TW202121934A - Plasma processing device and adjusting method thereof - Google Patents

Abstract

The invention discloses a plasma processing device and an adjusting method thereof. The plasma processing device comprises a processing cavity, a base, an electrostatic chuck, a focusing ring, a heat conduction ring and an expandable member, wherein the base is positioned at the bottom in the processing cavity; the electrostatic chuck is located on the base and used for bearing and adsorbing a to-be-processed substrate; the focusing ring surrounds the electrostatic chuck; the heat conduction ring is located below the focusing ring and surrounds the base; and the expandable member is fixed to the bottom of the processing cavity and is connected with the heat conduction ring, the expandable member includes a material having a high coefficient of thermal expansion, a first fluid groove is formed in the expandable member and used for containing first fluid, the expandable member can be expanded and contracted by changing the temperature of the first fluid, and the height of the focusing ring is changed by driving the heat conduction ring to move in the direction perpendicular to the surface of the electrostatic chuck. The plasma processing device can dynamically adjust the collimation of edge etching of the to-be-processed substrate.

Description

Plasma processing device and its adjusting method

The present invention relates to the field of semiconductors, in particular to a plasma processing device and an adjustment method thereof.

Existing plasma processing equipment includes capacitively coupled plasma etching equipment (CCP) and inductively coupled plasma etching equipment (ICP). Since the inductively coupled plasma (ICP) etching device and the capacitively coupled plasma (CCP) etching device are simple in structure and relatively cheap, they are widely used in the dry etching field.

The density distribution of plasma in the plasma processing device is proportional to the etching rate of the substrate to be processed. The higher the plasma density, the higher the etching rate, and the lower the plasma density, the lower the etching rate. Due to the effect of plasma airflow, the plasma density in the central area of the substrate to be processed decreases, and the plasma density at the edge of the substrate to be processed increases, resulting in a decrease in the etching rate of the central area of the surface of the substrate to be processed, and an increase in the etching rate of the edge. , Which in turn leads to uneven etching rate of the substrate to be processed.

In order to solve the above problems, a focus ring is arranged on the periphery of the substrate to be processed, which is equivalent to expanding the radius of the substrate to be processed outwards, so that plasma with the same conditions as that on the substrate to be processed is generated above the focus ring, effectively removing The edge of the plasma distribution above the substrate to be processed extends to the outer side wall of the focusing ring, which increases the distribution range of the plasma, broadens the density distribution curve of the plasma on the surface of the substrate to be processed, and makes the density of the plasma on the substrate to be processed The distribution tends to be flat, and the plasma density distribution on the substrate to be processed is more uniform, which helps to ensure the uniformity of the etching process in the edge area and the center area.

Usually, silicon or silicon carbide is used as the material of the focus ring. As the etching process time increases, the surface of the focus ring will also be consumed by plasma etching. The height of the surface of the focus ring is reduced, so that the plasma sheath above the focus ring moves downward, and the etching collimation of the edge area of the substrate to be processed is poor. However, unless a new focus ring is replaced, it is difficult for the existing plasma processing device to adjust the height of the focus ring, which makes it difficult to adjust the etching collimation of the edge of the substrate to be processed in real time.

The method of the present invention to solve the technical problem is to provide a plasma processing device and an adjustment method thereof, so as to dynamically adjust the alignment of the edge etching of the substrate to be processed without replacing a new focus ring.

In order to solve the above technical problems, the present invention provides a plasma processing device, which includes: a processing chamber; a base located at the bottom of the processing chamber; an electrostatic chuck located on the base and used for bearing and adsorbing the substrate to be processed; focusing; The ring surrounds the electrostatic chuck; the heat conduction ring is located below the focus ring and surrounds the base; the expandable part is fixed at the bottom of the processing chamber and is connected with the heat conduction ring. The expandable part includes a material with a high thermal expansion coefficient and is inside the expandable part There is a first fluid groove, the first fluid groove is used to contain the first fluid, change the temperature of the first fluid, so that the expandable member is heated to expand or cool down, and the heat transfer ring is driven to move in the direction perpendicular to the surface of the electrostatic chuck to realize the alignment Changes in the height of the focus ring.

Preferably, the material of the expandable member is a metal material with a high thermal expansion coefficient; the metal material with a high thermal expansion coefficient includes an aluminum alloy.

Preferably, the material of the expandable member is an organic material with a high thermal expansion coefficient; the organic material with a high thermal expansion coefficient includes: polymethyl methacrylate, polyvinyl chloride, and polyamide.

Preferably, the top of the expandable member is connected to the bottom of the heat conducting ring.

Preferably, the side wall of the expandable member is connected to the side wall of the heat conduction ring, and the expandable member surrounds the heat conduction ring.

Preferably, the expandable element and the heat conducting ring are fixed by screws.

Preferably, it further comprises: a heat isolation ring located between the expandable member and the heat conduction ring.

Preferably, the expandable member has a cylindrical structure.

Preferably, the number of expandable members is greater than one, and the plurality of expandable members are separated from each other and distributed around the thermal base.

Preferably, it further comprises: an edge ring, the edge ring is located on the expandable member, and there is a gap between the expandable member and the edge ring, so that the expandable member has enough space for expansion.

Preferably, it further includes: a mounting substrate on the top of the processing chamber and a gas shower head on the mounting substrate, the gas shower head being arranged opposite to the electrostatic chuck.

Preferably, it further comprises: an insulating window located on the top of the processing chamber; and an inductor coil located on the insulating window.

Preferably, it further comprises: an insulating ring located between the expandable member and the bottom of the processing chamber.

Correspondingly, the present invention further provides a plasma processing device adjustment method, including: providing the plasma processing device described above, and the distance between the top of the focus ring and the electrostatic chuck exceeds a preset range; and inputting the first fluid tank into the first fluid tank. A fluid that adjusts the temperature of the first fluid to expand or contract the expandable member, driving the heat transfer ring and the focusing ring to move in a direction perpendicular to the surface of the electrostatic chuck until the distance between the focusing ring and the electrostatic chuck is within a preset range Inside.

Preferably, the first plasma process is performed in the plasma processing device, and the distance between the top of the focus ring and the electrostatic chuck in the initial stage of the first plasma process is set to L, and as the first plasma process proceeds , The distance between the top of the focus ring and the electrostatic chuck is gradually less than L. When the distance between the top of the focus ring and the electrostatic chuck exceeds the preset range L-ΔL, the temperature of the first fluid is increased to expand the expandable part , To drive the focus ring to move upward until the distance between the top of the focus ring and the electrostatic chuck is restored to L.

Preferably, after the first plasma process is performed in the plasma processing device, the second plasma process is performed; the second plasma process has a different preset range from the first plasma process. By adjusting the temperature of the first fluid, The expandable member is expanded or contracted to drive the heat conduction ring and the focus ring to move in a direction perpendicular to the surface of the electrostatic chuck until the distance between the focus ring and the electrostatic chuck is within the preset range of the second plasma process.

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

In the plasma processing device provided by the technical scheme of the present invention, the expandable member includes a material with a high thermal expansion coefficient, and the expandable member can be expanded or contracted by adjusting the temperature of the first fluid in the expandable member. Since the expandable member is connected with the heat conducting ring, when the expandable member expands or contracts, the heat conducting ring will be driven to move. The heat conduction ring is located below the focus ring. Therefore, when the expandable member expands or contracts, the focus ring can be raised or lowered, so that the height difference between the focus ring and the surface of the electrostatic chuck can be adjusted, and the surface of the electrostatic chuck The direction of the electric field in the edge area of the substrate to be processed can be adjusted, so it is beneficial to dynamically adjust the collimation of the edge area of the substrate to be processed.

Further, the side wall of the expandable member is connected with the side wall of the heat conduction ring, so that the height of the expandable member is higher, and when the expandable member rises to a certain temperature, the expansion compensation amount of the expandable member is larger. In other words, to achieve the same expansion compensation amount, because the height of the expandable member is larger, the temperature of the expandable member that needs to be raised is lower.

As described in the prior art, the existing plasma processing device is difficult to adjust the alignment of the edge etching of the substrate to be processed. In order to solve the above technical problems, the technical solution of the present invention provides a plasma processing device, including: a processing chamber; a base, Located at the bottom of the processing chamber; electrostatic chuck, located on the base, used to carry and adsorb the substrate to be processed; focusing ring, surrounding the electrostatic chuck; heat conduction ring, located below the focusing ring and surrounding the base; expandable The expandable element is connected with the heat conduction ring. The expandable element includes a material with a high thermal expansion coefficient. The expandable element has a first fluid groove in the expandable element, and the first fluid groove is used for accommodating the first fluid. The plasma processing device can dynamically adjust the alignment of the etching in the edge area of the substrate to be processed without replacing a new focus ring.

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 plasma processing device of the present invention.

Please refer to FIG. 1, the present invention provides a plasma processing device, including: a processing chamber 100; a base 101 located at the bottom of the processing chamber 100; an electrostatic chuck 102, located on the base 101, used to carry and adsorb to be processed Substrate; focusing ring 103, surrounding the electrostatic chuck 102; thermally conductive ring 104, located below the focusing ring 103 and surrounding the base 101; expandable member 105, connected to the thermally conductive ring 104, the expandable member 105 includes a material with a high thermal expansion coefficient , The expandable member 105 has a first fluid groove 105a, and the first fluid groove 105a is used to contain the first fluid, change the temperature of the first fluid, so that the expandable member 105 expands or contracts, and drives the heat conduction ring 104 along the vertical direction of the static electricity. The direction movement of the surface of the chuck 102 realizes the change of the height of the focus ring 103.

In this embodiment, the plasma processing device is a capacitively coupled plasma etching device (CCP), and the plasma processing device further includes: a mounting substrate (not shown in the figure) on the top of the processing chamber 100 and a mounting substrate (in the figure) (Not shown) on the gas shower head 106, the gas shower head 106 is arranged opposite to the electrostatic chuck 102; the gas supply device 107 connected to the gas shower head 106, the gas supply device 107 is used to supply the gas shower head 106 The reaction gas is conveyed inside; the radio frequency power source connected to the gas shower head 106 or the base 101, the corresponding gas shower head 106 or the base 101 is grounded, and the radio frequency signal generated by the radio frequency power source passes through the gas shower head 106 and the base The capacitor formed by 101 converts the reaction gas into plasma, and the plasma is used for plasma processing of the substrate to be processed.

The focus ring 103 is arranged on the periphery of the substrate to be processed, which is equivalent to expanding the radius of the substrate to be processed outwards, so that the plasma above the focus ring 103 and the same condition as that on the substrate to be processed is generated, effectively reducing the size of the substrate to be processed. The upper plasma distribution edge extends to the outer side wall of the focusing ring 103, which increases the distribution range of the plasma and broadens the density distribution curve of the plasma on the surface of the substrate to be processed, so that the density distribution of the plasma on the substrate to be processed If it tends to be flat, the plasma density distribution on the substrate to be processed is more uniform, which helps to ensure the uniformity of the etching process in the edge area and the center area.

The material of the focus ring 103 includes silicon or silicon carbide, and the material of the substrate to be processed includes silicon. Therefore, it is easy to etch the surface of the focus ring 103 during the plasma treatment on the surface of the substrate to be processed. In other words, in the process of plasma processing on the surface of the substrate to be processed, the height of the focus ring 103 will be continuously reduced. In view of this, the initial design height of the focus ring 103 is slightly higher than the height of the substrate to be processed. The difference between the initial design height of the focus ring 103 and the surface of the substrate to be processed is defined as L. At this time, the edge of the surface of the substrate to be processed The collimation of the area and the central area is better.

As the etching process progresses, the height of the focus ring 103 is continuously reduced, so that the height difference between the focus ring 103 and the substrate to be processed is less than L. Within a certain reduction range of the height of the focus ring 103, the alignment of the edge area of the substrate to be processed is The straightness is acceptable, and it is defined that the height difference between the focus ring 103 and the surface of the substrate to be processed at this time is L-ΔL (greater than 0). When the height of the focus ring 103 continues to decrease, the height difference between the focus ring 103 and the substrate to be processed will be less than L-ΔL. At this time, the alignment of the edge of the substrate to be processed will exceed the acceptable range. The usual solution is to replace the focus ring 103 with a new one. However, replacing the focus ring 103 with a new one will inevitably increase the cost. The solution of the present invention includes: without replacing the focus ring 103 with a new one, the focus ring 103 is raised through the expandable member 105 to restore the height difference between the focus ring 103 and the substrate to be processed to L. The raising of the focus ring 103 by the expandable member 105 will be described in detail below.

In this embodiment, the material of the expandable member 105 includes: a metal material with a high thermal expansion coefficient; and a metal material with a high thermal expansion coefficient includes aluminum alloy (the thermal expansion coefficient is 23.3×10 ^-6 /degree Celsius).

In other embodiments, the material of the expandable member includes: an organic material with a high thermal expansion coefficient; an organic material with a high thermal expansion coefficient includes: polymethyl methacrylate (thermal expansion coefficient of 130×10 ^-6 /degree Celsius), polyvinyl chloride (The coefficient of thermal expansion is 80×10 ^-6 / degree Celsius) and polyamide (the coefficient of thermal expansion is between 110×10 ^-6 / degree Celsius ~ 140×10 ^-6 / degree Celsius).

Since the expandable member 105 is rigidly connected to the heat conduction ring 104, the heat conduction ring 104 is located below the focus ring 103 and is used to support the focus ring 103 and control the temperature of the focus ring. Therefore, the expandable member 105 can be expanded by increasing the temperature of the first fluid. In this way, the expandable member 105 will drive the heat conducting ring 104 to push up the focusing ring 103, so that the plasma sheath on the surface of the focusing ring 103 is raised. It is beneficial to improve the direction of the electric field in the edge area of the substrate to be processed. Therefore, it is beneficial to improve the collimation of the edge area of the substrate to be processed, and improve the uniformity of etching between the edge area and the central area of the substrate to be processed.

The first fluid includes liquid or gas.

In this embodiment, it further includes: a thermally conductive coupling ring 108 located between the focus ring 103 and the thermally conductive ring 104; disposed at the interface between the thermally conductive coupling ring 108 and the focus ring 103, and the interface between the thermally conductive coupling ring 108 and the thermally conductive ring 104处的热热胶109。 At the thermally conductive glue 109.

The thermally conductive coupling ring 108 can promote heat conduction between the thermally conductive ring 104 and the focusing ring 103. The material of the thermally conductive coupling ring 108 includes: a material with good thermal conductivity but electrical insulation, for example, the material of the thermally conductive coupling ring 108 includes: alumina or quartz.

The thermally conductive glue 109 is used to improve the heat transfer at the interface between the thermally conductive coupling ring 108 and the focusing ring 103 and the interface between the thermally conductive coupling ring 108 and the thermally conductive ring 104, which is beneficial for the thermally conductive ring 104 to better control the temperature of the focusing ring 103.

The focus ring 103 is continuously bombarded by plasma during the plasma treatment process, so that the temperature of the focus ring 103 is relatively high. The temperature of the focus ring 103 is relatively high, which is not conducive to improving the distribution of plasma. Therefore, a second fluid groove 104a is provided in the heat conduction ring 104. By controlling the temperature of the second fluid in the second fluid groove 104a, the focus ring 103 can be controlled. The temperature is lowered to prevent the temperature of the focus ring 103 from being too high.

The significance of the connection between the expandable member 105 and the heat conduction ring 104 is that the expandable member 105 drives the heat conduction ring 104 to push up the focus ring 103. On the one hand, the capacitance between the focus ring 103 and the heat conduction ring 104 does not change, while the heat conduction ring 104 and the susceptor 101 are equipotential, the capacitance between the focus ring 103 and the susceptor 101 does not change, so that the thickness of the plasma sheath in the edge area of the substrate to be processed does not change. On the other hand, during the movement, the thermal conduction ring 104 can still independently control the temperature of the focus ring 103, so that the temperature difference between the focus ring 103 and the edge of the substrate to be processed can be adjusted, and the polymer at the edge of the substrate to be processed can be adjusted. The distribution of is conducive to the formation of grooves that meet the requirements of the process in the edge area of the substrate to be processed.

In addition, when the expandable member 105 drives the heat conduction ring 104 to lift the focus ring 103, the heat conduction ring 104, the heat conduction coupling ring 108, and the focus ring 103 are lifted at the same time, instead of only the focus ring 103 being lifted, so that the focus ring 103 is lifted. There is no gap between the focus ring 103 and the thermally conductive coupling ring 108 due to the lifting of the focus ring 103 and the thermally conductive coupling ring 108 is not lifted. Therefore, it is beneficial to avoid arc discharge between the focus ring 103 and the thermally conductive coupling ring 108. At the same time, the heat conduction ring 104, the heat conduction coupling ring 108 and the focus ring 103 are raised and lowered at the same time, which can effectively ensure the temperature transfer between the focus ring 103 and the heat conduction ring 104.

In this embodiment, the side wall of the expandable member 105 is connected to the side wall of the heat conduction ring 104, the expandable member 105 surrounds the heat conduction ring 104, and the bottom of the expandable member 105 is connected to the processing chamber 100, so that the height of the expandable member 105 is relatively high. high. The formula for the compensation amount of the expandable member 105 is Δd=d*(T-T0)*α. Among them, Δd is the compensation amount of the expandable member 105, d is the height of the expandable member 105, T is the temperature of the expandable member 105, and T0 is the reference temperature of the expandable member 105. It can be seen from the formula for the compensation amount of the expandable member 105 that when T-T0 is constant, the higher the height of the expandable member 105, the greater the compensation amount of the expandable member 105, or in other words, when the compensation amount of the expandable member 105 is constant, The higher the height of the expandable member 105, the higher the temperature can be achieved.

In this embodiment, a thermal isolation ring 110 is provided between the expandable member 105 and the heat conduction ring 104. The thermal isolation ring 110 is used to prevent mutual interference between the expandable member 105 and the heat conduction ring 104.

In this embodiment, the plasma processing device further includes: an edge ring 111, the edge ring 111 is located on the expandable member 105, and there is a gap 150 between the expandable member 105 and the edge ring 111, so that the expandable member 105 has enough The space expands; the isolation ring 112 located below the edge ring 111, the isolation ring 112 surrounds the expandable member 105; the bottom ground ring 113 surrounding the isolation ring 112; the plasma confinement ring 114 located between the bottom ground ring 113 and the processing chamber 100 .

In this embodiment, the height of the expandable member 105 is not too high, which is beneficial to the layout of the edge ring 111.

In this embodiment, an insulating ring 160 is further provided between the expandable member 105 and the bottom of the processing chamber 100. The insulating ring 160 is used to separate the expandable member 105 from the processing chamber 100. Although the heat conduction ring 104 is at a high potential and the processing chamber 100 is grounded, since the insulating ring 160 separates the expandable member 105 from the processing chamber 100, arc discharge is unlikely to occur between the heat conduction ring 104 and the expandable member 105. At the same time, the heat conduction ring 104, the heat conduction coupling ring 108 and the focus ring 103 are raised and lowered at the same time, which can effectively ensure the temperature transfer between the focus ring 103 and the heat conduction ring 104.

In this embodiment, the device for driving the lifting and lowering of the focus ring 103 is relatively simple, avoiding a complicated mechanical lifting device.

In addition to the above-mentioned raising of the focus ring 103, the expandable member 105 restores the height difference between the focus ring 103 and the substrate to be processed to L to continue the original plasma manufacturing process, the expandable member 105 can be further used for adjustment The height of the focus ring 103 can meet the requirements of other plasma processes. This is because: in order to increase the utilization rate of the plasma processing device, the plasma processing device does not only perform one plasma process, but can perform a variety of different plasma processes, and different plasma processes affect the top of the focus ring 103 The requirements for the distance to the electrostatic chuck 102 are different. Therefore, by adjusting the temperature of the first fluid, the expandable member 105 can be expanded or contracted to drive the heat conduction ring 104 and the focusing ring 103 to move in a direction perpendicular to the surface of the electrostatic chuck 102 until the focusing ring 103 reaches the electrostatic chuck 102. The distance between them meets the needs of different plasma processes.

Fig. 2 is a schematic structural diagram of another plasma processing device of the present invention.

Please refer to FIG. 2, the present invention provides a plasma processing device, including: a processing chamber 200; a base 201, located at the bottom of the processing chamber 200; an electrostatic chuck 202, located on the base 201, for carrying and adsorbing to be processed Substrate; focusing ring 203, surrounding the electrostatic chuck 202; heat conducting ring 204, located below the focusing ring 203 and surrounding the base 201; expandable member 205, connected to the heat conducting ring 204, the expandable member 205 includes a material with a high thermal expansion coefficient , The expandable member 205 has a first fluid groove 205a, and the first fluid groove 205a is used to contain the first fluid, change the temperature of the first fluid, so that the expandable member 105 expands or contracts, and drives the heat conducting ring 104 along the vertical direction of the static electricity. The direction movement of the surface of the chuck 102 realizes the change of the height of the focus ring 103.

In this embodiment, the plasma processing device is an inductively coupled plasma etching equipment (ICP). The plasma processing device includes: an insulating window 206 on the top of the processing chamber 200; an inductor coil 207 on the insulating window 206; and a gas delivery channel 208, used to deliver reaction gas into the processing chamber 200. The inductance coil 207 is connected to a radio frequency power source (not shown in the figure), and the radio frequency power source drives the inductance coil 207 to generate a strong high-frequency alternating magnetic field, which converts the reaction gas into plasma, which is used to process the surface of the substrate to be processed. Plasma process processing.

In this embodiment, the top of the expandable member 205 is connected to the bottom of the heat conducting ring 204.

Similar to the above embodiment, the expandable member 205 can raise the focus ring 203 to restore the height difference between the focus ring 203 and the substrate to be processed to L to continue the original plasma process, the expandable member 205 can be further It is used to adjust the height of the focus ring 203 to meet the requirements of different plasma processes. In this embodiment, a thermally conductive coupling ring and a thermally conductive adhesive are further provided between the focusing ring 203 and the thermally conductive ring 204, and the thermally conductively coupled ring and thermally conductive adhesive are the same as those in the foregoing embodiment, and will not be repeated here.

The expandable member 205 raises or lowers the heat conduction ring 204, the heat conduction coupling ring, and the focus ring 203 at the same time. On the one hand, the capacitance between the focus ring 203 and the heat conduction ring 204 remains unchanged, and the heat conduction ring 204 and the base 201 have the same potential. Therefore, the capacitance between the focus ring 203 and the base 201 does not change, so that the thickness of the plasma sheath in the edge region of the substrate to be processed does not change. On the other hand, during the movement, the thermal conduction ring 204 can still independently control the temperature of the focus ring 203, so that the temperature difference between the focus ring 203 and the edge of the substrate to be processed can be adjusted, and the polymer at the edge of the substrate to be processed can be adjusted. The distribution of is conducive to the formation of grooves that meet the requirements of the process in the edge area of the substrate to be processed.

In addition, the expandable member 205 raises or lowers the heat conducting ring 204 and the focusing ring 203 at the same time, instead of only raising or lowering the focusing ring 203, so that the focusing ring 203 and the thermally conductive coupling ring will not be lifted due to the focusing ring 203. The thermally conductive coupling ring is not lifted or lowered to form a gap. Therefore, it is beneficial to avoid arc discharge between the focus ring 203 and the thermally conductive coupling ring.

In this embodiment, an insulating ring 260 is further provided between the expandable member 205 and the processing chamber 200, and the insulating ring 260 is the same as that of the foregoing embodiment, and will not be repeated here.

In this embodiment, the device for driving the lifting and lowering of the focus ring 203 is relatively simple, avoiding a complicated mechanical lifting device.

In either the plasma processing device in Figure 1 or Figure 2, the expandable member can be a cylindrical structure; or, the number of expandable members is greater than one, and the plurality of expandable members are separated from each other and surround the base. Block distribution. Hereinafter, description will be given with a top view of the expandable member and the heat conducting ring in the plasma processing device in FIG. 1.

FIG. 3 is a top view of an expandable member and a heat conduction ring in the plasma processing device of FIG. 1. FIG.

Please refer to FIG. 3, the expandable member 105 surrounds the heat conducting ring 104, and the side wall of the expandable member 105 and the side wall of the heat conducting ring 104 are connected by a connecting member 300.

In this embodiment, the expandable member 105 has a cylindrical structure. The connecting member 300 is distributed between the expandable member 105 and the heat conducting ring 104.

In this embodiment, the connecting member 300 is a screw. In other embodiments, the connecting member may further be other connecting devices.

In this embodiment, it further includes: a thermal isolation ring 110 located between the expandable member 105 and the heat conduction ring 104. The thermal isolation ring 110 is used to achieve thermal isolation between the expandable member 105 and the heat conduction ring 104.

Fig. 4 is a top view of another expandable member and a heat conducting ring in the plasma processing device in Fig. 1.

Please refer to FIG. 4, the expandable member 105 surrounds the heat conducting ring 104, and the side wall of the expandable member 105 and the side wall of the heat conducting ring 104 are connected through a connecting member 400.

In this embodiment, the expandable member 105 has an arc-shaped structure, and the number of expandable members 105 is greater than one. A plurality of expandable members 105 are distributed on the periphery of the heat conduction ring 104. When the height is different, it can be achieved by adjusting the expandable member 105 in different regions, which is beneficial to improve the uniformity of plasma distribution in the circumferential direction of the focusing ring.

In this embodiment, it further includes a heat isolation ring 110 between the expandable member 105 and the heat conduction ring 104.

The thermal isolation ring 110 and the connecting member 400 are the same as the embodiment shown in FIG. 3, and will not be repeated here.

Fig. 5 is a flow chart of the adjustment method of the plasma processing device of the present invention.

Please refer to FIG. 5, step S1: the above plasma processing device is provided, and the distance from the top of the focus ring to the surface of the electrostatic chuck exceeds a preset range.

Step S2: Input the first fluid into the first fluid tank, adjust the temperature of the first fluid, expand or contract the expandable member, and drive the heat conducting ring and the focusing ring to move in a direction perpendicular to the surface of the electrostatic chuck until the focusing ring reaches The distance between the electrostatic chucks is within a preset range.

The first plasma process is performed in the plasma processing device. Considering that the focus ring will be constantly worn out during the process of processing the surface of the substrate to be processed, the height of the new focus ring is slightly higher than the surface of the substrate to be processed. The difference between the height of the focus ring and the height of the substrate to be processed is L. At this time, the plasma processing device has good alignment of etching in the edge area and the center area of the surface of the substrate to be processed. As the etching process progresses, the height of the focus ring is continuously reduced, so that the height difference between the focus ring and the substrate to be processed is less than L. Within a certain reduction range of the height of the focus ring, the alignment of the edge area of the substrate to be processed remains It is acceptable. At this time, the height difference between the focus ring and the surface of the substrate to be processed is defined as L-ΔL. When the height of the focus ring continues to decrease, the height difference between the focus ring and the substrate to be processed will be greater than L-ΔL. At this time, the alignment of the edge of the substrate to be processed will exceed the acceptable range.

The time required for the height difference between the new focus ring and the substrate to be processed to change from L to L-ΔL is the first life, and the preset range is: L~(L-ΔL).

When the height difference between the focus ring and the surface of the substrate to be processed is L-ΔL, the expandable member expands and raises the focus ring, so that the height difference between the focus ring and the substrate to be processed is restored to L, so as to continue to satisfy the first plasma Process needs.

Specifically, the quantitative analysis of raising the focus ring to restore the height difference between the focus ring and the substrate to be processed L is as follows:

In this embodiment, (1) the height of the expandable part d=200mm, and the temperature range of the first fluid in the expandable part is T: 0°C~100°C; (2) the material of the expandable part is aluminum alloy, which is thermally expanded The coefficient is α=23.3*10 ^-6 /degree Celsius; (3) The initial height difference between the focus ring and the substrate to be processed is L=2mm, the first standard lifetime is T1=200 RF hrs, and the corresponding focus ring height is reduced by ΔL= 0.2mm; (4) The amount of compensation for the height of the focus ring by the expandable ring is: Δd=d*(T-T0)*α, where T0 is the reference temperature of the expandable part, assuming T0=Tlow=0 degrees Celsius.

In other embodiments, the height of the expandable member may further have other values.

According to the above conditions, the compensation amount obtained for the expandable part changes with the temperature of the expandable part as follows: Temperature of expandable parts (degrees Celsius) 20 40 60 80 100 Focus ring height compensation amount (mm) 0.09 0.19 0.28 0.37 0.47

It can be seen from the above table that when the first life is over, the temperature of the first fluid can be raised to 40 degrees Celsius. At this time, the height compensation amount of the focus ring by the expandable member is 0.19 mm. When the focus ring is raised by 0.19mm, the focus ring is basically restored to the initial position. At this time, the etching alignment of the edge area of the substrate to be processed is better. When the height compensation amount of the focus ring is 0.19mm, continue to perform the etching process on the substrate to be processed. Only when the height difference between the focus ring and the substrate to be processed is greater than L-ΔL, the second life of the focus ring will end. Roughly thinking that the second life is equal to the first life, then the total life of the focus ring will be extended to twice the first life at this time, that is, the total life of the focus ring at this time is 400 RF hrs.

When the second life of the focus ring ends, the temperature of the first fluid is raised to about 80 degrees Celsius to compensate the height of the focus ring again, and the compensation amount is 0.18 mm. When the focus ring is raised by 0.18 mm, the focus ring is basically restored to the initial position. At this time, the etching alignment of the edge area of the substrate to be processed is better. When the height compensation amount of the focus ring is 0.18mm, continue to perform etching processing on the substrate to be processed. When the height difference between the focus ring and the substrate to be processed is greater than L-ΔL, the third life of the focus ring will end, which is roughly regarded as the third life It is equal to the first life, then the total life of the focus ring at this time will be extended to 3 times the first life, that is, the total life of the focus ring at this time is 600 RF hrs.

When the third life of the focus ring is over, the temperature of the first fluid is raised to the highest point 100 degrees Celsius to complete the last compensation of the focus ring. This time the height compensation amount for the focus ring is 0.1mm, and the total life of the focus ring Will be extended to 3.5 times the first life, that is, the total life of the focus ring at this time is 700 RF hrs.

In summary, the factors affecting the service life of the focus ring include: the upper limit of the temperature of the first fluid. Specifically, the higher the upper limit of the temperature of the first fluid, the longer the service life of the focus ring. Conversely, when the upper limit of the first fluid temperature is lower, the service life of the focus ring is shorter.

When the upper limit temperature of the first fluid temperature and the initial height of the focus ring are sufficiently high, the service life of the focus ring will be extended to the Nth life, and Tn=N*T1, where T1 is the first life.

The heating method of the first fluid can be a jump heating, such as: 0°C-40°C-80°C-100°C; or, the heating method of the first fluid is a gradual heating method, such as: 0°C-5°C-10°C... -100 degrees Celsius.

However, in an actual plasma processing device, not only the first plasma process is performed in the plasma processing device, but also the second plasma process is performed. The preset range of the second plasma process is different from that of the first plasma process. By adjusting the temperature of the first fluid, the expandable member is expanded or contracted to drive the heat transfer ring and the focus ring to move in a direction perpendicular to the surface of the electrostatic chuck. Until the distance between the focus ring and the electrostatic chuck is within the preset range of the second plasma process.

Although the present invention is disclosed as above, the present invention is not limited to this. Anyone with ordinary knowledge in the field 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 of the patent application.

100,200: processing chamber 101, 201: Pedestal 102, 202: Electrostatic chuck 103,203: Focus ring 104, 204: heat conduction ring 104a: Second fluid tank 105,205: expandable parts 105a, 205a: first fluid tank 106: Gas sprinkler 107: Gas supply device 108: Thermally conductive coupling ring 109: Thermal conductive glue 110: Thermal isolation ring 111: Edge Ring 112: isolation ring 113: Grounding ring 114: Plasma Confinement Ring 150: gap 160,260: insulating ring 200: processing chamber 206: insulated window 207: Inductance coil 208: Gas delivery channel 300, 400: connector S1, S2: steps

Figure 1 is a schematic diagram of the structure of a plasma processing device of the present invention; Fig. 2 is a schematic structural diagram of another plasma processing device of the present invention; Fig. 3 is a top view of an expandable member and a heat conduction ring in the plasma processing device of Fig. 1; 4 is a top view of another expandable member and heat conducting ring in the plasma processing device of FIG. 1; Fig. 5 is a flow chart of the adjustment method of the plasma processing device of the present invention.

104: Heat conduction ring

105: expandable parts

110: Thermal isolation ring

300: connector

Claims (16)

A plasma processing device includes: A processing chamber; A base located at the bottom of the processing chamber; An electrostatic chuck, located on the base, for carrying and absorbing the substrate to be processed; A focusing ring surrounding the electrostatic chuck; A heat conduction ring located below the focusing ring and surrounding the base; An expandable member is fixed at the bottom of the processing chamber and connected to the heat conduction ring. The expandable member includes a material with a high thermal expansion coefficient. The expandable member has a first fluid groove in it, and the first fluid groove is used for accommodating a The first fluid changes the temperature of the first fluid to cause the expandable member to expand or contract, and the height of the focus ring is changed by driving the heat conducting ring to move in a direction perpendicular to the surface of the electrostatic chuck. The plasma processing device according to claim 1, wherein the material of the expandable member is a metal material with a high thermal expansion coefficient; the metal material with a high thermal expansion coefficient includes an aluminum alloy. The plasma processing device according to claim 1, wherein the material of the expandable member is an organic material with a high thermal expansion coefficient; the organic material with a high thermal expansion coefficient includes: polymethyl methacrylate, polyvinyl chloride, and polyamide. The plasma processing device according to claim 1, wherein the top of the expandable member is connected to the bottom of the heat conduction ring. The plasma processing device according to claim 1, wherein the side wall of the expandable member is connected to the side wall of the heat conduction ring, and the expandable member surrounds the heat conduction ring. The plasma processing device according to claim 1, wherein the expandable member and the heat conducting ring are fixed by screws. The plasma processing device according to claim 1, further comprising: a heat isolation ring located between the expandable member and the heat conduction ring. The plasma processing device according to claim 1, wherein the expandable member has a cylindrical structure. The plasma processing device according to claim 1, wherein the number of the expandable members is greater than one, and the plurality of expandable members are separated from each other and distributed around the base. The plasma processing device according to claim 5, further comprising: an edge ring, the edge ring is located on the expandable member, and there is a gap between the expandable member and the edge ring, so that the expandable member has Enough space for expansion. The plasma processing device according to claim 1, further comprising: a mounting substrate on the top of the processing chamber and a gas shower head on the mounting substrate, the gas shower head being arranged opposite to the electrostatic chuck . The plasma processing device according to claim 1, further comprising: an insulating window located on the top of the processing chamber; and an inductor coil located on the insulating window. The plasma processing device according to claim 1, further comprising: an insulating ring located between the expandable member and the bottom of the processing chamber. A method for adjusting a plasma processing device includes: To provide a plasma processing device according to any one of claim 1 to claim 13, wherein the distance from the top of the focus ring to the electrostatic chuck exceeds a preset range; Input the first fluid into the first fluid tank, adjust the temperature of the first fluid, make the expandable member expand or contract, and drive the heat conducting ring and the focusing ring to move in a direction perpendicular to the surface of the electrostatic chuck, Until the distance between the focus ring and the electrostatic chuck is within a preset range. The method for adjusting a plasma processing device according to claim 14, wherein a first plasma processing is performed in the plasma processing device, and the focus ring is set to the static electricity in the initial stage of the first plasma processing. The distance between the chucks is L. With the progress of the first plasma process, the distance from the top of the focus ring to the electrostatic chuck is gradually less than L. When the top of the focus ring to the electrostatic chuck is When the distance exceeds the preset range L-ΔL, the temperature of the first fluid is increased to expand the expandable member to drive the focus ring to move upward until the distance between the top of the focus ring and the electrostatic chuck is restored to L. The method for adjusting a plasma processing device according to claim 15, wherein after the first plasma processing is performed in the plasma processing device, a second plasma processing is performed; the second plasma processing is the same as the first plasma processing The preset range of the plasma manufacturing process is different. By adjusting the temperature of the first fluid, the expandable member is expanded or contracted, which drives the heat conducting ring and the focusing ring to move in a direction perpendicular to the surface of the electrostatic chuck until the focusing The distance between the ring and the electrostatic chuck is within the preset range of the second plasma process.

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