Electrode and method for realizing low-temperature and high-temperature plasma etching processes simultaneously

Abstract

The application belongs to the technical field of plasma etching, and particularly relates to an electrode for simultaneously realizing low-temperature and high-temperature plasma etching processes and a regulation method. The electrode comprises an electrode body, which comprises a heating table, a heat-conducting plate and a water-cooling plate arranged in sequence from top to bottom. The upper surface of the water-cooling plate is provided with a heat-conducting plate embedding groove at a middle position. There is a gap h between the groove bottom of the heat-conducting plate embedding groove and the lower surface of the heating table. The heat-conducting plate is embedded in the heat-conducting plate embedding groove, and the thickness of the heat-conducting plate is h1, h1 < h. The outer side area of the heating table and the outer side area of the water-cooling plate are connected into an integrated whole through flange fitting connection. The regulation method comprises regulation under two working conditions of high temperature and low temperature. The electrode is used for carrying a wafer, and the regulation method is used for providing a suitable temperature required by an etching process for the wafer.

Description

Technical Field

[0001] This invention belongs to the field of plasma etching technology, specifically relating to an electrode and control method for simultaneously realizing low-temperature and high-temperature plasma etching processes. Background Technology

[0002] As the structure that supports the wafer during the process, the electrode assembly is the most important factor affecting the uniformity of wafer etching. Among these factors, the temperature of the electrode assembly accounts for a large proportion, and the temperature of the electrode assembly directly affects the surface temperature of the wafer to be etched.

[0003] Different process types require different wafer surface temperatures. In these cases, the wafer temperature can only be regulated by the temperature of the electrode assembly. For some special processes, such as InP etching, very high wafer temperatures are required, sometimes exceeding 400 degrees Celsius. However, existing electrode solutions typically use ordinary rubber rings to directly seal between electrode assemblies and process chambers. But at temperatures above 400 degrees Celsius, ordinary rubber rings become ineffective, leading to air leakage and malfunction. Furthermore, in current technologies, the electrodes are integrated, requiring either high-temperature or low-temperature processes, meaning it's impossible to choose the appropriate low-temperature or / and high-temperature process based on the specific conditions. Therefore, a special electrode assembly needs to be designed to meet the process requirements. Summary of the Invention

[0004] This invention provides an electrode and control method for simultaneously realizing low-temperature and high-temperature plasma etching processes. By adjusting the thickness h1 of the heat-conducting plate, the gap h-h1 between the heat-conducting plate and the heating stage is adjusted, thereby regulating the heat transfer effect between the low temperature of the water-cooled plate and the high temperature of the heating stage, thus providing the appropriate temperature for the etching process of the wafer.

[0005] The technical solution adopted by this invention to solve its technical problem is: an electrode that simultaneously realizes low-temperature and high-temperature plasma etching processes, comprising an electrode body, wherein the electrode body includes a heating stage, a heat-conducting plate, and a water-cooling plate arranged sequentially from top to bottom, wherein:

[0006] The upper surface of the water-cooled plate has a heat-conducting plate groove at the middle position, and there is a gap h between the bottom of the heat-conducting plate groove and the lower surface of the heating platform.

[0007] The heat-conducting plate is embedded in the heat-conducting plate groove, and the thickness of the heat-conducting plate is h1. <h;

[0008] The outer area of ​​the heating platform and the outer area of ​​the water-cooled plate are connected as one unit by a flange connection.

[0009] As a further preferred embodiment of the present application, the electrode body is provided with a central hole passing through the center position, and a first through hole, a second through hole and a third through hole are respectively arranged around the central hole;

[0010] The first through hole, the second through hole and the third through hole are arranged in sequence through the water-cooling plate and the heat-conducting plate, and are communicated with the blind holes arranged at the corresponding positions of the lower structure of the heating table.

[0011] As a further preferred embodiment of the present application, the heating table comprises an upper layer plate and a lower layer plate which can be connected as a whole; the upper layer plate is arranged above the lower layer plate, and the lower layer plate is internally provided with heating wires; the lower layer plate is the lower structure of the heating table; and the blind holes are arranged at the bottom of the lower layer plate.

[0012] As a further preferred embodiment of the present application, the heating table further comprises a cylindrical shaft assembly arranged on the blind holes of the lower layer plate, wherein the cylindrical shaft assembly comprises a first cylindrical shaft, a second cylindrical shaft and a third cylindrical shaft.

[0013] The first cylindrical shaft is connected with one of the blind holes of the lower layer plate through the first through hole, and the first cylindrical shaft is internally provided with a temperature measuring optical fiber;

[0014] The second cylindrical shaft is connected with one of the blind holes of the lower layer plate through the second through hole, and the second cylindrical shaft is internally provided with a helium gas hole for passing helium gas;

[0015] The third cylindrical shaft is connected with one of the blind holes of the lower layer plate through the third through hole, and the third cylindrical shaft is internally provided with a heating wire outlet.

[0016] A control method for simultaneously realizing low-temperature and high-temperature plasma etching processes is also provided, which comprises control in two working conditions, one of which is high-temperature working condition and the other of which is low-temperature working condition.

[0017] In the high-temperature working condition, the control method comprises the following steps:

[0018] Step S1, sealing the first cylindrical shaft, the second cylindrical shaft and the third cylindrical shaft;

[0019] Step S2, setting the temperature required to be reached by the heating table and the temperature of the cooling liquid input into the electrode body;

[0020] Step S3, inputting helium gas into the helium gas hole in the second cylindrical shaft to achieve sufficient contact between the helium gas and the bottom of the wafer on the upper layer plate, while the heating wires in the third cylindrical shaft are heated, and the heating table starts to heat up;

[0021] Step S4, cooling the water-cooled plate by introducing cooling liquid into the electrode body, the temperature of the water-cooled plate being transmitted to the heating table through the heat-conducting plate;

[0022] Step S5, the temperature-measuring optical fiber in the first cylindrical shaft feeding back the temperature of the heating table to the computer in real time;

[0023] Step S6, according to the temperature fed back in step S5, making the following determination:

[0024] When the temperature of the heating table reaches the expected temperature, starting the high-temperature etching process, the heating wire stops heating, and the introduction of cooling liquid is stopped;

[0025] When the temperature of the heating table does not reach the expected temperature, there are two adjustment methods, one is to continue to heat by the heating wire, and the other is to raise the temperature of the cooling liquid, so that the temperature of the heating table reaches the expected temperature;

[0026] Then repeat steps S5 and S6.

[0027] In low-temperature working condition, the regulation method specifically regulates the following steps:

[0028] Step S1, sealing the outside of the first cylindrical shaft, the second cylindrical shaft and the third cylindrical shaft;

[0029] Step S2, setting the temperature required to be reached by the heating table and the temperature of the cooling liquid input into the electrode body;

[0030] Step S3, introducing helium into the helium hole in the second cylindrical shaft to achieve sufficient contact between the helium and the bottom of the wafer on the upper plate, and the heating wire in the third cylindrical shaft starts heating or does not work;

[0031] Step S4, cooling the water-cooled plate by introducing cooling liquid into the electrode body, the temperature of the water-cooled plate being transmitted to the heating table through the heat-conducting plate;

[0032] Step S5, the temperature-measuring optical fiber in the first cylindrical shaft feeding back the temperature of the heating table to the computer in real time;

[0033] Step S6, according to the temperature fed back in step S5, making the following determination:

[0034] When the temperature of the heating table reaches the expected temperature, starting the low-temperature etching process, the heating wire does not work, and the introduction of cooling liquid is stopped;

[0035] When the temperature of the heating table does not reach the expected temperature, the temperature of the cooling liquid is lowered;

[0036] Then repeat steps S5 and S6.

[0037] As a further preferred embodiment of the present application, the first cylindrical shaft comprises a first thin cylindrical shaft portion for accommodating the temperature measuring optical fiber, and a first distal disc portion at one end of the first thin cylindrical shaft portion away from the lower layer plate for sealing;

[0038] The second cylindrical shaft comprises a second thin cylindrical shaft portion for passing helium, and a second distal disc portion at one end of the second thin cylindrical shaft portion away from the lower layer plate for sealing;

[0039] The third cylindrical shaft comprises a third thin cylindrical shaft portion for accommodating the heating wire, and a third distal disc portion at one end of the third thin cylindrical shaft portion away from the lower layer plate for sealing.

[0040] As a further preferred embodiment of the present application, in the high-temperature working condition step S1 and the low-temperature working condition step S1, the first cylindrical shaft, the second cylindrical shaft and the third cylindrical shaft are respectively sealed by the first welded bellows, the second welded bellows and the third welded bellows with consistent structures, wherein:

[0041] The first welded bellows is sleeved outside the first cylindrical shaft, the top of the first welded bellows is sealed to the bottom of the water-cooled plate, and the bottom of the first welded bellows is sealed to the bottom of the first distal disc portion;

[0042] The second welded bellows is sleeved outside the second cylindrical shaft, the top of the second welded bellows is sealed and connected to the bottom of the water-cooled plate, and the bottom of the second welded bellows is sealed to the bottom of the second distal disc portion;

[0043] The third welded bellows is sleeved outside the third cylindrical shaft, the top of the third welded bellows is sealed and connected to the bottom of the water-cooled plate, and the bottom of the third welded bellows is sealed to the bottom of the third distal disc portion.

[0044] As a further preferred embodiment of the present application, in the high-temperature working condition step S3 and the low-temperature working condition step S3, the helium is introduced into the lower layer plate through the shunt groove and the plurality of uniform gas grooves arranged on the lower layer plate, wherein:

[0045] The shunt groove and the plurality of uniform gas grooves are both arranged on the top surface of the lower layer plate, and the shunt groove is in communication with the plurality of uniform gas grooves;

[0046] The shunt groove is in communication with the helium gas hole and divides the helium into the plurality of uniform gas grooves.

[0047] As a further preferred embodiment of the present application, in the high-temperature working condition step S3 and the low-temperature working condition step S3, helium is introduced into the upper plate and fully contacts the bottom surface of the wafer through the helium groove and the plurality of gas inlets arranged on the upper plate, wherein:

[0048] The helium groove is arranged on the top surface of the upper plate, and the plurality of gas inlets penetrate the upper plate and are distributed in the helium groove;

[0049] The plurality of gas inlets are in communication with the plurality of gas distribution grooves.

[0050] As a further preferred embodiment of the present application, in the high-temperature working condition step S4 and the low-temperature working condition step S4, the water-cooled plate is cooled by introducing a cooling liquid into the liquid channel provided on the water-cooled plate, wherein:

[0051] The liquid channel is formed by a water-stopping plate and a water passage groove, and the water passage groove is arranged on the bottom of the water-cooled plate, and the water-stopping plate is arranged on the water passage groove.

[0052] Through the above technical solutions, compared with the prior art, the present application has the following beneficial effects:

[0053] 1. The electrode adjusts the thickness h1 of the heat-conducting plate to adjust the gap h-h1 between the heat-conducting plate and the heating table, thereby adjusting the heat transfer effect between the low temperature of the water-cooled plate and the high temperature of the heating table.

[0054] 2. When the temperature of the heating table of the electrode reaches about 400 DEG C, the existence of the thin shaft part of the cylindrical shaft assembly can cause a substantial temperature drop in the region of the heating table, and when the temperature is transmitted to the distal disc part, a relatively low temperature can be obtained, which is beneficial to the use of the sealing rings installed in the first sealing groove and the second sealing groove.

[0055] 3. When the temperature of the heating table of the electrode is high, the second cylindrical shaft not only has thermal expansion in the radial direction, but also has thermal expansion in the axial direction. In order to prevent the leakage phenomenon caused by the change of the position of the sealing surface of the first sealing groove and the second sealing groove due to the axial thermal expansion, a second welded bellows is used to realize the sealing between the water-cooled plate and the bottom of the second cylindrical shaft; the second welded bellows can satisfy the expansion and contraction problem caused by the axial thermal expansion of the second cylindrical shaft, and when the second cylindrical shaft is elongated or contracted, the bottom flange of the second welded bellows can change, without affecting the sealing effect.

[0056] 4. The electrode device realizes low temperature and local cooling by introducing a cooling liquid:

[0057] In the low-temperature working condition, a cooling liquid with a suitable temperature is introduced to realize low temperature;

[0058] In the high-temperature working condition, the cooling liquid in the water channel can cool the sealing ring in the third sealing groove to prevent the sealing ring from losing the sealing function due to the high temperature; meanwhile, the cooling liquid in each cooling groove can cool the sealing rings in each first sealing groove and second sealing groove.

[0059] 5、The control method of the application adjusts the temperature of the heating table through the temperature controller and controls the temperature of the water-cooled plate through the water chiller to realize the high-temperature plasma etching process and the low-temperature plasma etching process; and in the high-temperature working condition, the temperature of the water-cooled plate is controlled through the water chiller to prevent the sealing rings in each sealing groove from directly contacting the high temperature. BRIEF DESCRIPTION OF DRAWINGS

[0060] The application will be further described below in combination with the drawings and examples.

[0061] Figure 1 is an overall structure explosion schematic diagram of the application;

[0062] Figure 2 is a heating table structure explosion diagram a of the application;

[0063] Figure 3 is a heating table structure explosion diagram b of the application;

[0064] Figure 4 is a water-cooled plate structure explosion diagram a of the application;

[0065] Figure 5 is a water-cooled plate structure explosion diagram b of the application;

[0066] Figure 6 is a cross-sectional schematic diagram of the application;

[0067] Figure 7 is a water-cooled plate bottom structure schematic diagram of the application;

[0068] Figure 8 is a temperature control flow diagram of the electrode in the high-temperature process of the application;

[0069] Figure 9 is a temperature control flow diagram of the electrode in the low-temperature process of the application;

[0070] Figure 10 is a connection schematic diagram between the equipment end and the auxiliary device of the application.

[0071] In the figure: 2, electrode; 201, joint; 203, water inlet; 204, air inlet; 205, water outlet; 50, heating platform; 501, upper layer plate; 502, lower layer plate; 503, helium groove; 504, air uniformizing groove; 505, first cylinder shaft; 506, second cylinder shaft; 507, third cylinder shaft; 508, second groove; 509, first groove; 510, air inlet hole; 511, shunt groove; 516, helium hole; 526, second thin shaft part; 536, second distal disc part; 546, first sealing groove; 556, second sealing groove; 60, water cooling plate; 601, center hole; 602, water passage groove; 603, water blocking plate; 604, water distribution joint; 606, first through hole; 607, second through hole; 608, third through hole; 609, third sealing groove; 70, heat conduction plate; 80, second welded corrugated pipe; 801, second cooling groove; 90, first welded corrugated pipe; 100, third welded corrugated pipe. DETAILED DESCRIPTION

[0072] The present application will now be described in further detail with reference to the drawings. These drawings are simplified schematic diagrams which only show the basic structure of the present application in a schematic manner, and thus only show the components relevant to the present application.

[0073] In the description of the present application, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and "first", "second" and the like do not represent the importance of the parts, and therefore cannot be understood as limiting the present application. The specific dimensions used in this embodiment are only for the purpose of illustrating the technical solutions and do not limit the protection scope of the present application.

[0074] Example 1

[0075] This embodiment provides a preferred embodiment of an electrode for simultaneously implementing low-temperature and high-temperature plasma etching processes, as shown in Figure 1 and Figure 10 The electrode 2 is located at the center of the process chamber, used to carry the wafer and provide the wafer with the appropriate temperature required for the etching process.

[0076] As shown in Figure 1 The above-mentioned electrode 2 is mainly divided into three parts, namely the heating platform 50, the water cooling plate 60 and the heat conduction plate 70, and the heating platform 50, the heat conduction plate 70 and the water cooling plate 60 are arranged in sequence from top to bottom.

[0077] The electrode 2 further comprises an electrode body, which is penetrated along a center position, and a center hole 601 is arranged for mounting a needle lifting mechanism; a first through hole 606, a second through hole 607 and a third through hole 608 are arranged at the periphery of the center hole 601, and the first through hole 606, the second through hole 607 and the third through hole 608 are sequentially penetrated through the water-cooled plate 60 and the heat-conducting plate 70 and communicated with the blind hole arranged at the corresponding position of the lower structure of the heating table 50.

[0078] As shown in Figure 2 , the heating table 50 comprises an upper plate 501 and a lower plate 502 which can be connected as a whole, the upper plate 501 is arranged above the lower plate 502, and a heating wire is arranged in the lower plate 502. The lower plate 502 is the lower structure of the heating table 50, and the blind hole is arranged at the bottom of the lower plate 502.

[0079] As shown in Figure 2 and Figure 3 , the upper plate 501 is a thin plate, a first groove 509 is formed on the upper surface of the upper plate 501 to the lower surface, and the first groove 509 is used to limit the position of the wafer. A helium groove 503 is arranged at the bottom of the first groove 509, and the helium groove 503 preferably comprises a plurality of circular ring grooves with the center of the bottom of the first groove 509 as the center and a plurality of straight grooves diverging from the center of the bottom of the first groove 509 to the periphery. A plurality of gas inlets 510 are arranged on the lower surface of the upper plate 501 corresponding to the positions of the helium groove 503, so that the helium gas enters the helium groove 503 through the gas inlets 510, and then spreads in the helium groove 503, so that the helium gas can be uniformly distributed on the back of the wafer. The temperature of the heating table 50 is transmitted to the back of the wafer by the helium gas, and the temperature of the wafer surface can be controlled by controlling the temperature of the heating table 50.

[0080] As shown in Figure 2 and Figure 3 , the lower plate 502 is a disc, and a flow distribution groove 511 and a plurality of uniform gas grooves 504 are arranged on the joint surface of the lower plate 502 and the upper plate 501, and the helium gas entering from the bottom of the lower plate 502 is distributed to each of the uniform gas grooves 504 through the flow distribution groove 511. Preferably, the uniform gas grooves 504 are composed of at least two circular ring grooves with different diameters and the center of the upper surface of the lower plate 502 as the center, and the positions of the plurality of circular ring grooves on the uniform gas grooves 504 correspond to the positions of the circular ring grooves on the helium groove 503.

[0081] The helium gas from the bottom of the lower plate 502 first passes through the shunt groove 511, and then is shunted by the shunt groove 511 to the uniform gas groove 504 for dispersion, and then spreads to the helium gas groove 503 through the gas inlet hole 510, so that the helium gas is uniformly distributed on the back of the wafer to a large extent, thereby better cooling and heating. The lower plate 502 is internally provided with a heating wire for heating the entire heating table 50 when a high-temperature process is performed. The bottom surface of the lower plate 502 has a second groove 508 with a depth ranging from 3 to 5 mm.

[0082] The cylindrical shaft assembly is installed at the blind hole on the lower plate 502, which includes a first cylindrical shaft 505, a second cylindrical shaft 506, and a third cylindrical shaft 507. The first cylindrical shaft 505 is connected to the blind hole on the lower plate 502 through the first through hole 606, and a temperature measuring optical fiber is installed inside the first cylindrical shaft 505 to detect the temperature of the heating table 50 and achieve precise temperature control. The second cylindrical shaft 506 is connected to the blind hole on the lower plate 502 through the second through hole 607, and a helium gas hole 516 is provided inside the second cylindrical shaft 506 for helium gas to pass through. The helium gas hole 516 is coaxially installed with the shunt groove 511, and the shunt groove 511 is in communication with the helium gas hole 516. The helium gas hole 516 is connected to the gas inlet interface 204, so that the helium gas enters the helium gas hole 516 through the gas inlet interface 204, and then enters the shunt groove 511 through the helium gas hole 516. The helium gas is then dispersed in the uniform gas groove 504, and then enters the helium gas groove 503 through the gas inlet hole 510, and is uniformly distributed in the helium gas groove 503. The third cylindrical shaft 507 is connected to the blind hole on the lower plate 502 through the third through hole 608, and a heating wire is provided inside the third cylindrical shaft 507.

[0083] Further, each cylindrical shaft of the cylindrical shaft assembly has a thin cylindrical feature and a distal disc feature. That is, the first cylindrical shaft 505 includes a first thin shaft portion in the form of a thin cylinder and a first distal disc portion in the form of a disc provided at the end of the first thin shaft portion away from the lower plate 502. The second cylindrical shaft 506 includes a second thin shaft portion 526 in the form of a thin cylinder and a second distal disc portion 536 in the form of a disc provided at the end of the second thin shaft portion 526 away from the lower plate 502. The third cylindrical shaft 507 includes a third thin shaft portion in the form of a thin cylinder and a third distal disc portion in the form of a disc provided at the end of the third thin shaft portion away from the lower plate 502.

[0084] Further, the water cooling plate 60 comprises a water channel 602 and a water blocking plate 603. The water channel 602 is arranged on the bottom of the water cooling plate 60, and preferably, the water channel 602 is arranged on the bottom surface of the water cooling plate 60, and occupies the bottom surface of the water cooling plate 60 as much as possible while avoiding the first through hole 606, the second through hole 607, the third through hole 608 and the center hole 601. The water blocking plate 603 has the same shape as the water channel 602, and is arranged on the water channel 602. The water inlet 203 and the water outlet 205 are arranged on the side of the water blocking plate 603 away from the water channel 602, so that a liquid channel for the cooling liquid is formed between the water blocking plate 603 and the water channel 602. Preferably, the water blocking plate 603 is connected to the water channel 602 by welding, and cooperates with the water inlet 203 and the water outlet 205, so that the cooling liquid can circulate in the liquid channel, and cool the water blocking plate 603 and the components arranged on the water blocking plate 603. A plurality of water distribution joints 604 are arranged on the side of the water blocking plate 603 away from the water channel 602.

[0085] The first welded bellows 90, the second welded bellows 80 and the third welded bellows 100 have the same structure. The first welded bellows 90 is sleeved on the outside of the first cylindrical shaft 505, and the top of the first welded bellows 90 is sealingly connected to the bottom of the water cooling plate 60, and the bottom of the first welded bellows 90 is sealingly connected to the first distal disc part. The second welded bellows 80 is sleeved on the outside of the second cylindrical shaft 506, and the top of the second welded bellows 80 is sealingly connected to the bottom of the water cooling plate 60, and the bottom of the second welded bellows 80 is sealingly connected to the second distal disc part 536. The third welded bellows 100 is sleeved on the outside of the third cylindrical shaft 507, and the top of the third welded bellows 100 is sealingly connected to the bottom of the water cooling plate 60, and the bottom of the third welded bellows 100 is sealingly connected to the third distal disc part.

[0086] As Figure 6As shown, further, a first sealing groove 546 and a second sealing groove 556 are provided between the bottom of the second welded bellows 80 and the second distal disc portion 536, and a sealing ring is installed in both the first sealing groove 546 and the second sealing groove 556. When the temperature of the heating platform 50 reaches approximately 400°C, the presence of the second thin shaft portion 526 of the second cylindrical shaft 506 allows for a significant temperature drop in this region. The temperature is then transferred to the second distal disc portion 536, resulting in a relatively lower temperature. In other words, the temperature is buffered during the transfer through the second thin shaft portion 526 of the second cylindrical shaft 506, allowing for a certain degree of temperature reduction. This prevents the sealing rings in the first sealing groove 546 and the second sealing groove 556 from directly contacting the high temperature, thus ensuring the effectiveness of the sealing rings. This ensures that even when the temperature of the heating platform 50 reaches approximately 400°C, the sealing rings in the first sealing groove 546 and the second sealing groove 556 can still prevent air leakage.

[0087] Furthermore, because the heating platform 50 is at a high temperature, the second cylindrical shaft 506, in addition to radial thermal expansion, will also experience axial thermal expansion. Figure 6 In the vertical direction, thermal expansion occurs. To prevent air leakage caused by changes in the position of the sealing surfaces of the first sealing groove 546 and the second sealing groove 556 due to axial thermal expansion, the bottom seal of the water-cooled plate 60 and the second cylindrical shaft 506 is achieved by the second welded bellows 80. A third sealing groove 609 is provided at the bottom of the water-cooled plate 60 and coaxial with the second welded bellows 80. A sealing ring is pressed between the top of the second welded bellows 80 and the water-cooled plate 60 and installed in the third sealing groove 609. The bottom of the second welded bellows 80 is pressed against the sealing ring installed in the first sealing groove 546 and the second sealing groove 556.

[0088] Preferably, the first welded corrugated pipe 90, the second welded corrugated pipe 80 and the third welded corrugated pipe 100 are all finished products, and all are of the structure of setting a soft and compressible elongated metal corrugated pipe between the upper flange and the bottom flange. This feature can meet the expansion problem caused by the axial thermal expansion of the second cylindrical shaft 506. When the second cylindrical shaft 506 is elongated or contracted, the bottom flange of the second welded corrugated pipe 80 can change accordingly, without affecting the sealing effect. Similarly, the expansion problem caused by the axial thermal expansion of the first cylindrical shaft 505 can be met. When the first cylindrical shaft 505 is elongated or contracted, the bottom flange of the first welded corrugated pipe 90 can change accordingly, without affecting the sealing effect of the bottom flange of the first welded corrugated pipe 90; the expansion problem caused by the axial thermal expansion of the third cylindrical shaft 507 can be met. When the third cylindrical shaft 507 is elongated or contracted, the bottom flange of the third welded corrugated pipe 100 can change accordingly, without affecting the sealing effect of the bottom flange of the third welded corrugated pipe 100.

[0089] Further, in order to ensure that the sealing ring installed in the first sealing groove 546 and the second sealing groove 556 can be cooled sufficiently, and improve the safety in use, the second cooling groove 801 is arranged inside the bottom flange of the second welded corrugated pipe 80. Preferably, the second cooling groove 801 can be in communication with the water channel 602 inside the water-cooled plate 60. The joint 201 installed on the bottom flange of the second welded corrugated pipe 80 is connected with a water distribution joint 604 welded on the water stop plate 603 through a water pipe, so as to realize the communication between the second cooling groove 801 and the water channel 602. As shown in Figure 7 the drawing, when the cooling liquid circulates inside the water channel 602 to cool the liquid-cooled plate 60, the bottom flange of the second welded corrugated pipe 80 can also be cooled synchronously. The bottom flange of the second welded corrugated pipe 80 transmits the low temperature to the second distal disc part 536, and cools the sealing ring installed on the second distal disc part 536.

[0090] Further, the working and cooling modes of the first cylindrical shaft 505 and the third cylindrical shaft 507 are the same as those of the second cylindrical shaft 506. That is, the first cooling groove is arranged inside the bottom flange of the first welded corrugated pipe 90. The joint 201 installed on the bottom flange of the first welded corrugated pipe 90 is connected with a water distribution joint 604 welded on the water stop plate 603 through a water pipe, so as to realize the communication between the first cooling groove and the water channel 602, and thus cooling. The third cooling groove is arranged inside the bottom flange of the third welded corrugated pipe 100. The joint 201 installed on the bottom flange of the third welded corrugated pipe 100 is connected with a water distribution joint 604 welded on the water stop plate 603 through a water pipe, so as to realize the communication between the third cooling groove and the water channel 602.

[0091] The above-mentioned electrode 2 can be used for both low-temperature plasma etching and high-temperature plasma etching. When performing high-temperature plasma etching, the heating wire inside the heating table 50 works to heat the above-mentioned electrode 2 to the set temperature. At this time, a coolant at a certain temperature is passed through the liquid channel to cool all the sealing rings to ensure the normal vacuum degree of the etching equipment. When performing the low-temperature plasma etching process, the heating wire inside the heating table 50 works at a low temperature or does not work. However, due to the existence of the plasma above the electrode 2, the heating table 50 continuously heats up and it is impossible to achieve precise temperature control. At this time, the low temperature of the water-cooling plate 60 needs to be transferred to the heating table 50, and the function of the heat conduction plate 70 is to adjust the temperature transfer effect between the heating table 50 and the water-cooling plate 60.

[0092] The thickness of the above-mentioned heat conduction plate 70 is h1, and h1 < h. The heat conduction plate 70 is tightened on the water-cooling plate 60, and there is a gap h - h1 between the upper part of the heat conduction plate 70 and the heating table 50. In the actual application process, by adjusting the thickness h1 of the heat conduction plate 70, the gap h - h1 between the heat conduction plate 70 and the heating table 50 is adjusted, so as to adjust the heat transfer effect between the low temperature of the water-cooling plate 60 and the high temperature of the heating table 50. If it is found during the etching process that a large amount of the low temperature of the water-cooling plate 60 is transferred to the heating table 50 by the heat conduction plate 70 during the high-temperature process, affecting the temperature uniformity of the heating table 50, the heat conduction plate 70 with a thinner thickness can be replaced; while in the low-temperature process, if it is found that the temperature of the heating table 50 is too high, the heat conduction plate 70 with a larger thickness can be replaced to improve the cooling efficiency.

[0093] As Figure 10 shown, it is a schematic connection diagram between the equipment end and the auxiliary device. This implementation scheme further includes a computer, a temperature controller, and a chiller. There is a two-way transmission between the computer and the temperature controller, and a two-way transmission between the computer and the chiller; the temperature controller is also connected to the heating wire inside the third cylinder shaft 507, and the temperature measurement optical fiber inside the first cylinder shaft 505 transmits the signal to the temperature controller; the chiller is respectively connected to the water inlet 203 and the water outlet 205 provided on the water blocking plate 603.

[0094] Figure 8 and Figure 9The temperature control flow chart of the electrode when high-temperature process and low-temperature process are carried out respectively. When high-temperature and low-temperature processes are carried out respectively, the actual temperature of the surface of the heating table 50 is fed back through the temperature measuring optical fiber installed at the bottom of the electrode 2, the signal is fed back to the computer end, the input power of the heating table 50 and the temperature of the cooling liquid output by the water chiller are set through the computer end control temperature controller, so as to achieve the ideal process temperature. The etching process of the present scheme can meet-30℃~400℃, and according to the actual process, the best process temperature range of the machine table is about 0℃~260℃.

[0095] As shown in Figure 8 The temperature control specific process of the electrode 2 when high-temperature process is carried out is as follows (high temperature is above 180 degrees Celsius):

[0096] Step S1, the first welded corrugated pipe 90, the second welded corrugated pipe 80 and the third welded corrugated pipe 100 are sealed respectively to the first cylindrical shaft 505, the second cylindrical shaft 506 and the third cylindrical shaft 507;

[0097] Step S2, set the temperature required to be reached by the heating table 50 and the cooling liquid temperature input into the electrode body;

[0098] Step S3, helium is introduced into the helium hole 516 in the second cylindrical shaft 506 to achieve sufficient contact between the helium and the bottom of the wafer on the upper plate 501, and the temperature controller controls the heating of the heating wire in the third cylindrical shaft 507, and the heating table 50 starts to heat up;

[0099] Step S4, cooling liquid is introduced into the electrode body to cool the water-cooled plate 60, and the temperature of the water-cooled plate 60 is transmitted to the heating table 50 through the heat-conducting plate 70;

[0100] Specifically, the water chiller introduces cooling liquid into the joint 201 installed on the water inlet 203 and the water outlet 205 through the water pipe, so that the cooling liquid enters the liquid passage; the cooling liquid in the liquid passage is introduced into the first cooling groove in the first welded corrugated pipe 90, the second cooling groove in the second welded corrugated pipe 80 and the third cooling groove in the third welded corrugated pipe 100 through the water distribution interface 604 respectively;

[0101] Step S5, the temperature measuring optical fiber in the first cylindrical shaft 505 feeds back the temperature of the heating table 50 to the computer in real time;

[0102] Step S6, according to the temperature fed back in step S5, the following determination is made:

[0103] When the temperature of the heating table 50 reaches the expected temperature, the high-temperature etching process starts, the heating wire stops heating, and the water chiller stops introducing cooling liquid;

[0104] When the temperature of the heating platform 50 does not reach the expected temperature, there are two adjustment methods: one is to continue to heat up by heating wire, and the other is to increase the temperature of the coolant so that the temperature of the heating platform 50 reaches the expected temperature.

[0105] Then repeat steps S5 and S6.

[0106] like Figure 9 As shown, the specific process for electrode temperature control during low-temperature processing is as follows (low temperature is below 20 degrees Celsius):

[0107] Step S1: The first welded bellows 90, the second welded bellows 80, and the third welded bellows 100 are used to seal the first cylindrical shaft 505, the second cylindrical shaft 506, and the third cylindrical shaft 507, respectively.

[0108] Step S2: Set the required temperature of the heating stage 50 and input the temperature of the coolant in the electrode body;

[0109] Step S3: Helium gas is introduced into the helium gas hole 516 in the second cylindrical shaft 506 to achieve full contact between the helium gas and the bottom of the wafer on the upper plate 501. At the same time, the heating wire in the third cylindrical shaft 507 starts heating or stops working.

[0110] Step S4: Cooling liquid is introduced into the electrode body to cool the water-cooled plate 60, and the temperature of the water-cooled plate 60 is transferred to the heating stage 50 through the heat-conducting plate 70.

[0111] Specifically, the chiller introduces coolant into the connector 201 installed on the inlet 203 and outlet 205 through water pipes, thereby introducing coolant into the liquid channel; the coolant in the liquid channel is introduced into the first cooling tank in the first welded corrugated pipe 90, the second cooling tank in the second welded corrugated pipe 80, and the third cooling tank in the third welded corrugated pipe 100 through the water distribution interface 604 respectively.

[0112] Step S5: The temperature-sensing optical fiber inside the first cylindrical shaft 505 feeds back the temperature of the heating table 50 to the computer in real time;

[0113] Step S6: Based on the temperature feedback from step S5, make the following determination:

[0114] When the temperature of the heating stage 50 reaches the expected temperature, the low-temperature etching process begins, and the chiller stops supplying coolant.

[0115] Wherein, if the heating wire is heated as described in step S3 above, the heating wire stops heating as described in step S6; if the heating wire is not working as described in step S3 above, the heating wire is still not working as described in step S6.

[0116] When the temperature of the heating table 50 does not reach the expected temperature, the computer controls the water chiller to reduce the temperature of the cooling liquid inputted;

[0117] Then, the step S5 and the step S6 are repeated.

[0118] Those skilled in the art can understand that, unless otherwise defined, all the terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that the terms such as those defined in a general dictionary should be understood in the context of the present application and should not be interpreted in an idealized or overly formal sense unless otherwise defined herein.

[0119] The meaning of "and / or" described in the present application means that each single existence or both existences at the same time are included.

[0120] The meaning of "connection" described in the present application can be a direct connection between components or an indirect connection between components through other components.

[0121] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. An electrode that simultaneously performs low-temperature and high-temperature plasma etching processes, comprising an electrode body, characterized in that: The electrode body includes a heating platform (50), a heat-conducting plate (70), and a water-cooling plate (60) arranged sequentially from top to bottom, wherein: The upper surface of the water-cooled plate (60) has a heat-conducting plate groove at the middle position, and there is a gap h between the bottom of the heat-conducting plate groove and the lower surface of the heating table (50). The heat-conducting plate (70) is embedded in the heat-conducting plate groove, and the thickness of the heat-conducting plate (70) is h1. <h; There is a gap h-h1 between the upper part of the heat-conducting plate (70) and the heating platform (50). By replacing the heat-conducting plate (70) and adjusting the thickness h1 of the heat-conducting plate (70), the gap h-h1 between the upper part of the heat-conducting plate (70) and the heating platform (50) can be adjusted, thereby adjusting the heat transfer effect between the low temperature of the water-cooled plate (60) and the high temperature of the heating platform (50). The heating platform (50) includes an upper plate (501) and a lower plate (502) that can be connected as a whole; the upper plate (501) covers the lower plate (502), and heating wires are installed inside the lower plate (502); the lower plate (502) is the lower structure of the aforementioned heating platform (50). The outer area of ​​the heating platform (50) and the outer area of ​​the water-cooled plate (60) are connected as one unit by a flange connection. Low temperatures range from -30℃ to 20℃, and high temperatures range from 180℃ to 400℃.

2. The electrode according to claim 1, which simultaneously realizes low-temperature and high-temperature plasma etching processes, is characterized in that: The electrode body has a central hole (601) through it along the center position, and a first through hole (606), a second through hole (607), and a third through hole (608) are respectively provided around the central hole (601). The first through hole (606), the second through hole (607), and the third through hole (608) are all arranged to pass through the water-cooled plate (60) and the heat-conducting plate (70) in sequence, and are connected to the blind holes provided at the corresponding positions of the lower structure of the heating platform (50).

3. An electrode that simultaneously achieves low-temperature and high-temperature plasma etching processes according to claim 2, characterized in that: The blind hole is formed at the bottom of the lower plate (502).

4. An electrode that simultaneously achieves low-temperature and high-temperature plasma etching processes according to claim 3, characterized in that: It also includes a cylindrical shaft assembly for the blind hole mounted on the lower plate (502), the cylindrical shaft assembly comprising a first cylindrical shaft (505), a second cylindrical shaft (506), and a third cylindrical shaft (507), wherein: The first cylindrical shaft (505) passes through the first through hole (606) and is connected to a blind hole on the lower plate (502), and a temperature measuring optical fiber is installed inside the first cylindrical shaft (505); The second cylindrical shaft (506) passes through the second through hole (607) and is connected to a blind hole on the lower plate (502), and a helium hole (516) for helium to pass through is opened inside the second cylindrical shaft (506); The third cylindrical shaft (507) passes through the third through hole (608) and connects with a blind hole on the lower plate (502), and the heating wire is supplied from inside the third cylindrical shaft (507).

5. A method for controlling low-temperature and high-temperature plasma etching processes simultaneously, characterized in that: The control method utilizes the electrode of the etching process described in claim 4 for control, and the control method includes control under two operating conditions: one is a high-temperature condition, and the other is a low-temperature condition, wherein: Under high-temperature conditions, the specific control steps of the control method are as follows: Step S1: Seal the exterior of the first cylindrical shaft (505), the second cylindrical shaft (506), and the third cylindrical shaft (507); Step S2: Set the temperature required for the heating stage (50) and input the temperature of the coolant in the electrode body; Step S3: Helium gas is introduced into the helium gas hole (516) in the second cylindrical shaft (506) to achieve full contact between the helium gas and the bottom of the wafer on the upper plate (501). At the same time, the heating wire in the third cylindrical shaft (507) is heated, and the heating stage (50) begins to heat up. Step S4: Cooling liquid is introduced into the electrode body to cool the water-cooled plate (60), and the temperature of the water-cooled plate (60) is transferred to the heating stage (50) through the heat-conducting plate (70); Step S5: The temperature measuring fiber inside the first cylindrical shaft (505) feeds back the temperature of the heating table (50) to the computer in real time; Step S6: Based on the temperature feedback from step S5, make the following determination: When the temperature of the heating stage (50) reaches the expected temperature, the high-temperature etching process begins, the heating wire stops heating, and the coolant flow stops. When the temperature of the heating platform (50) does not reach the expected temperature, there are two adjustment methods: one is to continue to heat up by heating wire, and the other is to increase the temperature of the coolant so that the temperature of the heating platform (50) reaches the expected temperature. Then repeat steps S5 and S6.

6. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 5, characterized in that: Under low-temperature operating conditions, the specific control steps of the control method are as follows: Step S3: Helium gas is introduced into the helium gas hole (516) in the second cylindrical shaft (506) to achieve full contact between the helium gas and the bottom of the wafer on the upper plate (501), while the heating wire in the third cylindrical shaft (507) starts to heat up or stops working. When the temperature of the heating stage (50) reaches the expected temperature, the low-temperature etching process begins, the heating wire stops working, and the coolant flow stops. If the temperature of the heating platform (50) does not reach the expected temperature, the temperature of the incoming coolant is reduced.

7. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 5, characterized in that: The first cylindrical shaft (505) includes a first thin cylindrical shaft portion for accommodating the temperature measuring optical fiber, and the end of the first thin shaft portion away from the lower plate (502) is a first distal disk portion in the shape of a disk for sealing. The second cylindrical shaft (506) includes a thin cylindrical second thin shaft portion (526) through which helium gas passes, and the end of the second thin shaft portion (526) away from the lower plate (502) is a disk-shaped second distal disk portion (536) for sealing. The third cylindrical shaft (507) includes a thin cylindrical third shaft portion for accommodating the heating wire, and the end of the third shaft portion away from the lower plate (502) is a disk-shaped third distal disk portion for sealing.

8. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 7, characterized in that: In both high-temperature and low-temperature operating steps S1, the first cylindrical shaft (505), the second cylindrical shaft (506), and the third cylindrical shaft (507) are sealed using a first welded bellows (90), a second welded bellows (80), and a third welded bellows (100) with identical structures, respectively. The first welded bellows (90) is sleeved on the outside of the first cylindrical shaft (505), the top of the first welded bellows (90) seals the bottom of the water-cooled plate (60), and the bottom of the first welded bellows (90) seals the bottom of the first distal disc portion. The second welded bellows (80) is sleeved outside the second cylindrical shaft (506), the top of the second welded bellows (80) is sealed to the bottom of the water-cooled plate (60), and the bottom of the second welded bellows (80) is sealed to the bottom of the second distal disc (536). The third welded bellows (100) is sleeved outside the third cylindrical shaft (507), the top of the third welded bellows (100) is sealed to the bottom of the water-cooled plate (60), and the bottom of the third welded bellows (100) is sealed to the bottom of the third distal disc.

9. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 8, characterized in that: In both the high-temperature and low-temperature operating conditions, step S3 involves introducing helium gas into the lower plate (502) through a distribution channel (511) and several gas equalization channels (504) provided on the lower plate (502). The diversion channel (511) and the plurality of gas equalization channels (504) are all opened on the top surface of the lower plate (502), and the diversion channel (511) and the plurality of gas equalization channels (504) are all connected. The diversion groove (511) is connected to the helium gas hole (516) and diverts the helium gas into each of the gas equalization grooves (504).

10. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 9, characterized in that: In both the high-temperature and low-temperature operating steps S3, helium gas is introduced into the upper plate (501) through a helium gas tank (503) and several gas inlets (510) provided on the upper plate (501) and fully contacts the bottom surface of the wafer, wherein: The helium tank (503) is disposed on the top surface of the upper plate (501), and a plurality of air inlets (510) penetrate the upper plate (501) and are distributed in the helium tank (503); Several of the air inlets (510) are connected to several of the air distribution grooves (504).

11. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 9, characterized in that: In step S4 of both high-temperature and low-temperature conditions, the water-cooled plate (60) is cooled by introducing coolant into the liquid channels on the water-cooled plate (60), wherein: The liquid channel is formed by a water-blocking plate (603) and a water-passing groove (602). The water-passing groove (602) is opened at the bottom of the water-cooling plate (60), and the water-blocking plate (603) covers the water-passing groove (602).

12. The method for controlling low-temperature and high-temperature plasma etching processes according to claim 11, characterized in that: It also includes a first cooling bath, a second cooling bath (801), and a third cooling bath, wherein: The first cooling tank is located inside the bottom flange of the first welded corrugated pipe (90), and the first cooling tank is connected to the water channel (602) through a water pipe; The second cooling tank (801) is located inside the bottom flange of the second welded corrugated pipe (80), and the second cooling tank (801) is connected to the water tank (602) through a water pipe; The third cooling tank is located inside the bottom flange of the third welded corrugated pipe (100), and the third cooling tank is connected to the water channel (602) via a water pipe.

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