Upper electrode device and semiconductor process equipment

Abstract

The present invention provides an upper electrode device and semiconductor processing equipment for use in semiconductor processing equipment. The device comprises a first coil, a second coil, and a third coil nested within each other and arranged in descending radii, and a switch assembly. The first and third coils are connected in parallel and electrically connected to a radio frequency source, and the direction of current flowing through the first coil is the same as the direction of current flowing through the third coil. The switch assembly is used to selectively connect and disconnect the second coil from the radio frequency source. When the switch assembly connects the second coil to the radio frequency source, the direction of current flowing through the second coil is opposite to the direction of current flowing through the first coil. The upper electrode device and semiconductor processing equipment provided by the present invention can solve the problem that the existing technology is not suitable for processes requiring high etching rates.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to an upper electrode device and semiconductor process equipment. Background Art

[0002] With the development of semiconductor manufacturing processes, the requirements for uniformity in semiconductor etching processes are becoming increasingly stringent. The main factors affecting etching process uniformity include: plasma uniformity on the wafer surface, uniformity of ion energy distribution controlled by the lower electrode loop, and uniformity of density distribution of etching reactants reaching the wafer surface. Taking inductively coupled plasma (ICP) equipment as an example, since the plasma reaching the wafer surface is generated by the coil in the upper electrode loop through inductive coupling, and then reaches the wafer surface through diffusion, electromigration, and convection mechanisms, the plasma distribution in the generation area determines the plasma uniformity on the wafer surface to a certain extent, which in turn can affect the uniformity of the etching process. For many years, scientists and engineers around the world have been committed to developing coil structures that can generate more uniform plasma on the wafer surface.

[0003] Existing coil structures typically consist of two coils, one inner and one outer, arranged 180° symmetrically along the axial direction. These coils are connected in parallel and electrically connected to an RF power supply via a matching device, which also adjusts the current ratio between the inner and outer coils. However, in practical applications, while the magnetic fields generated by the inner and outer coils can be offset by directing the currents in opposite directions, improving the uniformity of the overall magnetic field and, consequently, the plasma distribution, this offsetting effect results in significant power loss, which reduces the etching rate and makes this approach unsuitable for processes requiring higher etching rates. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes an upper electrode device and semiconductor process equipment, which can solve the problem that the prior art cannot be applied to processes with high etching rate requirements.

[0005] To achieve the purpose of the present invention, an upper electrode device is provided for use in semiconductor process equipment, comprising a first coil, a second coil, and a third coil nested with each other and arranged in descending order of radius, and a switch assembly, wherein:

[0006] The first coil and the third coil are connected in parallel to each other and are electrically connected to a radio frequency source, and a direction of a current flowing through the first coil is the same as a direction of a current flowing through the third coil;

[0007] The switch component is used to selectively connect or disconnect the second coil and the RF source. When the switch component connects the second coil and the RF source, the direction of the current flowing through the second coil is opposite to the direction of the current flowing through the first coil.

[0008] Optionally, when the switch assembly connects the second coil and the radio frequency source, the first coil, the second coil and the third coil are connected in parallel;

[0009] The winding direction of the first coil and the third coil is the same and opposite to the winding direction of the second coil; the winding starting ends of the first coil, the second coil and the third coil are all one of the RF feed end and the RF feed end, and the winding ending ends of the first coil, the second coil and the third coil are all the other of the RF feed end and the RF feed end; or,

[0010] The first coil, the second coil, and the third coil have the same winding direction, and the winding starting ends of the first coil and the third coil and the winding ending ends of the second coil are both one of the RF feed end and the RF feed end, and the winding ending ends of the first coil and the third coil and the winding starting end of the second coil are both the other of the RF feed end and the RF feed end.

[0011] Optionally, when the switch component connects the second coil and the radio frequency source, the second coil and the first coil or the third coil are connected in series;

[0012] The winding direction of the first coil and the third coil is the same and opposite to the winding direction of the second coil; the winding starting ends of the first coil, the second coil and the third coil are all one of the RF feed end and the RF feed end, and the winding ending ends of the first coil, the second coil and the third coil are all the other of the RF feed end and the RF feed end.

[0013] Optionally, the switch assembly includes a first connecting line, a second connecting line, and an on-off switch provided on the first connecting line, wherein:

[0014] Two ends of the first connecting wire are electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source respectively;

[0015] Two ends of the second connecting wire are electrically connected to the other of the winding start end and the winding end end of the second coil and the other of the input end and the output end of the radio frequency source respectively;

[0016] The on-off switch is used to connect or disconnect the first connecting line.

[0017] Optionally, the on-off switch is a single-pole single-throw relay, which has a first coil terminal, a second coil terminal, a first contact terminal, and a second contact terminal, wherein:

[0018] When the first coil terminal and the second coil terminal are conductive, the first contact terminal and the second contact terminal are attracted to connect the first connecting line;

[0019] When the first coil terminal and the second coil terminal are not conductive, the first contact terminal and the second contact terminal are separated to disconnect the first connection line.

[0020] Optionally, the switch assembly further includes a circuit board and a control unit, wherein the single-pole single-throw relay is mounted on the circuit board; the first connecting line includes a first connecting bar and a second connecting bar electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source, respectively;

[0021] The circuit board is provided with a first trace, a second trace, a third trace, and a fourth trace, wherein the first trace is connected in series between the first contact terminal and the first connecting strip; the second trace is connected in series between the second contact terminal and the second connecting strip; the third trace is connected in series between the first coil terminal and the signal output terminal of the control unit; and the fourth trace is connected in series between the second coil terminal and the signal input terminal of the control unit;

[0022] The control unit is used to output a high-level signal or a low-level signal to the first coil terminal; when the first coil terminal receives the high-level signal, it is connected to the second coil terminal; when the first coil terminal receives the low-level signal, it is not connected to the second coil terminal.

[0023] Optionally, the switch assembly includes a first connecting line, a second connecting line, a third connecting line, a fourth connecting line and a selection switch, wherein:

[0024] Two ends of the first connecting wire are electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source, respectively; a first end of the second connecting wire is electrically connected to the first connecting wire; a first end of the third connecting wire is electrically connected to the other of the winding start end and the winding end end of the second coil; a first end of the fourth connecting wire is electrically connected to one of the winding start end and the winding end end of the first coil or the third coil; and the other of the winding start end and the winding end end of the first coil or the third coil is electrically connected to the other of the input end and the output end of the radio frequency source;

[0025] The selection switch is used to selectively connect the second end of the fourth connection line with the second end of the second connection line to disconnect the second coil from the radio frequency source, or connect the second end of the fourth connection line with the second end of the third connection line to connect the second coil to the radio frequency source, and the second coil is connected in series with the first coil or the third coil.

[0026] Optionally, the selection switch is a single-pole double-throw relay, and the single-pole double-throw relay has a first coil terminal, a second coil terminal, a first contact terminal, a second contact terminal and a third contact terminal, wherein,

[0027] When the first coil terminal and the second coil terminal are conductive, the first contact terminal and the second contact terminal are attracted and separated from the third contact terminal, so as to connect the second end of the fourth connecting line with the second end of the third connecting line;

[0028] When the first coil terminal and the second coil terminal are not conductive, the first contact terminal and the second contact terminal are separated and attracted to the third contact terminal to connect the second end of the fourth connecting line with the second end of the second connecting line.

[0029] Optionally, the switch assembly further comprises a circuit board and a control unit, wherein the single-pole double-throw relay is mounted on the circuit board;

[0030] The circuit board is provided with a first trace, a second trace, a third trace, a fourth trace, and a fifth trace, wherein the first trace is connected in series between the first contact terminal and the fourth connecting line; the second trace is connected in series between the second contact terminal and the third connecting line; the third trace is connected in series between the third contact terminal and the second connecting line; the fourth trace is connected in series between the first coil terminal and the signal output terminal of the control unit; and the fifth trace is connected in series between the second coil terminal and the signal input terminal of the control unit.

[0031] The control unit is used to output a high-level signal or a low-level signal to the first coil terminal; when receiving the high-level signal, the first coil terminal and the second coil terminal are connected; when receiving the low-level signal, the first coil terminal and the second coil terminal are not connected.

[0032] As another technical solution, the present invention further provides a semiconductor process equipment, including a process chamber and an upper electrode device arranged above the process chamber, wherein the upper electrode device adopts the above-mentioned upper electrode device provided by the present invention.

[0033] The present invention has the following beneficial effects:

[0034] The upper electrode device provided by the present invention includes a first coil, a second coil, and a third coil that are nested with each other and arranged in order from large to small radius, and a switch assembly, which is used to selectively connect or disconnect the second coil to the radio frequency source to achieve switching between a three-coil operating mode and a two-coil operating mode. Under the premise that the direction of the current flowing through the first coil is the same as the direction of the current flowing through the third coil, when the switch assembly connects the second coil to the radio frequency source, by making the direction of the current flowing through the second coil opposite to the direction of the current flowing through the first coil, the magnetic field generated by the second coil and the magnetic fields generated by the other two coils can be offset to improve the uniformity of the total magnetic field, thereby improving the uniformity of the plasma distribution, and thus being suitable for processes with high requirements for etching uniformity. When the switch assembly disconnects the second coil from the radio frequency source, there is no current in the second coil, eliminating the above-mentioned offsetting effect, thereby ensuring the etching rate, and thus being suitable for processes with high requirements for etching rate.

[0035] The semiconductor process equipment provided by the present invention can switch between a three-coil working mode and a two-coil working mode by adopting the above-mentioned upper electrode device provided by the present invention, so that it can be suitable for processes with high requirements on etching uniformity and processes with high requirements on etching rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A functional block diagram of an upper electrode device according to a first embodiment of the present invention;

[0037] Figure 2 A structural diagram of an upper electrode device provided in a first embodiment of the present invention;

[0038] Figure 3 Another structural diagram of the upper electrode device provided in the first embodiment of the present invention;

[0039] Figure 4 A schematic diagram of a single-pole, single-throw relay used in the first embodiment of the present invention;

[0040] Figure 5 A top view of the installation of a single-pole, single-throw relay used in the first embodiment of the present invention;

[0041] Figure 6 A side view of the installation of a single-pole single-throw relay used in the first embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of plasma distribution on the wafer surface when the switch component is connected to and not connected to the second coil and the RF source;

[0043] Figure 8 A functional block diagram of an upper electrode device according to a second embodiment of the present invention;

[0044] Figure 9 A structural diagram of an upper electrode device provided in a second embodiment of the present invention;

[0045] Figure 10 A schematic diagram of a single-pole double-throw relay used in a second embodiment of the present invention;

[0046] Figure 11 A top view of the installation of a single-pole double-throw relay used in a second embodiment of the present invention;

[0047] Figure 12 A side view of the installation of a single-pole double-throw relay used in a second embodiment of the present invention;

[0048] Figure 13 This is a structural diagram of a semiconductor process equipment provided by the third embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the technical solution of the present invention, the upper electrode device and semiconductor process equipment provided by the present invention are described in detail below with reference to the accompanying drawings.

[0050] First embodiment

[0051] Please also refer to Figure 1 and Figure 2 The upper electrode device provided in an embodiment of the present invention is applied to semiconductor process equipment and is used to excite process gas in a process chamber of the semiconductor process equipment to form plasma. The upper electrode device includes a first coil 1, a second coil 2, and a third coil 3, which are nested with each other and arranged in descending order of radius, and a switch component 4. The first coil 1, the second coil 2, and the third coil 3 are, for example, planar coils. Of course,

[0052] In practical applications, coils of other structures, such as three-dimensional spiral coils, may also be used. Furthermore, the first coil 1 and the third coil 3 are connected in parallel and electrically connected to an RF source 5 (e.g., including a matching device 51 and an RF power supply 52). The direction of the current flowing through the first coil 1 is the same as the direction of the current flowing through the third coil 3. The switch assembly 4 is used to selectively connect and disconnect the second coil 2 from the RF source 5. When the switch assembly 4 connects the second coil 2 to the RF source 5, the direction of the current flowing through the second coil 2 is opposite to the direction of the current flowing through the first coil 1.

[0053] By selectively connecting or disconnecting the second coil 2 from the RF source 5 with the aid of the switch assembly 4, switching between a three-coil operating mode and a two-coil operating mode is achieved. On the premise that the direction of the current flowing through the first coil 1 is the same as the direction of the current flowing through the third coil 3, when the switch assembly 4 connects the second coil 2 to the RF source 5, by making the direction of the current flowing through the second coil 2 opposite to the direction of the current flowing through the first coil 1, the magnetic field generated by the second coil 2 and the magnetic fields generated by the other two coils can be offset, thereby improving the uniformity of the total magnetic field, thereby improving the uniformity of the plasma distribution, and thus being suitable for processes with high requirements for etching uniformity. When the switch assembly disconnects the second coil 2 from the RF source 5, there is no current in the second coil 2, eliminating the above-mentioned offsetting effect, thereby ensuring the etching rate, making it suitable for processes with high requirements for etching rate.

[0054] Specifically, if Figure 7 As shown, Curve A shows the plasma distribution curve on the wafer surface when the switch assembly 4 is not connected to the second coil 2 and the RF source 5, that is, in the two-coil operating mode; Curve B shows the plasma distribution curve on the wafer surface when the switch assembly 4 is connected to the second coil 2 and the RF source 5, that is, in the three-coil operating mode. Comparing Curves A and B, it can be seen that in the two-coil operating mode, the plasma density is higher, and the corresponding etching rate is faster. However, the plasma density near the radial midpoint of the wafer S is higher than in other areas, resulting in less uniform plasma density distribution. In the three-coil operating mode, the magnetic field generated by the second coil 2 and the magnetic fields generated by the other two coils cancel each other out, reducing the plasma density near the radial midpoint of the wafer S, thereby improving etching uniformity.

[0055] In addition, by adopting the switch component 4, the second coil 2 can be directly connected to the current loop, or disconnected from the current loop. Compared with other adjustment methods for achieving current reversal, such as adjusting the impedance in the current loop through a variable capacitor, current reversal can be achieved by switching mechanical components. The switching method is simpler and has a lower cost than that of a variable capacitor.

[0056] There are two ways to achieve that the direction of the current flowing through the first coil 1 is the same as the direction of the current flowing through the third coil 3, and the direction of the current flowing through the second coil 2 is opposite to the direction of the current flowing through the first coil 1. The first way is: Figure 2 As shown, the winding direction of the first coil 1 and the third coil 3 is the same and opposite to the winding direction of the second coil 2. For example, in the top view, the winding direction of the first coil 1 and the third coil 3 is counterclockwise, and the winding direction of the second coil 2 is clockwise. In addition, the winding starting points of the first coil 1, the second coil 2, and the third coil 3 (for example Figure 2The inner end in ( ) is one of the RF feed-in end and the RF feed-out end, and the winding ends of the first coil 1, the second coil 2 and the third coil 3 (eg Figure 2 The external end in the figure is the other of the RF feed-in end and the RF feed-out end.

[0057] The second way is: Figure 3 As shown, the first coil 1, the second coil 2, and the third coil 3 are wound in the same direction. For example, when viewed from above, the first coil 1, the second coil 2, and the third coil 3 are all wound in a counterclockwise direction. Furthermore, the winding starting ends of the first coil 1 and the third coil 3 and the winding ending end of the second coil 2 are both one of the RF feed end and the RF feed end, while the winding ending ends of the first coil 1 and the third coil 3 and the winding starting end of the second coil 2 are both the other of the RF feed end and the RF feed end.

[0058] In some optional embodiments, when the switch assembly 4 connects the second coil 2 to the RF source 5, the first coil 1, the second coil 2, and the third coil 3 are connected in parallel. In practical applications, the matcher 51 has, for example, two output terminals and two input terminals, wherein the RF feed-in terminal and the RF feed-out terminal of the first coil 1 are electrically connected to one of the output terminals and the input terminals, respectively, and the RF feed-in terminal and the RF feed-out terminal of the third coil 3 are electrically connected to the other output terminal and the input terminal, respectively. The RF feed-in terminal and the RF feed-out terminal of the second coil 2 can be connected to the same output terminal and input terminal of the matcher 51 as the RF feed-in terminal and the RF feed-out terminal of the third coil 3, respectively, or can be connected to the same output terminal and input terminal of the matcher 51 as the RF feed-in terminal and the RF feed-out terminal of the first coil 1.

[0059] In some optional embodiments, such as Figure 1 As shown, the switch assembly 4 includes a first connecting line 41, a second connecting line 42, and an on-off switch 43 provided on the first connecting line 41, wherein the two ends of the first connecting line 41 are electrically connected to one of the winding start and winding end of the second coil 2 (e.g., the RF feed end) and one of the input end and output end of the matcher 51 (e.g., the output end); the two ends of the second connecting line 42 are electrically connected to the other of the winding start and winding end of the second coil 2 (e.g., the RF feed end) and the other of the input end and output end of the matcher 51 (e.g., the input end); the on-off switch 43 is used to connect or disconnect the first connecting line 41. When the on-off switch 43 connects the first connecting line 41, the second coil 2 can be connected to the matcher 51 to switch to the three-coil operating mode; when the on-off switch 43 disconnects the first connecting line 41, the second coil 2 can be disconnected from the matcher 51 to switch to the two-coil operating mode.

[0060] In some optional embodiments, such as Figure 1 、 Figure 4 and Figure 5 As shown, the on-off switch 43 is a single-pole, single-throw relay having a first coil terminal 431, a second coil terminal 432, a first contact terminal 433, and a second contact terminal 434. When the first coil terminal 431 and the second coil terminal 432 are conductive, the first contact terminal 433 and the second contact terminal 434 are attracted to connect the first connecting line 41 (i.e., connect the first connecting bar 411 and the second connecting bar 412). When the first coil terminal 431 and the second coil terminal 432 are not conductive, the first contact terminal 433 and the second contact terminal 434 are separated to disconnect the first connecting line 41 (i.e., disconnect the first connecting bar 411 and the second connecting bar 412). By using a single-pole, single-throw relay, the first connecting line 41 is turned on and off through internal mechanical transmission, making the switching method simpler. Optionally, if more processes are used that require a higher etching rate, the single-pole single-throw relay may be a normally open relay; if more processes are used that require a higher etching rate, the single-pole single-throw relay may be a normally closed relay.

[0061] The embodiment of the present invention has no particular limitation on the manner in which the switch assembly is mounted on the first connecting line 41. In some optional embodiments, for example, Figure 5 and Figure 6As shown, the switch assembly 4 also includes a circuit board 44 and a control unit (not shown in the figure), wherein the single-pole single-throw relay is mounted on the circuit board 44, for example, soldered to the circuit board 44 in a pin package. Specifically, the single-pole single-throw relay has four pins, corresponding to the first coil terminal 431, the second coil terminal 432, the first contact terminal 433 and the second contact terminal 434 respectively. The first connecting line 41 includes a first connecting strip 411 and a second connecting strip 412 electrically connected to one of the winding start and winding end of the second coil 2 and one of the input end and output end of the matcher 51 respectively; a first trace 441, a second trace 442, a third trace 443 and a fourth trace 444 are provided on the circuit board 44, wherein the first trace 441 is connected in series between the first contact terminal 433 and the first connecting strip 411, and the circuit board 44 can be fixedly connected to the first connecting strip 411 by means of screws 47; the second trace 442 is connected in series between the second contact terminal 434 and the second connecting strip 412, and the circuit board 44 can be fixedly connected to the second connecting strip 412 by means of screws 47; the third trace 443 is connected in series between the second contact terminal 434 and the second connecting strip 412, and the circuit board 44 can be fixedly connected to the second connecting strip 412 by means of screws 47; The line 443 is connected in series between the first coil terminal 431 and the signal output end of the control unit; the fourth line 444 is connected in series between the second coil terminal 432 and the signal input end of the control unit; the above-mentioned control unit is used to output a high-level signal or a low-level signal to the first coil terminal 431; when the first coil terminal 431 receives a high-level signal, it is connected to the second coil terminal 432. At this time, the first contact terminal 433 and the second contact terminal 434 are attracted to connect the first connection line 41; when the first coil terminal 431 receives the low-level signal, it is not connected to the second coil terminal 432. At this time, the first contact terminal 433 and the second contact terminal 434 are separated to disconnect the first connection line 41.

[0062] Second embodiment

[0063] Please also refer to Figure 8 and Figure 9 The upper electrode device provided in this embodiment of the present invention differs from the first embodiment described above in that, when the switch assembly 4' connects the second coil 2 to the RF source 5, the second coil 2 is connected in series with the first coil 1 or the third coil 3. When the switch assembly 4 connects the second coil 2 to the RF source 5, the magnetic field generated by the second coil 2 can also offset the magnetic fields generated by the other two coils, thereby improving the uniformity of the total magnetic field and thus improving the uniformity of the plasma distribution. Furthermore, the series connection of the second coil 2 with the first coil 1 or the third coil 3 helps to increase the etching rate.

[0064] On the basis of the second coil 2 being connected in series with the first coil 1 or the third coil 3, a method for achieving that the direction of the current flowing through the first coil 1 is the same as the direction of the current flowing through the third coil 3, and the direction of the current flowing through the second coil 2 is opposite to the direction of the current flowing through the first coil 1 is as follows: the winding direction of the first coil 1 and the third coil 3 is the same, and opposite to the winding direction of the second coil 2. For example, Figure 9 As shown, in a top view, the winding direction of the first coil 1 and the third coil 3 is counterclockwise, and the winding direction of the second coil 2 is clockwise. Furthermore, the winding starting end of the first coil 1, the second coil 2, and the third coil 3 is one of the RF feed end and the winding ending end of the first coil 1, the second coil 2, and the third coil 3 is the other of the RF feed end and the RF feed end.

[0065] In some optional embodiments, such as Figure 8 As shown, the switch assembly 4' includes a first connecting line 41', a second connecting line 42', a third connecting line 43', a fourth connecting line 44' and a selection switch 45', wherein the two ends of the first connecting line 41' are electrically connected to one of the winding start and winding end of the second coil 2 (for example, the RF feed end) and one of the input end and output end of the matcher 51 (for example, the input end) respectively; the first end of the second connecting line 42' is electrically connected to the first connecting line 41'; the first end of the third connecting line 43' is electrically connected to the other of the winding start and winding end of the second coil 2 (for example, the RF feed end); the first end of the fourth connecting line 44' is electrically connected to one of the winding start and winding end of the first coil 1 or the third coil 3 (for example, the RF feed end); the other of the winding start and winding end of the first coil 1 or the third coil 3 (for example, the RF feed end) is electrically connected to the other of the input end and output end of the matcher 51 (for example, the output end).

[0066] The switch assembly 4' is used to selectively connect the second end of the fourth connecting wire 44' to the second end of the second connecting wire 42' to disconnect the second coil 2 from the matcher 51, or connect the second end of the fourth connecting wire 44' to the second end of the third connecting wire 43' to connect the second coil 2 to the matcher 51, and connect the second coil 2 in series with the first coil 1 or the third coil 3. When the selection switch 45' connects the second end of the fourth connecting wire 44' to the second end of the third connecting wire 43', the second coil 2 is connected to the matcher 51, switching to a three-coil operating mode. When the selection switch 45' connects the second end of the fourth connecting wire 44' to the second end of the second connecting wire 42', the second coil 2 is disconnected from the matcher 51, switching to a two-coil operating mode.

[0067] In some optional embodiments, such as Figure 10As shown, the selector switch 45' is a single-pole double-throw relay having a first coil terminal 451, a second coil terminal 452, a first contact terminal 453, a second contact terminal 454, and a third contact terminal 455. When the first coil terminal 451 and the second coil terminal 452 are conducting, the first contact terminal 453 and the second contact terminal 454 are closed and separated from the third contact terminal 455, thereby connecting the second end of the fourth connecting line 44' to the second end of the third connecting line 43'. When the first coil terminal 451 and the second coil terminal 452 are not conducting, the first contact terminal 453 and the second contact terminal 454 are separated and closed from the third contact terminal 455, thereby connecting the second end of the fourth connecting line 44' to the second end of the second connecting line 42'. By using a single-pole double-throw relay, the connection between the second end of the fourth connecting line 44' and the second end of the third connecting line 43' or the second end of the second connecting line 42' is achieved through internal mechanical transmission, making the switching method simpler.

[0068] The embodiment of the present invention has no particular limitation on the manner in which the switch assembly is mounted on the second connecting wire 42', the third connecting wire 43' and the fourth connecting wire 44'. In some optional embodiments, for example, Figure 11 and Figure 12As shown, the switch assembly 4' also includes a circuit board 46' and a control unit (not shown in the figure), wherein the above-mentioned single-pole double-throw relay is mounted on the circuit board 46'. Specifically, the single-pole double-throw relay has five pins, corresponding to the first coil terminal 451, the second coil terminal 452, the first contact terminal 453, the second contact terminal 454 and the third contact terminal 455 respectively. The circuit board 46' is provided with a first trace 461', a second trace 462', a third trace 463', a fourth trace 464' and a fifth trace 465', wherein the first trace 461' is connected in series between the first contact terminal 453 and the fourth connection line 44'; the second trace 462' is connected in series between the second contact terminal 454 and the third connection line 43'; the third trace 463' is connected in series between the third contact terminal 455 and the second connection line 42'; the fourth trace 464' is connected in series between the first coil terminal 451 and the signal output terminal of the above-mentioned control unit; the fifth trace 465' is connected in series between the second coil terminal 452 and the signal input terminal of the above-mentioned control unit; the above-mentioned control unit The unit is used to output a high-level signal or a low-level signal to the first coil terminal 451. When the first coil terminal 451 receives a high-level signal, it is connected to the second coil terminal 452. At this time, the first contact terminal 453 and the second contact terminal 454 are attracted, and separated from the third contact terminal 455, so as to connect the second end of the fourth connection line 44' with the second end of the third connection line 43'; when the first coil terminal 451 receives a low-level signal, it is not connected to the second coil terminal 452. At this time, the first contact terminal 453 and the second contact terminal 454 are separated, and attracted to the third contact terminal 455, so as to connect the second end of the fourth connection line 44' with the second end of the second connection line 42'.

[0069] The upper electrode device provided by an embodiment of the present invention includes a first coil, a second coil, and a third coil, which are nested with each other and arranged in descending radii, and a switch assembly. The switch assembly is used to selectively connect or disconnect the second coil to the radio frequency source to switch between a three-coil operating mode and a two-coil operating mode. Under the premise that the direction of the current flowing through the first coil is the same as the direction of the current flowing through the third coil, when the switch assembly connects the second coil to the radio frequency source, by making the direction of the current flowing through the second coil opposite to the direction of the current flowing through the first coil, the magnetic field generated by the second coil and the magnetic fields generated by the other two coils can be offset, thereby improving the uniformity of the total magnetic field, thereby improving the uniformity of the plasma distribution, and thus being suitable for processes with high requirements for etching uniformity. When the switch assembly disconnects the second coil from the radio frequency source, there is no current in the second coil, eliminating the above-mentioned offsetting effect, thereby ensuring the etching rate, and thus being suitable for processes with high etching rate requirements.

[0070] Third embodiment

[0071] As another technical solution, see Figure 13 An embodiment of the present invention further provides a semiconductor process equipment, including a process chamber 100 and an upper electrode device arranged above the process chamber 100, and the upper electrode device adopts the above-mentioned upper electrode device provided by an embodiment of the present invention.

[0072] Specifically, a dielectric window 102 is provided at the top of the process chamber 100. An upper electrode assembly is used to excite process gas in the process chamber of a semiconductor process equipment to form plasma, which is then fed into the process chamber 100 through the dielectric window 102. A susceptor 101 is provided within the process chamber 100 for supporting a wafer. Optionally, the susceptor 101 is electrically connected to a lower RF source 103 for attracting the plasma toward the wafer surface. The lower RF source 103 includes a matcher and an RF power supply.

[0073] The semiconductor process equipment provided by the embodiment of the present invention can switch between three-coil working mode and two-coil working mode by adopting the above-mentioned upper electrode device provided by the embodiment of the present invention, so that it can be suitable for processes with high requirements on etching uniformity and processes with high requirements on etching rate.

[0074] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An upper electrode device, applied to semiconductor process equipment, characterized in that: The invention comprises a first coil, a second coil and a third coil which are nested with each other and arranged in descending order of radius, and a switch assembly, wherein: The first coil and the third coil are connected in parallel to each other and are electrically connected to a radio frequency source, and a direction of a current flowing through the first coil is the same as a direction of a current flowing through the third coil; The switch component is used to selectively connect or disconnect the second coil and the radio frequency source, and when the switch component connects the second coil and the radio frequency source, the direction of the current flowing through the second coil is opposite to the direction of the current flowing through the first coil, and When the switch assembly connects the second coil and the radio frequency source, the first coil, the second coil and the third coil are connected in parallel; The winding direction of the first coil and the third coil is the same and opposite to the winding direction of the second coil; the winding starting ends of the first coil, the second coil and the third coil are all one of the RF feed end and the RF feed end, and the winding ending ends of the first coil, the second coil and the third coil are all the other of the RF feed end and the RF feed end; or, The first coil, the second coil, and the third coil have the same winding direction, and the winding starting ends of the first coil and the third coil and the winding ending ends of the second coil are both one of the RF feed end and the RF feed end, and the winding ending ends of the first coil and the third coil and the winding starting end of the second coil are both the other of the RF feed end and the RF feed end.

2. The upper electrode device according to claim 1, characterized in that: The switch assembly includes a first connecting line, a second connecting line, and an on-off switch provided on the first connecting line, wherein: Two ends of the first connecting wire are electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source respectively; Two ends of the second connecting wire are electrically connected to the other of the winding start end and the winding end end of the second coil and the other of the input end and the output end of the radio frequency source respectively; The on-off switch is used to connect or disconnect the first connecting line.

3. The upper electrode device according to claim 2, characterized in that: The on-off switch is a single-pole single-throw relay having a first coil terminal, a second coil terminal, a first contact terminal and a second contact terminal, wherein: When the first coil terminal and the second coil terminal are conductive, the first contact terminal and the second contact terminal are attracted to connect the first connecting line; When the first coil terminal and the second coil terminal are not conductive, the first contact terminal and the second contact terminal are separated to disconnect the first connection line.

4. The upper electrode device according to claim 3, characterized in that: The switch assembly further includes a circuit board and a control unit, wherein the single-pole single-throw relay is mounted on the circuit board; the first connecting line includes a first connecting bar and a second connecting bar electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source, respectively; The circuit board is provided with a first trace, a second trace, a third trace, and a fourth trace, wherein the first trace is connected in series between the first contact terminal and the first connecting strip; the second trace is connected in series between the second contact terminal and the second connecting strip; the third trace is connected in series between the first coil terminal and the signal output terminal of the control unit; and the fourth trace is connected in series between the second coil terminal and the signal input terminal of the control unit; The control unit is used to output a high-level signal or a low-level signal to the first coil terminal; when the first coil terminal receives the high-level signal, it is connected to the second coil terminal; when the first coil terminal receives the low-level signal, it is not connected to the second coil terminal.

5. An upper electrode device, applied to semiconductor process equipment, characterized in that: The invention comprises a first coil, a second coil and a third coil which are nested with each other and arranged in descending order of radius, and a switch assembly, wherein: The first coil and the third coil are connected in parallel to each other and are electrically connected to a radio frequency source, and a direction of a current flowing through the first coil is the same as a direction of a current flowing through the third coil; The switch component is used to selectively connect or disconnect the second coil and the radio frequency source, and when the switch component connects the second coil and the radio frequency source, the direction of the current flowing through the second coil is opposite to the direction of the current flowing through the first coil, and When the switch component connects the second coil and the radio frequency source, the second coil and the first coil or the third coil are connected in series; The winding direction of the first coil and the third coil is the same and opposite to the winding direction of the second coil; the winding starting ends of the first coil, the second coil and the third coil are all one of the RF feed end and the RF feed end, and the winding ending ends of the first coil, the second coil and the third coil are all the other of the RF feed end and the RF feed end.

6. The upper electrode device according to claim 5, characterized in that: The switch assembly includes a first connecting line, a second connecting line, a third connecting line, a fourth connecting line and a selection switch, wherein: Two ends of the first connecting wire are electrically connected to one of the winding start end and the winding end end of the second coil and one of the input end and the output end of the radio frequency source, respectively; a first end of the second connecting wire is electrically connected to the first connecting wire; a first end of the third connecting wire is electrically connected to the other of the winding start end and the winding end end of the second coil; a first end of the fourth connecting wire is electrically connected to one of the winding start end and the winding end end of the first coil or the third coil; and the other of the winding start end and the winding end end of the first coil or the third coil is electrically connected to the other of the input end and the output end of the radio frequency source; The selection switch is used to selectively connect the second end of the fourth connection line with the second end of the second connection line to disconnect the second coil from the radio frequency source, or connect the second end of the fourth connection line with the second end of the third connection line to connect the second coil to the radio frequency source, and the second coil is connected in series with the first coil or the third coil.

7. The upper electrode device according to claim 6, characterized in that: The selection switch is a single-pole double-throw relay having a first coil terminal, a second coil terminal, a first contact terminal, a second contact terminal and a third contact terminal, wherein: When the first coil terminal and the second coil terminal are conductive, the first contact terminal and the second contact terminal are attracted and separated from the third contact terminal, so as to connect the second end of the fourth connecting line with the second end of the third connecting line; When the first coil terminal and the second coil terminal are not conductive, the first contact terminal and the second contact terminal are separated and attracted to the third contact terminal to connect the second end of the fourth connecting line with the second end of the second connecting line.

8. The upper electrode device according to claim 7, characterized in that: The switch assembly further comprises a circuit board and a control unit, wherein the single-pole double-throw relay is mounted on the circuit board; The circuit board is provided with a first trace, a second trace, a third trace, a fourth trace, and a fifth trace, wherein the first trace is connected in series between the first contact terminal and the fourth connecting line; the second trace is connected in series between the second contact terminal and the third connecting line; the third trace is connected in series between the third contact terminal and the second connecting line; the fourth trace is connected in series between the first coil terminal and the signal output terminal of the control unit; and the fifth trace is connected in series between the second coil terminal and the signal input terminal of the control unit. The control unit is used to output a high-level signal or a low-level signal to the first coil terminal; when receiving the high-level signal, the first coil terminal and the second coil terminal are connected; when receiving the low-level signal, the first coil terminal and the second coil terminal are not connected.

9. A semiconductor process equipment comprising a process chamber and an upper electrode device disposed above the process chamber, characterized in that: The upper electrode device adopts the upper electrode device according to any one of claims 1-8.

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