Semiconductor processing equipment

Abstract

The present invention discloses a semiconductor processing device, which includes a semiconductor processing device. It is characterized by comprising a process chamber, an upper electrode RF coil, a lower RF power supply, a lower electrode assembly, an electrical connector, and an adjustable device. The lower electrode assembly includes a base, an electrostatic chuck, a first lower electrode, and a second lower electrode. The electrostatic chuck is located above the base for carrying a wafer. The first lower electrode is disposed inside the base and connected to the lower RF power supply. The second lower electrode is disposed around and spaced apart from the first lower electrode. The inner sidewall of the process chamber is electrically connected to the second lower electrode through the electrical connector, so that the coupling current generated by the upper electrode RF coil on the inner sidewall of the process chamber is introduced into the second lower electrode. The adjustable device is used to adjust the magnitude of the coupling current introduced from the inner sidewall of the process chamber into the second lower electrode. The above technical solution can adjust the processing rates of the edge region and the central region of the wafer, and improve the uniformity of the wafer.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and particularly to a semiconductor processing device. Background Art

[0002] In the process of semiconductor manufacturing, plasma etching process is an important etching process. Inductively coupled plasma equipment and capacitively coupled plasma equipment are two most commonly used plasma sources. In the inductively coupled plasma equipment, affected by factors such as the intake mode of process gas and the specific process environment in the process chamber, under the action of the same lower electrode, the distribution uniformity of plasma in different regions corresponding to the center and the edge of the lower electrode in the process chamber may still be different, which results in a difference in the processing rate between the edge region and the center region of the wafer, seriously affecting the uniformity of the wafer. Summary of the Invention

[0003] The present invention discloses a semiconductor processing device to solve the problem that in the current semiconductor processing device, affected by various factors, under the action of the same lower electrode, the distribution uniformity of plasma in different regions in the process chamber may still be different, which results in a difference in the processing rate between the edge region and the center region of the wafer, seriously affecting the uniformity of the wafer.

[0004] To solve the above problems, the present invention adopts the following technical solutions:

[0005] The present invention discloses a semiconductor processing device, which includes a process chamber, an upper electrode radio frequency coil, a lower radio frequency power supply, a lower electrode assembly, an electrical connector and an adjustable device. The lower electrode assembly includes a base, an electrostatic chuck, a first lower electrode and a second lower electrode. The electrostatic chuck is located above the base for carrying a wafer. The first lower electrode is disposed inside the base and connected to the lower radio frequency power supply. The second lower electrode is disposed around and spaced apart from the first lower electrode. The inner sidewall of the process chamber is electrically connected to the second lower electrode through the electrical connector, so that the coupled current generated by the upper electrode radio frequency coil on the inner sidewall of the process chamber is introduced into the second lower electrode. The adjustable device is used to adjust the magnitude of the coupled current introduced from the inner sidewall of the process chamber into the second lower electrode.

[0006] The technical solutions adopted by the present invention can achieve the following beneficial effects:

[0007] An embodiment of the present application discloses a semiconductor processing apparatus, which includes a process chamber, an upper electrode RF coil, a lower RF power supply lower electrode assembly, an electrical connector, and an adjustable device. The upper electrode RF coil is installed on the process chamber to provide the function of ionizing a process gas to generate plasma. The lower electrode assembly includes a base, an electrostatic chuck, a first lower electrode, and a second lower electrode. The electrostatic chuck is installed above the base and provides the function of carrying a wafer. The first lower electrode is installed inside the base, and the second lower electrode is disposed around and spaced apart from the first lower electrode to basically prevent the energization states of the two from being related. The first lower electrode is connected to the lower RF power supply, so that the first lower electrode can provide a bias electric field for the wafer, and then draw the plasma in the process chamber to act on the corresponding area of the wafer. At the same time, the inner wall of the process chamber is electrically connected to the second lower electrode through the electrical connector, so that the coupling current generated by the upper electrode RF coil can be introduced into the second lower electrode through the electrical connector, so that the second lower electrode can also provide a bias electric field for the wafer, and then draw the plasma in the process chamber to act on the corresponding area of the wafer, so that both the first lower electrode and the second lower electrode act in the processing process of the wafer.

[0008] Wherein, an adjustable device is also provided in the semiconductor processing apparatus disclosed in the embodiment of the present application. The adjustable device can be used to adjust the magnitude of the coupling current introduced from the inner side wall of the process chamber into the second lower electrode, so as to achieve the purpose of adjusting the magnitude of the current in the second lower electrode. Based on this, during the processing of the wafer, if there is a difference in the processing rates of the center and the edge of the wafer, the current introduced into the second lower electrode can be adjusted by means of the adjustable device according to the actual processing situation of the wafer, so that the electric field action provided by the second lower electrode changes, the processing rate of the part of the wafer corresponding to the second lower electrode is changed, and the process uniformity of the wafer is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0010] Figure 1 is a schematic structural diagram of the semiconductor processing apparatus disclosed in the embodiment of the present invention;

[0011] Figure 2 is a schematic diagram of a relative position of the first lower electrode and the second lower electrode in the semiconductor processing apparatus disclosed in the embodiment of the present invention;

[0012] Figure 3 is a schematic diagram of another relative position of the first lower electrode and the second lower electrode in the semiconductor processing apparatus disclosed in the embodiment of the present invention;

[0013] Figure 4Schematic diagram of the lifting mechanism in the semiconductor processing equipment disclosed in the embodiments of the present invention;

[0014] Figure 5 Schematic diagram of the equivalent circuit between the second variable capacitor and the upper electrode RF coil disclosed in the embodiments of the present invention.

[0015] Explanation of reference numerals:

[0016] 100 - Process chamber,

[0017] 200 - Upper electrode RF coil,

[0018] 310 - First lower electrode, 320 - Second lower electrode, 330 - Base, 340 - Electrostatic chuck, 350 - First wire, 360 - Second wire,

[0019] 410 - Lower RF power supply, 420 - Lower RF matcher, 430 - Upper RF power supply, 440 - Upper RF matcher, 450 - DC power supply, 460 - Vacuum pump,

[0020] 510 - Conductive part, 520 - Third wire,

[0021] 610 - First variable capacitor, 620 - Inductive coil, 630 - Second variable capacitor, 640 - Third variable capacitor, 650 - Fourth variable capacitor,

[0022] 710 - Driving device, 711 - Base, 712 - Driving shaft, 720 - Support member, 730 - Sealing member, 740 - Lifting plate, 750 - Fine adjustment device, 760 - Insulating member, 771 - Fixing member, 772 - Adapter, 773 - Guide sleeve, 774 - Counterweight, 775 - Support plate, 776 - Guide rod. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] The following will, in conjunction with the drawings, detail the technical solutions disclosed in each embodiment of the present invention.

[0025] As Figures 1-4 shown, the embodiments of the present invention disclose a semiconductor processing equipment. As Figure 1As shown, the semiconductor processing equipment includes a process chamber 100, an upper electrode RF coil 200, a lower RF power supply 410, a lower electrode assembly, an electrical connection component, and an adjustable device. Among them, the lower electrode assembly includes a base 330, an electrostatic chuck 340, a first lower electrode 310, and a second lower electrode 320. The electrostatic chuck 340 is used to hold a wafer, and the electrostatic chuck 340 is located above the base 330. In addition, devices such as a DC power supply 450 and a vacuum pump 460 are usually also provided in the semiconductor processing equipment. The DC power supply 450 is electrically connected to the first lower electrode 310, enabling the first lower electrode 310 to have an adsorption effect, so that the wafer can be stably located above the first lower electrode 310 and be held on the electrostatic chuck 340. The vacuum pump 460 is connected to the process chamber 100 and can evacuate the waste gas generated during the processing in the process chamber 100 to the outside of the process chamber 100, ensuring that the processing in the process chamber 100 can continue to proceed normally.

[0026] As Figure 1 shown, the upper electrode RF coil 200 is installed in the process chamber 100. The upper electrode RF coil 200 provides an ionization effect for the process gas introduced into the process chamber 100 from the gas inlet of the process chamber 100 to generate plasma. Of course, to ensure the normal operation of the upper electrode RF coil 200, as Figure 1 shown, the upper electrode RF coil 200 also needs to be connected to an upper RF power supply 430 and an upper RF matcher 440.

[0027] Specifically, the upper electrode RF coil 200 can include at least one of a three-dimensional coil and a planar coil. The upper electrode RF coil 200 can be installed at a position near the gas inlet in the side wall of the process chamber 100, and / or the upper electrode RF coil 200 can also be installed on the top wall of the process chamber 100, so that after the process gas enters the process chamber 100, the ionization process can occur under the action of the upper electrode RF coil 200. In addition, parameters such as the number and number of turns of the upper electrode RF coil 200 are not limited in this article.

[0028] As Figure 1As shown, the first lower electrode 310 is disposed inside the base 330. Specifically, the first lower electrode 310 can be directly or indirectly supported on the bottom of the base 330 through other structural members. The base 330 is installed at the bottom of the process chamber 100 to achieve the purpose of installing the first lower electrode 310 in the process chamber 100. At the same time, the second lower electrode 320 is disposed around and spaced apart from the first lower electrode 310. That is, the second lower electrode 320 is an annular structural member and is sleeved outside the first lower electrode 310. Since the second lower electrode 320 and the first lower electrode 310 are spaced apart from each other, they are basically in an insulated state from each other, and thus the energization states of the first lower electrode 310 and the second lower electrode 320 are also basically not related to each other.

[0029] Specifically, the shapes and sizes of the first lower electrode 310 and the second lower electrode 320 can be determined according to actual situations. Considering that the wafers processed by semiconductor processing equipment are usually circular structural members, optionally, the first lower electrode 310 is specifically a circular structure. Correspondingly, the second lower electrode 320 can be an annular structural member. In this case, optionally, the spacing between the first lower electrode 310 and the second lower electrode 320 in the radial direction of the first lower electrode 310 is 1 mm - 10 mm, which can basically ensure a relatively reliable insulation relationship between the two. At the same time, since both the first lower electrode 310 and the second lower electrode 320 need to provide an electric field effect on the wafer, in the case of adopting the above technical solution, it can also prevent the etching efficiency of the wafer corresponding to the gap from being greatly affected due to a large gap between the two. Of course, the first lower electrode 310 can also be a non-circular structural member. In this case, the distance between the first lower electrode 310 and the second lower electrode 320 in the direction perpendicular to the thickness direction of the base 330 can also be 1 mm - 10 mm. The second lower electrode 320 is also installed inside the base 330, and the second lower electrode 320 can be relatively fixed to the base 330 or the second lower electrode 320 can be capable of moving relative to the base 330.

[0030] In a specific embodiment, the first lower electrode 310 is a circular structural member, the second lower electrode 320 is an annular structural member, and the outer diameter of the second lower electrode 320 can be made larger than the diameter of the wafer, so as to ensure that the second lower electrode 320 can provide an electric field effect on the wafer to be processed. In another embodiment of the present application, optionally, the difference between the outer diameter of the second lower electrode 320 and the diameter of the wafer is ±5 mm, which can also basically ensure that the second lower electrode 320 can provide an electric field effect that meets the requirements for the wafer. On the one hand, the sizes of the second lower electrode 320 and the first lower electrode 310 can be minimized as much as possible. On the other hand, it can also prevent the plasma outside the corresponding area of the wafer from being interfered by the second lower electrode 320 when the size of the second lower electrode 320 exceeds the size of the wafer too much, which has an adverse impact on the processing process of the wafer.

[0031] More specifically, the outer diameter of the second lower electrode 320 may be 295 mm to 305 mm, and the inner diameter of the second lower electrode 320 may be 285 mm to 295 mm. The first lower electrode 310 is disposed inside the second lower electrode 320 to form a combined structure. The combined structure formed by the first lower electrode 310 and the second lower electrode 320 with such dimensions can basically provide an electric field for wafers of the current mainstream sizes.

[0032] As described above, both the first lower electrode 310 and the second lower electrode 320 can provide an electric field effect for the wafer. For this purpose, the first lower electrode 310 is electrically connected to the lower radio frequency power supply 410, so that radio frequency power can be loaded on the first lower electrode 310, and then the first lower electrode 310 can generate a bias electric field to provide a traction effect for the plasma in the process chamber 100. Correspondingly, the inner sidewall of the process chamber 100 is electrically connected to the second lower electrode 320 through an electrical connector, so that the coupled current generated by the upper electrode radio frequency coil 200 on the inner sidewall of the process chamber 100 can be introduced into the second lower electrode 320, and then the second lower electrode 320 can also provide a bias electric field for the wafer.

[0033] Specifically, the electrical connector is a conductive device. Further, the resistance of the electrical connector can be relatively small, so that most of the coupled current generated by the upper electrode radio frequency coil 200 can be transmitted from the inner sidewall of the process chamber 100 to the second lower electrode 320 through the electrical connector. Since the impedance of a metal wire is usually relatively small, based on this, the electrical connector can be a metal wire, specifically a copper wire. Of course, the second lower electrode 320 also needs to be grounded through other devices to form a complete circuit. Optionally, the second lower electrode 320 can be directly grounded through devices such as wires. Of course, other methods can also be used to form a complete grounding circuit for the second lower electrode 320.

[0034] Based on the above technical solutions, both the first lower electrode 310 and the second lower electrode 320 have the function of providing an electric field effect for the wafer. Furthermore, in order to make the electric field effect provided by the two for the wafer adjustable, as described above, the semiconductor processing equipment disclosed in the embodiments of the present application further includes an adjustable device, and the adjustable device is used to adjust the magnitude of the coupled current introduced from the inner sidewall of the process chamber 100 into the second lower electrode 320. Under the action of the adjustable device, by changing the magnitude of the current introduced into the second lower electrode 320, the electric field effect of the second lower electrode 320 can be changed. Furthermore, during the processing of the wafer, if the process uniformity of the central and edge regions of the wafer is relatively poor, then the magnitude of the current introduced into the second lower electrode 320 can be correspondingly changed according to the actual processing effect of the wafer, so as to achieve the purpose of adjusting the processing uniformity of the wafer.

[0035] Specifically, the adjustable device can be an adjustable resistor. By connecting the adjustable device into the grounding circuit of the second lower electrode 320, when the resistance value of the adjustable device changes, the magnitude of the current in the second lower electrode 320 can be changed, thereby changing the effect of the electric field provided by the second lower electrode 320. Of course, the adjustable device can also be other devices such as a variable capacitor. By installing the adjustable device at the corresponding position in the semiconductor processing equipment, it can also affect the magnitude of the current passing through the second lower electrode 320 from the inner sidewall of the process chamber 100 through the electrical connection member, so as to achieve the purpose of changing the effect of the electric field of the second lower electrode 320.

[0036] An embodiment of the present application discloses a semiconductor processing equipment, which includes a process chamber 100, an upper electrode radio frequency coil 200, a lower radio frequency power supply 410, a lower electrode assembly, an electrical connection member, and an adjustable device. The upper electrode radio frequency coil 200 is installed on the process chamber 100 to provide the function of ionizing the process gas to generate plasma. The lower electrode assembly includes a base 330, an electrostatic chuck 340, a first lower electrode 310, and a second lower electrode 320. The electrostatic chuck 340 is installed above the base 330 and provides the function of carrying the wafer. The first lower electrode 310 is installed inside the base 330, and the second lower electrode 320 surrounds and is spaced outside the first lower electrode 310 to basically prevent the energization states of the two from being related. The first lower electrode 310 is connected to the lower radio frequency power supply 410, so that the first lower electrode 310 can provide a bias electric field for the wafer, and then draw the plasma in the process chamber 100 to act on the corresponding area of the wafer. At the same time, the inner wall of the process chamber 100 is electrically connected to the second lower electrode 320 through the electrical connection member, so that the coupled current generated by the upper electrode radio frequency coil 200 can be introduced into the second lower electrode 320 through the electrical connection member, so that the second lower electrode 320 can also provide a bias electric field for the wafer, and then draw the plasma in the process chamber 100 to act on the corresponding area of the wafer, so that both the first lower electrode 310 and the second lower electrode 320 act in the processing technology of the wafer.

[0037] Among them, an adjustable device is also provided in the semiconductor processing equipment disclosed in the embodiment of the present application. The adjustable device can be used to adjust the magnitude of the coupled current passing from the inner sidewall of the process chamber 100 into the second lower electrode 320, so as to achieve the purpose of adjusting the magnitude of the current in the second lower electrode 320. Based on this, during the processing of the wafer, if there is a difference in the processing rates of the center and the edge of the wafer, the current passing through the second lower electrode 320 can be adjusted by means of the adjustable device according to the actual processing situation of the wafer, so that the electric field effect provided by the second lower electrode 320 changes, the processing rate of the part of the wafer corresponding to the second lower electrode 320 is changed, and the process uniformity of the wafer is improved.

[0038] As described above, the adjustable device can specifically be a variable resistor. In a specific embodiment of the present application, the adjustable device is connected in series to the grounding circuit of the second lower electrode 320, and the adjustable device includes a first variable capacitor 610 and an inductor coil 620. By setting the parameter ranges of both the first variable capacitor 610 and the inductor coil 620, it can be ensured that the grounding circuit where the second lower electrode 320 is located remains in a connected state. Meanwhile, by adjusting the parameters of the first variable capacitor 610, the impedance of the grounding circuit where the second lower electrode 320 is located can be adjusted, thereby changing the magnitude of the current flowing from the inner sidewall of the process chamber 100 to the second lower electrode 320 through the electrical connector, causing the electric field effect generated by the second lower electrode 320 to change correspondingly.

[0039] In another embodiment of the present application, the adjustable device is connected in series to the grounding circuit of the upper electrode RF coil 200, and the adjustable device includes a second variable capacitor 630. In the case of adopting this technical solution, by adjusting the capacitance value of the second variable capacitor 630, the impedance of the grounding circuit of the upper electrode RF coil 200 can be changed, thereby changing the magnitudes of the coupling current generated by the upper electrode RF coil 200 flowing into the grounding circuit of the upper electrode RF coil 200 and the second lower electrode 320 respectively, and further changing the electric field effect generated by the second lower electrode 320.

[0040] In addition, in the case of adopting the above technical solution, the second variable capacitor 630 is equivalent to generating a negative voltage to provide a virtual grounding position for the upper electrode RF coil 200 by using the second variable capacitor 630, and the virtual grounding position is located between the two ends of the upper electrode RF coil. In the case of adopting the above technical solution, the electric field effect of the upper electrode RF coil 200 on the wafer can be reduced, and thus the bombardment effect of the plasma generated by the upper electrode RF coil 200 on the wafer can be reduced, improving the processing effect on the wafer.

[0041] Among them, the virtual grounding position of the upper electrode RF coil 200 (i.e., Figure 5 the L in coil ) is specifically related to the capacitance value of the second variable capacitor 630. For example, when the impedance generated by the capacitance of the second variable capacitor 630 is equal to half of the impedance generated by the inductance of the upper electrode RF coil 200, as Figure 5 shown, that is, it satisfies LCω 2= 2, or 1 / ωC = 0.5ωL. Assuming that the potential of the upper electrode RF coil 200 with respect to the ground is 2V, the second variable capacitor 630 generates a potential of -V, which is equivalent to forming a virtual ground with zero potential at the middle half position of the upper electrode RF coil 200. However, since excessive reduction of capacitive coupling may cause problems such as difficulty in discharge ignition, furthermore, by making the capacitance of the second variable capacitor 630 variable, the capacitive coupling can be adjusted according to the following formula.

[0042] U = XI

[0043] X = R + j(ωL - 1 / ωC)

[0044] Wherein, U is the voltage of the upper electrode RF coil 200 with respect to the ground, X is the impedance of the grounding loop where the upper electrode RF coil 200 and the second variable capacitor 630 are located, I is the current of the upper electrode RF coil 200, L is the inductance of the upper electrode RF coil 200, C is the capacitance of the second variable capacitor 630, ω is the angular frequency, such as the angular frequency of an RF coil with a frequency of 13.56 MHz is equal to 2π * 13.56 * 10 6 Hz.

[0045] As described above, the coupling current generated by the upper electrode RF coil 200 can be introduced into the second lower electrode 320 by means of an electrical connector, and the magnitude of the current introduced into the second lower electrode 320 can be adjusted by using an adjustable device. Considering that the magnitude of the coupling current generated by the upper electrode RF coil 200 is usually relatively small, in order to further enhance the magnitude of the electric field effect generated by the second lower electrode 320, in the semiconductor processing equipment disclosed in the embodiments of the present application, the second lower electrode 320 can also be provided with a radio frequency power supply. Specifically, the first lower electrode 310 and the second lower electrode 320 can each be provided with a separate radio frequency power supply.

[0046] Optionally, in order to reduce the number of components provided, the number of the lower RF power supply 410 can be one, and both the first lower electrode 310 and the second lower electrode 320 are connected to the lower RF power supply 410, so that the lower RF power supply 410 can simultaneously load RF power for the first lower electrode 310 and the second lower electrode 320. Specifically, the first lower electrode 310 and the second lower electrode 320 can be connected to the lower RF power supply 410 by using wires. More specifically, as Figure 1 shown, the first lower electrode 310 can be connected to the lower RF power supply 410 through the first wire 350, and the second lower electrode 320 can be connected to the lower RF power supply 410 through the second wire 360, so that the first lower electrode 310 and the second lower electrode 320 form a parallel connection relationship. Of course, the first lower electrode 310 and the second lower electrode 320 are also connected to the RF matcher 420 to ensure that processes such as starting the glow can proceed normally.

[0047] As described above, the coupling current generated by the upper electrode RF coil 200 can be transmitted to the second lower electrode 320 through the electrical connector. In this case, since the lower RF power supply 410 can also apply RF power to the second lower electrode 320, the current range on the second lower electrode 320 is relatively larger, and thus the electric field effect that the second lower electrode 320 can provide is relatively stronger. As a result, the effect of the second lower electrode 320 on the edge portion of the wafer is relatively stronger, improving the adjustment effect on the processing rates of the central portion and the edge portion of the wafer.

[0048] To further improve the control ability of the current flowing into the second lower electrode 320, optionally, the semiconductor processing equipment disclosed in the embodiments of the present application may further include a third variable capacitor 640 and a fourth variable capacitor 650. And, as Figure 1 shown, the third variable capacitor 640 is provided on the first wire 350, and the fourth variable capacitor 650 is provided on the second wire 360. The third variable capacitor 640 and the fourth variable capacitor 650 can be used to adjust the power distribution between the first lower electrode 310 and the second lower electrode 320. Furthermore, during the process of processing a wafer using the semiconductor processing equipment disclosed in the embodiments of the present application, according to the actual situation such as the etching rate of different regions on the wafer, the power applied by the lower RF power supply 410 to the first lower electrode 310 and the second lower electrode 320 respectively can be adjusted correspondingly through the third variable capacitor 640 and the fourth variable capacitor 650 on the first wire 350 and the second wire 360, further improving the adjustment ability of the uniformity within the wafer.

[0049] For example, when the lower RF power supply 410 is used to provide RF power to both the first lower electrode 310 and the second lower electrode 320 simultaneously, if the situation occurs that the uniformity of the wafer cannot be adjusted to meet the requirements only by using the adjustable device, the power distribution of the lower RF power supply 410 between the first lower electrode 310 and the second lower electrode 320 can be further adjusted by using the third variable capacitor 640 and the fourth variable capacitor 650. Alternatively, the process uniformity of the wafer can also be adjusted first by using the third variable capacitor 640 and the fourth variable capacitor 650, and then the uniformity of the wafer can be finely adjusted by using the adjustable device to complete the adjustment process of the uniformity of the wafer.

[0050] In order to further improve the regulation performance of the plasma in the region corresponding to the second lower electrode 320 in the process chamber 100, optionally, the semiconductor processing equipment disclosed in the embodiments of the present application further includes a lifting mechanism. The lifting mechanism includes a driving device 710. The driving device 710 is installed in the process chamber 100, and the second lower electrode 320 is connected to the driving shaft 712 of the driving device 710. Furthermore, when the driving device 710 operates, the driving device 710 can drive the second lower electrode 320 to move relative to the first lower electrode 310 in the thickness direction of the base 330.

[0051] When the technical solution disclosed in this embodiment is adopted, the magnitude of the coupling current introduced onto the second lower electrode 320 can be adjusted by the adjustable device. At the same time, by operating the driving device 710, the second lower electrode 320 can be driven to move in the thickness direction of the base 330 towards or away from the wafer, increasing or decreasing the electric field intensity of the electric field generated by the coupling current on the second lower electrode 320 acting on the plasma in the corresponding region, and further adjusting the regulation performance of the processing rates at different regions on the wafer.

[0052] In addition, when the second lower electrode 320 is connected to the lower radio frequency power supply 410, the position of the second lower electrode 320 can be adjusted flexibly according to parameters such as the preset loading power of the second lower electrode 320 and in combination with the etching rates at different positions in the wafer. By moving the second lower electrode 320 away from or towards the wafer in the thickness direction of the base 330, the etching rates at various positions on the wafer can be made substantially the same, improving the etching uniformity of the wafer.

[0053] Specifically, the driving device 710 can be a linear motor or a cylinder, etc. By forming a fixed relationship between the base 711 of the driving device 710 and the process chamber 100, and fixing the second lower electrode 320 to the driving shaft 712 of the driving device 710, it can be ensured that when the driving device 710 operates, the second lower electrode 320 can be driven to move in the driving direction of the driving device 710 through the driving shaft 712. Correspondingly, during the installation of the driving device 710, by making the driving direction of the driving device 710 parallel to the thickness direction of the base 330, it can be ensured that the driving device 710 can drive the second lower electrode 320 to move relative to the first lower electrode 310 in the thickness direction of the base 330. More specifically, the driving device 710 can be installed at the bottom inside the process chamber 100.

[0054] In another embodiment of the present application, optionally, the driving device 710 is installed outside the process chamber 100 to minimize the number of devices inside the process chamber 100 and prevent the driving device 710 from having an adverse impact on the environmental atmosphere inside the process chamber 100. Specifically, the driving device 710 can be fixed to the process chamber 100 with the assistance of connecting devices such as a mounting seat and screws, or the driving device 710 can also be fixed to the outer surface of the process chamber 100 by means of bonding or the like, which is not limited herein.

[0055] As described above, the inner sidewall of the process chamber 100 is electrically connected to the second lower electrode 320 through an electrical connector, and the second lower electrode 320 is provided with a grounding circuit. Optionally, the electrical connector is a wire, and the part that provides the grounding function for the second lower electrode 320 can also be a wire, and by extending the wire outside the process chamber 100, the grounding function is provided. When the driving device 710 is arranged outside the process chamber 100, optionally, the electrical connector includes a conductive member 510 and a third wire 520. The conductive member 510 is sleeved outside the support member 720. One end of the conductive member 510 is electrically connected to the second lower electrode 320 through the third wire 520, and the other end of the conductive member 510 is electrically connected to the inner sidewall of the process chamber 100, so as to introduce the coupling current on the inner sidewall of the process chamber 100 into the second lower electrode 320 through the conductive member 510 and the third wire 520.

[0056] At the same time, by electrically connecting both the second lower electrode and the driving device 710 to the support member 720 and grounding the driving device 710, the second lower electrode 320 can achieve the purpose of grounding by using the support member 720 and the driving device 710. Based on this, a grounding circuit for the coupling current is formed by the inner sidewall of the process chamber 100, the conductive member 510, the third wire 520, the second lower electrode 320, the support member 720, and the driving device 710.

[0057] Specifically, the conductive member 510 and the support member 720 can be the outer part and the inner part of a coaxial cable respectively, which enables the conductive member 510 to form an electrical connection relationship with the chamber wall of the process chamber 100 and ensures that the support member 720 can be electrically connected to both the second lower electrode 320 and the driving device 710 at the same time, so as to achieve the purpose of grounding the second lower electrode 320.

[0058] As described above, the adjustable device can be connected in series to the grounding circuit of the second lower electrode 320. In this case, as Figure 1As described above, the adjustable device can be connected between the second lower electrode 320 and the support member 720. By providing an insulating structural member such as insulating glue between the second lower electrode 320 and the support member 720, it can be ensured that the support member 720 can form a fixed connection relationship with the second lower electrode 320, so that under the action of the driving device 710, the second lower electrode 320 can be driven to move. At the same time, by electrically connecting the adjustable device, specifically including the first variable capacitor 610 and the inductor coil, between the second lower electrode 320 and the support member 720, it can be ensured that an electrical connection relationship can also be formed between the second lower electrode 320 and the support member 720.

[0059] When the driving device 710 is disposed outside the process chamber 100, in order to ensure that the driving device 710 can drive the second lower electrode 320 in the process chamber 100 to move, in the semiconductor processing equipment disclosed in the embodiments of the present application, as Figure 4 shown, the lifting mechanism may further include a support member 720. One end of the support member 720 is connected to the driving shaft 712 of the driving device 710, and the other end of the support member 720 extends into the process chamber 100 and is fixedly connected to the second lower electrode 320, ensuring that the driving force of the driving device 710 located outside the process chamber 100 can be transmitted to the second lower electrode 320 inside the process chamber 100 through the support member 720, so as to drive the second lower electrode 320 to move relative to the first lower electrode 310 along the thickness direction of the base 330. Specifically, the support member 720 may be a rod-shaped structural member, and in order to ensure that the support member 720 has good hardness and stiffness, the support member 720 may be formed of a hard material such as metal or plastic.

[0060] During the operation of the semiconductor processing equipment, the environment inside the process chamber 100 is usually different from the environment outside the process chamber 100. For example, the inside of the process chamber 100 may be a vacuum environment. Based on this, in order to ensure that the process chamber 100 provided with the support member 720 can still operate normally, the lifting mechanism disclosed in the embodiments of the present application further includes a seal member 730. The seal member 730 is sleeved outside the support member 720 to seal the process chamber 100.

[0061] Since the driving device 710 drives the support member 720 to move relative to the process chamber 100 during operation, the size of the part of the support member 720 located outside the process chamber 100 changes. In order to ensure that the seal member 730 sleeved outside the support member 720 can always provide a reliable sealing effect for the process chamber 100, specifically, the seal member 730 may be an elastic bellows, which has good sealing performance and elastic telescopic ability, so that the seal member 730 can always provide a good sealing effect for the process chamber 100 while deforming with the movement of the support member 720.

[0062] More specifically, one end of the seal 730 can be sealingly connected to the surface of the process chamber 100, and the other end of the seal 730 facing away from the process chamber can be sealingly connected to the housing of the driving device 710, specifically, it can be connected to the end face of the base 711 of the driving device 710.

[0063] In another embodiment of the present application, optionally, as Figure 4 shown, the base 711 of the driving device 710 is fixed to the process chamber 100, so that the driving device 710 can form a fixed connection relationship with the process chamber 100. In this case, the lifting mechanism may further include a lifting plate 740. One end of the driving shaft 712 of the driving device 710 and the support member 720 are both connected to the lifting plate 740, so as to indirectly connect the driving device 710 and the support member 720 by using the lifting plate 740 as an intermediate member. The lifting plate 740 can be specifically formed of materials such as metal or plastic, and its specific size can be determined according to the actual situation such as the cross-sectional size of components such as the seal 730 and the support member 720, and is not limited herein.

[0064] When the lifting plate 740 is included in the lifting mechanism, the seal 730 can be correspondingly mounted on the lifting plate 740. Specifically, one end of the seal 730 is sealingly connected to the surface of the process chamber 100, and the other end of the seal 730, that is, the end of the seal 730 facing away from the process chamber 100, can be sealingly connected to the surface of the lifting plate 740 facing the process chamber 100, so as to ensure that the seal 730 can provide a reliable sealing effect for the process chamber 100. Of course, as described above, when one end of the seal 730 abuts against the surface of the lifting plate 740, it is necessary to ensure that the size of the lifting plate 740 is larger than the size of the seal 730.

[0065] As described above, the driving device 710 can be fixed to the process chamber 100 by means of connection devices such as screws, or by means of bonding. At the same time, when the driving device 710 is working, the driving device 710 may be charged, which may affect the electric potential of the process chamber 100. Based on this, the driving device 710 can be adhesively fixed to the surface of the process chamber 100 by using a glue with good insulation, so as to ensure that the driving device 710 and the process chamber 100 form an insulating relationship.

[0066] In another embodiment of the present application, optionally, the lifting mechanism further includes an insulating member 760. The insulating member 760 is disposed between the driving device 710 and the process chamber 100 to ensure that a good insulating relationship is formed between the driving device 710 and the process chamber 100. The insulating member 760 can be formed of insulating materials such as rubber or plastic, and its size and shape can be determined according to actual needs.

[0067] When the insulating member 760 is provided in the lifting mechanism, the driving device 710 and the process chamber 100 can be connected by connecting devices such as screws. More specifically, the lifting mechanism also includes a fixing member 771 and an adapter 772, the insulating member 760 is connected to one end of the adapter 772, the other end of the adapter 772 is connected to the driving device 710 through the fixing member 771, and the driving shaft 712 of the driving device 710 is connected to the lifting plate 740, so as to further reduce the difficulty of forming a fixed connection relationship between the driving device 710 and the process chamber 100.

[0068] In order to further improve the accuracy of the driving action of the driving device 710, a guide rod 776 can be further arranged between the lifting plate 740 and the fixing member 771. The guide rod 776 is fixed on one of the lifting plate 740 and the fixing member 771, and a perforation structure and the like can be arranged on the other of the two. In the process of relative movement between the lifting plate 740 and the fixing member 771, the lifting plate 740 can be provided with a guiding and limiting effect by utilizing the mutually cooperating guide rod 776 and perforations.

[0069] Optionally, the lifting mechanism may further include a guide sleeve 773, which is disposed between the bottom of the process chamber 100 and the second lower electrode 320. The guide sleeve 773 may be fixed to the bottom wall of the process chamber 100 by welding or the like, so as to provide a guide for the portion of the support member 720 located within the process chamber 100, thereby further improving the accuracy of the second lower electrode 320 when performing lifting and lowering motions along the thickness direction of the first lower electrode 310.

[0070] In order to improve the movement stability of the support member 720, optionally, there are multiple support members 720, and the multiple support members 720 are all connected around the driving device 710, and the second lower electrode 320 is connected to the ends of the multiple support members 720 that are away from the lifting plate 740. Further, the lifting mechanism also includes a counterweight block 774, which can be set in the process chamber 100, and the counterweight block 774 is fixedly connected to the multiple support members 720, so as to further stabilize the relative position relationship between the multiple support members 720 and improve the driving stability of the entire lifting mechanism.

[0071] As described above, one end of the support member 720 may be directly connected to the second lower electrode 320. In order to prevent the lifting mechanism from affecting the electrical properties of the second lower electrode 320, the lifting mechanism may optionally further include a support plate 775. Specifically, the support plate 775 may be made of an insulating hard material, and the second lower electrode 320 may be supported on the support plate 775, and the support plate 775 is connected to one end of the support member 720 to indirectly drive the second lower electrode 320 to move.

[0072] When a plurality of support members 720 are provided on the lifting plate 740, further, the lifting mechanism disclosed in the embodiment of the present application may further include a plurality of fine-tuning devices 750, and the fine-tuning devices 750 may specifically be screw adjustment mechanisms or the like. The plurality of support members 720 are respectively connected to the lifting plate 740 through the plurality of fine-tuning devices 750. Thus, when the position states of one or more support members 720 are different from those of the remaining support members 720, the positional relationship between the support members 720 and the lifting plate 740 can be adjusted through the fine-tuning devices 750.

[0073] Optionally, as Figure 4 shown, support members 720 are provided on both opposite sides of the driving device 710. Each support member 720 is symmetrically distributed with respect to the center of the second lower electrode 320, so that the same driving device 710 drives two support members 720 simultaneously, providing a relatively stable lifting effect for the second lower electrode 320. Moreover, each support member is adjustably connected to the lifting plate 740 through the fine-tuning device 750 in the thickness direction of the base 330, so that in the case where the overall structure of the lifting mechanism is relatively simple, the driving device 710 can provide a relatively reliable lifting driving effect for the second lower electrode 320 through the two support members 720.

[0074] As described above, the second lower electrode 320 is an annular structural member. Based on this, the number of driving devices 710 can be one. In this case, the stability of the fixing relationship between the second lower electrode 320 and the lifting mechanism can be enhanced by the above-described method of providing a plurality of support members 720 or the like, so that the driven conditions at any position on the second lower electrode 320 are the same. In another embodiment of the present application, optionally, the number of driving devices 710 is multiple. The multiple driving devices 710 are uniformly and spaced along the circumference of the second lower electrode 320, and the multiple driving devices 710 are all connected to the second lower electrode 320 through the support members 720. Thus, the second lower electrode 320 is driven by the multiple driving devices 710 together, greatly improving the stability when the second lower electrode 320 is driven.

[0075] In addition, during the working process of the semiconductor processing equipment disclosed in the embodiment of the present application, if the preset power of the second lower electrode 320 is less than the standard power value corresponding to normal starting, the foregoing standard power value can be loaded onto the second lower electrode 320, and the lifting mechanism is used to move the second lower electrode 320 in a direction away from the wafer, so as to reduce the electric field intensity acting on the wafer by the second lower electrode 320. Thus, when the starting operation can be carried out normally, the parameters of the actual bias electric field provided by the second lower electrode 320 for the corresponding area on the wafer can be close to or equivalent to the parameters of the preset bias electric field.

[0076] In the above embodiments of the present invention, the differences between the various embodiments are mainly described. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity in writing, they will not be elaborated here.

[0077] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A semiconductor processing device, characterized in that, It includes a process chamber, an upper electrode RF coil, a lower RF power supply, a lower electrode assembly, an electrical connector, and an adjustable device. The lower electrode assembly includes a base, an electrostatic chuck, a first lower electrode, and a second lower electrode. The electrostatic chuck is located above the base for holding a wafer. The first lower electrode is disposed inside the base and connected to the lower RF power supply. The second lower electrode is disposed around and spaced apart from the first lower electrode. The inner sidewall of the process chamber is electrically connected to the second lower electrode through the electrical connector, so that the coupling current generated by the upper electrode RF coil on the inner sidewall of the process chamber is introduced into the second lower electrode. The adjustable device is used to adjust the magnitude of the coupling current introduced from the inner sidewall of the process chamber into the second lower electrode.

2. The semiconductor processing equipment according to claim 1, wherein, The adjustable device is connected in series to the grounding circuit where the second lower electrode is located. The adjustable device includes a first variable capacitor and an inductance coil for adjusting the impedance of the grounding circuit where the second lower electrode is located.

3. The semiconductor processing equipment according to claim 1, characterized in that, The adjustable device is connected in series to the grounding circuit of the upper electrode RF coil. The adjustable device includes a second variable capacitor.

4. The semiconductor processing equipment according to claim 1, characterized in that, The first lower electrode is connected to the lower RF power supply through a first wire, and the second lower electrode is connected to the lower RF power supply through a second wire.

5. The semiconductor processing equipment according to claim 4, characterized in that, The semiconductor processing equipment further includes a third variable capacitor and a fourth variable capacitor. The third variable capacitor is provided on the first wire, and the fourth variable capacitor is provided on the second wire.

6. The semiconductor processing equipment according to claim 1, wherein The semiconductor processing equipment further includes a lifting mechanism. The lifting mechanism includes a driving device and a support member. The driving device is installed outside the process chamber. One end of the support member is connected to the driving shaft of the driving device, and the other end of the support member extends into the process chamber and is fixedly connected to the second lower electrode. The driver drives the support member to drive the second lower electrode to move relative to the first lower electrode along the thickness direction of the base.

7. The semiconductor processing equipment according to claim 6, characterized in that, The electrical connector includes a conductive member and a third wire. The conductive member is sleeved outside the support member. One end of the conductive member is electrically connected to the second lower electrode through the third wire, and the other end of the conductive member is electrically connected to the inner sidewall of the process chamber. Both the second lower electrode and the driving device are electrically connected to the support member. The driving device is grounded, so that the inner sidewall of the process chamber, the conductive member, the third wire, the second lower electrode, the support member, and the driving device form the grounding circuit of the coupling current.

8. The semiconductor processing equipment according to claim 6, wherein, The lifting mechanism further includes a lifting plate and a sealing member. The base of the driving device is fixed to the process chamber. The driving shaft of the driving device and one end of the support member are both connected to the lifting plate. One end of the sealing member is sealingly connected to the process chamber, and the end of the sealing member facing away from the process chamber is sealingly connected to the lifting plate.

9. The semiconductor processing equipment according to claim 8, wherein, The support members are provided on both opposite sides of the driving device. Each of the support members is symmetrically distributed with respect to the center of the second lower electrode, and each of the support members is adjustably connected to the lifting plate in the thickness direction of the base through a fine adjustment device.

10. The semiconductor processing equipment according to claim 1, characterized in that, The first lower electrode is a circular structural member, the second lower electrode is an annular structural member, the distance between the second lower electrode and the first lower electrode in the radial direction of the first lower electrode is 1 mm - 10 mm, and the difference between the outer diameter of the second lower electrode and the diameter of the wafer is ±5 mm.

Images