TW202314773A - Constraint ring, plasma processing device and exhaust control method of plasma processing device - Google Patents

Abstract

A confinement ring, a plasma processing apparatus and an exhaust control method thereof are provided, the confinement ring surrounds between a base periphery in a reaction chamber of the plasma processing apparatus and a side wall of the reaction chamber, the confinement ring includes at least one annular assembly forming an annular structure, the annular assembly includes a main body portion having a plurality of gas channels, and the gas channels are formed in the main body portion. And the height adjusting device is used for adjusting the height of the gas channel. A height adjusting device in the annular assembly is driven to move, and the height of a gas channel in the annular assembly is adjusted, so that the gas flow distribution in the reaction cavity is adjusted. The gas flow distribution in the reaction cavity is adjusted and balanced by uniformly or respectively adjusting the height of the gas channel in the restraint ring in multiple areas, and the device is high in operability and adaptability. The gas pressure in the reaction cavity can be reduced under the condition that the gas inlet flow is not changed, gas exchange in the reaction cavity and extraction of reaction by-products are facilitated, deposition of the reaction by-products on a wafer is reduced, and therefore the etching performance is improved.

Description

Confinement ring, plasma processing device and exhaust control method thereof

The invention relates to devices in the field of semiconductors, in particular to a confinement ring, a plasma processing device and an exhaust control method thereof.

Plasma processing processes used in the manufacture of integrated circuits include plasma deposition processes and plasma etching processes. In the process of processing a wafer through a plasma treatment process, the wafer is first fixedly placed in a plasma reaction chamber, and a patterned microelectronic layer is formed on the wafer. Then, the radio frequency energy is transmitted into the plasma reaction chamber through the radio frequency power transmitting device to form a radio frequency electric field; then various reactive gases (etching gas or deposition gas) are injected into the plasma reaction chamber, and the injected reaction gas is injected under the action of the radio frequency electric field. The top of the wafer is excited into a plasma state; finally, a chemical reaction and/or physical action (such as etching, deposition, etc.) occurs between the plasma and the wafer to form various characteristic structures, and the volatile reaction products formed in the chemical reaction It is separated from the surface of the material to be etched, and is pumped out of the plasma reaction chamber by the vacuum system.

In order to prevent the reaction by-products from carrying the plasma to areas other than the plasma processing area when they are discharged from the reaction chamber and causing damage to the area, a plasma confinement ring is usually set between the base carrying the wafer and the side wall of the reaction chamber. Also known as FEIS Ring (Flow Equalizing Ion Shield Ring). The confinement ring has a plurality of gas channels running through the upper and lower surfaces of the confinement ring, and the confinement ring can ensure that when the plasma gas formed above the base flows through the confinement ring, all the charged particles in it are extinguished and become neutral gas to flow downward.

With the gradual reduction of technology nodes in the semiconductor industry, in the plasma etching with the feature size (CD critical dimension) shrinking day by day, especially when the feature size is below 3nm, the requirements for small hole etching are getting higher and higher. For example, in the small hole etching of BARC (Bottom Anti-Reflective Coatings), when the technology node with a feature size of 3nm is reached, the BARC in the small hole will easily remain at the bottom of the hole, which will affect the subsequent process. The BARC residue at the bottom of the hole is due to the very small feature size, which makes it more difficult to enter the etching gas and extract the by-products, resulting in reduced etching performance and affecting the wafer processing quality and processing rate.

The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

The object of the present invention is to provide a confinement ring, a plasma processing device and its exhaust control method, which have strong operability and high adaptability, are conducive to the gas exchange in the reaction chamber and the extraction of reaction by-products, and reduce the deposition of reaction by-products on the wafer , improve etching performance.

In order to achieve the above object, the present invention provides a confinement ring for a plasma processing device, the plasma processing device includes a reaction chamber, a base for supporting a substrate is arranged in the reaction chamber, and the confinement ring is arranged around Between the periphery of the base and the sidewall of the reaction chamber, the confinement ring includes: at least one ring component, and the ring components together form a ring structure;

The ring assembly includes:

a body portion having a plurality of gas passages for venting gas to an exhaust region below the confinement ring;

a height adjusting device, the height adjusting device is used for adjusting the height of the gas channel.

The height adjusting device includes: an extension part movably arranged along the side wall of the gas passage, the shape of the extension part matches the shape of the gas passage.

On the one hand, when the gas channel is an annular channel, the main body part includes: at least two arc-shaped baffles arranged concentrically.

The length of the arc-shaped baffle gradually decreases from the outside to the inside of the side wall of the reaction chamber.

The main body part includes: at least one connecting rib, and the connecting rib is used for connecting the curved baffle.

The height adjusting device comprises: at least two concentrically arranged arc-shaped baffle extension pieces, and the arc-shaped baffle extension pieces are movably connected with the arc-shaped baffle.

The arc-shaped baffle extension piece has a groove, and the groove is used for accommodating the arc-shaped baffle.

The length of the arc-shaped baffle extension piece matches the length of the arc-shaped baffle it accommodates.

On the other hand, when the gas channel is a hole-shaped channel, the main body part includes: a plurality of through holes.

The height adjusting device includes: a plurality of extension tubes, and the extension tubes are movably arranged in the corresponding through holes.

The height of the gas channel is greater than or equal to twice the width of the gas channel.

The number of the ring components is at least two, the ring components are fan-shaped, and the central angles of the ring components are equal or unequal.

The annular assembly further includes: a connecting piece, the connecting piece is used for fixedly connecting the annular assembly to the side wall of the reaction chamber.

The height adjustment device also includes: at least one lifting rod, the lifting rod is connected to the arc-shaped baffle extension piece or the extension tube, and the lifting rod is used to drive the arc-shaped baffle extension piece or the extension tube to move up and down .

The height adjusting device also includes: a driving device, the driving device is used to drive the lifting rod to move.

The driving device includes one of a motor device, a hydraulic device or a pneumatic device.

It also includes a control mechanism for controlling the driving device to work.

The present invention also provides a plasma processing device, comprising:

A reaction chamber, a base for supporting the substrate is arranged in the reaction chamber;

As for the confinement ring, the confinement ring is arranged around the periphery of the base and the side wall of the reaction chamber.

The present invention also provides an exhaust control method for a plasma processing device, comprising the following steps:

providing said plasma processing apparatus; and

When the environment of the reaction chamber in the plasma processing device needs to be adjusted, the driving device is used to drive the height adjustment device in the annular assembly to move, and the height of the gas channel in the annular assembly is adjusted;

By adjusting the height of the gas channel in the ring component, the gas flow distribution in the reaction chamber is adjusted.

The driving device drives the elevating rod to drive the arc-shaped baffle extension piece or the extension tube to move up and down, thereby adjusting the height of the gas channel in the ring assembly.

On the one hand, the heights of the gas channels in the different annular components are the same.

On the other hand, the heights of the gas passages in different annular assemblies are different.

The heights of the gas passages in the annular assembly decrease in order according to the distance from the annular assembly to the exhaust area.

The invention adjusts and balances the gas flow distribution in the reaction chamber by uniformly or separately adjusting the height of the gas channel in the confinement ring in multiple regions, and has strong operability and high adaptability. The present invention can reduce the air pressure in the reaction chamber under the condition of constant intake flow rate, facilitate the gas exchange in the reaction chamber and the extraction of reaction by-products, reduce the deposition of reaction by-products on the wafer, thereby improving the etching performance.

A preferred embodiment of the present invention will be specifically described below with reference to FIGS. 1 to 11 .

Fig. 1 shows a kind of plasma treatment apparatus that comprises confinement ring, described plasma treatment apparatus 1 has a reaction chamber 10, and reaction chamber 10 is substantially columnar, and reaction chamber sidewall is vertical substantially, has in reaction chamber 10 The upper electrode 11 and the lower electrode 13 are arranged oppositely. Typically, the area between the upper electrode 11 and the lower electrode 13 is the processing area A, which will generate high frequency energy to ignite and maintain the plasma. The lower electrode 13 includes a base 131 on which the wafer W to be processed is placed. The reaction gas is input into the reaction chamber 10 from the gas source 12, and one or more radio frequency power sources 14 can be applied separately on the lower electrode 13 or simultaneously applied on the upper electrode 11 and the lower electrode 13 respectively, in order to The radio frequency power is delivered to the lower electrode 13 or the upper electrode 11 and the lower electrode 13 , so as to generate a large electric field inside the reaction chamber 10 . Most of the electric field lines are contained in the processing region A between the upper electrode 11 and the lower electrode 13, and this electric field accelerates a small amount of electrons present inside the reaction chamber 11 to collide with gas molecules of the input reaction gas. These collisions result in ionization of the reaction gas and excitation of the plasma, thereby generating a plasma within the reaction chamber 10 . The neutral gas molecules of the reactive gas lose electrons when subjected to these strong electric fields, leaving behind positively charged ions. Positively charged ions are accelerated toward the lower electrode 13 , combine with neutral substances in the wafer W to be processed, and excite processing of the wafer W, that is, etching, deposition, and the like. An exhaust area is provided at a suitable position of the plasma processing device 1, and the exhaust area is connected to an external exhaust device (such as a vacuum pump 15) to remove the used reaction gas and The by-product gas is drawn out of the processing area A, through which the gas flows and builds up the proper pressure in the processing area A. The plasma processing device 1 in FIG. 1 also includes a fixed confinement ring 16 , which is arranged around the periphery of the susceptor and the side wall of the reaction chamber. The charged particles in the plasma are extinguished through the confinement ring 16 to prevent the inner wall of the reaction chamber and the exhaust pipe below the confinement ring from being polluted.

As shown in Figure 2, the confinement ring has a plurality of gas passages 17 that run through the upper and lower surfaces of the confinement ring. The opening size and depth of these gas passages 17 are designed to ensure that when the plasma gas formed above the susceptor flows through the confinement ring, The ions in it are all extinguished and become neutral gas to flow downward. In order for the confinement ring to be able to confine the plasma well, a condition needs to be met: the height S' of the gas channel 17 on the confinement ring is greater than or equal to twice the width g' of the gas channel.

In BARC (Bottom Anti-Reflective Coatings) small hole etching, in order to improve the entry of etching gas and the extraction of by-products, it tends to use a process system that makes the pressure in the plasma reaction chamber smaller and the gas flow rate larger ( process regime), so as to obtain a faster etching rate in the small hole to reduce the residue of BARC in the hole.

When the air pressure in the reaction chamber is constant, the valve opening of the vacuum pump 15 will increase with the increase of the gas flow input from the gas source 12; when the gas flow reaches a certain value, the valve opening of the vacuum pump 15 will It will reach the maximum limit. In order to ensure that the pressure in the reaction chamber remains unchanged, the air flow cannot be increased further. On the other hand, when the gas flow input into the reaction chamber 10 is constant, the air pressure in the reaction chamber 10 will also have a minimum limit (the opening of the valve reaches the maximum limit at this time). In some etching processes, we hope to reduce the pressure in the reaction chamber without changing the gas flow, which will help the extraction of reaction by-products and reduce the deposition of reaction by-products on the wafer.

，另一個等離子反應裝置1中的約束環高度為

。向該兩個等離子體處理裝置1的反應腔10內輸入反應氣體的氣流量相同。在約束環高度為

時，反應腔10內氣壓的最低極限值能够達到15mT，且隨著真空泵15閥開度的變化，反應腔10內氣壓的最低極限值的調節範圍為10~25mT。在約束環高度為

時，反應腔10內氣壓的最低極限值只能到20mT，反應腔10內氣壓的最低極限值的調節範圍為20~25mT。該實驗證明，調整約束環16的高度能够拓寬反應腔10內的氣壓調節範圍，增大製程參數的窗口。並且，當閥開度相同時，約束環高度為a的氣壓較約束環高度為1.5a的氣壓低，因此，降低約束環16的高度有利於增加反應腔10內的流導（conductance），因此流進相同的氣流時反應腔10內能够達到更低的氣壓，所述反應腔10內的氣壓降低有助於反應物進入小洞以及反應副産物的抽出，減少反應副産物在晶圓W上的沉積。限定了反應腔10內氣壓的等離子體處理裝置被證明能够在晶圓W上製造和/或形成不斷縮小的特徵。蝕刻製程中，當氣流量不變，反應腔10內氣壓值越小，越有利於反應腔內氣體交換及反應副産物的抽出，從而提高蝕刻性能。 As shown in Figure 3, in an experiment, two plasma processing devices 1 as shown in Figure 1 are provided, each of which is provided with a confinement ring 16 in the two plasma processing devices 1, wherein one of the plasma reaction devices 1 The height of the confinement ring is

, the height of the confinement ring in another plasma reactor 1 is

. The flow rates of the reaction gases input into the reaction chambers 10 of the two plasma processing apparatuses 1 are the same. The height of the confinement ring is

, the minimum limit value of the air pressure in the reaction chamber 10 can reach 15mT, and with the change of the valve opening of the vacuum pump 15, the adjustment range of the minimum limit value of the air pressure in the reaction chamber 10 is 10~25mT. The height of the confinement ring is

, the lowest limit value of the air pressure in the reaction chamber 10 can only reach 20mT, and the adjustment range of the lowest limit value of the air pressure in the reaction chamber 10 is 20~25mT. This experiment proves that adjusting the height of the confinement ring 16 can widen the air pressure adjustment range in the reaction chamber 10 and increase the window of process parameters. Moreover, when the valve openings are the same, the air pressure at the height of the confinement ring a is lower than the air pressure at the height of the confinement ring 1.5a. Therefore, reducing the height of the confinement ring 16 is conducive to increasing the conductance (conductance) in the reaction chamber 10, so When the same airflow flows into the reaction chamber 10, a lower air pressure can be achieved, and the reduction of the air pressure in the reaction chamber 10 helps the reactants to enter the small holes and the extraction of the reaction by-products, reducing the deposition of the reaction by-products on the wafer W . A plasma processing apparatus that defines the gas pressure within reaction chamber 10 has been shown to be capable of fabricating and/or forming ever-shrinking features on wafer W. During the etching process, when the gas flow remains constant, the smaller the pressure in the reaction chamber 10 is, the more favorable the gas exchange and extraction of reaction by-products in the reaction chamber are, thereby improving the etching performance.

和

的約束環16。圖4顯示，在相同的製程參數下，當約束環高度為

時，小洞洞底無反應副産物殘留（圖4的左圖）；而當約束環高度為

時，小洞洞底有明顯的反應副産物殘留（圖4的右圖）。 The effect of the height of the confinement ring 16 on the wafer hole etching process was further verified by using the two plasma reaction devices 1 used in the above experiment. Figure 4 shows a comparison of two TEM (Transmission Electron Microscope transmission electron microscope) results of small hole etching when the feature size is less than 10nm. The plasma processing device 1 corresponding to the left and right diagrams in Fig. 4 respectively adopts a height of

and

The confinement ring 16. Figure 4 shows that under the same process parameters, when the confinement ring height is

When , no reaction by-products remain at the bottom of the small hole (left figure in Fig. 4); while when the height of the confinement ring is

At the same time, there are obvious reaction by-products left at the bottom of the small hole (the right picture of Figure 4).

The above exemplarily described the need to reduce the height of the confinement ring to be suitable for the BARC layer etching process. It can be seen that the adjustment of the height of the confinement ring 16 has a significant impact on the air pressure in the reaction chamber 10, because a variety of different processes need to be carried out in a reaction chamber. For the etching process, some processes require a large flow rate and low pressure of process gas, while some processes require the opposite. Therefore, by changing the height of the confinement ring 16, the pressure in the reaction chamber 10 can meet different process requirements.

Based on this, the present invention provides a confinement ring 16 for a plasma processing device, the confinement ring is arranged around the periphery of the base and the side wall of the reaction chamber, as shown in Figure 5, in this embodiment, the confinement ring The ring 16 comprises a complete annular ring assembly 23, the annular assembly 23 comprises a fixed body part, and a height adjusting device detachably connected with the body part, the body part has multiple A gas channel 17 is used to discharge gas to the exhaust area below the confinement ring, and the height adjusting device is used to adjust the height of the gas channel 17. As shown in Figures 5 and 6, the main body part includes a plurality of annular baffles 19, gas channels 17 are formed between adjacent annular baffles 19, and the annular baffles 19 are concentric circles. Set, the diameter of described annular baffle plate 19 decreases successively from outside to inside from reaction chamber side wall, to guarantee to form gas channel 17 between adjacent annular baffle plate 19, the width of gas channel 17 can be consistent, In another embodiment, it is also possible to set the width of the gas channel 17 to be inconsistent. Exemplarily, the outermost annular baffle 19 can be fixed to the side wall of the reaction chamber to complete the fixing of the annular ring assembly 23, or the circular ring assembly 23 can be fixed by using a connector (not shown in the figure). An annular ring assembly 23 is fixedly connected to the side wall of the reaction chamber. Furthermore, connecting ribs 20 are used to connect all the annular baffles 19 to prevent the annular baffles 19 from falling. The connecting ribs 20 can be located under all the annular baffles 19, that is, on the side away from the processing area A. In other embodiments, since the height adjustment device is generally installed under the main body, the In order to prevent the connecting rib 20 from obstructing the action of the height adjusting device, the connecting rib 20 can be arranged at a position relatively close to the top of the main body part. Since a complete annular ring assembly 23 is used in this embodiment, several connecting ribs 20 can be provided along the radial direction of the annular ring assembly 23 to ensure the uniformity and stability of the connection. As shown in Figures 5 and 6, the height adjustment device includes a plurality of annular baffle extensions 21, and the material of the annular baffle extensions 21 is the same as that of the annular baffle 19. , and the annular baffle extension 21 and the annular baffle 19 have also been surface treated, the number of the annular baffle extension 21 is the same as that of the annular baffle 19 The number is consistent, and the circular baffle extension piece 21 is also concentrically arranged, and the circular baffle extension piece 21 has a groove whose shape and size are the same as those of the circular baffle 19 The shape and size of each ring-shaped baffle 19 are correspondingly arranged in the groove of the matching ring-shaped baffle extension piece 21 . The thickness of both side walls of the groove of the annular baffle extension piece 21 should not be too thick, and it should be ensured that it does not affect the width of the gas channel 17 defined by the annular baffle 19 . In order to carry the circular baffle extension piece 21 and realize the up and down movement of the circular baffle extension piece 21, a connecting rod 22 is set, which is fixedly connected to all the circular baffle extension pieces 21, the The connecting rod 22 drives the circular-shaped baffle extension piece 21 to move up and down under the drive of the driving device (not shown in the figure), and when the circular-shaped baffle extension piece 21 moves upward, it is in contact with the circular-shaped baffle extension piece 21. Partial overlap of the baffle 19 reduces the height of the gas channel 17, and when the circular baffle extension 21 moves downward, the circular baffle 19 at least partially protrudes from the circular baffle extension 21 , the height of the gas channel 17 is raised. In the same way, since what is used in this embodiment is a complete annular ring assembly 23, several connecting rods 22 can be arranged along the radial direction of the annular ring assembly 23 to ensure the uniformity and stability of the connection. stability. As shown in FIG. 6 , in this embodiment, the connecting rod 22 is arranged at the bottom of the circular baffle extension piece 21 to facilitate its connection with the driving device. As shown in Figure 7, in another embodiment, the connecting rod 22 can be arranged in the middle of the circular baffle extension piece 21, respectively connected to the side walls of the circular baffle extension piece 21, also The function of simultaneously driving all the circular baffle extension pieces 21 to move up and down can be achieved. The driving device includes one or more of an electric device, a hydraulic device or a pneumatic device, and the computer system can be used to automatically control the driving device according to the semiconductor manufacturing process, or it can be manually controlled according to the semiconductor manufacturing process. In the above embodiment, the driving device drives the connecting rod 22 to drive the circular baffle extension piece 21 to move up and down along the circular baffle 19 to realize the height adjustment of the gas channel 17. The height of the gas channel 17 in the ring 16 reduces the pressure in the reaction chamber, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, and reduces the deposition of reaction by-products on the wafer, thereby improving the etching performance.

In another embodiment of the present invention, as shown in FIG. 8, the confinement ring 16' may be composed of a plurality of sector-shaped components 18, and all sector-shaped components 18 together form a ring-shaped structure. The structure of the fan ring assembly 18 is the same as that of the circular ring assembly 23 shown in FIGS. Adjustment device. In this embodiment, the central angles of each ring sector assembly 18 are set to be the same, for example, 6 or 8 ring sector assemblies 18 may be uniformly arranged. As shown in Figure 8, the main body part includes a plurality of arc-shaped baffles 19', and gas passages 17' are formed between adjacent arc-shaped baffles 19', and the arc-shaped baffles 19' are arranged concentrically, so The lengths of the arc-shaped baffles 19' gradually decrease from the side wall of the reaction chamber from the outside to the inside, so as to ensure that the width of each gas channel 17' is consistent. The outermost arc-shaped baffle 19' is fixed to the side wall of the reaction chamber to complete the fixing of the sector ring assembly 18, or a connector (not shown) may be used to securely connect the sector ring assembly 18 to the the side wall of the reaction chamber. Further adopt connecting rib 20' to connect all arc-shaped baffles 19' to prevent the arc-shaped baffles 19' from falling. In this embodiment, if the central angle of a single fan ring component 18 is not large (such as less than 60°), then only a single connecting rib 20' can be used, and if the central angle of a single fan ring component 18 is relatively large (For example, more than 60°), then two or three connecting ribs 20' can be considered to ensure the uniformity and stability of the connection. As shown in Figure 8 and Figure 6, the height adjustment device includes a plurality of arc-shaped baffle extension pieces 21', and the number of the arc-shaped baffle extension pieces 21' is consistent with the number of the arc-shaped baffles 19' , and the arc-shaped baffle extension piece 21' is also arranged concentrically, and the arc-shaped baffle extension piece 21' has a groove whose shape and size are consistent with the shape and size of the arc-shaped baffle 19' Size matching, each arc baffle 19' is correspondingly arranged in the groove of the matching arc baffle extension 21', the length of each arc baffle extension 21' is the same as the matching arc baffle 19' are equal in length. The thickness of the two side walls of the groove of the arc-shaped baffle extension piece 21' should not be too thick, and it should be ensured that it does not affect the width of the gas channel 17' determined by the arc-shaped baffle 19'. In order to carry the arc-shaped baffle extension piece 21' and realize the upward and downward movement of the arc-shaped baffle extension piece 21', a connecting rod 22' is provided, which is fixedly connected to all the arc-shaped baffle extension pieces 21', so that The connecting rod 22' drives the arc-shaped baffle extension piece 21' to move up and down under the drive of the driving device (not shown in the figure), when the arc-shaped baffle extension piece 21' moves upward, The arc-shaped baffle 19' partially overlaps, reducing the height of the gas channel 17', and when the arc-shaped baffle extension 21' moves downward, the arc-shaped baffle 19' is at least partly removed from the arc-shaped baffle extension 21 protruding, raising the height of the gas channel 17'. Similarly, if the central angle of a single fan ring component 18 is not large (such as less than 60°), then only a single connecting rod 22' can be used; if the central angle of a single fan ring component 18 is relatively large (such as more than 60°), then two or three connecting rods 22' can be considered to ensure the uniformity and stability of the connection. As shown in Fig. 8, in this embodiment, the connecting rod 22' is arranged at the bottom of the arc-shaped baffle extension piece 21', so as to facilitate its connection with the driving device. As shown in FIG. 7, in another embodiment, the connecting rod 22' can be arranged in the middle of the arc-shaped baffle extension piece 21', respectively connected to the side walls of the arc-shaped baffle extension piece 21', Likewise, the function of simultaneously driving all arc-shaped baffle extension pieces 21' to move up and down can be achieved. The driving device includes one or more of an electric device, a hydraulic device or a pneumatic device, and the computer system can be used to automatically control the driving device according to the semiconductor manufacturing process, or it can be manually controlled according to the semiconductor manufacturing process.

In the above embodiment, the height adjustment of the gas channel 17' is realized by driving the connecting rod 22' to drive the arc-shaped baffle extension piece 21' to move up and down along the arc-shaped baffle 19'. In this embodiment, since a plurality of fan ring assemblies 18 are provided, the height of the gas channel 17' in each fan ring assembly 18 can be adjusted separately. The heights of the gas passages 17' in all the fan ring assemblies 18 can be adjusted to the same height, or the heights of the gas passages 17' in each fan ring assembly 18 can be adjusted respectively according to the requirements of the process technology, because in the reaction chamber The exhaust device is generally arranged on one side of the bottom wall of the reaction chamber, so some fan-shaped ring components 18 in the confinement ring 16' are relatively close to the exhaust device, and accordingly, the reactants are drawn out faster, while Some fan ring components 18 in the confinement ring 16' are relatively far away from the exhaust device, and correspondingly, the reactant is extracted relatively slowly. In order to adapt to this situation, the height of the gas channel 17' in the fan ring assembly 18 that is closer to the exhaust device can be reduced, and the gas channel 17' in the fan ring assembly 18 that is farther away from the exhaust device can be reduced. The height of the fan ring assembly 18 is adjusted lower, so that the height of the gas channel 17' in the fan ring assembly 18 decreases sequentially according to the distance from the fan ring assembly 18 to the exhaust device. The air pressure can reduce the air pressure in the reaction chamber, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, and reduces the deposition of reaction by-products on the wafer, thereby improving the etching performance.

In another embodiment of the present invention, as shown in FIG. 9, the confinement ring 16' may be composed of a plurality of sector-shaped components 18, and all sector-shaped components 18 together form a ring-shaped structure, the The structure of the fan ring assembly 18 is the same as that of the circular ring assembly 23 shown in FIGS. Adjustment device. The difference between this embodiment and the embodiment shown in Figure 8 is that the central angle of each fan ring assembly 18 is set to be different, for example, the central angle of the fan ring assembly 18 that is relatively close to the exhaust device can be set relatively small (for example, less than 60°), the central angle of the fan ring assembly 18 that is relatively far away from the exhaust device can be set relatively large (for example, greater than 120°), or according to the needs of the manufacturing process, each fan ring can be specifically set Shape component 18 size and length. In this way, finer regulation of the air pressure in the entire reaction chamber can be achieved by adjusting the heights of the gas passages 17' in different fan ring assemblies 18 respectively, and by reducing the height of the gas passages 17' in the confinement ring 16' to reduce The air pressure in the reaction chamber is conducive to the gas exchange in the reaction chamber and the extraction of reaction by-products, reducing the deposition of reaction by-products on the wafer, thereby improving the etching performance.

In another embodiment of the present invention, the present invention provides a confinement ring 16-1 for a plasma processing device, the confinement ring is arranged around the periphery of the base and the side wall of the reaction chamber, as shown in FIG. 10 , In this embodiment, the confinement ring 16-1 comprises a complete annular ring component 23-1, and the ring component 23-1 comprises a fixed main body part and a detachable part from the main body part. Connected and movable height adjustment device, the main body part has a plurality of gas passages 17-1 for discharging gas to the exhaust area below the confinement ring, the height adjustment device is used to adjust the gas passages 17-1 1 height. As shown in FIG. 10 , the main body includes a plurality of through holes 24, each of which forms a gas channel 17-1, and the through holes 24 can be arranged in random order or in an orderly array, for example They can be arranged in concentric rings to form multiple concentric rings, and can also be arranged radially along the radial direction of the annular ring component 23-1. By setting the diameter of the through hole 24, the diameter of the gas passage 17-1 can be set to be uniform or non-uniform. The annular ring assembly 23-1 can be directly fixed to the side wall of the reaction chamber, or a connector (not shown) can be used to fix the annular ring assembly 23-1 to the side wall of the reaction chamber. side wall. As shown in Figure 11, the height adjustment device includes a plurality of extension tubes 25, the material of the extension tubes 25 is the same as that of the annular ring component 23-1, and the extension tubes 25 and the The annular ring assembly 23-1 has also been surface treated, the number of the extension tubes 25 is consistent with the number of the through holes 24, and the outer diameter of the extension tubes 25 is the same as the inner diameter of the through holes 24. Diameter size matching, each extension tube 25 is correspondingly arranged in the through hole 24 matched with it, the side wall of the extension tube 25 should not be too thick, and it should be guaranteed that it does not affect the gas channel 17- defined by the through hole 24. 1 diameter. In order to carry the extension tube 25 and realize the up and down movement of the extension tube 25, a connecting rod 26 is set, which is fixedly connected to all the extension tubes 25, and the connecting rod 26 is driven by the driving device (not shown in the figure). Drive the extension tube 25 to move up and down. When the extension tube 25 moves upward, it partially overlaps with the through hole 24, reducing the height of the gas channel 17-1. When the extension tube 25 moves downward, the The extension tube 25 protrudes at least partially from the through hole 24, raising the height of the gas channel 17-1. In the same way, since a complete annular ring assembly 23-1 is used in this embodiment, several connecting rods 26 can be provided along the radial direction of the annular ring assembly 23-1 to ensure the connection uniformity and stability. In this embodiment, the connecting rod 26 is arranged at the bottom of the extension pipe 25 to facilitate its connection with the driving device. In another embodiment, the connecting rods 26 can be arranged in the middle of the extension tubes 25 to connect the side walls of the extension tubes 25 respectively, so as to simultaneously drive all the extension tubes 25 to move up and down. The driving device includes one or more of an electric device, a hydraulic device or a pneumatic device, and the computer system can be used to automatically control the driving device according to the semiconductor manufacturing process, or it can be manually controlled according to the semiconductor manufacturing process.

In the above embodiment, the connecting rod 26 is driven by the driving device to drive the extension tube 25 to move up and down along the through hole 24 to realize the height adjustment of the gas channel 17-1. The height of the gas channel 17-1 reduces the pressure in the reaction chamber, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, and reduces the deposition of reaction by-products on the wafer, thereby improving the etching performance.

Similarly, the confinement ring 16-1 can also be composed of a plurality of fan-shaped components (not shown in the figure), and all the fan-shaped components together form a circular ring structure, and the structure of the fan-shaped components Same as the structure of the annular ring assembly 23-1 shown in FIGS. 10-11 , it also includes a fixed main body part and a height adjustment device that is detachably connected with the main body part and is movable. In this embodiment, the central angles of each ring sector component are set to be the same or different. In this way, finer adjustment of the air pressure in the entire reaction chamber can be achieved by adjusting the heights of the gas passages in different fan ring components respectively, and the air pressure in the reaction chamber can be reduced by reducing the height of the gas passages in the confinement ring, which is beneficial Gas exchange and extraction of reaction by-products in the reaction chamber reduce the deposition of reaction by-products on the wafer, thereby improving etching performance. The height-adjustable plasma confinement ring disclosed by the present invention can be applied to many different processes of plasma processing devices. It reduces the efficiency loss caused by the need to open the cavity to replace the plasma confinement rings of different heights when switching between different processes. At the same time, when the plasma confinement ring is set as several fan ring components, it can The height of the gas channel realizes the dynamic adjustment of the air pressure distribution at different positions in the reaction chamber, and ensures that the pressure in each area of the processing area A is consistent or deliberately realizes the inconsistency of the pressure so as to realize the compensation of other parameters. The driving device for controlling the lifting of the extension sheet in the present invention can be automatically controlled by a computer system according to the semiconductor manufacturing process, or manually controlled according to the semiconductor manufacturing process, so as to realize flexible adjustment.

The invention adjusts and balances the gas flow distribution in the reaction chamber by uniformly or separately adjusting the height of the gas channel in the confinement ring in multiple regions, and has strong operability and high adaptability. The present invention can reduce the air pressure in the reaction chamber under the condition of constant intake flow rate, facilitate the gas exchange in the reaction chamber and the extraction of reaction by-products, reduce the deposition of reaction by-products on the wafer, thereby improving the etching performance.

It should be noted that, in the embodiments of the present invention, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments, rather than indicating or implying that the referred device or element must have Certain orientations, constructed and operative in certain orientations, therefore are not to be construed as limitations on the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those having ordinary skill in the art of the present invention after reading the above disclosure. Therefore, the protection scope of the present invention should be limited by the scope of the appended patent application.

1: Plasma treatment device 10: Reaction chamber 11: Upper electrode 12: Gas source 13: Lower electrode 131: base 14: RF power supply 15: Vacuum pump 16: Constraint ring 16': Constraint ring 16-1: Constraint ring 17: Gas channel 17': gas channel 17-1: Gas channel 18: Fan ring component 19: Circular baffle 19': curved baffle 20: Connecting ribs 20': connecting rib 21: Circular baffle extension piece 22: connecting rod 23: ring component 23-1: Ring ring component 24: Through hole 25: extension tube 26: connecting rod A: Processing area g': width S': height W: Wafer

FIG. 1 is a schematic diagram of a plasma processing device including a confinement ring. Fig. 2 is a schematic diagram of the thickness of the confinement ring and the width of the gas channel in the present invention. Fig. 3 is a schematic diagram of the change of the minimum limit value of the air pressure in the reaction chamber with the opening of the vacuum pump valve under different confinement ring heights according to the present invention. Fig. 4 is a schematic diagram showing the comparison of the remaining bottom of the small hole at different confinement ring heights in the etching of small holes with a characteristic size of less than 10nm according to the present invention. Fig. 5 is a top view of a confinement ring provided in one embodiment of the present invention. Fig. 6 is a cross-sectional view along the line B-B in Fig. 5 in one embodiment. Fig. 7 is a cross-sectional view along B-B in Fig. 5 in another embodiment. Fig. 8 is a top view of the confinement ring provided in the third embodiment of the present invention. Fig. 9 is a top view of a confinement ring provided in a fourth embodiment of the present invention. Fig. 10 is a top view of a confinement ring provided in another embodiment of the present invention. Fig. 11 is a sectional view along C-C in Fig. 10 .

19: Circular baffle

20: Connecting ribs

21: Circular baffle extension piece

22: connecting rod

Claims (23)

A confinement ring for a plasma processing device, the plasma processing device includes a reaction chamber, a base for supporting a substrate is arranged in the reaction chamber, wherein the confinement ring is arranged around the periphery of the base and the reaction chamber Between the sidewalls of the chamber, the confinement ring comprises: at least one ring component that together forms a ring structure; The ring assembly contains: a body portion having a plurality of gas passages for venting gas to an exhaust region below the confinement ring; and A height adjustment device, the height adjustment device is used to adjust the height of the plurality of gas passages. The confinement ring for a plasma processing device as claimed in Claim 1, wherein the height adjustment device includes: an extension part movably arranged along the side walls of the plurality of gas channels, the shape of the extension part is consistent with that of the plurality of gas channels shape matches. The confinement ring for a plasma processing device as claimed in Claim 2, wherein when the plurality of gas channels are annular channels, the main body part includes: at least two arc-shaped baffles arranged concentrically. The confinement ring for a plasma processing device as claimed in Claim 3, wherein the length of the arc-shaped baffle gradually decreases from the outside to the inside of the side wall of the reaction chamber. The confinement ring for a plasma processing device as claimed in claim 4, wherein the main body part includes: at least one connecting rib, and the connecting rib is used for connecting the arc-shaped baffle. The confinement ring for a plasma processing device according to claim 3, wherein the height adjustment device comprises: at least two concentrically arranged arc-shaped baffle extension pieces, the arc-shaped baffle extension pieces and the arc-shaped baffle active connection. The confinement ring for a plasma processing device as claimed in claim 6, wherein the arc-shaped baffle extension piece has a groove for accommodating the arc-shaped baffle. The confinement ring for a plasma processing device as claimed in claim 5, wherein the length of the arc-shaped baffle extension piece matches the length of the arc-shaped baffle accommodated therein. The confinement ring for a plasma processing device according to claim 2, wherein when the plurality of gas channels are hole-shaped channels, the main body part includes: a plurality of through holes. The confinement ring for a plasma processing device as claimed in Claim 9, wherein the height adjustment device includes: a plurality of extension tubes, and the plurality of extension tubes are movably arranged in the plurality of through holes matched therewith. The confinement ring for a plasma processing device as claimed in Claim 1, wherein the height of the plurality of gas channels is greater than or equal to twice the width of the plurality of gas channels. The confinement ring for a plasma processing device as described in Claim 1, wherein the number of the ring components is at least two, the ring components have a fan-shaped structure, and the central angles of the two ring components are equal or different . The confinement ring for a plasma processing device as claimed in claim 12, wherein the ring component further comprises: a connecting piece, the connecting piece is used for fixedly connecting the ring component to the side wall of the reaction chamber. The confinement ring for a plasma processing device as claimed in claim 6 or 10, wherein the height adjustment device further comprises: at least one lifting rod connected to the arc-shaped baffle extension piece or the plurality of extension pipes, The lifting rod is used to drive the arc baffle extension piece or the plurality of extension tubes to move up and down. The confinement ring for a plasma processing device as claimed in claim 14, wherein the height adjusting device further includes: a driving device, the driving device is used to drive the lifting rod to move. The confinement ring for a plasma processing device as claimed in claim 15, wherein the driving device includes one of a motor device, a hydraulic device or a pneumatic device. The confinement ring for a plasma processing device as claimed in claim 16, further comprising a control mechanism for controlling the driving device to work. A plasma processing device comprising: A reaction chamber, a base for supporting the substrate is arranged in the reaction chamber; A confinement ring as claimed in any one of claims 1-17, the confinement ring is arranged around the periphery of the base and the side wall of the reaction chamber. A method for controlling exhaust gas of a plasma processing device, comprising the following steps: Provide a plasma processing device as described in claim 18; When the environment of a reaction chamber in the plasma processing device needs to be adjusted, a driving device is used to drive a height adjustment device in a ring component to move, and adjust the height of a gas channel in the ring component; and By adjusting the height of the gas channel in the annular component, the gas flow distribution in the reaction chamber is adjusted. The exhaust control method of the plasma processing device as claimed in claim 19, wherein the driving device drives the lifting rod to drive the arc-shaped baffle extension piece or the extension tube to move up and down, thereby adjusting the gas passage in the annular assembly. high. The exhaust gas control method of a plasma processing apparatus as claimed in claim 19, wherein the heights of the gas passages in different annular components are the same. The exhaust gas control method of a plasma processing apparatus as claimed in claim 19, wherein the heights of the gas passages in different annular components are different. The exhaust control method of the plasma processing apparatus as claimed in claim 22, wherein the height of the gas channel in the annular assembly decreases in order according to the distance from the annular assembly to the exhaust area.

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