TWI822325B - Electrostatic chuck and semiconductor processing equipment - Google Patents

Abstract

an electrostatic chuck and a semiconductor processing equipment. In the electrostatic chuck, an air passage structure includes an annular air passage, a main air passage group and a secondary air passage group, wherein the annular air passage is located at an edge close to the upper surface of a chuck body, so as to define and form a heat exchange area inside; The main airway group surrounds the central air inlet, and the secondary airway group surrounds the main airway group; The main air passage group is communicated with the central air inlet hole and the secondary air passage group respectively, and is configured to improve the speed of conveying the back blowing gas flowing out of the central air inlet hole to the secondary air passage group; The secondary air passage group is communicated with the main air passage group and the annular air passage respectively, and is arranged to make the back blown gas evenly distributed at different positions in the heat exchange area.

Description

Electrostatic chuck and semiconductor processing equipment

The present invention relates to the field of semiconductor manufacturing, and in particular, to an electrostatic chuck and semiconductor processing equipment.

Electrostatic Chuck (ESC for short) is used to carry wafers using electrostatic adsorption to prevent the wafers from moving or dislocating during the manufacturing process. During the process, it is also necessary to introduce a certain pressure of back-blow gas into the gap between the electrostatic chuck and the wafer to improve the heat transfer capability of the electrostatic chuck to the wafer and avoid vacuum insulation, thereby improving the electrostatic chuck. The chuck has the ability to control the wafer temperature; in addition, the electrostatic chuck can also provide radio frequency bias for the wafer.

The electrostatic chuck is usually placed in a vacuum chamber. Taking Physical Vapor Deposition (PVD) equipment as an example, when the wafer is transferred to the vacuum chamber of the PVD equipment and placed on the electrostatic chuck , the vacuum chamber is in a background vacuum state (the background vacuum degree is usually on the order of 10 ^-8 Torr or 10 ^-9 Torr). At this time, the wafer and the electrostatic chuck are in a vacuum insulated state. The electrostatic chuck cannot control the temperature of the wafer. It is necessary to introduce back-blow gas into the gap between the two and maintain a certain air pressure (for example, 1- 20Torr), the back-blown gas can transfer heat between the electrostatic chuck and the wafer to achieve the temperature control capability of the electrostatic chuck.

Electrostatic chucks can be divided into two types: Coulomb type and Johnsen-Rahbek effect (J-R type). The working principle of Coulomb type electrostatic chuck is to use the electrostatic attraction generated between the electrode and the wafer to align the crystal. The working principle of the J-R electrostatic chuck is to use the electrostatic attraction generated between the upper surface of the electrostatic chuck and the wafer to adsorb the wafer. In order to improve the heat transfer efficiency, air channels are usually provided on the upper surface of the electrostatic chuck to help the back blow gas diffuse to different locations on the wafer through the air channels. However, due to the distance between the electrodes in the above-mentioned Coulomb type electrostatic chuck and the wafer, The closer distance results in the thinner dielectric layer above the electrode, making it impossible to set up the above-mentioned air channel. However, the electrode in the J-R type electrostatic chuck is far away from the wafer, and the dielectric layer above the electrode is thicker, so the air channel can be made.

However, for the J-R type electrostatic chuck, the existing air channel structure requires back-blowing gas to be passed through for a long time (more than 100s) before the stability and uniformity of the back-blowing air pressure can meet the process requirements, and then the PVD process can be started, and PVD The process time is generally only in the range of 20-100s, resulting in low equipment productivity and inability to be used in industrial production.

The present invention aims to solve at least one of the technical problems existing in the prior art. It proposes an electrostatic chuck and semiconductor processing equipment, which can effectively shorten the back-blowing gas pressure while ensuring that the back-blowing air pressure reaches the stability and uniformity requirements. ventilation time, thereby increasing equipment productivity.

In order to achieve the purpose of the present invention, an electrostatic chuck is provided, which is used in semiconductor processing equipment and includes a chuck body. The upper surface of the chuck body is provided with a bump structure, a central air inlet hole and an air channel structure, wherein the bump structure The point structure is located in the non-air channel area of the upper surface of the chuck body for carrying the wafer, and the bump structure has a bearing surface for bearing the wafer, between the bearing surface and the upper surface of the chuck body Has preset spacing; The air channel structure includes an annular air channel, a primary air channel group and a secondary air channel group, wherein the annular air channel is located at the edge of the upper surface of the chuck body to define a heat exchange area inside the chuck body; the primary air channel group and the secondary air channel The groups are distributed in the heat exchange area, and the main air duct group surrounds the central air inlet hole, and the secondary air duct group surrounds the main air duct group; the main air duct group is connected to the central air inlet hole and the secondary air duct group respectively. The airway group is connected and is configured to increase the speed at which the back-blown gas flowing out of the central air inlet is delivered to the secondary airway group; the secondary airway group is connected to the main airway group and the annular airway respectively, and is configured to The back-blown gas can be evenly distributed at different positions in the heat exchange area.

Optionally, the orthographic projection area of the main airway group on the upper surface of the chuck body accounts for less than or equal to 50% of the designated area area of the upper surface of the chuck body, and the designated area area is based on the upper surface of the chuck body. The center of the surface is the center of the circle and the diameter is the area of the circle of the specified diameter.

Optional, the specified diameter is less than or equal to 50mm.

Optionally, the main air channel group includes a plurality of main air channels evenly distributed along the circumferential direction of the central air inlet, each of the main air channels is arranged along the radial direction of the central air inlet, and each of the main air channels The air inlets are connected to the central air inlet, and the air outlets of each main airway are connected to the secondary airway group.

Optionally, the width of the main airway is greater than or equal to 0.5mm and less than or equal to 3mm; the depth of the main airway is greater than or equal to 0.1mm and less than or equal to 0.4mm; the number of the main airways is greater than or equal to 9 and less than or equal to 20. .

Optionally, the secondary airway group includes a first-level sub-airway group, the sub-airway group includes a plurality of secondary airways, and the air outlet end of each main airway is connected to the air inlet end of at least one secondary airway, and is connected to the same airway. Multiple secondary airways connected to the main airway are located away from the outlet end of the main airway. The central air inlet extends in different directions; alternatively, the secondary airway group includes a multi-stage sub-airway group that surrounds in a direction away from the central air inlet, and the sub-airway group at each level includes a plurality of secondary airways, each of which The air outlet end of the main airway is connected to the air inlet end of at least one secondary airway in the adjacent first-level sub-airway group, and multiple secondary airways connected to the same main airway are connected to the main airway. The air outlet ends extend in different directions away from the central air inlet; the air outlet end of each secondary air channel of the upstream level is connected to the air inlet end of at least one secondary air channel of the adjacent downstream level, and is connected to the air inlet end of the upstream level A plurality of downstream secondary air passages connected to the same primary air passage extend from the air outlet end of the upstream primary secondary air passage in different directions away from the central air inlet.

Optionally, the width of the secondary airway is greater than or equal to 0.5mm and less than or equal to 3mm; the depth of the secondary airway is greater than or equal to 0.1mm and less than or equal to 0.4mm; the number of the secondary airways is greater than or equal to 9 and less than or equal to 100. .

Optionally, the secondary airway group includes two levels of the sub-airway group, namely a first-level airway group and a second-level airway group, wherein the first-level airway group includes a plurality of primary airways, each of the primary airway groups. The air outlet ends of the airways are all connected to the air inlet ends of three of the primary airways, and among the three primary airways connected to the same main airway, the middle primary airway is coaxial with the main airway. , the two first airways on both sides are symmetrically distributed relative to the first airway in the middle; and are connected to different main airways, and the air outlets of any two adjacent first airways converge. The second-stage airway group includes a plurality of secondary airways. Among the three primary airways connected to the same main airway, the air outlet end of the middle primary airway and two of the primary airways are The air inlet ends of the second air passages are connected to each other, and each of the first common air outlet ends is connected to the air inlet ends of two of the second air passages; and any two adjacent ones are connected to the first air outlet. The outlet end of the secondary airway The connected second air channel and the air outlet end of the second air channel connected to the first common air outlet converge to form a second common air outlet, and the second common air outlet ends are both connected to the annular air channel.

Optionally, the secondary airway group also includes a plurality of transitional airways, the air inlet end of each transitional airway is connected to each of the second common air outlets in a one-to-one correspondence, and the air outlet end of each transitional airway is connected to the second common air outlet. The circular airways are connected.

Optionally, the diameter of the annular centerline of the annular airway is greater than or equal to 270mm and less than or equal to 290mm; the radial width of the annular airway is greater than or equal to 0.5mm and less than or equal to 3mm; the depth of the annular airway is greater than or equal to 0.1mm, and Less than or equal to 0.4mm.

Optionally, the bump structure includes a plurality of bumps evenly distributed in the non-airway area, and the total orthographic projected area of the plurality of bumps on the upper surface of the chuck body is larger than the upper surface of the chuck body. The proportion of area is greater than or equal to 2% and less than or equal to 10%.

Optionally, the preset spacing is greater than or equal to 2 μm and less than or equal to 10 μm.

As another technical solution, the present invention also provides a semiconductor processing equipment, including a process chamber and an electrostatic chuck disposed in the process chamber. The electrostatic chuck adopts the above-mentioned electrostatic chuck provided by the present invention.

The present invention has the following beneficial effects: The air channel structure of the electrostatic chuck provided by the present invention includes an annular air channel, a main air channel group and a secondary air channel group, wherein the annular air channel is located at the edge close to the upper surface of the chuck body, for A heat exchange area is defined on the inside to ensure that the air pressure in this area will not be affected by the chamber pressure, ensuring the stability of the air pressure, so that the back-blown gas can perform heat exchange normally; the main air channel group and the secondary air channel group are both distributed in this area In the heat exchange area, the main air duct group surrounds the central air inlet, is connected to the central air inlet and the secondary air duct group respectively, and is set to improve the central air inlet. The speed at which the back-blown gas flowing out of the stomata is transported to the secondary air duct group can ensure that the back-blown gas can quickly diffuse from the central air inlet to the surroundings. The secondary air duct group surrounds the above-mentioned main air duct group and is connected with the main air duct group and the annular air duct respectively. are connected and arranged to enable the back-blown gas to be evenly distributed at different locations in the heat exchange area. The above-mentioned main airway group plays a major role in making the back-blown air pressure quickly reach the stability requirements, while the secondary airway group plays a major role in making the back-blown gas quickly reach the uniformity requirements. Therefore, by combining the above-mentioned main airway group and the secondary airway group Used in combination, the ventilation time of the back-blowing gas can be effectively shortened while ensuring that the back-blowing air pressure reaches the stability and uniformity requirements, thereby increasing equipment productivity.

The semiconductor processing equipment provided by the present invention, by using the above-mentioned electrostatic chuck provided by the present invention, can effectively shorten the ventilation time of the back-blowing gas on the premise of ensuring that the back-blowing air pressure reaches the stability and uniformity requirements, thereby improving the equipment production capacity.

1:Electrostatic chuck

2:wafer

11:Chuck body

12:Electrode

13:Bump

31: Circular airway

32: Main airway

33:Secondary airway

33a: First airway

33b: Second airway

34: Transitional airway

111: Upper surface

111a: Inner circle area

111b: Outer ring area

111c: Edge area

112: Center air inlet

331: First airway

332: First airway

A:Public outlet

A1: The first public outlet

A2: The second public air outlet

R: Specified area area

The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

Figure 1 is a schematic side cross-sectional view of the electrostatic chuck provided by the first embodiment of the present invention; Figure 2 is a top view of the air channel structure of the electrostatic chuck provided by the first embodiment of the present invention; Figure 3 is a first embodiment of the present invention Another top view of the air channel structure of the electrostatic chuck provided; Figure 4 is a top view of the air channel structure of the electrostatic chuck provided by the second embodiment of the present invention; Figure 5 is an overall top view of the electrostatic chuck provided by the third embodiment of the present invention ; Figure 6 is a partial top view of the electrostatic chuck in Figure 5; Figure 7 is the relationship between the electrostatic chuck used in the third embodiment of the present invention and the electrostatic chuck in the prior art. A curve comparison chart of average air pressure versus time; Figure 8 is a curve comparison chart of air pressure and wafer position between the electrostatic chuck used in the third embodiment of the present invention and the electrostatic chuck in the prior art.

The following disclosure provides many different embodiments or examples of different means for implementing the disclosure. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these are examples only and are not intended to be limiting. For example, the following description in which a first member is formed over or on a second member may include embodiments in which the first member and the second member are formed in direct contact, and may also include embodiments in which additional members Embodiments may be formed between the first member and the second member such that the first member and the second member may not be in direct contact. Additionally, the present disclosure may repeat reference numbers and/or letters in various instances. This repetition is for simplicity and clarity and does not inherently indicate a relationship between the various embodiments and/or configurations discussed.

In addition, for ease of description, spatially relative terms such as “below,” “below,” “lower,” “above,” “upper,” and the like may be used herein to describe one element or component in relation to another(s). The relationship between components or components, as illustrated in the figure. Spatially relative terms are intended to cover different orientations of the device in use or operation other than the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the values stated in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, as used herein, the term "about" generally means within 10%, 5%, 1% or 0.5% of a given value or range. Alternatively, the term "approximately" means that when considered by one of ordinary skill in the art Within one acceptable standard error of the mean. Except in operating/working examples, or unless otherwise expressly specified, all numerical ranges such as quantities, durations of time, temperatures, operating conditions, ratios of quantities, and the like for materials disclosed herein, Quantities, values and percentages should be understood to be modified in all instances by the term "approximately". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the patent claims of this disclosure and accompanying invention claims are approximations that may vary as necessary. At a minimum, each numerical parameter should be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques. Ranges may be expressed herein as from one endpoint to the other endpoint or between two endpoints. All ranges disclosed herein include endpoints unless otherwise specified.

First embodiment

Please refer to Figure 1. This embodiment provides an electrostatic chuck 1, which includes a chuck body 11. The chuck body 11 is provided with an electrode 12. The electrode 12 is usually electrically connected to a DC power supply and is used to provide a vacuum for adsorbing wafers. electrical energy. Generally, the part of the chuck body 11 located above the electrode 12 is the dielectric layer, and the part located below the electrode 12 is the base. The dielectric layer and the base are both made of ceramic materials, and the above-mentioned electrodes 12 can be embedded in the ceramic materials by sintering.

The electrostatic chuck 1 provided in this embodiment is a Johnsen-Rahbek effect (J-R type for short) electrostatic chuck, and its working principle is to use it between the upper surface 111 of the chuck body 11 and the wafer 2 The generated electrostatic attraction exerts an adsorption effect on the wafer 2 . Based on this, in this embodiment, the upper surface 111 of the chuck body 11 is provided with a bump structure, a central air inlet hole and an air channel structure, wherein the bump structure includes a structure evenly distributed in the non-air channel area (except for the central air inlet hole). and a plurality of bumps 13 in the area outside the air channel structure). The bearing surface composed of the plurality of bumps 13 is used to carry the wafer 2, and there is a predetermined gap between the bearing surface and the upper surface 111 of the chuck body 11. The preset spacing (i.e., the height of the bumps 13) is set to allow the chuck body to A sufficiently large electrostatic attraction is generated between the upper surface 111 of 11 and the wafer 2 to ensure that the wafer 2 is prevented from moving or dislocating during the manufacturing process.

The following formula is Coulomb's law formula:

Among them, F is the electrostatic attraction; K is the Coulomb constant, Q is the charge quantity of the upper surface 111, q is the charge quantity of the lower surface of the wafer 2, r is the difference between the lower surface of the wafer 2 and the upper surface 111 of the chuck body 11 spacing between them (for J-R type electrostatic chuck).

According to the formula of Coulomb's law, it can be known that the electrostatic attraction F is inversely proportional to the square of the distance r. Therefore, the size of the electrostatic attraction F mainly depends on the size of the distance r. The smaller the distance r, the greater the electrostatic attraction F. In addition, the electrostatic attraction F is proportional to the charge Q of the upper surface 111 . Therefore, the larger the area of the upper surface 111 except for the bump structure and the air channel structure, the greater the electrostatic attraction F.

Based on the above principle, optionally, the preset distance between the bearing surface composed of the plurality of bumps 13 and the upper surface 111 of the chuck body 11 is greater than or equal to 2 μm and less than or equal to 10 μm. By setting the above-mentioned preset spacing within this numerical range, it can be ensured that the electrostatic attraction force F will not be insufficient due to the preset spacing being too large, which may cause the wafer 2 to move or be dislocated during the process; Because the preset spacing is smaller than the molecular mean free path of the back-blow gas flowing between the wafer 2 and the upper surface 111 during the process, the heat conductivity of the back-blow gas becomes poor, thereby affecting the temperature control capability of the electrostatic chuck.

In addition, optionally, the total orthogonal projected area of the plurality of bumps 13 on the upper surface 111 of the chuck body 11 accounts for greater than or equal to 2% and less than or equal to 10% relative to the area of the upper surface 111 . By setting the above-mentioned proportion within this numerical range, it can be ensured that the area of the upper surface 111 will not be insufficient due to the proportion being too large, thereby causing the charge quantity Q of the upper surface 111 to be insufficient. Ultimately, the electrostatic attraction force F is insufficient, and it can ensure that the wafer 2 will not be uniformly and firmly supported due to the small proportion.

In some optional embodiments, multiple protrusions 13 can be evenly arranged in the non-airway area on multiple circles with the center of the upper surface 111 as the center and different radii, such as the multiple protrusions shown in Figure 5 . The arrangement of points 13. Alternatively, they can also be arranged in an array in the non-airway area, and the array is, for example, a rectangular array or an array of other arbitrary shapes. The present invention has no particular limitations on the number and arrangement of the plurality of bumps 13 .

In some optional embodiments, the bumps 13 may be made of TAC (hydrogen-free diamond-like carbon film) material and made using a filtered cathode vacuum arc (FCVA) method. The bumps made by this method have good wear resistance and can withstand high temperatures, thereby extending the life of the electrostatic chuck.

In some optional embodiments, the distance between the electrode 12 and the upper surface 111 of the chuck body 11 is greater than or equal to 0.5 mm and less than or equal to 2 mm. By setting the distance within this range, better static electricity can be obtained. Gravity F.

Please refer to Figure 2. The central air inlet hole 112 is located at the center of the upper surface 111 of the chuck body 11, and is used to pass back-blow gas between the upper surface 111 and the wafer 2 to achieve heat exchange between the two. Realize the temperature control of electrostatic chuck.

Please refer to Figure 2. The airway structure includes an annular airway 31, a primary airway group and a secondary airway group. The annular airway 31 is located near the edge of the upper surface 111 of the chuck body 11, and is used to define the above-mentioned heat exchange area inside it. (Including the inner ring area 111a and the outer ring area 111b), since the edge area 111c of the upper surface 111 of the chuck body 11 is connected to the inside of the chamber, the air pressure in this area will drop suddenly, resulting in the back blow gas being unable to flow in this edge area 111c. To carry out heat exchange, in this case, with the help of the above-mentioned annular air channel 31, the heat exchange inside the annular air channel 31 can be ensured. The air pressure in the exchange area (including the inner ring area 111a and the outer ring area 111b) will not be affected by the chamber pressure, ensuring the stability of the air pressure, so that the back-blown gas can perform heat exchange normally.

In some optional embodiments, the diameter of the annular centerline of the annular airway 31 is greater than or equal to 270mm and less than or equal to 290mm, preferably 280mm; the radial width of the annular airway 31 is greater than or equal to 0.5mm, and less than or equal to 3mm, preferably 2mm; the depth of the annular airway 31 is greater than or equal to 0.1mm and less than or equal to 0.4mm, preferably 0.2mm. The setting ranges of the diameter, radial width and depth of the annular center line of the annular air passage 31 can not only ensure that the area of the above heat exchange area is expanded as much as possible, but also ensure that the air pressure in the heat exchange area inside the annular air passage 31 will not be affected. The influence of chamber pressure ensures the stability of air pressure and enables normal heat exchange of back-blown gas.

The main airway group and the secondary airway group are both distributed in the above-mentioned heat exchange area. The main airway group surrounds the central air inlet 112, for example, located in the inner ring area 111a in Figure 2; the secondary airway group surrounds the main airway group, For example, it is located in the outer ring area 111b in Figure 2; wherein, the main air channel group is connected to the central air inlet hole 112 and the secondary air channel group respectively, and is configured to improve the delivery of the back-blown gas flowing out of the central air inlet hole 112 to the secondary air channel. group, thereby ensuring that the back-blow gas can quickly diffuse from the central air inlet hole 112 to the surroundings, that is, increasing the diffusion speed of the back-blow gas. This main air channel group plays a major role in enabling the back-blow air pressure to quickly reach stability requirements. .

Since the above-mentioned main air channel group is located in the inner ring area 111a adjacent to the central air inlet hole 112, and the air pressure at the central air inlet hole 112 is higher than other areas, if the orthographic projection area of the main air channel group on the upper surface 111 of the chuck body 11 If it is too large, it will easily lead to high air pressure in the inner ring area 111a, causing the wafer to "bulge" in this area. In order to solve this problem, the orthographic projection area of the main air channel group on the upper surface 111 of the chuck body 11 is relatively small. The proportion of the designated area R is less than or equal to 50%. The designated area R is the center of the above surface 111 as the center of the circle. The diameter is the area of a circle with a specified diameter, that is, the area within the outer peripheral edge of the inner ring area 111a. Optionally, the specified diameter is, for example, less than or equal to 50 mm, for example, 50 mm. Of course, the front projection area of the main air channel group on the upper surface 111 of the chuck body 11 should not be too small to ensure that the back-blowing gas can quickly diffuse from the central air inlet 112 to the surroundings, so that the back-blowing air pressure can quickly meet the stability requirements. .

In some optional embodiments, the above-mentioned main air channel group includes a plurality of main air channels 32 evenly distributed along the circumferential direction of the central air inlet hole 112, and each main air channel 32 is arranged along the radial direction of the central air inlet hole 112, so as to The path of the back-blowing gas flowing to the outer ring area 111b is made the shortest, thereby ensuring that the back-blowing gas can quickly diffuse from the central air inlet hole 112 to the surroundings. Moreover, the air inlet end of each main air channel 32 is connected with the central air inlet hole 112, and the air outlet end of each main air channel 32 is connected with the secondary air channel group. The back-blown gas flowing out through the central air inlet hole 112 diffuses to the surroundings through each main air channel 32 and flows into the secondary air channel group.

In some optional embodiments, the orthogonal projected area of the main airway group on the upper surface 111 of the chuck body 11 can be adjusted by setting the number, width, depth and other parameters of the above-mentioned main airway 32 , for example, the area of the main airway 32 The width is greater than or equal to 0.5mm, and less than or equal to 3mm, preferably 2mm; the depth of the main airway 32 is greater than or equal to 0.1mm, and less than or equal to 0.4mm, preferably 0.2mm; the number of the main airways 32 is greater than or equal to 9, and less than or equal to 20 strips, preferably 10 strips. For example, 15 main airways 32 are shown in FIG. 2 . By setting the number, width, and depth of the main air channels 32 within the above numerical range, it can be ensured that the orthogonal projected area of the main air channel group on the upper surface 111 of the chuck body 11 will not be too large, causing the air pressure in the inner ring area 111a Higher, thereby causing the wafer to appear "bulging" in this area, and ensuring that the front projection area on the upper surface 111 of the chuck body 11 is large enough so that the back blow gas can quickly flow from the central air inlet hole 112 to the surroundings Diffusion, thereby achieving back-blowing air pressure to quickly reach stability requirements.

It should be noted that the main airway group is not limited to the structure adopted in the above embodiment. In practical applications, any other structure can be used as long as the back-blowing air pressure can quickly reach the stability requirements.

The secondary air channel group is connected to the above-mentioned main air channel group and the annular air channel 31 respectively, and is configured to enable the back-blown gas to be evenly distributed at different positions in the heat exchange area (including the inner ring area 111a and the outer ring area 111b), that is to say , the secondary airway group can make the back-blown gas spread quickly and evenly. The secondary airway group plays a major role in making the back-blowing gas quickly reach the uniformity requirements. Therefore, by combining the above-mentioned main airway group and the secondary airway group, it is possible to ensure that the back-blowing air pressure reaches the stability and uniformity requirements. Effectively shorten the ventilation time of back-blown gas, thereby increasing equipment productivity.

It should be noted that since the distance between the air channel area where the above-mentioned main air channel group and the secondary air channel group are located and the wafer surface is large, while the distance between the non-air channel area of the upper surface 111 and the wafer surface is small, the above-mentioned main air channel group The airway group and the secondary airway group can guide the diffusion of back-blown gas, and both are connected to the non-airway area. Therefore, after the back-blown gas flows along the above-mentioned main airway group and secondary airway group in sequence, it will flow toward The non-air channel area is further diffused, and finally the entire heat exchange area is filled with back-blown gas, thereby achieving uniform and stable air pressure between the heat exchange area and the wafer surface.

In some optional embodiments, the secondary airway group includes a first-level sub-airway group. As shown in FIG. 2 , this sub-airway group is located in the outer ring area 111b and includes a plurality of secondary airways 33 . Each main airway 32 has The air outlet ends are connected to the air inlet ends of two of the secondary air channels 33 , and the two secondary air channels 33 connected to the same main air channel 32 extend from the air outlet end of the main air channel 32 in different directions away from the central air inlet hole 112 , for example, the two secondary air passages 33 connected with the same main air passage 32 in FIG. 2 extend away from the central air inlet 112 and away from each other, and finally connect with the annular air passage 31 Connected. Since each two secondary air channels 33 serve as two branches of the main air channel 32, the back-blown gas flowing out of the main air channel 32 can be further diffused from the outlet end of the main air channel 32 in different directions away from the central air inlet hole 112. This can play a role in making the back-blown gas quickly reach the uniformity requirements.

It should be noted that in practical applications, the number of secondary airways 33 connected to the same main airway 32 can also be one. In this case, different secondary airways 33 can be connected to each other. This is also the case. It can play a role in making the back-blown gas quickly reach the uniformity requirements. Alternatively, the number of secondary airways 33 connected to the same main airway 32 may be more than three. For example, as shown in FIG. 3 , the number of secondary airways 33 connected to the same main airway 32 may also be three. The quantity can be freely set according to specific needs.

In some optional embodiments, the width of the secondary airway 33 is greater than or equal to 0.5mm and less than or equal to 3mm, preferably 2mm; the depth of the secondary airway 33 is greater than or equal to 0.1mm, and less than or equal to 0.4mm, preferably 0.2mm; The number of airways 33 is greater than or equal to 9 and less than or equal to 100, preferably 20. By setting the width, depth and number of the secondary air passages 33 within the above numerical range, the back-blowing gas can effectively achieve uniformity requirements quickly.

It should also be noted that the above-mentioned secondary air channel 33 is not limited to a straight channel, and may also be a channel of any other shape, such as a curved channel, a zigzag channel, etc., and the present invention has no particular limitation on this.

Second embodiment

Referring to FIG. 4 , the electrostatic chuck provided in this embodiment is different from the above-mentioned first embodiment only in that the structure of the secondary air channel group is different and a plurality of transition air channels 34 are added. Only the differences between this embodiment and the above-mentioned first embodiment will be described in detail below.

Specifically, as shown in Figure 4, on the upper surface 111 of the chuck body 11, an annular transition area 111d is further divided between the outer ring area 111b and the annular airway 31. On this basis, the secondary airway group includes a first-level sub-airway. The sub-airway group of this level is located in the outer ring area 111b and includes a plurality of secondary airways 33. The air outlet end of each main airway 32 is connected to the air inlet ends of two of the secondary airways 33 and is connected to the same main airway. Two secondary air passages 33 connected with each other extend from the outlet end of the main air passage 32 in different directions away from the central air inlet 112. For example, in Figure 2, the two secondary air passages 33 connected with the same primary air passage 32 extend in different directions away from the center. The air inlet holes 112 extend away from each other, and the air outlet ends of any two adjacent secondary air channels 33 connected to different main air channels 32 converge into a common air outlet end A, so as to realize the connection between the two secondary air channels 33. are interconnected, which can further improve the efficiency of back-blown gas to quickly achieve uniformity requirements.

Moreover, the above-mentioned secondary airway group also includes a plurality of transitional airways 34. The plurality of transitional airways 34 are located in the above-mentioned annular transition area 111d, and the air inlet end of each transitional airway 34 is connected to each common air outlet A in a one-to-one correspondence. The air outlet ends of the transition air passages 34 are all connected with the annular air passage 31 . With the help of the transition airway 34, the plurality of interconnected secondary airways 33 can be further connected with the annular airway 31.

It should be noted that in practical applications, the transition air channel 34 can also be omitted, that is, the annular transition area 111d is not provided, and the common air outlet A directly extends to the position of the annular air channel 31 and is connected with it.

Other structures and functions of the electrostatic chuck provided by this embodiment are the same as those of the above-mentioned first embodiment, and will not be described again here.

Third embodiment

As a preferred embodiment, please refer to Figures 5 and 6. Compared with the above-mentioned first and second embodiments, the electrostatic chuck provided by this embodiment only differs in: the secondary airway group The structure is different. Only the differences between this embodiment and the above-mentioned first and second embodiments will be described in detail below.

As shown in FIGS. 5 and 6 , the secondary airway group includes two-level sub-airway groups that surround one another in a direction away from the central air inlet 112 , and are all located in the above-mentioned outer ring area. The two-level sub-airway groups are respectively a first-level airway group and a second-level airway group. The first-level airway group includes a plurality of first airways 33a, and the second-level airway group includes a plurality of second airways 33b.

Among them, the air outlet end of each main airway 32 is connected with the air inlet end of three primary airways 33a, and among the three primary airways connected with the same main airway 32, the middle first airway 331 is connected with the air inlet end of the primary airway 33a. The main airway 32 is coaxial, and the two primary airways 332 on both sides are symmetrically distributed relative to the primary airway 331 in the middle; and are connected to different main airways 32, and any two adjacent first airways 331 are connected to each other. The air outlet ends of the air passages 331 converge into the first common air outlet end A1; among the three first air passages connected to the same main air passage 32, the air outlet ends of the middle first air passage 331 are equal to those of the two second air passages 33b. The air inlets are connected, and each first common air outlet A1 is connected to the air inlets of two of the second air channels 33b; and any two adjacent air outlets of the first air channels 331 are connected to the air inlets of the second air channels 33b. The secondary air channel 33b and the air outlet of the second air channel 33b connected to the first common air outlet A1 converge into the second common air outlet A2, or in other words, they are connected to different air outlets (including the air outlet of the first air channel 331 in the middle). The air outlet ends of any two adjacent second air channels 33b that are connected to the first common air outlet end A1) converge to form a second common air outlet end A2, and the second common air outlet ends 33b are all connected with the annular air channel 31.

Optionally, the above-mentioned secondary airway group also includes a plurality of transition airways 34. The air inlet end of each transition airway 34 is connected to each second common air outlet A2 in one-to-one correspondence. The air outlet end of each transition airway 34 is connected to The annular airways 31 are connected.

The following takes the air channel structure used in the electrostatic chuck shown in Figure 5 as an example to carry out the actual operation. The specific parameters include: the width of the main airway 32, the secondary airway 33, the annular airway 31 and the transition airway 34 are all 2mm; the number of the main airway 32 is 15; the total number of the secondary airways is 60; the annular shape of the annular airway 31 The diameter of the center line is 280mm.

Figure 7 is a graph comparing the curves of average air pressure and time between the electrostatic chuck used in the third embodiment of the present invention and the electrostatic chuck in the prior art. As shown in Figure 7, when the average air pressure reaches the B1 line, it is considered that the average air pressure meets the process requirements; when the average air pressure reaches the B2 line, the stability of the average air pressure is considered to meet the process requirements, and the process can start at this time. In the PVD process, usually the value of B1 is 90% of the value of B2. Curve S1 is the curve of the prior art electrostatic chuck with respect to average air pressure and time; Curve S2 is the curve of the electrostatic chuck used in the third embodiment of the present invention with respect to average air pressure and time. Through comparison, it can be seen that curve S1 corresponds to line B1 The time point t2 (above 100s) is greater than the time point t1 (about 12s) corresponding to the B1 line on the curve S2. That is, the electrostatic chuck used in the third embodiment of the present invention can reach the B1 line and B2 faster than the existing technology. line, it can be proved that the electrostatic chuck provided by this embodiment can effectively shorten the ventilation time of the back-blowing gas on the premise of ensuring that the back-blowing air pressure meets the stability requirements.

8 is a graph comparing the curves of air pressure and wafer position between the electrostatic chuck used in the third embodiment of the present invention and the electrostatic chuck in the prior art. As shown in Figure 8, curve S1 is the curve of the electrostatic chuck in the prior art with respect to air pressure and wafer position; curve S2 is the curve of the electrostatic chuck used in the third embodiment of the present invention with respect to air pressure and wafer position. It can be seen from comparison , the air pressure of curve S1 gradually decreases from the center position (150mm) of the wafer to the edge position, and the highest air pressure at the center position is 680Pa, and the lowest air pressure at the edge position is 340Pa. The uniformity of the air pressure is poor. The difference between the air pressure at the center (150mm) of the wafer and the air pressure at the edge of curve S2 is very small, both are around 680Pa. This proves that the electrostatic chuck provided by this embodiment can effectively improve back blowing Air pressure stability.

It should be noted that the above-mentioned third embodiment only provides a preferred embodiment, and the present invention is not limited thereto. In practical applications, the secondary airway group may also include sequentially surrounding air channels in a direction away from the central air inlet hole 112 A sub-airway group of three or more levels. In this case, the air outlet end of each main airway 32 is connected to the air inlet end of at least one secondary airway in the adjacent first-level sub-airway group, and is connected to the same airway. A plurality of secondary air passages connected to the main air passage 32 extend from the air outlet end of the main air passage 32 to different directions away from the central air inlet 112; the air outlet end of each secondary air passage of the upstream level is equal to that of the adjacent downstream level. The air inlet end of at least one secondary air passage is connected, and multiple secondary air passages at the downstream level connected to the same primary air passage at the upstream level extend from the air outlet end of the secondary air passage at the upstream level in different directions away from the central air inlet hole 112 .

Other structures and functions of the electrostatic chuck provided by this embodiment are the same as those of the above-mentioned first and second embodiments, and will not be described again here.

In summary, the electrostatic chuck provided by the above embodiments of the present invention, by combining the above-mentioned main airway group and the secondary airway group, can effectively shorten the back blowing air pressure on the premise of ensuring that the stability and uniformity requirements are met. The ventilation time of blowing gas can increase the equipment production capacity.

As another technical solution, an embodiment of the present invention also provides a semiconductor processing equipment, including a process chamber and an electrostatic chuck disposed in the process chamber. The electrostatic chuck adopts the electrostatic chuck provided by the above embodiments of the present invention. .

The semiconductor processing equipment provided by the embodiment of the present invention, by using the above-mentioned electrostatic chuck provided by the embodiment of the present invention, can effectively shorten the ventilation time of the back-blowing gas on the premise of ensuring that the back-blowing air pressure reaches the stability and uniformity requirements. This can increase equipment productivity.

The foregoing content summarizes the features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should understand that they can easily use this The disclosure serves as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments described herein. Those skilled in the art should also understand that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they can be variously changed, replaced, and altered herein without departing from the spirit and scope of the disclosure.

11:Chuck body

13:Bump

31: Circular airway

32: Main airway

33a: First airway

33b: Second airway

34: Transitional airway

112: Center air inlet

Claims (11)

An electrostatic chuck, used in semiconductor processing equipment, includes a chuck body, wherein the upper surface of the chuck body is provided with a bump structure, a central air inlet hole and an air channel structure, wherein the bump structure is located In the non-air channel area of the upper surface of the chuck body, the bump structure has a bearing surface for carrying the wafer, and there is a preset distance between the bearing surface and the upper surface of the chuck body; the air channel structure It includes an annular air channel, a primary air channel group and a primary air channel group, wherein the annular air channel is located at the edge of the upper surface of the chuck body to define a heat exchange area inside the chuck body; the primary air channel group and the secondary air channel group The air duct groups are distributed in the heat exchange area, and the main air duct group surrounds the central air inlet, and the secondary air duct group surrounds the main air duct group; the main air duct group is connected to the central air inlet and the central air inlet respectively. The secondary airway group is connected to each other and is configured to increase the speed of delivering the back-blown gas flowing out of the central air inlet to the secondary airway group; the secondary airway group is connected to the main airway group and the annular airway respectively, and It is configured to enable the back-blown gas to be evenly distributed at different positions in the heat exchange area; the main air channel group includes a plurality of main air channels evenly distributed along the circumferential direction of the central air inlet; the secondary air channel group includes a first A first-level airway group and a second-level airway group, wherein the first-level airway group includes a plurality of primary airways, and the air outlet end of each main airway is connected to the air inlet ends of three of the primary airways. , and among the three first airways connected to the same main airway, the middle first airway is coaxial with the main airway, and the two first airways on both sides are relative to the middle first airway. The airways are symmetrically distributed; and are connected to different main airways, and the air outlet ends of any two adjacent primary airways converge into a first common air outlet; the secondary airway group includes a plurality of second airways Airway, three airways connected to the same main airway Among the first air channels, the air outlet end of the middle first air channel is connected to the air inlet ends of two of the second air channels, and each of the first common air outlets is connected to two of the second air channels. The air inlet ends of the secondary air passages are connected; and the air outlets of any two adjacent second air passages connected to the air outlet ends of the first air passage and the second air passages connected to the first common air outlet end The two ends converge to form a second common air outlet end, and the second common air outlet ends are all connected with the annular airway. The electrostatic chuck according to claim 1, wherein each main air channel is arranged along the radial direction of the central air inlet, and the air inlet end of each main air channel is connected with the central air inlet. . The electrostatic chuck as described in claim 2, wherein the width of the main air channel is greater than or equal to 0.5 mm and less than or equal to 3 mm; the depth of the main air channel is greater than or equal to 0.1 mm and less than or equal to 0.4 mm; the number of the main air channels is greater than Equal to 9 and less than or equal to 20. The electrostatic chuck according to claim 1, wherein the orthographic projection area of the main airway group on the upper surface of the chuck body accounts for less than or equal to 50% of the designated area area of the upper surface of the chuck body. , the area of the specified area is the area of a circle with the center of the upper surface as the center and the diameter as the specified diameter. The electrostatic chuck according to claim 4, wherein the specified diameter is less than or equal to 50 mm. The electrostatic chuck according to claim 1, wherein the width of the first air channel and the second air channel is greater than or equal to 0.5 mm and less than or equal to 3 mm; the depth of the first air channel and the second air channel is greater than Equal to 0.1mm and less than or equal to 0.4mm; the number of the first airway and the second airway The quantity is greater than or equal to 9 items and less than or equal to 100 items. The electrostatic chuck according to claim 1, wherein the secondary airway group further includes a plurality of transitional airways, and the air inlet end of each transitional airway is connected to each of the second common air outlets in a one-to-one correspondence. The air outlet ends of the transitional airway are all connected with the annular airway. An electrostatic chuck, used in semiconductor processing equipment, includes a chuck body, wherein the upper surface of the chuck body is provided with a bump structure, a central air inlet hole and an air channel structure, wherein the bump structure is located In the non-air channel area of the upper surface of the chuck body, the bump structure has a bearing surface for carrying the wafer, and there is a preset distance between the bearing surface and the upper surface of the chuck body; the air channel structure It includes an annular air channel, a primary air channel group and a primary air channel group, wherein the annular air channel is located at the edge of the upper surface of the chuck body to define a heat exchange area inside the chuck body; the primary air channel group and the secondary air channel group The air duct groups are distributed in the heat exchange area, and the main air duct group surrounds the central air inlet, and the secondary air duct group surrounds the main air duct group; the main air duct group is connected to the central air inlet and the central air inlet respectively. The secondary airway group is connected to each other and is configured to increase the speed of delivering the back-blown gas flowing out of the central air inlet to the secondary airway group; the secondary airway group is connected to the main airway group and the annular airway respectively, and It is set to enable the back-blown gas to be evenly distributed at different positions of the heat exchange area; wherein, the diameter of the annular center line of the annular air channel is greater than or equal to 270 mm and less than or equal to 290 mm; the radial width of the annular air channel is greater than or equal to 0.5 mm, and less than or equal to 3mm; the depth of the annular airway is greater than or equal to 0.1mm, and less than or equal to 0.4mm. The electrostatic chuck according to claim 1, wherein the bump structure includes evenly distributed in the non- Multiple bumps in the airway area, the total orthographic projection area of the bumps on the upper surface of the chuck body accounts for greater than or equal to 2% and less than or equal to 10% relative to the upper surface area of the chuck body. %. An electrostatic chuck, used in semiconductor processing equipment, includes a chuck body, wherein the upper surface of the chuck body is provided with a bump structure, a central air inlet hole and an air channel structure, wherein the bump structure is located In the non-air channel area of the upper surface of the chuck body, the bump structure has a bearing surface for carrying the wafer, and there is a preset distance between the bearing surface and the upper surface of the chuck body; the air channel structure It includes an annular air channel, a primary air channel group and a primary air channel group, wherein the annular air channel is located at the edge of the upper surface of the chuck body to define a heat exchange area inside the chuck body; the primary air channel group and the secondary air channel group The air duct groups are distributed in the heat exchange area, and the main air duct group surrounds the central air inlet, and the secondary air duct group surrounds the main air duct group; the main air duct group is connected to the central air inlet and the central air inlet respectively. The secondary airway group is connected to each other and is configured to increase the speed of delivering the back-blown gas flowing out of the central air inlet to the secondary airway group; the secondary airway group is connected to the main airway group and the annular airway respectively, and It is configured to enable the back-blowing gas to be evenly distributed at different positions of the heat exchange area; wherein the preset spacing is greater than or equal to 2 μm and less than or equal to 10 μm. A semiconductor processing equipment includes a process chamber and an electrostatic chuck disposed in the process chamber, wherein the electrostatic chuck is the electrostatic chuck described in any one of claims 1-10.