TW202125576A - Lower electrode element, plasma processing device and working method thereof preventing is not easy to cause damage to the parts when in contacting with the cooling gas due to the low temperature - Google Patents

Abstract

A lower electrode element, a plasma processing device and a working method thereof are disclosed. The lower electrode element includes a base having a predetermined working temperature and having a cooling channel inside, in whichwherein the cooling channel comprises a cooling input end and a cooling output end; a cooling gas having a liquidation temperature lower than the predetermined working temperature; a cooling device configured for cooling the cooling gas; a first gas delivery pipe configured for delivering the cooling gas to the cooling device; a second gas delivery pipe communicating with the cooling input end and configured for delivering the cooled cooling gas into the cooling channel, in whichwherein the cooled cooling gas can cool the base to reach the predetermined working temperature; and a third gas delivery pipe communicating with the cooling output end and configured for outputting the cooling gas after the base is cooled. When the lower electrode element is used to cool the base, it is beneficial to reduce the damage to the parts in contact with the cooling gas and to enhance the sealing performance of the lower electrode element.

Description

Lower electrode element, plasma processing device and working method thereof

The present invention relates to the field of semiconductors, in particular to a lower electrode element, a plasma processing device and a working method thereof.

The plasma processing device includes: a vacuum reaction chamber; a susceptor, a susceptor located in the vacuum reaction chamber, and the susceptor is used to carry a substrate to be processed. The working principle of the plasma processing device is to pass a reaction gas containing a suitable etchant source gas into a vacuum reaction chamber, and then input radio frequency energy to the vacuum reaction chamber to activate the reaction gas to excite and maintain the plasma , The plasma is used to process the substrate to be processed.

A cooling channel is arranged in the base, and the cooling channel is used for conveying coolant, and the coolant is transported in the cooling channel to reduce the temperature of the base. However, the plasma processing apparatus of the prior art may cause damage to the contact components when cooling the base by the plasma processing apparatus, which makes the sealing performance of the base poor.

The technical problem solved by the present invention is to provide a lower electrode element, a plasma processing device and a working method thereof, so as to reduce the temperature of the susceptor, reduce the damage of the cooling gas to the contact parts, and improve the sealing performance of the lower electrode element.

In order to solve the above technical problems, the present invention provides a lower electrode element for a plasma processing device, comprising: a base with a preset operating temperature, and a cooling channel therein, the cooling channel including a cooling input end and a cooling output end ; Cooling gas, whose liquefaction temperature is lower than the preset operating temperature; cooling device, used to cool the cooling gas; a first gas delivery pipeline, used to deliver the cooling gas to the cooling device; second gas delivery pipeline, It is connected to the cooling input end, and is used to deliver the cooled cooling gas into the cooling channel, and the cooled cooling gas cools the base to reach the preset operating temperature; a third gas delivery pipe, and The cooling output end is connected to output the cooling gas after cooling the base.

Preferably, the cooling gas includes at least one of nitrogen, helium, methane or oxygen.

Preferably, the cooling device is a liquid nitrogen device.

Preferably, it further includes: a first control valve for controlling the flow rate of the cooling gas into the cooling device.

Preferably, it further includes: a recovery gas pipeline, which is connected to the third gas delivery pipeline, and is used to deliver the cooling gas output after cooling the base to the cooling device.

Preferably, it further includes: a gas output pipe connected to the third gas delivery pipe for outputting the cooling gas after cooling the base; and a second control valve for controlling the third gas delivery pipe and the The gas output pipeline is still in communication with the recovery gas pipeline.

Preferably, the number of the cooling device is one or more.

Preferably, a plurality of the cooling devices are arranged in series between the first gas conveying pipe and the second gas conveying pipe.

Preferably, a plurality of the cooling devices are arranged in parallel between the first gas conveying pipe and the second gas conveying pipe.

Preferably, a plurality of the cooling devices are arranged between the first gas conveying pipe and the second gas conveying pipe in a combination of series and parallel.

Preferably, the material of the base includes titanium.

Correspondingly, the present invention also provides a plasma processing device, including: a reaction chamber; the above-mentioned lower electrode assembly is located at the bottom of the reaction chamber. Preferably, the plasma processing device includes a capacitively coupled plasma processing device or an inductively coupled plasma processing device.

Correspondingly, the present invention also provides a working method of a plasma processing device, including: providing the above-mentioned plasma processing device; Cooling the cooling gas; the cooling gas after cooling is transported to the cooling channel through the second gas delivery pipe, the base is cooled to a preset operating temperature; the cooling gas after cooling the base is passed through The third gas delivery pipeline output.

Preferably, the preset operating temperature is -110 degrees Celsius to 25 degrees Celsius.

Preferably, the temperature of the cooling gas before entering the cooling device through the first gas delivery pipe is: 10 degrees Celsius to 30 degrees Celsius; the flow rate of the cooling gas is: 0 ml/min to 1000 ml/min.

Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

In the lower electrode element provided by the technical scheme of the present invention, the cooling gas is transported to the cooling device through the first gas delivery pipe, and the temperature is lowered under the action of the cooling device, and the cooled cooling gas is delivered to the cooling channel by the second gas delivery pipe Inside. The cooled cooling gas cools the base during the flow of the cooling channel to reach the preset working temperature. Since the liquefaction temperature of the cooling gas is lower than the preset working temperature of the base, the cooling gas does not need to be cooled into a liquefied state by the cooling device, that is, the cooling gas remains in a gaseous state after being cooled by the cooling device, and the cooled cooling gas The temperature is not too low, so that when the cooled cooling gas is transported in the cooling channel, it is not easy to cause damage to the parts in contact with the cooling gas due to the low temperature. Therefore, it is beneficial to improve the sealing performance of the lower electrode assembly.

In order to make the above-mentioned objectives, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below in conjunction with the drawings.

As mentioned in the background art, when cooling the base in the prior art, it is easy to cause damage to the bottom electrode element.

The research found that in some semiconductor manufacturing processes, such as deep silicon etching processes, low temperature conditions (minus 70 degrees Celsius or lower) are required to increase the aspect ratio of the etching and reduce the roughness of the sidewalls. It is found that a good etching effect can be achieved at minus 110 degrees Celsius. The prior art uses cryogenic liquid such as looped liquid nitrogen to cool the base. Although it can meet the low temperature demand, the cryogenic liquid poses a great challenge to the low temperature resistance/tightness of the contacting parts.

In view of this, the present invention provides a lower electrode element, a plasma processing device and a working method thereof, wherein the lower electrode element includes: a base having a preset operating temperature, and a cooling channel therein, the cooling channel including a cooling input End and cooling output end; cooling gas, the liquefaction temperature of which is lower than the preset operating temperature; cooling device, used to cool the cooling gas; the first gas delivery pipe, used to transport the cooling gas to the cooling device; Two gas delivery pipes, which are connected to the cooling input end, and are used to deliver the cooled cooling gas into the cooling channel, and the cooled cooling gas cools the base to reach the preset operating temperature; third The gas delivery pipe is connected with the cooling output end and is used for outputting the cooling gas after the temperature of the base is lowered. When the lower electrode element is used to cool the susceptor, it is beneficial to reduce the damage to the contact parts caused by the cooling gas and improve the sealing performance of the lower electrode element.

In order to make the above objectives, features and beneficial effects of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the structure of a lower electrode element used in a plasma processing apparatus of the present invention.

Please refer to FIG. 1, the base 100 has a preset operating temperature and has a cooling channel 101 therein. The cooling channel 101 includes a cooling input terminal A1 and a cooling output terminal B1; the cooling gas 102 has a liquefaction temperature lower than the preset operating temperature Temperature; cooling device 103, used to cool the cooling gas 102; first gas delivery pipe 104, used to deliver the cooling gas 102 to the cooling device 103; second gas delivery pipe 105, connected to the cooling input A1 , Used to deliver the cooled cooling gas 102 into the cooling channel 101, and the cooled cooling gas 102 cools the susceptor 100 to reach the preset operating temperature; the third gas delivery pipe 106 is connected to the cooling channel 101. The cooling output port B1 is in communication, and is used to output the cooling gas 102 after the temperature of the susceptor 100 is lowered.

The base 100 is used to carry the substrate to be processed. In different manufacturing processes, the preset operating temperature of the base 100 is different. In some semiconductor manufacturing processes, such as deep silicon etching processes, lower presets are required. The working temperature is used to increase the aspect ratio of the etching and reduce the roughness of the sidewall.

In this embodiment, the preset operating temperature ranges from -110 degrees Celsius to 25 degrees Celsius.

In this embodiment, the cooling gas 102 is nitrogen. In other embodiments, the cooling gas includes at least one of helium, methane, or oxygen, or a combination of nitrogen and at least one of helium, methane, or oxygen.

In this embodiment, the significance of selecting nitrogen as the cooling gas 102 is that on the one hand, nitrogen is cheaper, on the other hand, nitrogen is an inert gas, which is safer during use.

In this embodiment, the cooling device 103 is a liquid nitrogen device. In other embodiments, the cooling device may also be another device with cooling capability. The cooling gas 102 is delivered to the cooling device 103 through the first gas delivery pipe 104, and the cooling device 103 is used to cool the cooling gas 102.

In this embodiment, it further includes: a first control valve 107 for controlling the flow rate of the cooling gas 102. When the preset operating temperature of the base is low, the flow rate of the cooling gas 102 can be reduced to make the cooling gas 102 flow through the cooling device 103 for a longer time. Then the cooling gas 102 is cooled by the cooling device 103. More sufficient, the temperature of the cooling gas 102 flowing out of the cooling device 103 is lower, which is conducive to making the temperature of the susceptor reach a lower preset operating temperature; on the contrary, when the preset operating temperature of the susceptor is higher, The flow rate of the cooling gas 102 can be increased to shorten the time for the cooling gas 102 to flow through the cooling device 103, and the cooling gas 102 is not sufficiently cooled by the cooling device 103, and the cooling gas 102 flowing out of the cooling device 103 The higher temperature is beneficial to make the temperature of the base reach a higher preset working temperature.

The cooling gas 102 cooled by the cooling device 103 is input to the cooling input end A1 of the cooling channel 101 through the second gas delivery pipe 105, and the cooling gas 102 cools the susceptor 100 during the transmission process in the cooling channel 101. The preset operating temperature is reached.

Since the liquefaction temperature of the cooling gas 102 is lower than the preset working temperature, the cooling gas 102 only needs to be cooled to the preset working temperature when it is cooled by the cooling device 103, and the cooling gas 102 remains at the preset working temperature. It is a gas, that is, the temperature of the cooling gas 102 is not too low, so that the cooling gas 102 is not easy to cause damage to the cooling gas contact parts, which is beneficial to improve the sealing performance of the lower electrode element.

In this embodiment, the material of the susceptor 100 includes titanium. Titanium is selected as the material of the susceptor 100 to prevent the susceptor 100 from being cracked when the cooling gas 102 cools the susceptor 100 because the temperature of the cooling gas 102 is too low. .

The cooling gas 102 flows out through the cooling output port B1 and is output through the third gas delivery pipe 106.

In this embodiment, since the cooling gas 102 is nitrogen and nitrogen is a harmless gas, the cooling gas 102 output from the cooling output port B1 can be directly discharged into the atmosphere.

In other embodiments, it further includes: a recovery gas pipeline, which is connected to the third gas delivery pipeline, and is used to deliver the cooling gas output after cooling the base to the cooling device; a gas output pipeline is connected to the third gas delivery pipeline. The conveying pipe is connected to output the cooling gas after cooling the base; the second control valve is used to control whether the third gas conveying pipe is in communication with the gas output pipe or the recovered gas pipe.

In this embodiment, the number of the cooling device 103 is taken as one for description. In other embodiments, the number of the cooling device is greater than one.

Fig. 2 is a schematic structural diagram of another lower electrode element used in a plasma processing apparatus of the present invention.

In this embodiment, the number of the cooling device 203 is two, and the two cooling devices 203 are connected in parallel.

In other embodiments, the number of the cooling devices is plural, and the plural cooling devices are connected in parallel.

In this embodiment, the cooling gas 202 is branched while being transported through the first gas delivery pipe 204. A part of the cooling gas 202 is cooled by the cooling device 203a, and the other part of the cooling gas 202 is cooled by the cooling device 203b. Compared with the cooling gas 202 passing through a cooling device 203, the contact area between the cooling gas 202 and the cooling device 203a and the cooling device 203b is larger. Therefore, when the flow rate is equal, the cooling gas 202 passes through the cooling device 203a and the cooling device 203b. The lower temperature is conducive to improving cooling efficiency.

Fig. 3 is a schematic structural diagram of another lower electrode element used in a plasma processing apparatus of the present invention.

In this embodiment, the number of the cooling device 303 is two, and the two cooling devices 303 are connected in series. In other embodiments, the number of the cooling devices is more than two, and more than two cooling devices are connected in series.

In this embodiment, because two cooling devices 303 are connected in series, the cooling gas 302 is sequentially cooled by each cooling device 303, so that the temperature of the cooling gas 302 is continuously reduced. When the flow rate of the device 303 is equal, the temperature delivered to the cooling channel 301 is lower. Therefore, when the preset working temperature remains unchanged, the flow rate of the cooling gas 302 can be increased to achieve the preset working temperature, which is beneficial to increase Cooling efficiency.

In other embodiments, a plurality of the cooling devices are arranged in combination in series and in parallel.

FIG. 4 is a schematic diagram of the structure of a plasma processing apparatus of the present invention.

Please refer to FIG. 4, the reaction chamber 400; the lower electrode assembly 401 is located at the bottom of the reaction chamber 400.

In this embodiment, the plasma processing apparatus is described as a capacitively coupled plasma processing apparatus. When the plasma processing device is a capacitively coupled plasma processing device, it further includes: a gas shower head 402 located in the reaction chamber 400, and the gas shower head 402 is arranged opposite to the lower electrode assembly 401;

In other embodiments, the plasma processing device includes: an inductively coupled plasma processing device, and the inductively coupled plasma processing device further includes an insulating window on the top of the reaction chamber and an inductor coil located on the insulating window.

Please refer to Fig. 5, step S1: providing the above plasma processing device; step S2: providing cooling gas, passing the first gas delivery pipe to transport the cooling gas to the cooling device, and using the cooling device to cool the cooling gas; step S3: The cooling gas after cooling is delivered to the cooling channel through the second gas delivery pipe, and the temperature of the base is lowered; Step S4: the cooling gas after cooling the base is output through the third gas delivery pipe.

In this embodiment, the preset operating temperature is -110 degrees Celsius to 25 degrees Celsius.

In this embodiment, the temperature of the cooling gas before entering the cooling device through the first gas delivery pipe is: 10 degrees Celsius to 30 degrees Celsius; the flow rate of the cooling gas is: 0 ml/min to 1000 ml/min.

The cooling gas is delivered to the cooling device through the first gas delivery pipe, and the temperature is lowered under the action of the cooling device, and the cooled cooling gas is delivered into the cooling channel by the second gas delivery pipe. The cooled cooling gas cools the base during the flow of the cooling channel to reach the preset working temperature. Since the liquefaction temperature of the cooling gas is lower than the preset working temperature of the base, the cooling gas does not need to be cooled into a liquefied state by the cooling device, that is, the cooling gas remains in a gaseous state after being cooled by the cooling device, and the cooled cooling gas The temperature is not too low, so that when the cooled cooling gas is transported in the cooling channel, it is not easy to cause damage to the parts in contact with the cooling gas due to the low temperature. Therefore, it is beneficial to improve the sealing performance of the lower electrode assembly.

Although the present invention is disclosed as above, the present invention is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the patent scope.

In summary, regardless of the purpose, means, and effects of this case, it is showing its technical characteristics that are very different from conventional knowledge, and its first invention is suitable for practical use, and it is also in line with the patent requirements of the invention. Granting patents as soon as possible will benefit the society and feel the virtues.

100: Pedestal 101, 301: cooling channel 102, 202, 302: cooling gas 103, 203, 203a, 203b, 303: cooling device 104, 204: The first gas transmission pipeline 105: The second gas pipeline 106: The third gas pipeline 107: The first control valve 400: reaction chamber 401: Lower electrode assembly 402: Gas sprinkler A1: Cooling input B1: Cooling output S1-S4: step flow

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those who are generally knowledgeable in this field, they can also obtain other schemas based on these schemas without paying creative work. 1 is a schematic diagram of the structure of a lower electrode element used in a plasma processing apparatus of the present invention; FIG. 2 is a schematic structural diagram of another lower electrode element used in a plasma processing apparatus according to the present invention; FIG. 3 is a schematic structural diagram of another lower electrode element used in a plasma processing apparatus according to the present invention; 4 is a schematic diagram of the structure of a plasma processing device of the present invention; Fig. 5 is a flow chart of the working method of the plasma processing apparatus of the present invention.

100: Pedestal

101: cooling channel

102: Cooling gas

103: Cooling device

104: The first gas transmission pipeline

105: The second gas pipeline

106: The third gas pipeline

107: The first control valve

A1: Cooling input

B1: Cooling output

Claims (16)

A lower electrode element used in a plasma processing device, which includes: A base with a preset operating temperature and a cooling channel inside, the cooling channel including a cooling input end and a cooling output end; A cooling gas whose liquefaction temperature is lower than the preset operating temperature; A cooling device for cooling the cooling gas; A first gas delivery pipe for delivering the cooling gas to the cooling device; A second gas delivery pipe, which is connected to the cooling input end, is used to deliver the cooled cooling gas into the cooling channel, and the cooled cooling gas cools the base to achieve the preset work Temperature; and A third gas delivery pipe is connected to the cooling output end and is used to output the cooling gas after the base has been cooled. The lower electrode element for a plasma processing apparatus according to claim 1, wherein the cooling gas includes at least one of nitrogen, helium, methane, or oxygen. The lower electrode element for a plasma processing device according to claim 1, wherein the cooling device is a liquid nitrogen device. The lower electrode element for a plasma processing apparatus according to claim 1, which further includes: A first control valve is used to control the flow rate of the cooling gas into the cooling device. The lower electrode element for a plasma processing apparatus according to claim 1, which further includes: A recovered gas pipeline communicates with the third gas delivery pipeline and is used to deliver the cooling gas output after cooling the base to the cooling device. The lower electrode element for a plasma processing apparatus according to claim 5, which further includes: A gas output pipe connected with the third gas conveying pipe for outputting the cooling gas after cooling the base; and A second control valve is used to control whether the third gas delivery pipeline is connected to the gas output pipeline or the recovery gas pipeline. The lower electrode element for a plasma processing device according to claim 1, wherein the number of the cooling device is one or more. The lower electrode element for a plasma processing apparatus according to claim 7, wherein a plurality of the cooling devices are arranged in series between the first gas conveying pipe and the second gas conveying pipe. The lower electrode element for a plasma processing device according to claim 7, wherein a plurality of the cooling devices are arranged in parallel between the first gas delivery pipe and the second gas delivery pipe. The lower electrode element for a plasma processing device according to claim 7, wherein a plurality of the cooling devices are arranged between the first gas delivery pipe and the second gas delivery pipe in a combination of series and parallel. The lower electrode element for a plasma processing apparatus according to claim 1, wherein the material of the base includes titanium. A plasma processing device, which includes: A reaction chamber; and The lower electrode element according to any one of claims 1 to 11, which is located at the bottom of the reaction chamber. The plasma processing device according to claim 12, wherein the plasma processing device includes a capacitively coupled plasma processing device or an inductively coupled plasma processing device. A working method of a plasma processing device includes: Provide a plasma processing device as described in claim 12 or 13; Provide a cooling gas to pass through a first gas delivery pipe so that the cooling gas is delivered to a cooling device, and the cooling device is used to cool the cooling gas, wherein the liquefaction temperature of the cooling gas is lower than a preset operating temperature; The cooled cooling gas is transported into the cooling channel through a second gas delivery pipe, and the cooled cooling gas is cooled to the preset working temperature during the transmission of the cooling channel; and The cooling gas after cooling the susceptor is output through a third gas delivery pipe. The working method of the plasma processing apparatus according to claim 14, wherein the preset working temperature is -110 degrees Celsius to 25 degrees Celsius. The working method of the plasma processing device according to claim 15, wherein the temperature of the cooling gas before entering the cooling device through the first gas delivery pipe is: 10 degrees Celsius to 30 degrees Celsius; and the flow rate of the cooling gas is: 0 ml/min to 1000 ml/min.

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