TW202110281A - Plasma processing device capable of effectively isolating radio frequency interference - Google Patents

Abstract

The present invention provides a plasma processing device. The plasma processing device includes a vacuum reaction chamber internally provided with a plasma for processing a substrate; a base that carries the substrate is provided at the bottom of the reaction chamber; a focusing ring is provided around an outer edge of the base; a first insulating ring is provided under the focusing ring, and the first insulating ring surrounds the base; a heater is provided inside or under the first insulating ring; a shielding ring is provided under the first insulating ring, and the shielding ring is grounded and surrounds the base; a circuit wiring is provided inside the shielding ring, and the circuit wiring is used to supply electric power to the heater. The invention can perform heating on the focus ring more uniformly and achieve more accurate, precise, fast and sensitive temperature control and adjustment, and also, the circuit design is simple and reliable, and can effectively isolate radio frequency interference.

Description

Plasma processing device

The present invention relates to the manufacturing field of semiconductor devices, in particular to a plasma processing device.

The plasma processing device ignites and maintains by passing a reaction gas containing a suitable etchant or deposition source gas into the vacuum reaction chamber, and then applying radio frequency energy to the vacuum reaction chamber to activate and dissociate the reaction gas Plasma is used to etch the material layer on the surface of the substrate or deposit the material layer on the surface of the substrate through the plasma, and then process the semiconductor substrate or plasma plate.

As shown in Figure 1, in a conventional capacitively coupled plasma (CCP) processing device, a vacuum reaction chamber 1 is composed of a top cover at the top, a bottom wall at the bottom, and a top cover connected to it. The side wall between the bottom wall and the bottom wall forms an airtight internal reaction space. A gas shower head 2 is provided under the top cover in the reaction chamber 1 for introducing reaction gas into the reaction chamber 1; an upper electrode is provided on the top cover to couple it to the earth or radio frequency potential. A susceptor 3 is provided on the bottom wall of the reaction chamber 1, and the substrate 4 is adsorbed by the electrostatic chuck provided on the susceptor 3 during the etching process; a lower electrode is provided at the susceptor 3 and a radio frequency is applied to it The power RF is used to form a radio frequency electric field in the reaction chamber 1 and excite the introduced reaction gas to generate plasma, and finally use the generated plasma to perform an etching operation on the substrate on the susceptor.

Further, a focusing ring 5 is arranged around the outer edge of the substrate 4, which realizes the control of plasma uniformity by adjusting the distribution of the entire radio frequency electric field in the reaction chamber 1, especially the electric field distribution at the edge of the substrate 4 . In addition to electrical effects, the temperature of the focus ring 5 will also affect the deposition of polymer at the edge of the substrate 4, resulting in differences in microscopic critical dimensions. And with the demand for high aspect ratio in semiconductor etching technology, high power (low frequency) etching has been widely used. High-power (low-frequency) etching will cause the temperature in the reaction chamber 1 to rise sharply, causing both the substrate 4 and the focusing ring 5 to obtain a large amount of heat. In order to ensure the uniformity of the etching of the substrate 4, a cooling medium pipeline of a cooling system that maintains a constant temperature of the substrate 3 is provided inside the susceptor 3, so that the substrate 4 can quickly dissipate heat directly by the electrostatic chuck on the susceptor 3. At the same time, if the focus ring 5 does not have a good heat dissipation path, the temperature difference between the focus ring 5 and the substrate 4 will increase. This will cause the edge etching technique of the substrate 4 to be detuned.

Considering the above-mentioned problems, in the prior art, an insulating ring 6 or the like is usually arranged around the outer edge of the base 3 below the focus ring 5 as a heat conduction layer to transfer the heat of the focus ring 5 to the base 3 for cooling and heat dissipation.

However, different etching technology processes have different requirements for the working temperature of the focus ring 5. The conventional technology sets the insulating ring 6 as a thermal conductive layer, and only considers how to improve the heat transfer performance of the focus ring 5 or how to keep its temperature constant, but There is a lack of effective technical means to further control and adjust the working temperature of the focus ring 5. In addition, since the focus ring 5 is located in the radio frequency area of the reaction chamber 1, if one considers directly installing a heater or similar temperature adjustment device on the focus ring 5, not only the circuit layout is complicated, but also a filter must be installed to filter high frequency. , Otherwise it will produce radio frequency interference, which will affect the treatment response effect of the entire plasma treatment device.

Based on the above, the present invention proposes a plasma processing device to solve the shortcomings and limitations existing in the prior art.

The purpose of the present invention is to provide a plasma processing device that heats the focus ring more uniformly, realizes more accurate, precise, rapid and sensitive temperature control and adjustment, and has simple and reliable circuit design, which can effectively isolate radio frequency interference.

In order to achieve the above objective, the present invention provides a plasma processing device, including: a vacuum reaction chamber, inside the vacuum reaction chamber there is plasma for processing the substrate; the bottom of the vacuum reaction chamber is provided with a supporting base The base of the sheet; a focusing ring is arranged around the outer edge of the base; wherein a first insulating ring is arranged below the focusing ring, and the first insulating ring surrounds the base; A heater is arranged inside or below the first insulating ring; a shielding ring is arranged below the first insulating ring, and the shielding ring is grounded and surrounding the base; and a circuit wiring is arranged inside the shielding ring , The circuit wiring is used to provide power to the heater.

The plasma processing device of the present invention further includes: a second insulating ring is also arranged around the shielding ring and the base.

In an optional embodiment of the present invention, the heater is arranged below the first insulating ring, and extends from the shielding ring to above a part of the second insulating ring.

Wherein, the connection between the heater and the lower surface of the first insulating ring includes: pasting or vulcanizing.

In an optional embodiment of the present invention, the upper surface of the heater is directly coated on the lower surface of the first insulating ring, and the heater is located above the shielding ring and part of the second insulating ring.

In an optional embodiment of the present invention, the first insulation ring includes: a middle insulation ring, an upper insulation ring located above the middle insulation ring, and a lower insulation ring located below the middle insulation ring; The side walls of the insulating ring, the middle insulating ring and the lower insulating ring are in contact with the side walls of the base; the upper surface of the part of the middle insulating ring away from the base is not covered by the upper insulating ring, so that the upper insulating ring and the middle insulating ring are formed between The first groove; part of the lower surface of the middle insulation ring away from the base is not covered by the lower insulation ring, so that a second groove is formed between the lower insulation ring and the middle insulation ring; part of the second insulation ring is located in the Inside the second groove.

The heater is arranged on the lower surface of the middle insulating ring at the bottom of the second groove, and extends from the shielding ring to above a part of the second insulating ring.

Wherein, the connection between the heater and the lower surface of the middle insulating ring includes: pasting or vulcanizing.

The upper surface of the heater is directly plated and arranged on the lower surface of the middle insulating ring at the bottom of the second groove.

In the plasma processing device of the present invention, an insulating film is provided on the surface of the heater; the material of the insulating film includes: polyimide material or ceramic.

In the plasma processing device of the present invention, a first heat conducting pad is provided at the contact interface between the focus ring and the first insulating ring; and a second heat conducting pad is provided at the contact interface between the first insulating ring and the base. pad.

Wherein, the materials of the first thermal pad and the second thermal pad include: elastic silicone material.

The plasma processing device of the present invention further includes: a temperature detector for real-time detection of the temperature of the focus ring; a temperature controller for controlling the heater to turn on or off according to the temperature signal fed back by the temperature detector.

Wherein, the temperature detector is arranged under the first insulating ring, and its circuit wiring is arranged in the shielding ring, and is led to the outside of the reaction chamber to be connected to the temperature controller.

The plasma processing device of the present invention further includes: a compression ring is arranged around the outer edge of the focusing ring, a part of the compression ring is located in the first groove, the compression ring and the side wall of the first groove The side wall of the upper insulating ring is in contact with each other; a covering ring is provided above the focusing ring and the pressing ring and surrounding the outer edge of the first insulating ring.

Compared with the conventional technology, the plasma processing device provided by the present invention has the following advantages and beneficial effects:

1. By embedding the heater inside the first insulating ring, the heater is set closer to the focus ring, the heat transfer effect is better, the heating of the focus ring is more uniform, and the temperature control is more accurate and flexible;

Either by coating the upper and lower surfaces of the heater with a thin film and placing it under the first insulating ring, or by directly plating the heater on the bottom of the first insulating ring, the thermal resistance of the heater is smaller, thereby reducing the thermal resistance of the heater. The focus ring has better heat conduction effect, and the temperature control of the focus ring is more accurate and flexible.

2. By arranging the circuit wiring in a metal grounded shielding ring, it can effectively shield the radio frequency signal in the reaction chamber from interference to the heater power supply. There is no need to set an additional radio frequency filter, making the circuit design simple and reliable, and Can effectively save costs.

3. With the combination of the cooling path and the heat conduction path, the focus ring can achieve more accurate, precise, rapid and sensitive temperature control, so that the temperature can be adjusted during the plasma etching process, so as to meet higher and more precise technical requirements.

In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly, completely and in detail below in conjunction with FIGS. 2 to 5 in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person with ordinary knowledge in the technical field without making progressive work shall fall within the protection scope of the present invention.

As shown in FIG. 2, it is a plasma processing device provided by the present invention, especially a capacitive coupling type plasma processing device. Wherein, the plasma processing device includes a reaction chamber 1, which is composed of a top cover at the top end, a bottom wall at the bottom end, and side walls connected between the top cover and the bottom wall, forming an airtight internal reaction space During the plasma etching process, the reaction space is in a vacuum state.

A gas shower head 2 is provided under the top cover in the reaction chamber 1 and is connected to a reactive gas source for introducing reactive gas for etching the substrate 4 and maintaining a certain flow rate. At the same time, the top cover is provided with a grounded upper electrode.

A base 3 is provided on the bottom wall of the reaction chamber 1 to carry the substrate 4 to be processed placed on the base 3; the base 3 may be made of aluminum, and a support base is provided inside it. The cooling system with a constant temperature of the base 3 enables the substrate 4 to quickly dissipate heat directly through the base 3 during the etching process. At the same time, the susceptor 3 is provided with a lower electrode to which radio frequency power RF is applied. A radio frequency electric field is formed between the upper electrode and the lower electrode in the reaction chamber 1 to dissociate the reaction gas introduced into the reaction chamber 1. A plasma for etching reaction is formed in the area between the susceptor 3 and the gas shower head 2, and the substrate 4 placed on the susceptor 3 in the reaction chamber 1 is subjected to technical processing such as surface etching.

A focusing ring 5 is arranged around the outer edge of the base 3 to control the uniformity of the plasma during the etching process. Further, a first insulating ring 6 is provided around the bottom of the focusing ring 5 and on the step 301 at the edge of the susceptor 3. During the etching process, the first insulating ring 6 removes the plasma formed in the reaction chamber 1 The heat radiated to the focusing ring 5 is transferred downward to the susceptor 3 without affecting the electric field distribution in the reaction chamber 1. In an alternative embodiment of the present invention, the first insulating ring 6 may be made of ceramic material.

In the present invention, a grounded shielding ring 8 is provided below the first insulating ring 6 and the outer edge of the step 301 surrounding the base 3 to limit the radio frequency electric field formed in the reaction chamber 1 mainly on the substrate 4. And above, it can be concentrated and effectively used for the etching reaction, preventing the plasma from spreading to other positions in the reaction chamber 1, thereby causing the utilization rate to decrease. The shielding ring 8 is made of metal material. Between the shielding ring 8 and the outer edge of the step 301 of the base 3, a second insulating ring 7 is also arranged around, and the second insulating ring 7 can be made of ceramic material. A heater 9 is provided inside or below the first insulating ring 6. The heater 9 is connected to a power source 10 that provides electric energy for it through a circuit connection, thereby forming a heating source and adjusting the temperature of the focus ring 5. Wherein, the circuit wiring is embedded and arranged inside the shielding ring 8 made of metal, so it can effectively isolate the radio frequency interference caused by the high frequency of the circuit wiring to the radio frequency coupling, and there is no need to set up a high frequency filter device, so that The circuit wiring design is simple and reliable, and effectively saves costs.

As shown in Figure 2, in an alternative embodiment of the present invention, the heater 9 is embedded and arranged inside the first insulating ring 6, and the circuit connection between the heater 9 and the power source 10 is first connected by the first insulating ring 6 After passing through the bottom position of the first insulating ring 6, the corresponding position of the top of the shielding ring 8 under the first insulating ring 6 is directly penetrated into its interior, and the shielding ring 8 is drawn from the bottom of the shielding ring 8 to the outside of the reaction chamber and connected to the power supply 10, thereby The wiring connection between the heater 9 and the power source 10 is realized. Since the circuit wiring is arranged directly opposite to the penetration position of the first insulating ring 6 and the penetration position of the shielding ring 8, the layout design of the circuit wiring is effectively simplified, and the radio frequency interference caused by the exposure of the circuit wiring is effectively isolated. Moreover, since the heater 9 in this embodiment is directly embedded in the interior of the first insulating ring 6, compared to the traditional heater directly arranged on the focus ring 5, it not only saves more space in the reaction chamber 1, but also And it effectively simplifies the wiring layout, thereby reducing the impact on the etching reaction; at the same time, because the distance between the heater 9 and the focus ring 5 is relatively close, the heat transfer effect is better, so that it affects the focus ring 5 The heating is more uniform, and the temperature control is more accurate and flexible, and the feedback is faster and more sensitive. In addition, the area of the heater 9 is larger, so that the heater 9 has a better heating effect on the focus ring 5.

Optionally, the heater 9 adopts a heating element (resistor) made of metal materials, or adopts a heating element (resistor) made of non-metallic materials.

As shown in Figure 3, in another alternative embodiment of the present invention, the heater 9 is arranged below the first insulating ring 6, and extends from the shielding ring 8 to a part of the second insulating ring 7. Above, the circuit wiring between it and the power supply 10 directly penetrates from the top of the shielding ring 8 below it into its interior, and leads from the bottom of the shielding ring 8 to the outside of the reaction chamber to connect to the power supply 10, thereby realizing a heater Line connection between 9 and power supply 10. Since the position where the circuit wiring leads from the heater 9 and the penetration position of the shielding ring 8 are directly opposite to each other, the layout design of the circuit wiring is effectively simplified, and the radio frequency interference caused by the exposure of the circuit wiring is effectively isolated. The second insulating ring 7 can avoid the contact between the heater 9 and the base 3, so that the heating source generated by the heater 9 can be effectively transferred to the focusing ring 5 without contact with the base 3, thereby making Part of the heating source is directly taken away by the cooling system in the base 3, resulting in a decrease in heating efficiency.

Furthermore, a film is plated on the upper surface of the heater 9 so that the heater 9 and the first insulating ring 6 can be effectively isolated and insulated; the lower surface of the heater 9 is also plated with a film, Therefore, the heater 9 and the second insulating ring 7 and the shielding ring 8 can also be effectively isolated and insulated. In this embodiment, the heating structure of the thin-film coating is formed by coating the upper and lower surfaces of the heater 9 respectively, which will not affect the transfer of the heating source generated by itself to the focus ring 5, and can effectively isolate the contact with it. Upper and lower parts. Moreover, since the heater 9 in this embodiment is arranged under the first insulating ring 6, compared with the traditional heater directly arranged on the focus ring 5, it not only saves the space position in the reaction chamber 1 but also This effectively simplifies the wiring layout, thereby reducing the impact on the etching reaction; at the same time, because the location of the heater is still closer to the focus ring 5, the heating of the focus ring 5 is more uniform, and the temperature control is more accurate, and the feedback is better. Fast and sensitive. In addition, the heater 9 is arranged under the first insulating ring 6, and the thermal resistance is small, so that the heat conduction effect is better.

Further, the connection between the heater 9 and the lower surface of the first insulating ring 6 includes: pasting or vulcanizing. When the heater 9 is connected to the first insulating ring 6 by pasting, if the heater 9 is damaged and needs to be replaced, just remove the damaged heater and replace it with a new heater. There is no need to replace the first insulating ring 6.

The heater 9 adopts a heating element (resistor) made of metal materials, or adopts a heating element (resistance) made of non-metallic materials.

The film is made of polyimide material or ceramic material.

As shown in FIG. 4, in another alternative embodiment of the present invention, the first insulation ring 6 includes: a middle insulation ring 6b, an upper insulation ring 6a located above the middle insulation ring 6b, and an upper insulation ring 6a located above the middle insulation ring 6b. The lower insulating ring 6c under the insulating ring 6b, the side walls of the upper insulating ring 6a, the middle insulating ring 6b and the lower insulating ring 6c are all in contact with the side wall of the base 3. Wherein, the upper surface of the middle insulation ring 6b away from the base 3 is not covered by the upper insulation ring 6a, that is, the upper surface of the middle insulation ring 6b is exposed to the outside, so that the upper insulation ring 6a and the middle insulation ring 6b are exposed. A first groove is formed between the middle insulating ring 6b and the part of the lower surface of the middle insulating ring 6b away from the base 3 is not covered by the lower insulating ring 6c, that is, the lower surface of the insulating ring 6b in this part is exposed to the outside, so that the lower insulating ring A second groove is formed between 6c and the middle insulating ring 6b. In addition, part of the second insulating ring 7 is arranged in the second groove.

Wherein, the heater 9 is arranged on the lower surface of the middle insulating ring 6b at the bottom of the second groove, and extends from the shielding ring 8 to above a part of the second insulating ring 7, and the circuit connection between it and the power supply 10 is directly It penetrates into the inside of the shielding ring 8 from the top of the shielding ring 8 below it, and leads out from the bottom of the shielding ring 8 to the outside of the reaction chamber to connect to the power supply 10, thereby realizing the wiring connection between the heater 9 and the power supply 10. The same as the two previous embodiments, since the position of the circuit wiring from the heater 9 and the penetration position of the shielding ring 8 are directly opposite to each other, the layout design of the circuit wiring is effectively simplified, and the circuit wiring is effectively isolated. Radio frequency interference caused by exposed wiring.

Moreover, since the second groove is formed between the lower insulating ring 6c and the middle insulating ring 6b, the heater 9 is located on the lower surface of the middle insulating ring 6b at the bottom of the second groove, so that the heater 9 and The distance between the susceptors 3 is relatively long, so the heater 9 and the susceptor 3 are not easily damaged by arc.

Further, the connection between the heater 9 and the lower surface of the middle insulating ring 6b at the bottom of the second groove includes: pasting or vulcanizing. When the heater 9 is connected to the middle insulating ring 6b by pasting, if the heater 9 is damaged and needs to be replaced, just remove the damaged heater 9 and replace it with a new heater 9. There is no need to replace the first insulating ring 6.

Of course, in this embodiment, the heater 9 can alternatively be directly plated on the lower surface of the middle insulating ring 6b at the bottom of the second groove, and since the middle insulating ring 6b itself is made of insulating material Therefore, only a thin film is plated on the lower surface of the heater 9 so that the heater 9 can be effectively isolated from the second insulating ring 7 and the shielding ring 8. Since the heater 9 is directly plated and arranged on the lower surface of the middle insulating ring 6b, when the heater 9 does not meet the technical requirements or is damaged, the heater 9 can be removed by chemical corrosion without replacing the first An insulating ring 6.

The heater 9 adopts a heating element (resistor) made of metal materials, or adopts a heating element (resistance) made of non-metallic materials.

The film is made of polyimide material or ceramic material.

As shown in FIG. 5, in another alternative embodiment of the present invention, the heater 9 is still the same as described in the embodiment of FIG. 3 or FIG. 4, and is arranged under the first insulating ring 6. And it extends from the shielding ring 8 to above a part of the second insulating ring 7. Wherein, the heater 9 is arranged in a ring shape along the circumferential direction of the first insulating ring 6. The circuit wiring arrangement with the power supply 10 is also arranged in the same way, that is, arranged in the shielding ring 8. Since the first insulating ring 6 itself is made of insulating material, it can be directly plated on the bottom surface of the first insulating ring 6 on the upper surface of the heater 9 in FIG. 3 or 4, and on the lower surface of the heater 9 In addition, a layer of film is plated, so that the heater 9 and the second insulating ring 7 and the shielding ring 8 can be effectively isolated and insulated. Similarly, the structure of the heater 9 in this embodiment will not affect the transfer of the heating source generated by itself to the focusing ring 5, and can effectively isolate the upper and lower parts in contact with it, and because the thermal resistance is smaller, the heat conduction effect is better. Good, so that the heating of the focus ring 5 is more uniform, the temperature control is more accurate, and the feedback is faster and more sensitive.

Since the heater 9 is directly plated and arranged on the lower surface of the first insulating ring 6, when the heater 9 does not meet the technical requirements or is damaged, the heater 9 can be removed by chemical corrosion without replacing it. First insulating ring 6.

The heater 9 adopts a heating element (resistor) made of metal materials, or adopts a heating element (resistance) made of non-metallic materials.

The film is made of polyimide material or ceramic material.

Regarding the structure and position setting of the heater in the above different embodiments, in practical applications, it can be selected according to the fine-tuning of different plasma processing devices on the internal structure of the reaction chamber 1 and the requirements of different etching processes. One of the best use effects.

In the present invention, a first thermally conductive pad 11 is provided at the interface between the focus ring 5 and the first insulating ring 6 in contact with each other; and the first thermally conductive pad 11 is made of elastic silicone material, so that it is connected to the upper and lower parts respectively. The contact surface can be reliably and tightly attached, that is, the upper surface of the first thermal pad 11 is closely attached to the focusing ring 5, and the lower surface is closely attached to the first insulating ring 6. During the etching process, when the power supply 10 controls the heater 9 to turn on, the formed heating source is transferred to the focus ring 5 via the first insulating ring 6 and the first thermal pad 11 to adjust the temperature of the focus ring 5.

In the present invention, a second thermally conductive pad 12 is provided at the interface between the first insulating ring 6 and the base 3 in contact with each other; and the second thermally conductive pad 12 is made of elastic silicone material, so that it is connected to the upper and lower parts respectively. The contact surface can be reliably and tightly attached, that is, the upper surface of the second thermal pad 12 is closely attached to the first insulating ring 6, and the lower surface is closely attached to the base 3. During the etching process, the heat radiated from the plasma formed in the reaction chamber 1 to the focusing ring 5 is sequentially transferred downward to the base 3 through the first thermal pad 11, the first insulating ring 6, and the second thermal pad 12. And finally the heat is taken away by the cooling system set in the base 3.

In the present invention, in order to control the temperature of the focus ring 5 more accurately, the focus ring temperature adjustment device further includes a temperature detector (not shown in the figure) for real-time detection of the temperature of the focus ring 5. Since it is necessary to consider the circuit wiring arrangement of the temperature detector (including how to isolate radio frequency interference) and to ensure the accuracy of the temperature detection of the focus ring 5, the temperature detector is arranged below the first insulating ring 6, and The circuit wiring is arranged in the shielding ring 8 and is led to the outside of the reaction chamber 1 to be connected to the temperature controller. Furthermore, the temperature controller also needs to be connected to the power supply 10 in the shielding ring 8 through circuit wiring. By feeding back the real-time detected temperature signal of the focus ring 5 to the temperature controller, it controls whether the power supply 10 in the shielding ring 8 is turned on, so as to control whether the heater 9 needs to supplement the radiant heat to the focus ring 5 to achieve temperature regulation Function. Specifically, when the temperature controller determines that the currently detected temperature signal is higher than the preset value, the heater 9 is turned off by controlling the power supply 10; when the temperature controller determines that the currently detected temperature signal is lower than the preset value At this time, the heater 9 is turned on by controlling the power supply 10.

The temperature detector can use a temperature sensing probe that generates an electrical signal after detection, and uses the circuit wiring set in the shielding ring 8 to lead the electrical signal to the temperature controller; because the circuit wiring is set in the shielding ring 8, there is no need In addition, a filter is provided for radio frequency shielding. Alternatively, the temperature detector can also be a temperature-sensing probe based on optical signals, which emits optical signals of different frequency spectra or wavelengths to the detected different temperatures, and the optical fibers set in the shielding ring 8 are used to detect The light signal is led to the temperature controller.

In the present invention, a compression ring 13 is arranged around the outer edge of the focus ring 5 and covers the position of the first insulating ring 6 that is not covered by the focus ring 5 to limit the setting position of the focus ring 5 on the substrate 4 on the outer edge. Especially in the optional embodiment shown in FIG. 4, a part of the compression ring 13 is arranged in the first groove, so that the compression ring 13 is in contact with the outer side wall of the upper insulating ring 6a. The first groove is used to make the pressing ring 13 press the first insulating ring 6. Above the focusing ring 5 and the compression ring 13, and on the outer edge of the first insulating ring 6, a covering ring 14 is arranged around to prevent the plasma in the reaction chamber 1 from affecting the components below the covering ring 14. erosion.

Based on the plasma processing device of the present invention, the method for adjusting the temperature of the focusing ring is specifically as follows: during the etching process, the plasma in the reaction chamber 1 radiates the heat on the focusing ring 5 through the first thermal pad 11. The first insulating ring 6 and the second thermal pad 12 are transferred to the base 3 for cooling; based on the above cooling path, the temperature of the focus ring 5 will gradually decrease to the first temperature. During this process, the temperature detector continuously detects the temperature of the focus ring 5, and transmits the temperature signal detected immediately to the temperature controller.

If the temperature controller determines that the first temperature is lower than the temperature threshold that the focus ring 5 must reach in a certain etching process, the temperature of the focus ring 5 can be continuously adjusted by the present invention, specifically: The controller controls the power supply 10 to turn on to turn on the heater 9 to provide a heating source to the focus ring 5. The heat of the heating source is transferred to the focus ring 5 through the first insulating ring 6 and the first thermal pad 11; based on the above heat conduction path, The temperature drop of the focus ring 5 gradually rises until it reaches the required temperature threshold. During this process, the temperature detector continuously detects the temperature of the focus ring 5, and transmits the temperature signal detected immediately to the temperature controller. And when the temperature controller determines that the current temperature of the focus ring 5 reaches the required temperature threshold, the control power supply 10 is turned off to stop the heater 9 from continuing to provide the focus ring 5 with a heating source.

Throughout the entire etching process, by continuously repeating the above-mentioned cooling and heating steps, accurate and fine control and adjustment of the working temperature of the focus ring 5 are effectively realized, thereby meeting and achieving higher technical requirements.

Compared with the conventional technology, the plasma processing device provided by the present invention has the following advantages and beneficial effects:

1. By embedding the heater inside the first insulating ring, the heater is set closer to the focus ring, the heat transfer effect is better, the heating of the focus ring is more uniform, and the temperature control is more accurate and flexible;

Either by coating the upper and lower surfaces of the heater with a thin film and placing it under the first insulating ring, or by directly plating the heater on the bottom of the first insulating ring, the thermal resistance of the heater is smaller, thereby reducing the thermal resistance of the heater. The focus ring has better heat conduction effect, and the temperature control of the focus ring is more accurate and flexible.

2. By arranging the circuit wiring in a metal grounded shielding ring, it can effectively shield the radio frequency signal in the reaction chamber from interference to the heater power supply. There is no need to set an additional radio frequency filter, making the circuit design simple and reliable, and Can effectively save costs.

3. With the combination of the cooling path and the heat conduction path, the focus ring can achieve more accurate, precise, rapid and sensitive temperature control, so that the temperature can be adjusted during the plasma etching process, so as to meet higher and more precise technical requirements.

Although the content of the present invention has been described in detail through the above optional embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alternatives to the present invention will be obvious after reading the above content by those with ordinary knowledge in the technical field. Therefore, the scope of protection of the present invention should be limited by the scope of the attached patent application.

1: Reaction chamber 2: Gas shower head 3: Pedestal 4: Substrate 5: Focus ring 6, 6a, 6b, 6c: insulating ring 7: The second insulating ring 8: Shield ring 9: heater 10: Power 11: The first thermal pad 12: The second thermal pad 13: Compression ring 14: Cover ring 301: step RF: RF power

FIG. 1 is a schematic diagram of the structure of a plasma processing device in the prior art; 2 is a schematic diagram of the structure of a plasma processing device in the present invention; Fig. 3 is a schematic structural diagram of another plasma processing device in the present invention; Figure 4 is a schematic structural diagram of yet another plasma processing device in the present invention; Fig. 5 is a schematic diagram of the structure of the heater and the first insulating ring in still another plasma processing device of the present invention.

1: Reaction chamber

2: Gas shower head

3: Pedestal

4: Substrate

5: Focus ring

6, 6a, 6b, 6c: insulating ring

7: The second insulating ring

8: Shield ring

9: heater

10: Power

11: The first thermal pad

12: The second thermal pad

13: Compression ring

14: Cover ring

301: step

RF: RF power

Claims (15)

A plasma processing device includes: A vacuum reaction chamber in which there is plasma for processing a substrate; A base supporting the substrate is provided at the bottom of the vacuum reaction chamber; A focusing ring is arranged around the outer edge of the base; among them, A first insulating ring is arranged under the focusing ring, and the first insulating ring surrounds the base; A heater is arranged inside or below the first insulating ring; A shielding ring is provided under the first insulating ring, and the shielding ring is grounded and surrounds the base; A circuit wiring is arranged inside the shielding ring, and the circuit wiring is used to provide electric power to the heater. The plasma processing device according to claim 1, further comprising: a second insulating ring is arranged around the shielding ring and the base. The plasma processing device according to claim 2, wherein the heater is arranged below the first insulating ring, and extends from the shielding ring to above a part of the second insulating ring. The plasma processing device according to claim 3, wherein the connection between the heater and the lower surface of the first insulating ring includes: pasting or vulcanization. The plasma processing device according to claim 3, wherein the upper surface of the heater is directly coated on the lower surface of the first insulating ring, and the heater is located on the shielding ring and part of the second insulating ring Above. The plasma processing device according to claim 2, wherein the first insulation ring includes: a middle insulation ring, an upper insulation ring located above the middle insulation ring, and a lower insulation ring located below the middle insulation ring; The side walls of the upper insulating ring, the middle insulating ring and the lower insulating ring are all in contact with the side wall of the base; A part of the upper surface of the middle insulation ring away from the base is not covered by the upper insulation ring, so that a first groove is formed between the upper insulation ring and the middle insulation ring; A part of the lower surface of the middle insulation ring away from the base is not covered by the lower insulation ring, so that a second groove is formed between the lower insulation ring and the middle insulation ring; Part of the second insulating ring is located in the second groove. The plasma processing device according to claim 6, wherein the heater is disposed on the lower surface of the middle insulating ring at the bottom of the second groove, and extends from the shielding ring to part of the upper part of the second insulating ring. The plasma processing device according to claim 7, wherein the connection between the heater and the lower surface of the middle insulating ring includes: pasting or vulcanization. The plasma processing device according to claim 7, wherein the upper surface of the heater is directly plated on the lower surface of the middle insulating ring at the bottom of the second groove. The plasma processing device according to claim 3 or 7, wherein an insulating film is provided on the surface of the heater; the material of the insulating film includes: polyimide material or ceramic. The plasma processing device according to claim 1, wherein a first thermal pad is provided at the interface between the focus ring and the first insulating ring in contact with each other; The contact interface is provided with a second thermal pad. The plasma processing device according to claim 11, wherein the materials of the first thermal pad and the second thermal pad include: elastic silicone material. The plasma processing device according to claim 1, further comprising: A temperature detector for real-time detection of the temperature of the focus ring; A temperature controller is used to control the on or off of the heater according to the temperature signal fed back by the temperature detector. The plasma processing device according to claim 13, wherein the temperature detector is arranged under the first insulating ring, and its circuit wiring is arranged in the shielding ring, and is led out to the outside of the vacuum reaction chamber and the temperature Controller connection. The plasma processing device according to claim 6, further comprising: a compression ring is arranged around the outer edge of the focus ring, a part of the compression ring is located in the first groove, the compression ring and the The side wall of the upper insulating ring of the side wall of the first groove is in contact with the side wall; a covering ring is arranged around the outer edge of the first insulating ring and above the focusing ring and the pressing ring.

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