct; 21, through-hole; 22, first hole; 23, second hole; 24, first gas channel; 25, second gas channel; 26, coolant channel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] For the convenience of those skilled in the art, the present utility model will be further described below in conjunction with embodiments and the accompanying drawings. The content mentioned in the embodiments is not a limitation to the present utility model.

[0023] As Figures 1-5As shown in the figure, an electrostatic chuck provided with back-blow air holes includes a base 11, and a first dielectric layer 12, an adsorption electrode layer 15, a second dielectric layer 13, a heater layer 16, and a third dielectric layer 14 which are arranged in sequence from top to bottom. The lower surface of the third dielectric layer 14 is arranged on the upper surface of the base 11. The first dielectric layer 12, the second dielectric layer 13, and the third dielectric layer 14 are all ceramic dielectric layers. The adsorption electrode layer 15 and the heater layer 16 are respectively provided with an adsorption electrode lead-out end 17 and a heating electrode lead-out end 18. The adsorption electrode lead-out end 17 is used to connect to an external adsorption power supply, and the heating electrode lead-out end 18 is used to be electrically connected to an external heating power supply.

[0024] An air channel 20 and a gas inlet hole 19 communicating with the air channel 20 are provided at the bottom of the base 11. The electrostatic chuck is further provided with a plurality of through air holes 21. The through air holes 21 include a first hole channel 22 and a second hole channel 23 communicating with the upper end opening of the first hole channel 22. The first hole channel 22 is located above the inner cavity of the air channel 20 and communicates with the inner cavity of the air channel 20. The second hole channel 23 extends upward and penetrates through the first dielectric layer 12. The aperture of the first hole channel 22 is larger than that of the second hole channel 23.

[0025] When the electrostatic chuck of the present invention is in use, the gas inlet hole 19, the air channel 20, and the through air holes 21 form a helium gas source closed-loop channel. Helium gas can enter through the gas inlet hole 19, enter the interior of the base 11 along the air channel 20, and then enter the first hole channel 22 and the second hole channel 23 of the through air holes 21 in sequence from the interior of the base 11. The first hole channel 22 and the second hole channel 23 penetrate through the entire ceramic dielectric layer, and the heat of the heater layer 16 can be quickly transferred to the wafer, making the temperature distribution of the electrostatic chuck and the wafer more uniform. The through air holes 21 are set such that the aperture of the first hole channel 22 is larger than that of the second hole channel 23. If particles generated during the operation of the electrostatic chuck block the through air holes 21, only the second hole channel 23 at one end of the through air holes 21 is blocked, and the first hole channel 22 at the other end of the through air holes 21 is not easily blocked, which is convenient for later maintenance and cleaning and helps to save costs. The present invention makes the temperature of the electrostatic chuck and the wafer uniform through the back-blow gas technology method, ensuring the quality and stability of wafer processing. In this embodiment, the cross-section of the ceramic dielectric layer and the base 11 is circular, and in other embodiments, it can also be set as a polygonal structure such as a square. In this embodiment, a coolant channel 26 is provided inside the base 11, which can cooperate with the heating circuit to control the temperature of the wafer.

[0026] Further, the air duct 20 includes a first gas passage 24 and a second gas passage 25; the first gas passage 24 is annular and surrounds the gas inlet hole 19, both ends of the second gas passage 25 are respectively communicated with the gas inlet hole 19 and the first gas passage 24, and the first duct 22 is located above the inner cavity of the first gas passage 24 and is communicated with the first gas passage 24. The first gas passage 24 is arranged in a region of the base 11 close to the edge of the base 11.

[0027] Further, the second gas passage 25 is linear, and a first notch and a second notch are respectively formed on the side wall of the gas inlet hole 19 and the inner ring wall of the first gas passage 24; one end of the second gas passage 25 is communicated with the gas inlet hole 19 via the first notch, and the other end of the second gas passage 25 is communicated with the first gas passage 24 via the second notch. A plurality of the through holes 21 are annularly and arrayedly distributed above the inner cavity of the first gas passage 24.

[0028] Due to the above structure, helium can enter the second gas passage 25 and the first gas passage 24 in sequence through the gas inlet hole 19, enter into a plurality of uniformly distributed through holes 21 from the first gas passage 24, and be conveyed to the third dielectric layer 14, the heater layer 16, the second dielectric layer 13, the adsorption electrode layer 15 and the first dielectric layer 12 in sequence through the first duct 22 and the second duct 23. The heat of the heater layer 16 can be quickly transferred to the wafer, making the temperatures of the electrostatic chuck and the wafer more uniform, which is beneficial to ensuring the quality and stability of wafer processing.

[0029] Further, the first duct 22 extends upward along the axial direction of the base 11 from above the air duct 20 and penetrates through the upper end of the base 11, and the second duct 23 extends upward along the axial direction of the base 11 and sequentially penetrates through the third dielectric layer 14, the heater layer 16, the second dielectric layer 13, the adsorption electrode layer 15 and the first dielectric layer 12. In this embodiment, the first duct 22 and the second duct 23 are coaxially arranged. Since the aperture of the first duct 22 is larger than that of the second duct 23, the particles generated during the use of the electrostatic chuck are convenient to clean, which helps to ensure the smoothness of the helium channel, thereby effectively playing its cooling and heat transfer roles.

[0030] Further, the first channel 22 includes a plurality of channel segments that are sequentially connected from bottom to top. The plurality of channel segments respectively penetrate through the third dielectric layer 14, the heater layer 16, the second dielectric layer 13, the adsorption electrode layer 15, and the first dielectric layer 12. The aperture of the channel segment located below is not less than the aperture of the adjacent channel segment above. The first channel 22 of the present utility model can be set as channel segments with different apertures. When the aperture of the channel segment below is set to be larger than the aperture of the adjacent channel segment above, if the particles generated during the operation of the electrostatic chuck block the through-hole 21, only the channel segment located above is blocked, and the other channel segments are not easily blocked, which is convenient for later maintenance and cleaning.

[0031] Further, the adsorption electrode lead-out end 17 extends downward from the adsorption electrode layer 15 to the lower end of the base 11, and the heating electrode lead-out end 18 extends downward from the heater electrode layer 16 to the lower end of the base 11. Due to the setting of the above structure, it is convenient to connect the adsorption electrode lead-out end 17 and the heating electrode lead-out end 18 to an external power supply, with a compact structure and convenient assembly. In this embodiment, both the adsorption electrode lead-out end 17 and the heating electrode lead-out end 18 are two.

[0032] The above embodiments are the preferred implementation schemes of the present utility model. In addition, the present utility model can also be implemented in other ways. Any obvious replacement without departing from the concept of the present utility model is within the protection scope of the present utility model.

Claims

1. An electrostatic chuck provided with back-blowing air holes, characterized in that: It includes a base, and a first dielectric layer, an adsorption electrode layer, a second dielectric layer, a heater layer, and a third dielectric layer which are sequentially arranged from top to bottom. The lower surface of the third dielectric layer is disposed on the upper surface of the base; the first dielectric layer, the second dielectric layer, and the third dielectric layer are all ceramic dielectric layers; the adsorption electrode layer and the heater layer are respectively provided with an adsorption electrode lead-out end and a heating electrode lead-out end; The bottom of the base is provided with an air passage and a gas inlet hole communicating with the air passage. The electrostatic chuck is further provided with a plurality of through holes. The through holes include a first hole and a second hole communicating with the upper end opening of the first hole. The first hole is located above the inner cavity of the air passage and communicates with the inner cavity of the air passage. The second hole extends upward and penetrates the first dielectric layer. The aperture of the first hole is larger than that of the second hole.

2. The electrostatic chuck provided with a back-blowing air hole according to claim 1, wherein: The air passage includes a first gas passage and a second gas passage; the first gas passage is annular and surrounds the gas inlet hole. The two ends of the second gas passage are respectively communicated with the gas inlet hole and the first gas passage. The first hole is located above the inner cavity of the first gas passage and communicates with the first gas passage.

3. The electrostatic chuck provided with a back blowing hole according to claim 2, wherein: The second gas passage is linear. A first notch and a second notch are respectively formed on the side wall of the gas inlet hole and the inner ring wall of the first gas passage; one end of the second gas passage communicates with the gas inlet hole via the first notch, and the other end of the second gas passage communicates with the first gas passage via the second notch.

4. The electrostatic chuck provided with a back-blowing air hole according to claim 2, wherein: A plurality of the through holes are distributed in an annular array above the first gas passage.

5. The electrostatic chuck provided with a back-blowing air hole according to claim 1, wherein: The first hole extends upward along the axial direction of the base from above the air passage and penetrates the upper end of the base. The second hole extends upward along the axial direction of the base and sequentially penetrates the third dielectric layer, the heater layer, the second dielectric layer, the adsorption electrode layer, and the first dielectric layer.

6. The electrostatic chuck provided with a back-blowing air hole according to claim 1, wherein: The first hole and the second hole are coaxially arranged.

7. The electrostatic chuck provided with a back blowing hole according to claim 5, wherein: The first hole includes a plurality of hole segments sequentially communicated from bottom to top. The plurality of hole segments respectively penetrate the third dielectric layer, the heater layer, the second dielectric layer, the adsorption electrode layer, and the first dielectric layer. The aperture of the hole segment located below is not less than that of the adjacent hole segment above.

8. The electrostatic chuck provided with a back-blow air hole according to claim 2, wherein: The first gas passage is disposed in a region of the base close to the edge of the base.

9. The electrostatic chuck provided with a back blowing hole according to claim 1, wherein: The adsorption electrode lead-out end extends downward from the adsorption electrode layer to the lower end of the base.

10. The electrostatic chuck provided with a back blowing hole according to claim 1, characterized in that: The heating electrode lead-out end extends downward from the heater electrode layer to the lower end of the base.

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