TW202226739A - Electrostatic chuck, lower electrode element and plasma processing apparatus in which the electrostatic chuck includes a plurality of zones and a first ventilation hole provided in a protrusion part of one of the zones - Google Patents

Abstract

The present invention discloses an electrostatic chuck (ESC) for a plasma processing apparatus, a lower electrode element, and a plasma processing apparatus. The electrostatic chuck includes: a plurality of zones in which a first zone of the plurality of zones includes a protrusion part protruding toward the center of the electrostatic chuck; and a first ventilation hole provided in the protrusion part.

Description

Electrostatic chuck, lower electrode element and plasma processing device

The present invention relates to the field of semiconductor processing devices, in particular to electrostatic chucks, lower electrode elements and plasma processing devices.

Electrostatic chuck (ESC) is one of the most critical elements in plasma etching equipment, especially reactive ion etching (RIE) equipment. The electrostatic chuck absorbs and fixes the wafer to be processed placed on it by electrostatic force, and the temperature of the wafer to be processed can be adjusted through the base below. Advances in semiconductor technology and the diversity of etch applications place more stringent requirements on electrostatic chucks, such as better wafer temperature uniformity and better center-to-edge temperature regulation. In addition, the diversity of application environments requires electrostatic chucks to operate in a larger temperature range, higher power, higher voltage, and larger RF frequency range. This greatly increases the mechanical, thermal, chemical and electrical stress of the various parts in the electrostatic chuck element (ie the lower electrode element). Improper handling of these stresses can damage the electrostatic chuck. When the electrostatic chuck is damaged, it often becomes a major failure of the plasma processing unit. Combining all these factors presents serious challenges to the design and manufacture of electrostatic chucks.

In a first aspect, the present invention provides an electrostatic chuck for a plasma processing apparatus, the electrostatic chuck comprising: a plurality of regions, a first region of the plurality of regions comprising a protrusion protruding toward the center of the electrostatic chuck part; a first ventilation hole, the first ventilation hole is provided in the protruding part.

In a second aspect, the present invention provides a lower electrode element for a plasma processing device, comprising: the above-mentioned electrostatic chuck for carrying a substrate placed thereon; a base, disposed below the electrostatic chuck; A bonding layer is disposed between the electrostatic chuck and the base to bond the electrostatic chuck and the base.

As a third-party manufacturer, the present invention provides a plasma processing device, comprising: a reaction chamber; the above-mentioned lower electrode element, the lower electrode element is arranged in the reaction chamber, and the substrate to be processed is carried on the lower electrode element ; A gas supply device, which provides a reaction gas to the reaction chamber to generate a plasma treatment substrate.

In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be further described below with reference to the accompanying drawings. Of course, the present invention is not limited to the specific embodiment, and general replacements known to those skilled in the art in the technical field to which the present invention pertains are also covered within the protection scope of the present invention.

It is desirable to maintain good temperature uniformity on the substrate during plasma processing of the substrate. The ability to adjust the temperature between the center and edge of the substrate to compensate for non-uniformities caused by other processing or hardware conditions within the processing chamber is also desirable during processing. Various methods exist to improve temperature uniformity and adjustability. One approach is to construct multiple coolant channels in the base. An alternative approach is to construct multiple areas on the surface of the electrostatic chuck. Some factors that affect the temperature uniformity of the substrate and the corresponding means are briefly described below.

In order to control the temperature of the substrate being processed during etching, heat can be conducted away from the substrate through two main mechanisms:

(1) In the case where the substrate is attracted by the electrostatic chuck, heat is transferred from the substrate to the electrostatic chuck through solid-solid contact. Physical contact between the backside of the substrate and the topside of the electrostatic chuck promotes thermal conduction. Factors that affect this heat transfer are:

(A) The area between the substrate and the electrostatic chuck: The overlapping area between the substrate and the electrostatic chuck consists of a mechanical contact area and a non-mechanical contact area. The surface of the electrostatic chuck typically includes one or more sealing tapes to separate the helium gas between the substrate and the electrostatic chuck, as well as a stage (or stage point) that provides an additional point of mechanical support for the substrate placed on the electrostatic chuck . When the space between the substrate and the electrostatic chuck is filled with a gaseous medium such as helium, the heat transfer from the substrate to the electrostatic chuck can be through the mechanical contact area or the non-mechanical contact area.

(B) Roughness (Ra) of the electrostatic chuck surface: A smaller Ra, i.e. a smoother surface, has a higher thermal conductivity between the substrate and the electrostatic chuck.

(C) The clamping voltage between the substrate and the DC electrode buried in the electrostatic chuck, which in turn determines the clamping force between the substrate and the electrostatic chuck. Combining the two factors in (B) and (C) can be effectively translated into the concept of contact pressure.

(2) When the substrate is electrostatically adsorbed by the electrostatic chuck, heat is transferred from the substrate to the electrostatic chuck through the heat-conducting gas between the backside of the substrate and the top surface of the electrostatic chuck via solid-gas-solid contact.

Argon is typically used in physical vapor deposition (PVD) applications, while helium is typically used in etching applications. Reasons to use helium in etching applications are:

(I) Among all gases except hydrogen, helium has the highest thermal conductivity (see Table 1). For safety reasons, the use of hydrogen is generally avoided unless the benefits of using hydrogen outweigh its potential risks. In addition, hydrogen can cause harmful chemical reactions during the etching process. Due to its smaller atomic mass, hydrogen is also more difficult to pump out with a turbo pump and therefore has a greater effect on things like pressure and chemicals in the process.

(II) Helium is an inert gas and generally has little effect on the etching process. Although argon is also an inert gas, its atomic mass is much higher than helium, so it will have a greater impact on auxiliary ions during the etching process. gas Air Ar CO CO ₂ H He N ₂ Ne O ₂ Thermal Conductivity 0.026 0.018 0.025 0.017 0.182 0.151 0.026 0.049 0.027 Table 1 Thermal conductivity of various gases at 25°C (W/(m·K))

Several factors affect solid-gas-solid thermal conductivity, which process engineers can control during etching and which design engineers can leverage when designing electrostatic chuck functions. These factors are:

(A) The overlapping area between the substrate and the electrostatic chuck.

(B) Helium density between the substrate and the electrostatic chuck: The gas density can be controlled to a desired value by setting a specific gas pressure. (Gas density is proportional to gas pressure: PV=nRT, where P, V, T are gas pressure, volume, and temperature, respectively; n is gas density; R is ideal gas constant.)

(C) Mean free path of the gas: When the mean free path of the gas is greater than or equal to the gap between the substrate and the surface of the electrostatic chuck, the gas density factor is effective for thermal conductivity. Otherwise, the thermal conductivity through the gas medium will reach saturation after reaching a certain gas pressure, which is related to the above-mentioned gas density.

FIG. 1 shows a schematic diagram of a lower electrode element for a plasma processing apparatus according to one embodiment of the present invention. The lower electrode element 100 is mainly composed of an electrostatic chuck 101 and a base 102 , and the electrostatic chuck 101 is bonded to the base 102 of the lower electrode through a bonding layer 103 . The substrate 200 to be processed is carried above the electrostatic chuck 101 . The electrostatic chuck 101 is typically made of a semiconductor or insulating ceramic material, such as aluminum oxide or aluminum nitride. The base 102 is typically made of a conductive metallic material, such as aluminum, stainless steel, or titanium. Typically, radio frequency (RF) power is delivered to susceptor 102 through radio frequency power supply 250 to excite the plasma.

The pedestal 102 may include one or more embedded heating elements and conduits 105 for cooling fluid to control the lateral temperature distribution of the pedestal 102 . The conduit 105 may be fluidly coupled to a fluid source that circulates a temperature-regulated fluid through the conduit 105 . One or more embedded heating elements may be regulated by heater power. In one embodiment, the temperature of the susceptor 102 can be controlled using the conduit 105 and one or more embedded heating elements to heat and/or cool the electrostatic chuck 101 and the substrate 200 being processed. The temperature of the electrostatic chuck and heat transfer base 102 can be monitored using a number of temperature sensors, which can be monitored using a controller.

One or more first gas channels 106 connected to an external gas source are provided in the lower electrode element 100 , and the first gas channels 106 are correspondingly connected with one or more second gas channels 104 passing through the electrostatic chuck 101 to form a gas pipeline . During processing of the substrate 200 , a backside gas (eg, helium) may be provided into the gas line under controlled pressure to enhance heat transfer between the electrostatic chuck 101 and the substrate 200 . Factors affecting heat transfer between the backside of substrate 200 and electrostatic chuck 101 have been discussed above.

FIG. 2 illustrates a temperature profile of a silicon wafer during semiconductor processing, according to one embodiment. Typically, the edge of the substrate is at a higher temperature than the center of the substrate. In this embodiment, the temperature is lowest in the middle region between the central region and the edge region of the substrate. In practice, it is desirable to reduce the temperature of the edge of the substrate to improve the uniformity of the temperature of the substrate. More advantageously, it has the ability to adjust the temperature of the edge of the substrate to be higher, equal to or lower than the temperature of the center of the substrate.

Two factors that cause the edge of the substrate to be hotter are:

(1) The diameter of the substrate is larger than that of the electrostatic chuck, and overhangs about 1-2mm outside the edge of the electrostatic chuck (part 210 in Figure 1). There is no physical contact between the overhanging wafer area and the electrostatic chuck, so heat cannot be efficiently absorbed from the overhanging area, resulting in increased temperature.

(2) The helium pressure in the gas channel in the electrostatic chuck under the substrate is 10-80 Torr, and the chamber pressure during the etching process is in the range of 5-200 mTorr. This means that the gas pressure at the outside of the wafer is reduced from 10-80 Torr to 5-200 mTorr. As the helium pressure decreases, the thermal conductivity decreases and the efficiency of heat absorption from the substrate decreases, resulting in an increase in temperature.

To overcome this drawback, multiple helium regions can be constructed on the surface of the electrostatic chuck, for example, a higher helium pressure can be applied in the outer regions to reduce the temperature of the edges of the substrate, while a lower helium pressure can be applied in the inner regions Helium pressure.

3 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to one embodiment. The electrostatic chuck 300 is composed of aluminum nitride (AlN) or aluminum oxide (Al ₂ O ₃ ). The electrostatic chuck 300 may alternatively be composed of titanium oxide (TiO), titanium nitride (TiN), silicon carbide (SiC), or the like. A DC electrode can be embedded in the electrostatic chuck 300 to attract and fix the substrate above by electrostatic induction. The electrostatic chuck 300 includes two regions: an inner region 310 and an outer region 320 . In this embodiment, the inner region 310 is a circular region and the outer region 320 is an annular region. In the inner region 310, four gas channels 315 are provided. In the outer region 320, four gas channels 325 are also provided. For illustrative purposes, only 8 gas passages are shown. However, any number of gas channels may also be present in electrostatic chuck 300 . A heat transfer gas, such as helium, is introduced into the gas channels 315, 325 to absorb the heat of the substrate. The inner region 310 corresponds to the edge region of the substrate, and the outer region 320 corresponds to the central region of the substrate.

The inner area 310 and the outer area 320 are separated by the sealing tape 311, the side surface of the sealing tape 311 is in close contact with the inner area 310 and the outer area 320, and the upper surface is flush with the upper surface of the electrostatic chuck 300 or the upper surface of the table. flat, thereby separating the helium region between the substrate and the electrostatic chuck into two disconnected regions so that the heat transfer efficiency in each region can be adjusted independently. The sealing tape is made of insulating material, such as silicone. An outer ring sealing tape 321 is also provided on the outer periphery of the outer region 320 of the electrostatic chuck to prevent the helium gas in the outer region 320 from diffusing into the processing chamber and confine the helium gas in the outer region between the electrostatic chuck 300 and the substrate.

In one embodiment, electrostatic chuck 300 corresponds to electrostatic chuck 101 in FIG. 1 . The gas channels 315, 325 correspond to the first gas channel 104 in FIG. 1 .

When the gas channel 325 in the outer region 320 is too close to the edge of the electrostatic chuck, the width of the bonding layer 103 may not be sufficient to reliably prevent the leakage of helium gas from the gap between the electrostatic chuck and the base to the electrostatic chuck the edge of the suction cup as well as the cavity. For electrostatic chucks with dual helium zones, the location of the sealing band separating the inner and outer regions is typically in the range of Φ200mm to Φ280mm, depending on the transition point of raising the temperature to the edge of the substrate. For some configurations and applications, the temperature starts to increase closer to the edge of the electrostatic chuck, which means the outer area should be designed to be narrower.

4 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to another embodiment. In this embodiment, electrostatic chuck 400 includes two regions: inner region 410 and outer region 420 . The outer area 420 includes an annular area and a protrusion 450 protruding toward the center O of the electrostatic chuck 400 . In this embodiment, the protrusions 450 are semicircular. In other embodiments, the protrusions may also be regular or irregular shapes such as triangles, trapezoids, and rectangles. The gas channel 425 is provided in the protrusion 450 . This causes the gas channels 425 in the outer region 420 to be further away from the edge of the electrostatic chuck 400 than in FIG. 3 , so that the bonding layer 103 (in conjunction with FIG. 1 ) from the edge of the electrostatic chuck to the gas channels 425 is of sufficient width to provide protection against The sealing effect of gas leakage. In this way, the helium gas in the gas channel 425 does not leak from the bonding layer 103 to the edge of the electrostatic chuck 400 and into the cavity. In this embodiment, the distance from the gas channel 425 in the outer region 420 to the center O of the circle is greater than the distance from the gas channel 415 in the inner region 410 to the center O of the circle. In other embodiments, the distance from the gas channel 425 in the outer region 420 to the center O of the circle is less than or equal to the distance from the gas channel 415 in the inner region 410 to the center O of the circle.

As mentioned above, the edge temperature of the substrate in plasma processing is generally higher than the temperature at the center. The electrostatic chuck is divided into two parts, each part corresponds to a different area of the substrate, and the temperature uniformity of the upper substrate can be adjusted by adjusting the characteristics of each part.

In one embodiment, the pressure of helium introduced into the gas channel 425 of the outer region 420 is greater than the pressure of helium introduced into the gas channel 415 of the inner region 410 . Because the thermal conductivity is positively correlated with the gas pressure, when the helium pressure introduced into the gas channel 425 of the outer region 420 is larger, the heat from the edge region of the substrate can be conducted to the electrostatic chuck and the pedestal more quickly, thereby improving the to the effect of regulating the uniformity of the temperature of the substrate. In addition, the sub-regions of the electrostatic chuck can not only be used to control the temperature uniformity of the substrate, but also can adjust the temperature of each region of the substrate according to the needs of a specific process by independently setting the characteristics of each region. For example, the temperature of the edge region of the substrate may be greater than, equal to or less than that of the central region of the substrate according to process requirements.

In one embodiment, the upper surface of the electrostatic chuck 400 further includes a mesa structure protruding upward. The surface of electrostatic chuck 400 may have hundreds or thousands of mesas formed thereon. In some embodiments, the mesa has a height of between 2 microns and 200 microns and a size (eg, diameter) of between 0.5 millimeters and 5 millimeters. The side walls of the platform may be vertical or inclined. In one embodiment, each mesa has a rounded edge, that is, the mesa edge is rounded, and the substrate is in arcuate contact with the mesa edge, which can minimize chipping of the mesa and reduce particle contamination on the backside of the substrate. The edges also reduce or eliminate scratching of the backside of the substrate due to clamping. The countertop can also have chamfered edges.

The inner and outer regions are separated by a sealing tape 411, the side surface of the sealing tape 411 is in close contact with the inner and outer regions, and the upper surface is flush with the upper surface of the table portion of the electrostatic chuck 400, so as to separate the helium between the substrate and the electrostatic chuck The gas area is divided into two disconnected areas. The sealing tape is made of insulating material, such as silicone. In another embodiment, the upper surface of the outer ring sealing tape 421 is flush with the upper surface of the table portion of the electrostatic chuck 400 .

The upper surface of the table portion can be set into various shapes according to actual needs. Figures 5a and 5b show schematic views of two forms of protruding mesas from the upper surface of the electrostatic chuck. The upper surface of the mesa can be circular (Fig. 5a) or hexagonal (Fig. 5b). In one embodiment, the upper surface of the table portion 501 is in the shape of a dot, and its diameter is 0.5mm-3mm. The area of the upper surface of the table portion 501 accounts for 5%-30% of the upper surface area of the entire electrostatic chuck. In another embodiment, the upper surface of the table portion 502 is hexagonal, and the area of the upper surface accounts for 20%-80% of the upper surface area of the entire electrostatic chuck. The upper surface of the table portion is in direct contact with the substrate, and its contact area is a solid-solid heat transfer area, so the larger the area ratio of the upper surface, the better the heat transfer effect on the substrate. When the temperature of the edge region of the substrate needs to be lowered, a stage as shown in FIG. 5 b may be provided in the outer region 420 of the electrostatic chuck 400 , and a stage as shown in FIG. 5 a may be provided in the inner region 410 of the electrostatic chuck 400 . In other embodiments, the shape of the upper surface of the table portion is a rectangle, a triangle, an octagon, or the like. According to different process requirements, different area ratios of the upper surface can be set for the mesa in the inner and outer regions, so as to change the heat transfer coefficient of the substrate to the electrostatic chuck to control the temperature of the substrate.

The height of the table can be set according to actual needs. In one embodiment, the height of the mesa of the outer region 420 is lower than the height of the mesa of the inner region 410 . When the substrate is adsorbed on the electrostatic chuck, the backside of the substrate is in close contact with the table portion of the electrostatic chuck. When the substrate is processed, the heat is conducted from the substrate to the lower electrode element. When the height of the stage is larger, the heat transfer distance is larger, and the temperature drop is slower, so that the temperature drop in the inner area of the substrate is smaller than that in the outer area of the substrate. temperature drop.

The roughness of the upper surface of the table can also be set according to actual needs. In one embodiment, the roughness of the upper surface of the mesa of the outer region 420 is less than the roughness of the upper surface of the mesa of the inner region 410 . Because the heat conduction between the substrate and the electrostatic chuck depends on the surface roughness Ra, and the higher the surface roughness, the worse the heat transfer effect, the surface roughness of the inner and outer regions can be selected according to the desired different thermal conductivity of the inner and outer regions. For example, in order to reduce the temperature of the edge region of the substrate, the upper surface roughness of the outer region 420 of the electrostatic chuck is set to be less than 3 microinches, and the upper surface roughness of the inner region 410 of the electrostatic chuck is 4-8 microinches.

6 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to another embodiment. In this embodiment, the electrostatic chuck 600 includes three regions: a central region 610 , a middle region 620 and an outer region 630 . The outer area 630 includes an annular area and a protrusion 650 protruding toward the center O of the electrostatic chuck 600 . In this embodiment, the protrusions 650 are semicircular. In other embodiments, the protrusions may also be regular or irregular shapes such as triangles, trapezoids, and rectangles. The gas channel 625 is provided in the protrusion 650 . This causes the gas channels 425 in the outer region 630 to be further away from the edge of the electrostatic chuck 400, thereby allowing the bonding layer 103 to have a sufficient width to provide a sealing effect against gas leakage. In this way, the helium gas in the gas channel 625 does not leak from the bonding layer 103 to the edge of the electrostatic chuck 400 and into the cavity. In this embodiment, the distance from the gas channel 635 in the outer region 630 to the center O of the circle is greater than the distance from the gas channel 625 in the middle region 620 to the center O of the circle. In other embodiments, the distance from the gas channel 635 in the outer region 630 to the center O of the circle is less than or equal to the distance from the gas channel 625 in the middle region 620 to the center O of the circle. In other embodiments, gas channels are provided in the central region 610 .

In one embodiment, the upper surface of the electrostatic chuck 600 further includes a mesa structure protruding upward. The surface of electrostatic chuck 600 may have hundreds or thousands of mesas formed thereon. The upper surface of the table portion can be set into various shapes according to actual needs. The upper surface of the table portion may be circular or hexagonal, or may be other shapes such as rectangle, triangle, octagon, etc. In one embodiment, the upper surface of the platform portion of the intermediate region 620 is dot-shaped, and its diameter is 0.5mm-3mm. The area of the upper surface of the table portion accounts for 5%-30% of the upper surface area of the entire electrostatic chuck. The upper surfaces of the table portions of the outer region 630 and the central region 610 are hexagonal, and the area of the upper surface accounts for 20%-80% of the upper surface area of the entire electrostatic chuck. Such an arrangement can effectively improve the uniformity of the silicon wafer temperature as shown in FIG. 2 .

In one embodiment, the roughness of the upper surface of the mesa of the outer region 630 is less than the roughness of the upper surface of the mesa of the middle region 620 , and the roughness of the upper surface of the mesa of the center region 610 is less than that of the intermediate region 620 The roughness of the upper surface of the table portion.

The height of the table can be set according to actual needs. In one embodiment, the height of the mesa of the outer region 630 is lower than the height of the mesa of the middle area 620 , and the height of the mesa of the center area 610 is lower than the height of the mesa of the middle area 620 .

It should be noted that the sub-regions of the electrostatic chuck can not only be used to control the temperature uniformity of the substrate, but also can adjust the temperature of each region of the substrate according to the needs of a specific process by independently setting the characteristics of each region. For example, the temperature of the outer region of the substrate can be higher, equal to or lower than that of the middle region of the substrate, or the temperature of the central region of the substrate can be higher, equal to or lower than the middle region of the substrate according to process requirements.

Figure 7 shows a schematic diagram of the structure of a capacitively coupled plasma (CCP) etching equipment. The capacitively coupled plasma etching equipment is a kind of equipment that generates plasma in a reaction chamber and is used for etching by a radio frequency power supply applied to the plate through capacitive coupling. equipment. It includes a vacuum reaction chamber 700, the vacuum reaction chamber 700 includes a substantially cylindrical reaction chamber side wall 701 made of metal material, and an opening 702 is provided on the reaction chamber side wall for accommodating the substrate entering and exiting. The vacuum reaction chamber 700 is provided with a gas shower head 720 and a base 710 opposite to the gas shower head 720. The gas shower head 720 is connected to a gas supply device 725 for supplying the vacuum reaction chamber 700 transports the reaction gas and serves as the upper electrode of the vacuum reaction chamber 700 at the same time. An electrostatic chuck 712 is arranged above the base 710 and serves as the lower electrode of the vacuum reaction chamber 700 at the same time. A space is formed between the upper electrode and the lower electrode. reaction area. At least one radio frequency power supply 750 is applied to one of the upper electrode or the lower electrode through a matching network 752, and a radio frequency electric field is generated between the upper electrode and the lower electrode, so as to dissociate the reactive gas into plasma. It contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above active particles can undergo various physical and chemical reactions with the surface of the substrate to be treated, so that the morphology of the substrate surface changes, that is, Complete the etching process. An exhaust pump 740 is also disposed below the vacuum reaction chamber 700 for discharging reaction by-products from the vacuum reaction chamber 700 to maintain the vacuum environment of the vacuum reaction chamber 700 .

An electrostatic electrode 713 is disposed inside the electrostatic chuck 712 for generating electrostatic attraction, so as to realize the support and fixation of the substrate W to be processed during the manufacturing process. In one or more embodiments, the electrostatic chuck 712 is the electrostatic chuck 400 or the electrostatic chuck 600 in FIG. 4 or FIG. 6 .

A heating device 714 is arranged below the electrostatic chuck 712 for controlling the temperature of the substrate during the manufacturing process. A focus ring 732 and an edge ring 734 are arranged around the base. The focus ring 732 and the edge ring 734 are used to adjust the electric field or temperature distribution around the substrate W to improve the uniformity of the substrate W processing. A plasma confinement ring 735 is arranged around the edge ring 734, and an exhaust channel is provided on the plasma confinement ring 735. By reasonably setting the depth-to-width ratio of the exhaust channel, the reaction gas can be discharged while the plasma is confined. The reaction area between the upper and lower electrodes prevents the plasma from leaking to the non-reaction area, causing damage to components in the non-reaction area. A middle grounding ring 736 is arranged below the plasma confinement ring 735, and the middle grounding ring 736 is used to provide an electric field shield for the plasma confinement ring 735; a lower grounding ring 737, a middle grounding ring 736 and a lower grounding ring 737 are arranged below the middle grounding ring 736 Electrical connections are maintained to form an RF ground return within the vacuum chamber 700 . A shielding ring 738 is disposed between the lower grounding ring 737 and the base for shielding the radio frequency signal applied to the base in the base to achieve electrical isolation between the base and the lower grounding ring 737 .

In other embodiments, other types of plasma etching apparatuses may also be used, such as inductively coupled plasma etching apparatuses, electron cyclotron resonance type plasma etching apparatuses, and the like.

Although the present invention has been disclosed above with preferred embodiments, the above-described embodiments are merely examples for the convenience of description and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains do not depart from the spirit and Several changes and modifications can be made under the premise of the scope of the invention, and the protection scope claimed by the present invention shall be subject to the description in the scope of the patent application.

100: Lower electrode element 101, 300, 400, 600, 712: Electrostatic chuck 102, 710: Pedestal 103: Bonding Layer 104: Second gas channel 105: Pipes 106: First gas channel 200, W: substrate 250, 750: RF Power 310, 410: Inner area 311, 411: sealing tape 320, 420: Outer area 321, 421: Outer ring sealing tape 315, 325, 415, 425, 635: Gas channels 450, 650: Protrusions 501, 502: Taiwan Department 610: Central Area 620: Middle area 630: Outside area 700: Vacuum reaction chamber 701: Sidewall of the reaction chamber 702: Opening 713: Electrostatic electrode 714: Heating device 720: Gas Sprinkler 725: Gas Supply Unit 732: Focus Ring 734: Edge Ring 735: Plasma Confinement Ring 736: Middle ground ring 737: Lower Ground Ring 738: Mask Ring 752: match network 740: Exhaust pump O: center of circle

FIG. 1 shows a schematic diagram of a lower electrode element for a plasma processing apparatus according to one embodiment of the present invention. FIG. 2 illustrates a temperature profile of a silicon wafer during semiconductor processing, according to one embodiment. 3 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to one embodiment. 4 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to another embodiment. Figures 5a-5b show schematic diagrams of protruding mesas on the upper surface of the electrostatic chuck. 6 shows a top view of an exemplary pattern of an upper surface of an electrostatic chuck according to another embodiment. FIG. 7 shows a schematic structural diagram of a capacitively coupled plasma (CCP) etching apparatus according to one embodiment.

400: Electrostatic chuck

410: Inner Zone

411: sealing tape

420: Outer Zone

421: Outer ring sealing belt

415, 425: Gas channel

450: Protrusion

O: center of circle

Claims (18)

An electrostatic chuck for a plasma processing device, the electrostatic chuck comprising: a plurality of regions, a first region of the plurality of regions including a protrusion protruding toward the center of the electrostatic chuck; and A first vent hole is provided in the protrusion. The electrostatic chuck according to claim 1, wherein the electrostatic chuck further comprises a sealing tape, and the sealing tape divides the electrostatic chuck into a plurality of regions. The electrostatic chuck according to claim 2, wherein the electrostatic chuck further comprises an outer ring sealing tape disposed on the outer periphery of the electrostatic chuck. The electrostatic chuck according to claim 2, wherein the sealing tape divides the electrostatic chuck into two regions: an outer region and an inner region, the outer region including an outer annular portion of the electrostatic chuck and a portion of the electrostatic chuck facing the electrostatic chuck. The protruding part protruding from the center, the inner area is the area of the electrostatic chuck except the outer area; the first ventilation hole is arranged in the protrusion, the electrostatic chuck also includes a second ventilation hole, the second ventilation hole A vent hole is provided in the inner region of the electrostatic chuck. The electrostatic chuck according to claim 4, wherein the gas pressure in the first vent hole is higher than the gas pressure in the second vent hole. The electrostatic chuck according to claim 4, wherein the area of the outer region is smaller than that of the inner region. The electrostatic chuck according to claim 4, wherein the upper surface of the electrostatic chuck has a table portion protruding upward, and the ratio of the upper surface area of the table portion in the outer region to the area of the entire outer region is larger than that of the table portion in the inner region The ratio of the upper surface area of the portion to the area of the entire inner area. The electrostatic chuck according to claim 7, wherein the sealing tape is flush with the upper surface of the table portion of the electrostatic chuck. The electrostatic chuck according to claim 7, wherein the roughness of the upper surface of the table portion in the outer region is smaller than the roughness of the upper surface of the table portion in the inner region. The electrostatic chuck according to claim 7, wherein the shape of the upper surface of the table portion is any one of the following: a circle, a hexagon, a rectangle, and a triangle. The electrostatic chuck according to claim 7, wherein the upper surface of the stage portion of the outer region is hexagonal and the upper surface of the stage portion of the inner region is circular. The electrostatic chuck according to claim 7, wherein the height of the platform portion of the outer region is lower than the height of the platform portion of the inner region. The electrostatic chuck according to claim 2, wherein the sealing tape divides the electrostatic chuck into three regions: an outer region, a middle region and a central region, wherein the outer region includes an outer annular portion of the electrostatic chuck and the protrusion protruding toward the center of the electrostatic chuck, the first vent hole is arranged in the protrusion; the electrostatic chuck further includes a third ventilation hole, the third ventilation hole is arranged in the middle area of the electrostatic chuck middle. The electrostatic chuck according to claim 13, wherein the upper surface of the electrostatic chuck has a platform portion protruding upward, and the ratio of the upper surface area of the platform portion in the outer region to the area of the entire outer region is larger than that of the platform in the middle region The ratio of the upper surface area of the central area to the area of the entire central area, and the ratio of the upper surface area of the central area to the area of the entire central area is greater than the ratio of the upper surface area of the central area to the entire central area. The ratio of the area's area. The electrostatic chuck according to claim 14, wherein the roughness of the upper surface of the table portion of the outer region is smaller than the roughness of the upper surface of the table portion of the intermediate region, and the roughness of the upper surface of the table portion of the central region The degree is smaller than the roughness of the upper surface of the mesa of the intermediate region. The electrostatic chuck according to claim 14, wherein the height of the platform of the outer region is lower than the height of the platform of the middle region, and the height of the platform of the center region is lower than the height of the platform of the middle region . A lower electrode element for a plasma processing device, comprising: An electrostatic chuck according to any one of claims 1-16, for carrying a substrate placed thereon; a base disposed below the electrostatic chuck; and A bonding layer is disposed between the electrostatic chuck and the base to bond the electrostatic chuck and the base. A plasma processing device, comprising: a reaction chamber; A lower electrode element according to claim 17, the lower electrode element is arranged in the reaction chamber, and the substrate to be processed is carried on the lower electrode element; and A gas supply device supplies reactive gas to the reaction chamber to generate plasma-treated substrates.

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