Electrostatic chuck device and substrate processing device including the same

Abstract

To provide an electrostatic chuck device which can achieve both reduction in leak current and uniformity of plasma.SOLUTION: An electrostatic chuck device is used in a plasma space, and includes a stage having a circular substrate suction region (diameter represented by DS) to which a circular processed substrate is electrostatically sucked on its upper surface, and an ESC electrode which is embedded in the stage, has a diameter DE1 larger than the diameter DS of the substrate suction region, and is arranged concentrically with the center of the substrate suction region in plan view. The processed substrate is electrostatically sucked to the upper surface of the stage by Johnsen-Rahbek force by applying a direct current voltage to the ESC electrode, and the stage has a high resistance ring-like part for suppressing current leaked to the plasma space from the outside part when the direct current voltage is applied, in the outside part of the substrate suction region in plan view.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to an electrostatic chuck device and a substrate processing apparatus. [Background technology]

[0002] Electrostatic chucks, which fix a substrate to be processed by electrostatic attraction, can hold the substrate flat and are suitable for controlling the substrate temperature during plasma processing. Therefore, they are used to hold substrates during plasma processing such as dry etching, sputtering, and plasma CVD.

[0003] The electrostatic chuck has an internal electrode (ESC electrode) embedded in a disk-shaped ceramic plate having approximately the same diameter as a substrate to be processed, for example, a semiconductor wafer, and electrostatically attracts and fixes the semiconductor wafer to the ceramic plate by applying a DC voltage to the internal electrode (for example, Patent Document 1).

[0004] There are two types of electrostatic chucks: Coulomb type and Johnsen-Rahbek type. The main electrostatic attraction force of the Coulomb type is the Coulomb force between the different charges that are induced when a capacitor with the dielectric as capacitance is formed between the internal electrode and the semiconductor wafer, inducing charges of opposite polarity. On the other hand, the main electrostatic attraction force of the Johnsen-Rahbek type is the Johnsen-Rahbek force (hereinafter sometimes abbreviated as JR force) that occurs when a minute current flowing through the dielectric induces electrified polarization in the small gap at the interface between the semiconductor wafer and the dielectric, and the positive and negative charges attract each other. In high-temperature plasma processing, a Johnsen-Rahbek type electrostatic chuck, which has a large electrostatic attraction force, is generally used.

[0005] One of the challenges facing electrostatic chucks is to simultaneously reduce leakage current to stabilize the chucking force and ensure uniformity of the plasma.

[0006] In order to reduce the leakage current, Patent Document 1 proposes using an attraction electrode (ESC electrode) smaller than the wafer and an auxiliary electrode. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-088195 A Summary of the Invention [Problem to be solved by the invention]

[0008] In the configuration proposed in Patent Document 1, the distances from the stage (ceramic plate) surface to the chucking electrode and the auxiliary electrode are different, which causes a problem of poor plasma uniformity, especially near the edge of the wafer W. In addition, considering the manufacturing process, it is considered that it is not easy to form such an electrode structure with high precision due to deformation during sintering. Furthermore, Patent Document 1 focuses only on the resistance of aluminum nitride (AlN), which is the stage material, and the problem of reduced chucking force due to increased leakage current at high temperatures is caused by the resistance of the stage being smaller than the contact resistance with the wafer. Therefore, with such a configuration, it is difficult to achieve both reduced leakage current and plasma uniformity. [Means for solving the problem]

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are described in more detail below in the Detailed Description of Exemplary Embodiments of the Disclosure. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0010] A first aspect of the present disclosure is an electrostatic chuck device used in a plasma space, which has a circular substrate adsorption area (with a diameter of D) on which a circular substrate to be processed is electrostatically adsorbed. S a stage having a substrate suction area having a diameter D S Diameter D is larger than E1and ESC electrodes arranged concentrically with a center of the substrate adsorption region in a planar view, wherein a DC voltage is applied to the ESC electrodes, so that the substrate to be processed is electrostatically adsorbed on the upper surface of the stage by Johnsen-Rahbek force, and the stage has, in an outer portion of the substrate adsorption region in a planar view, a high-resistance ring-shaped portion which suppresses a current leaking from the outer portion to a plasma space when the DC voltage is applied.

[0011] A second aspect of the present disclosure is an electrostatic chuck device according to the first aspect, further comprising a heater provided in the stage below the ESC electrodes.

[0012] A third aspect of the present disclosure is directed to the electrostatic chuck device of the first or second aspect, in which the high-resistance ring-shaped portion is made of a high-resistance material having a volume resistivity higher than that of a stage material of a portion between the substrate adsorption region and the ESC electrodes.

[0013] A fourth aspect of the present disclosure is an electrostatic chuck device according to any one of the first to third aspects, in which the high-resistance material is the same base material as the portion other than the high-resistance ring-shaped portion, but has a different concentration of impurity elements.

[0014] A fifth aspect of the present disclosure is the electrostatic chuck device of any one of the first to fourth aspects, wherein the high-resistance material is aluminum nitride.

[0015] A sixth aspect of the present disclosure is an electrostatic chuck device according to the first or second aspect, wherein the high resistance ring-shaped portion is a ring-shaped convex portion arranged to surround the workpiece substrate and protruding upward above the substrate adsorption area.

[0016] A seventh aspect of the present disclosure is directed to the electrostatic chuck device of the sixth aspect, in which the ring-shaped convex portion is made of a high-resistance material having a volume resistivity higher than that of a stage material of a portion between the substrate adsorption region and the ESC electrodes.

[0017] An eighth aspect of the present disclosure is an electrostatic chuck device according to the sixth or seventh aspect, in which the high resistance material is the same base material as the portion other than the high resistance ring portion, but has a different concentration of impurity elements.

[0018] A ninth aspect of the present disclosure is the electrostatic chuck device of the first or second aspect, wherein the high resistance ring-shaped portion is a separate ring-shaped member disposed to surround the substrate to be processed.

[0019] A tenth aspect of the present disclosure is the electrostatic chuck device of the ninth aspect, wherein the ring-shaped member has a plurality of protrusions on a rear surface thereof.

[0020] An eleventh aspect of the present disclosure is, in the electrostatic chuck device of the ninth or tenth aspect, the ring-shaped member is made of a high-resistance material having a volume resistivity higher than that of a stage material of a portion between the substrate adsorption region and the ESC electrodes.

[0021] A twelfth aspect of the present disclosure relates to an electrostatic chuck device according to the third aspect, and further includes, as the high-resistance ring-shaped portion, a ring-shaped member that is separate from the portion made of the high-resistance material and is arranged so as to surround the workpiece substrate.

[0022] A thirteenth aspect of the present disclosure is the electrostatic chuck device of the twelfth aspect, wherein the ring-shaped member has a plurality of protrusions on a rear surface thereof.

[0023] A fourteenth aspect of the present disclosure is the electrostatic chuck device of the twelfth or thirteenth aspect, wherein the material of the ring-shaped member is the same as that of the portion made of the high resistance material.

[0024] A fifteenth aspect of the present disclosure is an electrostatic chuck device used in a plasma space, the electrostatic chuck device having a circular substrate adsorption area (with a diameter of D) on which a circular substrate to be processed is electrostatically adsorbed. S a stage having a substrate suction area having a diameter D S or the diameter D of the substrate adsorption area S Almost the same diameter D E2and an ESC electrode arranged concentrically with a center of the substrate suction region in a planar view, and an RF electrode for plasma generation that is embedded in the stage, has the same plane as the ESC electrodes, and is arranged outside the substrate suction region in a planar view, This is an electrostatic chuck device in which a DC voltage is applied to the ESC electrodes, and the substrate to be processed is electrostatically attracted to the upper surface of the stage by the Johnsen-Rahbek force.

[0025] A sixteenth aspect of the present disclosure is the electrostatic chuck device of the fifteenth aspect, in which the RF electrode is grounded via a rectifier circuit including a capacitor and / or an inductor so that the RF electrode and the ESC electrode have equivalent impedance.

[0026] A seventeenth aspect of the present disclosure is a substrate processing apparatus including a chamber, an electrostatic chuck device according to any one of aspects 1 to 16 provided in the chamber, and a showerhead provided above the electrostatic chuck device.

[0027] An eighteenth aspect of the present disclosure is a method for manufacturing a chuck apparatus comprising: a chamber; an electrostatic chuck device provided in the chamber; a showerhead provided above the electrostatic chuck device; and a flow control ring having a shape surrounding the electrostatic chuck device, the electrostatic chuck device being adapted to hold a circular substrate to be processed (with a diameter of D 0 The circular substrate adsorption area (diameter is D 1 a stage having a substrate suction area having a diameter D 1 or the diameter D of the substrate adsorption area 1 Almost the same diameter D E2 and an ESC electrode arranged concentrically with a center of the substrate suction area in a plan view, and a diameter D 1 is the diameter D of the substrate to be processed 0 and the flow control ring is made of metal and functions as an RF electrode for generating plasma.

[0028] A nineteenth aspect of the present disclosure is a method for manufacturing a chuck apparatus comprising: a chamber; an electrostatic chuck device provided in the chamber; a showerhead provided above the electrostatic chuck device; and a flow control ring having a shape surrounding the electrostatic chuck device, the electrostatic chuck device being adapted to receive a circular substrate to be processed (with a diameter of D 0 The circular substrate adsorption area (diameter is D 1 a stage having a substrate suction area having a diameter D 1 or the diameter D of the substrate adsorption area 1 Almost the same diameter D E2 and an ESC electrode arranged concentrically with a center of the substrate suction area in a plan view, and a diameter D 1 is the diameter D of the substrate to be processed 0 and the flow control ring is made of ceramic and has an RF electrode for generating plasma therein. [Brief description of the drawings]

[0029] It will be understood that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure.

[0030] [Figure 1A] 1 is a schematic cross-sectional view of an electrostatic chuck device according to a first embodiment, showing a state in which a substrate W to be processed is placed thereon. [Figure 1B] 1 is a schematic cross-sectional view of an electrostatic chuck device according to a first embodiment, showing a state in which a substrate W to be processed is not placed on the electrostatic chuck device. [Diagram 2] 1 is an equivalent circuit for explaining a leakage current. [Diagram 3] FIG. 4 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the first embodiment. [Figure 4A] FIG. 6 is a schematic cross-sectional view of an electrostatic chuck device according to a second embodiment. [Figure 4B] FIG. 11 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the second embodiment. [Figure 5A] FIG. 11 is a schematic cross-sectional view of an electrostatic chuck device according to a third embodiment. [Figure 5B] FIG. 13 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the third embodiment. [Figure 6A] FIG. 13 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the third embodiment. [Figure 6B] FIG. 13 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the third embodiment. [Figure 7] 1 is a schematic cross-sectional view of a substrate processing apparatus including an electrostatic chuck device according to an embodiment of the present invention; [Figure 8] 8 is a simplified representation of the configuration of FIG. 7 for easily explaining the operation during substrate processing. [Figure 9A] FIG. 13 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the fourth embodiment. [Figure 9B] FIG. 13 is a schematic cross-sectional view of an electrostatic chuck device showing a modified example of the fourth embodiment. [Figure 10A] 8 is a schematic cross-sectional view showing another embodiment of the substrate processing apparatus shown in FIG. [Figure 10B] 10B is a schematic cross-sectional view showing a modified example of the substrate processing apparatus shown in FIG. 10A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Although specific embodiments and examples are disclosed below, those skilled in the art will recognize that the specifically disclosed embodiments and / or applications of the invention, as well as obvious modifications and equivalents thereof, are within the scope of the present invention. Accordingly, it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0032] The term "substrate" as used herein may refer to any underlying material or materials, including those that may be modified or upon which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; or a combination thereof. Substrates may be in any form, such as powder, plate, workpiece, etc. Plate-type substrates include wafers of various shapes and sizes. Substrates may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0033] For example, powdered substrates may be used in pharmaceutical manufacturing. Porous substrates may include polymers. Examples of workpieces include medical devices (e.g., stents and syringes), jewelry, tools, battery manufacturing components (e.g., anodes, cathodes, or separators), or photovoltaic cell components.

[0034] The continuous substrate may extend beyond the boundaries of the process chamber in which the deposition process occurs. In some processes, the continuous substrate may be capable of moving within the process chamber such that the process continues until the edge of the substrate is reached. The continuous substrate may be provided from a continuous substrate supply system, which may enable the production and output of any suitable form of continuous substrate.

[0035] Non-limiting examples of continuous substrates include sheets, nonwoven films, rolls, foils, webs, flexible materials, continuous threads or bundles of fibers (e.g., ceramic fibers or polymeric fibers), etc. Continuous substrates may include carriers or sheets upon which non-continuous substrates are mounted.

[0036] The drawings presented herein are not intended to be actual illustrations of any particular materials, structures or devices, but merely idealized representations used to describe embodiments of the present disclosure.

[0037] The particular implementations shown and described herein are illustrative of the present invention and its best modes and are not intended to limit the scope of the aspects or implementations in any other manner. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the systems may not be described in detail. Moreover, the connecting lines shown in the various figures are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system and / or may not be present in some embodiments.

[0038] It should be understood that the configurations and / or approaches described herein are exemplary in nature and that numerous variations are possible, and therefore these specific embodiments or examples should not be considered in a limiting sense. The particular routines or methods described herein may represent one or more of any number of processing strategies. Thus, various illustrated operations may be performed in the order illustrated, in other orders, or in some cases omitted.

[0039] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various process, system, configurations, and other features, functions, operations, and / or properties disclosed herein, and all equivalents thereof.

[0040] 1A and 1B are schematic cross-sectional views of an electrostatic chuck device according to a first embodiment, in which FIG. 1A shows a state in which a substrate W to be processed is placed, and FIG. 1B shows a state in which the substrate W to be processed is not placed.

[0041] 1A and 1B is an electrostatic chuck device used in a plasma space. The electrostatic chuck device 100 has a circular substrate adsorption area 50A (with a diameter D SA stage 50 having a top surface 50a of a substrate suction region 50A with a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of the substrate attraction region 50A in a planar view. When a DC voltage is applied to the ESC electrode 30, the substrate W to be processed is electrostatically attracted to an upper surface 50a of the stage 50 by the Johnsen-Rahbek force. The stage 50 has a high-resistance ring-shaped portion 51B in a ring-shaped outer circumferential region 50B arranged adjacent to the outside of the substrate attraction region 50A in a planar view, the high-resistance ring-shaped portion 51B suppressing a leak current leaking from the outer circumferential portion 50B to a plasma space P (see FIG. 2 ) when a DC voltage is applied. The reference symbol 51C indicates, of the stage 50, a portion below the high resistance ring-shaped portion 51B and a portion below the ESC electrodes 30.

[0042] The stage 50 is made of a dielectric material, for example, a ceramic material such as aluminum nitride (AlN), alumina, silicon carbide (SiC), boron nitride (BN), etc. Moreover, the ESC electrodes 30 are made of a high-melting point metal, for example, tungsten, tantalum, molybdenum, niobium, ruthenium, hafnium, etc. The shape of the ESC electrodes 30 is, for example, a plate shape, a wire mesh shape, or a punching metal shape. Hereinafter, the materials and shapes of the stage and the ESC electrodes are similar to those in the other embodiments described below, and therefore the description will not be repeated.

[0043] FIG. 2 is a conceptual diagram for explaining a leakage current. In FIG. 2, when a DC voltage is applied to the ESC electrodes 30 to generate the JR force, an unintended current flows from the ring-shaped outer peripheral region 50B where no wafer is present through the plasma space. The unintended current is a leakage current I Leak When a DC voltage is applied to the ESC electrodes 30 to generate a JR force, a resistance R between the ESC electrodes 30 and the circular substrate attraction region 50A is in , and a resistance R between the ESC electrodes 30 and the ring-shaped outer circumferential region 50B out , and the small current I shown in FIG. 2 depending on the DC voltage. J-R This results in:

[0044] As mentioned above, the JR force is J-R This occurs when electrostatic polarization is induced in the small gap at the interface IF between the semiconductor wafer W and the dielectric 50, and the positive and negative charges attract each other. Leakage current I Leak is a current that flows from the ring-shaped outer peripheral region 50B where the wafer W is not present through the plasma space P. This leakage current I Leak not only does not contribute to the JR force, but also impairs the uniformity of the plasma in the vicinity of the ring-shaped outer peripheral region 50B, that is, in the vicinity of the edge of the wafer W.

[0045] The electrostatic chuck device of the present disclosure includes a high resistance ring-shaped portion and a resistance R in For resistance R out By increasing the leakage current I Leak This aims to reduce the diameter D of the ESC electrodes and improve the uniformity of the plasma in the vicinity of the edge of the wafer W. E1 is the diameter D of the wafer W 0 (Substantially the diameter D of the substrate adsorption area 50A S The diameter D of the ESC electrode is large enough for the E1 For example, is 10 mm larger than Ds.

[0046] In the electrostatic chuck device shown in FIGS. 1A and 1B, the high-resistance ring-shaped portion 51B is made of a high-resistance material having a volume resistivity higher than that of a stage material of a portion (wafer contact portion) 51A between the substrate adsorption region 50A and the ESC electrodes 30. Resistance R out is the resistance R in (i.e., R out >10R in It is preferable that the volume resistivity ρ of the high resistance material constituting the high resistance ring-shaped portion (wafer non-contact portion) 51B is 1. B [Ω·cm], and the volume resistivity ρ of the low-resistance material constituting the wafer contact portion 51A A [Ω cm] is R out >10R in It is preferable that each material is configured so as to satisfy the above. 1A and 1B is a case where a portion 51C below the high resistance ring-shaped portion 51B and below the ESC electrodes 30 is made of the same material as the low resistance material of the wafer contact portion 51A.

[0047] The resistance of the high resistance ring portion 51B is calculated by the following formula (1).

[0048]

number

[0049] In the electrostatic chuck device illustrated in FIGS. 1A and 1B , the high-resistance ring-shaped portion 51B is configured to be disposed so as to fill the space between the upper surface 50 a and the ESC electrodes 30; however, the high-resistance ring-shaped portion 51B may be configured to be disposed so as to fill a part of the space between the upper surface 50 a and the ESC electrodes 30, or may be configured to be disposed so as to extend to a part of the wafer contact portion 51A.

[0050] 1A and 1B, the stage 50 is made of a material having the same volume resistivity other than the high-resistance ring-shaped portion 51B, but is not limited to this. For example, the portion below the ESC electrodes 30 may be configured to be made of a material having a volume resistivity different from that of the wafer contact portion 51A.

[0051] In the electrostatic chuck device shown in FIGS. 1A and 1B, as illustrated in FIG. 7, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50.

[0052] 3 is a case where a stage 50-1 has a portion 51-1C below the high-resistance ring-shaped portion 51-1B and below the ESC electrodes 30, the portion 51-1C being made of the same high-resistance material as that of the high-resistance ring-shaped portion 51B. Components common to the components described above will be described using the reference characters used in FIGS. 1A and 1B. That is, the electrostatic chuck device 101 shown in FIG. 3 has a circular substrate adsorption area 50-1A (having a diameter of D) on which a circular substrate W to be processed is electrostatically adsorbed. S A stage 50-1 having a substrate suction region 50-1A having a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of a substrate adsorption region 50-1A in a planar view. When a DC voltage is applied to the ESC electrode 30, a substrate W to be processed is electrostatically adsorbed to an upper surface 50a of the stage 50-1 by the Johnsen-Rahbek force. The stage 50-1 has a high-resistance ring-shaped portion 51-1B in a ring-shaped outer peripheral region 50-1B arranged adjacent to the outside of the substrate adsorption region 50-1A in a planar view, the high-resistance ring-shaped portion 51-1B suppressing a leak current leaking from the outer portion 50-1B to a plasma space P when a DC voltage is applied.

[0053] The high resistance material constituting the high resistance ring-shaped portion 51B shown in FIG. 1B or the high resistance ring-shaped portion 51-1B shown in FIG. 3 is the same base material as the portion other than the high resistance ring-shaped portion, but it can be configured with a different concentration of impurity elements. Here, the base material means the main material. In this configuration, since the difference in thermal expansion coefficient between the high resistance material and the low resistance material is small, peeling is unlikely to occur between the high resistance material portion and the low resistance material portion even if the stage 50 is repeatedly heated and cooled. An example of such a material is aluminum nitride, which can be used as a high resistance material or a low resistance material by changing the content of impurity elements contained in the aluminum nitride.

[0054] Similarly, in the electrostatic chuck device shown in FIG. 3, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50-1.

[0055] The above-mentioned stage can be integrally fabricated by known methods, for example, by sintering.

[0056] FIG. 4A is a schematic cross-sectional view of an electrostatic chuck device according to the second embodiment.

[0057] The electrostatic chuck device 102 shown in Fig. 4A is an electrostatic chuck device used in a plasma space. The electrostatic chuck device 102 has a circular substrate attracting region 50-2A (having a diameter D S A stage 50-2 having a substrate suction region 50-2A having a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of the substrate attraction region 50-2A in a planar view. When a DC voltage is applied to the ESC electrode 30, the substrate W to be processed is electrostatically attracted to the upper surface 50a of the stage 50-2 by the Johnsen-Rahbek force. The stage 50-2 has a high-resistance ring-shaped portion 51-2B in an outer portion (ring-shaped outer peripheral region) 50-2B of the substrate attraction region 50-2A in a planar view, the high-resistance ring-shaped portion 51-2B suppressing a leak current leaking from the outer portion 50-2B to the plasma space P (see FIG. 2) when a DC voltage is applied.

[0058] The high resistance ring-shaped portion 51-2B is disposed so as to surround the substrate W to be processed, and is a ring-shaped protrusion protruding upward from the substrate suction region 50-exhaust 2A.

[0059] The electrostatic chuck device according to the second embodiment employs a configuration in which the thickness 1 of the high resistance ring portion 51-2B, which is included in the above formula (1), is made thick, thereby increasing the resistance and reducing the leakage current.

[0060] Resistance R between the ESC electrode 30 and the substrate attraction region 50-2A in , and the resistance R of the ring-shaped protrusion 51-2B, which is a high resistance ring-shaped portion out is the resistance R in (i.e., R out >10Rin ) is preferred. The ring-shaped convex portion 51-2B which is the high-resistance ring-shaped portion is preferably made of a high-resistance material having a volume resistivity higher than that of the stage material of the portion (wafer contact portion) 51-2A between the substrate adsorption region 50-2A and the ESC electrodes 30. This is because, in addition to the thickness of Formula (1), the effect of the large volume resistivity can make the resistance of the ring-shaped convex portion 51-2B larger, as in the first embodiment. The thickness of the ring-shaped protrusion 51-2B (H 1 +d 1 ) in H 1 , d 1 is R out >10R in It can be set to satisfy H 1 is the thickness (height) of the substrate protruding upward from the substrate adsorption region 50-2A, and d 1 is the thickness from the substrate attraction region 50-2A to the upper surfaces of the ESC electrodes 30. Thickness d 1 As an example of a guideline, the distance can be about several mm. More specifically, the distance can be about 1 to 2 mm.

[0061] As in the first embodiment, the high resistance material constituting the ring-shaped protrusion 51-2B is the same base material as the other parts except for the ring-shaped protrusion 51-2B, but the concentration of impurity elements can be different. In this configuration, since the difference in thermal expansion coefficient between the high resistance material and the low resistance material is small, peeling is unlikely to occur between the ring-shaped protrusion 51-2B, which is the high resistance material part, and the low resistance material part even if the stage 50-2 is repeatedly heated and cooled. An example of such a material is aluminum nitride, which can be used as a high resistance material or a low resistance material by changing the content of impurity elements contained in the aluminum nitride.

[0062] In the electrostatic chuck device shown in FIG. 4A, a portion 51-2C below the ring-shaped convex portion 51-2B and below the ESC electrodes 30 are made of the same low-resistance material as that of the wafer contact portion 51-1A.

[0063] Similarly, in the electrostatic chuck device shown in FIG. 4A, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50-2.

[0064] The above-mentioned stage can be fabricated in one piece by known methods, for example by sintering.

[0065] FIG. 4B shows a modified example of the electrostatic chuck device according to the second embodiment. The electrostatic chuck device 103 of the modified example shown in Fig. 4B differs from the electrostatic chuck device 102 shown in Fig. 4A in that a tapered portion 51-3Ba is formed on the wafer W side of the ring-shaped protrusion 51-3B. The tapered structure can reduce plasma concentration due to the edge effect. It is preferable to also have a tapered portion on the opposite side of the wafer W to prevent abnormal discharge. For the same purpose, a round structure may be used instead of the tapered structure.

[0066] The electrostatic chuck device 103 of the modified example shown in FIG. 4B has a circular substrate adsorption region 50-3A (having a diameter of D S A stage 50-3 having a substrate suction region 50-3A having a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of a substrate adsorption region 50-3A in a planar view. When a DC voltage is applied to the ESC electrode 30, a substrate W to be processed is electrostatically adsorbed onto an upper surface 50a of the stage 50-3 by the Johnsen-Rahbek force. The stage 50-3 has a ring-shaped convex portion 51-3B in an outer portion (ring-shaped outer peripheral region) 50-3B of the substrate adsorption region 50-3A in a planar view as a high-resistance ring-shaped portion that suppresses leakage current leaking from the outer portion 50-3B to a plasma space P when a DC voltage is applied.

[0067] The ring-shaped convex portion 51-3B which is the high-resistance ring-shaped portion is preferably made of a high-resistance material having a volume resistivity higher than that of the stage material of the portion (wafer contact portion) 51-3A between the substrate adsorption region 50-3A and the ESC electrodes 30. This is because, in addition to the thickness in Formula (1), the effect of the large volume resistivity can make the resistance of the ring-shaped convex portion 51-3B larger, as in the first embodiment.

[0068] In the electrostatic chuck device shown in FIG. 4B, a portion 51-3C below the ring-shaped convex portion 51-3B and below the ESC electrodes 30 are made of the same low-resistance material as that of the wafer contact portion 51-3A.

[0069] Similarly, in the electrostatic chuck device shown in FIG. 4B, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50-3.

[0070] FIG. 5A is a schematic cross-sectional view of an electrostatic chuck device according to a third embodiment.

[0071] The electrostatic chuck device 104 shown in Fig. 5A is an electrostatic chuck device used in a plasma space. The electrostatic chuck device 104 has a circular substrate attracting region 50-4A (having a diameter D S A stage 50-4 having a substrate suction region 50-4A with a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of a substrate adsorption region 50-4A in a planar view. When a DC voltage is applied to the ESC electrode 30, the substrate W to be processed is electrostatically adsorbed onto an upper surface 50a of the stage 50-4 by the Johnsen-Rahbek force. The stage 50-4 has a high-resistance ring-shaped portion 51-4B in an outer portion (ring-shaped outer peripheral region) 50-4B of the substrate adsorption region 50-4A in a planar view, the high-resistance ring-shaped portion 51-4B suppresses leakage current leaking from the outer portion 50-4B to a plasma space P (see FIG. 2) when a DC voltage is applied.

[0072] The high resistance ring portion 51-4B is a separate ring-shaped member disposed so as to surround the substrate W to be processed.

[0073] The electrostatic chuck device according to the third embodiment is provided with a separate ring-shaped member as a high resistance ring-shaped portion 51-4B.

[0074] Also in the electrostatic chuck device according to the third embodiment including the ring-shaped member 51-4B that is a separate high-resistance ring-shaped portion, as described above, when a DC voltage is applied to the ESC electrodes 30 to generate the JR force, the minute current I J-R However, compared to the above embodiment in which the high resistance ring portion is integrated, the leakage current I Leak Therefore, the suppression effect is further improved, and the uniformity of the plasma in the vicinity of the edge of the wafer W is further improved.

[0075] The electrostatic chuck device according to the third embodiment includes a separate ring-shaped member 51-4B as a high resistance ring-shaped portion, and the leakage current I Leak This aims to reduce the plasma density and improve the uniformity of the plasma in the vicinity of the edge of the wafer W. The material of the ring-shaped member 51-4B is preferably plasma resistant and highly resistive, and may be the same material as the stage 50-4. For example, it may be aluminum nitride (AlN). In order to increase the contact resistance, the back surface of the ring-shaped member 51-4B that comes into contact with the stage 50-4 may be configured to have multiple protrusions to reduce the contact area. For example, embossing may be applied. The configuration in which multiple protrusions are provided on the back surface of the ring-shaped member 51-4B corresponds to the effect of reducing the area S in formula (1). Moreover, it is preferable that the ring-shaped member 51-4B is made of a material that is resistant to temperature rise and has a small dielectric constant and thermal conductivity.

[0076] The ring-shaped member 51-4B that is the high-resistance ring-shaped portion is preferably made of a high-resistance material having a volume resistivity higher than that of the stage material of the portion (wafer contact portion) 51-4A between the substrate suction region 50-4A and the ESC electrodes 30.

[0077] Similarly, in the electrostatic chuck device shown in FIG. 5A, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50-4.

[0078] FIG. 5B is a schematic cross-sectional view of an electrostatic chuck device including a stage 50-4 having a ring-shaped member 51-4B placed on the stage 50 shown in FIGS. 1A and 1B. The electrostatic chuck device 105 shown in Fig. 5B is an electrostatic chuck device used in a plasma space. A stage 50-5 of the electrostatic chuck device 105 is separate from the stage 50 shown in Figs. 1A and 1B and has a ring-shaped member 51-4B. The electrostatic chuck device 105 has a circular substrate adsorption area 50A (with a diameter D S A stage 50 having a top surface 50a of a substrate suction region 50A with a diameter D S Diameter D is larger than E1 and an ESC electrode 30 arranged concentrically with a center O of the substrate adsorption region 50A in a planar view. When a DC voltage is applied to the ESC electrode 30, the target substrate W is electrostatically adsorbed onto the upper surface 50a of the stage 50-2 by the Johnsen-Rahbek force. The stage 50-5 includes a ring-shaped member 51-4B in a ring-shaped outer circumferential region 50B arranged adjacent to the outside of the substrate adsorption region 50A in a planar view. An electrostatic chuck device 105 shown in FIG. 5B has a configuration in which the electrostatic chuck device 100 shown in FIGS. 1A and 1B and the electrostatic chuck device 104 shown in FIG. 5A are combined.

[0079] The material of the ring-shaped member 51-4B can be the same as that of the high resistance ring-shaped portion 51B.

[0080] Similarly, in the electrostatic chuck device shown in FIG. 5B, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50.

[0081] Electrostatic chuck devices 106 and 107 shown in FIGS. 6A and 6B correspond to electrostatic chuck devices 104 and 105 shown in FIGS. 5A and 5B, respectively, and are configured to include a ring-shaped member 51-5B that covers the side surface of stage 50. When the plasma spreads to the side surface of the stage 50, it is preferable that the ring-shaped member 51-5B is configured to cover the side surface of the stage 50 in order to reduce leakage current from the side surface of the stage 50.

[0082] Similarly, in the electrostatic chuck device illustrated in FIGS. 6A and 6B, a heater (see reference symbol 28 in FIG. 7) may be provided below the ESC electrodes 30 in the stage 50-6 or the stage 50-7.

[0083] Fig. 7 is a schematic cross-sectional view showing an example of a substrate processing apparatus including the electrostatic chuck device described above. Fig. 7 shows an example in which the electrostatic chuck device includes the electrostatic chuck device 100 shown in Figs. 1A and 1B.

[0084] The substrate processing apparatus 1000 shown in Fig. 7 includes a chamber 12. A stage 50 according to the present disclosure and an upper electrode (shower head) 16 arranged opposite the stage 50 are provided in the chamber 12. A plurality of slits 16a are provided in the upper electrode 16. A material gas is supplied between the stage 50 and the upper electrode 16 through each of the slits 16a.

[0085] An exhaust duct 20 is fixed to the chamber 12 and the upper electrode 16 via an O-ring 21. The exhaust duct 20 surrounds the space between the upper electrode 16 and the stage 50. Gas that is supplied between the upper electrode 16 and the stage 50 and used for substrate processing is exhausted to the outside of the chamber 12 through the exhaust duct 20.

[0086] A flow control ring (FCR) 31 is provided to guide gas from the processing space 17 to the annular passage 20b. For example, the FCR 31 is placed on the chamber 12, and an O-ring is disposed therebetween. The FCR 31 and the exhaust duct 20 provide a slit 20a, through which gas supplied to the processing space 17 is guided to the annular passage 20b.

[0087] A first AC power source 22 and a second AC power source 24 are connected to the upper electrode 16. The first AC power source 22 provides AC power of a first frequency. The second AC power source 24 provides AC power of a second frequency that is lower than the first frequency. The first frequency may be in the range of 1 to 30 MHz, for example. This frequency band is called HRF (High Radio Frequency). The first AC power source 22 provides AC power of, for example, 13.56 MHz. The second frequency may be in the range of 100 kHz to 1000 kHz. This frequency band is called LRF (Low Radio Frequency). The second AC power source 24 provides AC power of, for example, 430 kHz.

[0088] The stage 50 is supported by the support portion 26. The stage 50 and the support portion 26 are an integrally formed susceptor. A heater 28 is embedded in the stage 50. The heater 28 is provided, for example, in a spiral shape in a plan view. The heater 28 is connected to a power source 29 by wiring that passes through the support portion 26. When the power source 29 supplies a current to the heater 28, the stage 50 is heated, and the substrate on the stage 50 is also heated. In the example shown in FIG. 7, the heater 28 is built into the stage 50, but the present invention is not limited to this configuration, and the heater 28 may be disposed outside the stage 50 to heat the wafer W.

[0089] The ESC electrodes 30 are provided in the stage 50. The ESC electrodes 30 are connected to a filter circuit 32 by wiring passing through the support portion 26. The ESC electrodes 30 and a DC power supply 34 are connected via the filter circuit 32. The DC power supply 34 applies a voltage to the ESC electrodes 30 to provide electrostatic chuck.

[0090] The filter circuit 32 has a capacitor connected between the ESC electrodes 30 and ground. This capacitor is provided mainly to pass the AC power of the first frequency provided from the first AC power supply 22.

[0091] Further, the filter circuit 32 is provided with a coil and a capacitor. The coil and the capacitor connect the wiring that connects the ESC electrodes 30 and the capacitor to the ground. A series circuit of the capacitor and the coil connects between the ESC electrodes 30 and the ground. The capacitor and the coil are provided mainly to pass the second frequency AC power provided from the second AC power supply 24.

[0092] The operation of the substrate processing apparatus during substrate processing will be described. FIG. 8 is a diagram that simply expresses the configuration of FIG. 7 in order to easily explain the operation during substrate processing. Substrate processing is started with the substrate W to be processed placed on the stage 50. The substrate W to be processed is, for example, a Si wafer. The substrate W to be processed is heated to a predetermined temperature by the heater 28. While supplying material gas between the upper electrode 16 and the stage 50, the first AC power supply 24 supplies AC power of the first frequency to the upper electrode 16. This generates plasma P between the upper electrode 16 and the stage 50. When an ESC voltage is applied to the ESC electrode 30 by the DC power supply 34 in this state, an ESC (DC) current flows to the upper electrode 16 side through the plasma between the electrodes, and charging polarization is induced at the interface gap between the substrate W to be processed and the stage 50, generating a Johnsen-Rahbek (JR) force, and the substrate W to be processed is electrostatically attracted to the stage 50. This allows electrostatic chucking to be performed. In the substrate processing apparatus 1000 shown in the figure, since there is one ESC electrode 30, electrostatic chuck can be provided only when plasma is generated.

[0093] 7 is not particularly limited as long as it involves plasma processing. For example, the substrate processing apparatus 1000 may be used as a plasma-enhanced atomic layer deposition apparatus (PEALD apparatus) or a plasma-enhanced chemical vapor deposition apparatus (PECVD apparatus).

[0094] 9A and 9B are schematic cross-sectional views of an electrostatic chuck device according to a fourth embodiment. Components common to those described above will be described using the reference numerals used in the drawings.

[0095] The electrostatic chuck device 108 shown in Fig. 9A is an electrostatic chuck device used in a plasma space. The electrostatic chuck device 108 has a circular substrate adsorption area 50-8A (with a diameter D S A stage 50-8 having a substrate suction region 50-8A having a diameter D S or the diameter D of the substrate adsorption region 50-8A S Almost the same diameter D E2 and an RF electrode 40 for generating plasma that is embedded in the stage 50-8, is flush with the ESC electrodes 30, and is located in an outer portion that is located outside the substrate adsorption region 50-8A in plan view. When a DC voltage is applied to the ESC electrode 30, the target substrate W is electrostatically adsorbed to the upper surface 50a of the stage 50-8 by the Johnsen-Rahbek force.

[0096] The electrostatic chuck device according to the fourth embodiment is, for example, a case where an electrode for capacitively coupled plasma also serves as an RF electrode. If the ESC electrode is made small, no current flows outside the outer periphery of the wafer, but since the RF electrode is also determined by the size of the ESC electrode, the plasma size also becomes small and the uniformity of the plasma on the wafer deteriorates. Therefore, the RF electrode is embedded in the stage so as to be grounded to the ESC electrode. The size of the ESC electrode can be made small to reduce the current outside the outer periphery, but this impairs the uniformity of the plasma, so the RF electrode is embedded in the stage to compensate for this.

[0097] As shown in FIG. 9B, no ESC voltage is applied to the RF electrode 40, and the RF electrode 40 is grounded or connected to a capacitor or a coil so that the impedances seen from the ESC electrode 30 and the RF electrode 40 are equal.

[0098] In the electrostatic chuck device 108, no leakage current occurs because no ESC voltage is applied to the RF electrode 40. Therefore, the uniformity of the plasma in the vicinity of the edge of the wafer W is maintained.

[0099] The electrostatic chuck device shown in FIGS. 9A and 9B can be used in the substrate processing apparatus shown in FIG.

[0100] 10A and 10B are cross-sectional schematic diagrams of a part of a substrate processing apparatus, in the vicinity of an electrostatic chuck device. Components common to those described above will be described using the reference numerals used in the drawings.

[0101] 10A includes an electrostatic chuck device used in a plasma space. The electrostatic chuck device includes a stage 50-9 having a circular substrate adsorption area (diameter D1) on the upper surface thereof, on which a circular substrate W (diameter D0) to be processed is electrostatically adsorbed, and a chuck member 50-4 embedded in the stage 50-9, the diameter of the substrate adsorption area being D 1 or the diameter D of the substrate adsorption area 1and the ESC electrodes 30 arranged concentrically with a center O of the substrate suction region in a plan view, and the diameter D 1 is the diameter D of the substrate W to be processed 0 are equivalent sizes within a range of ±5mm. In the substrate processing apparatus 1001, the flow control ring 31 (see FIG. 8) is made of metal and functions as an RF electrode for generating plasma.

[0102] The RF electrodes shown in Figures 9A and 9B are built into the stage, but in the configuration shown in Figures 10A and 10B, the stage itself is made to be about the same size as the wafer, and in a substrate processing apparatus equipped with a flow control ring (FCR), the flow control ring is installed in the same manner as the ring-shaped member described above to control the spread of plasma. Flow control rings are available in metal (Figure 10A) and ceramic (Figure 10B), and in the case of ceramic, the RF electrodes are embedded in the flow control ring to achieve the same effect as in Figures 9A and 9B.

[0103] In the substrate processing apparatus 1001, the flow control ring 31 functions as an RF electrode and the ESC voltage is not applied, so that no leakage current occurs. Therefore, the uniformity of the plasma near the edge of the wafer W is maintained.

[0104] The substrate processing apparatus 1002 shown in FIG. 10B includes an electrostatic chuck device used in a plasma space. The electrostatic chuck device holds a circular substrate W (with a diameter of D 0 The circular substrate adsorption area (diameter is D 1 a stage 50-9 having a substrate chucking region with a diameter D 1 or the diameter D of the substrate adsorption area 1 Almost the same diameter D E2 and an ESC electrode 30 arranged concentrically with a center O of the substrate suction region in a plan view, and a diameter D 1 is the diameter D of the substrate W to be processed 0are equivalent sizes within a range of ±5mm. In the substrate processing apparatus 1002, the flow control ring 31A (see FIG. 8) is made of ceramic, and an RF electrode 41 for generating plasma is built in the flow control ring 31A.

[0105] In the substrate processing apparatus 1002, the RF electrode 41 is built in the flow control ring 31A, and the ESC voltage is not applied, so that no leakage current occurs. Therefore, the uniformity of the plasma near the edge of the wafer W is maintained. [Explanation of symbols]

[0106] 30 ESC electrodes 50, 50-1, 50-2, 50-3, 50-4, 50-5, 50-6 stages 51B, 51-1B, 51-2B, 51-3B, 51-4B, 51-5B High resistance ring part 100, 101, 102, 103, 104, 105, 106, 107, 108 Electrostatic chuck device 1000, 1001, 1002 Substrate processing apparatus

Claims

1. An electrostatic chuck device for use in a plasma space, comprising: A circular substrate adsorption area (diameter: D) on which a circular substrate to be processed is electrostatically adsorbed. Ｓ a stage having a top surface on which the The diameter D of the substrate adsorption area is embedded in the stage. Ｓ Diameter D is larger than Ｅ１ and an ESC electrode arranged concentrically with a center of the substrate attraction region in a plan view, A DC voltage is applied to the ESC electrode, whereby the substrate to be processed is electrostatically attracted to the substrate attraction region of the stage by the Johnsen-Rahbek force; the stage has a high resistance ring-shaped portion at an outer portion of the substrate attracting area in a plan view, the high resistance ring-shaped portion suppressing current leaking from the outer portion into a plasma space when the DC voltage is applied.

2. The electrostatic chuck device according to claim 1 , further comprising a heater disposed within the stage below the ESC electrode.

3. 2 . The electrostatic chuck device according to claim 1 , wherein the high-resistance ring portion is made of a high-resistance material having a volume resistivity higher than that of a stage material in a portion between the substrate attraction region and the ESC electrode.

4. 4. The electrostatic chuck device according to claim 3, wherein the high resistance material of the high resistance ring-shaped portion includes the same base material as the portion other than the high resistance ring-shaped portion, and the concentration of impurity elements in the high resistance material of the high resistance ring-shaped portion is different from the concentration of impurity elements in the portion other than the high resistance ring-shaped portion.

5. 5. The electrostatic chuck device of claim 4, wherein the high resistance material of the high resistance ring portion is aluminum nitride.

6. 2. The electrostatic chuck device according to claim 1, wherein the high resistance ring portion is a ring-shaped protrusion disposed so as to surround the substrate to be processed and protruding upward beyond the substrate attracting region.

7. 7. The electrostatic chuck device according to claim 6, wherein the ring-shaped convex portion is made of a high resistance material having a volume resistivity higher than that of a stage material in a portion between the substrate attraction region and the ESC electrode.

8. 8. The electrostatic chuck device according to claim 7, wherein the high resistance material of the ring-shaped convex portion contains the same base material as the portion other than the ring-shaped convex portion, and the concentration of impurity elements in the high resistance material of the ring-shaped convex portion is different from the concentration of impurity elements in the portion other than the ring-shaped convex portion.

9. 2. The electrostatic chuck device according to claim 1, wherein the high resistance ring portion is a separate ring-shaped member disposed so as to surround the substrate to be processed.

10. The electrostatic chuck device according to claim 9 , wherein the ring-shaped member has a plurality of protrusions on a rear surface thereof.

11. 10. The electrostatic chuck device according to claim 9, wherein the ring-shaped member is made of a high-resistance material having a volume resistivity higher than that of a stage material in a portion between the substrate attraction region and the ESC electrode.

12. 4. The electrostatic chuck device according to claim 3, further comprising, as the high resistance ring-shaped portion, a ring-shaped member that is separately disposed on the portion made of the high resistance material so as to surround the substrate to be processed.

13. The electrostatic chuck device according to claim 12 , wherein the ring-shaped member has a plurality of protrusions on a rear surface thereof.

14. 14. The electrostatic chuck device according to claim 13, wherein the material of the ring-shaped member is the same as that of the portion made of the high resistance material.

15. An electrostatic chuck device for use in a plasma space, comprising: A circular substrate adsorption area (diameter: D) on which a circular substrate to be processed is electrostatically adsorbed. Ｓ a stage having a top surface on which the The diameter D of the substrate adsorption area is embedded in the stage. Ｓ or the diameter D of the substrate adsorption area Ｓ Approximately the same diameter D Ｅ２ an ESC electrode arranged concentrically with a center of the substrate attraction region in a plan view; an RF electrode for generating plasma that is embedded in the stage to the same depth as the ESC electrode and is located outside the substrate adsorption region in a plan view; Equipped with An electrostatic chuck device in which a DC voltage is applied to the ESC electrode, and the substrate to be processed is electrostatically attracted to a substrate attraction region of the stage by Johnsen-Rahbek force.

16. 16. The electrostatic chuck device according to claim 15, wherein the RF electrode is grounded via a rectifier circuit including a capacitor and / or a coil so that the RF electrode and the ESC electrode have equivalent impedances.

17. A chamber; The electrostatic chuck device of claim 1 provided in the chamber; a shower head provided above the electrostatic chuck device.

18. A chamber; 16. An electrostatic chuck apparatus as recited in claim 15 disposed within the chamber; a shower head provided above the electrostatic chuck device.

19. A chamber; an electrostatic chuck device provided in the chamber; A shower head provided above the electrostatic chuck device; a flow control ring having a shape surrounding the electrostatic chuck device. The electrostatic chuck device is configured to hold a circular substrate (with a diameter of D ０ The circular substrate adsorption area (with a diameter of D) is electrostatically adsorbed. １ a stage having a substrate suction area having a diameter D １ or the diameter D of the substrate adsorption area １ Approximately the same diameter D Ｅ２ an ESC electrode arranged concentrically with a center of the substrate attraction region in a plan view; The diameter D of the substrate adsorption region １ is the diameter D of the substrate to be processed ０ and the flow control ring is made of metal and functions as an RF electrode for generating plasma.

20. A chamber; an electrostatic chuck device provided in the chamber; A shower head provided above the electrostatic chuck device; a flow control ring having a shape surrounding the electrostatic chuck device. The electrostatic chuck device is configured to hold a circular substrate (with a diameter of D ０ The circular substrate adsorption area (with a diameter of D) is electrostatically adsorbed. １ a stage having a substrate suction area having a diameter D １ or the diameter D of the substrate adsorption area １ Approximately the same diameter D Ｅ２ an ESC electrode arranged concentrically with a center of the substrate attraction region in a plan view; The diameter D of the substrate adsorption region １ is the diameter D of the substrate to be processed ０ and the flow control ring is made of ceramic and has an RF electrode for generating plasma therein.

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