Substrate processing apparatus

Abstract

Provided is a substrate processing apparatus capable of suppressing deposition of products caused by plasma on the side surface of an electrostatic chuck. 【Solution means】This substrate processing apparatus 100 includes a processing chamber 10, a pedestal 21 disposed in the processing chamber 10 to which high-frequency power is applied, an electrostatic chuck 22 on which a substrate 1 is placed, a ring member 71 formed in an annular shape so as to cover the peripheral edge of the substrate 1 placed on the electrostatic chuck 22 from above and disposed spaced apart upward from the substrate 1, a quartz ring member 23b disposed below the substrate 1 so as to overlap the ring member 71 in a plan view and formed in an annular shape so as to surround the electrostatic chuck 22, and a ring member 23a formed in an annular shape so as to surround the electrostatic chuck 22 and disposed below the ring member 71. The quartz ring member 23b is formed of a material having a lower dielectric constant than that of the ring member 23a.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus, and more particularly to a substrate processing apparatus that processes a substrate by plasma.

Background Art

[0002] Conventionally, a substrate processing apparatus that processes a substrate by plasma has been known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a plasma processing apparatus (substrate processing apparatus) including a processing container, a mounting table disposed in the processing container to which high-frequency power is applied, and an electrostatic chuck disposed on the mounting table on which a substrate to be plasma-processed is mounted. Further, the plasma processing apparatus of Patent Document 1 is provided so as to surround the substrate and the electrostatic chuck in a plan view, and is provided with a focus ring for relaxing the difference between the central portion and the peripheral portion of the in-plane bias potential of the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the substrate processing apparatus of Patent Document 1, a gap is formed between the focus ring and the substrate. For this reason, plasma enters the gap between the focus ring and the substrate, and products due to the plasma that has entered the back surface of the substrate and the side surface of the electrostatic chuck adhere and accumulate.

[0006] Here, when performing deep trench etching on a silicon oxide film on a substrate using a processing gas containing carbon and fluorine (CF-based processing gas), it is necessary to perform plasma processing for a long time for the deep trench etching. In this case, the amount of products deposited on the back surface of the substrate and the electrostatic chuck also increases. After the substrate is processed, chamber cleaning is performed to remove the products deposited by dry etching. However, when the amount of deposited products is large, they cannot be completely removed and remain. Therefore, it is desired to suppress the deposition of products caused by plasma on the side surface of the electrostatic chuck.

[0007] The present invention has been made to solve the above problems, and one object of the present invention is to provide a substrate processing apparatus capable of suppressing the deposition of products caused by plasma on the side surface of an electrostatic chuck.

Means for Solving the Problems

[0008] To achieve the above object, a substrate processing apparatus according to one aspect of the present invention includes a processing chamber, a base disposed in the processing chamber to which high-frequency power is applied, an electrostatic chuck disposed on the base on which a substrate to be plasma-processed is placed, a first ring member formed in an annular shape so as to cover the peripheral portion in a plan view of the substrate placed on the electrostatic chuck from above and disposed at a distance above the substrate, a second ring member disposed below the substrate and disposed so as to overlap the first ring member in a plan view and formed in an annular shape so as to surround the electrostatic chuck in a plan view, and a third ring member formed in an annular shape so as to surround the electrostatic chuck in a plan view, disposed below the first ring member, and covering the upper part of the second ring member. The second ring member is formed of a material having a lower dielectric constant than that of the third ring member.

[0009] In the substrate processing apparatus according to one aspect of the present invention, as described above, a first ring member is formed in an annular shape so as to cover the peripheral portion of the substrate placed on the electrostatic chuck from above in a plan view, and is disposed spaced apart upward from the substrate; a second ring member is disposed so as to overlap the first ring member in a plan view, is disposed below the substrate, and is formed in an annular shape so as to surround the electrostatic chuck in a plan view; and a third ring member is formed in an annular shape so as to surround the electrostatic chuck in a plan view, is disposed below the first ring member, and covers the upper part of the second ring member. Further, the second ring member is formed of a material having a lower dielectric constant than that of the third ring member. As a result, since the peripheral portion of the substrate can be covered by the first ring member, even when there is a gap in the outer periphery of the electrostatic chuck on which the substrate is placed, it is possible to suppress the plasma from entering the gap. In addition, since the gap in the outer periphery of the electrostatic chuck can be reduced by the second ring member surrounding the electrostatic chuck, it is also possible to suppress the plasma from entering the gap thereby. Further, by forming the second ring member of a material having a relatively low dielectric constant, the combined capacitance of the region where the second ring member is disposed in a plan view can be reduced. As a result, the bias potential acting on the region where the second ring member is disposed can be made less effective. Thereby, it is possible to suppress the plasma from being attracted to the second ring member, and thus it is possible to suppress the plasma from entering the gap between the second ring member and the electrostatic chuck. As a result of these, it is possible to suppress the deposition of products caused by the plasma on the side surface of the electrostatic chuck. Thereby, it is possible to suppress the occurrence of abnormal adsorption of the substrate, such as a decrease in the adsorption force of the substrate pushed from below by the deposit and leakage of He gas on the back surface of the substrate, which is the cooling gas of the substrate, due to the deposition of products on the electrostatic chuck. In addition, it is possible to suppress an increase in the time required to remove the products deposited on the side surface of the electrostatic chuck by cleaning the inside of the processing chamber during substrate processing by dry etching. As a result, when continuously processing a plurality of substrates, it is possible to suppress a decrease in processing efficiency.Also, regarding the first ring member that overlaps with the second ring member, the bias potential can be made less effective, so that the action of the plasma can be suppressed. As a result, it is possible to suppress the generation of particles due to the etching of the reaction products generated by reacting with radicals in the plasma on the surface of the first ring member by the collision of ions in the plasma. Thereby, it is possible to suppress the scattering of products caused by the plasma from the first ring member onto the substrate. Further, since the bias potential in the region where the second ring member is disposed in plan view is less effective, the bias potential can be made more effective on the substrate side, so that the processing rate such as etching on the substrate can be improved.

[0010] In the substrate processing apparatus according to the above aspect, preferably, the first ring member is formed so as to cover the peripheral portion of the substrate with a width of 1 mm or more and 10 mm or less in plan view. With this configuration, by covering the peripheral portion of the substrate by 1 mm or more with the first ring member, the gap outside the electrostatic chuck on which the substrate is placed can be effectively covered, so that the entry of plasma into the gap on the side surface of the electrostatic chuck can be effectively suppressed. Further, by covering the peripheral portion of the substrate by 10 mm or less with the first ring member, it is possible to suppress the width of covering the peripheral portion of the substrate from becoming too large, so that it is possible to suppress the processing area of the substrate from becoming excessively small.

[0011] In the substrate processing apparatus according to the above aspect, preferably, a concave portion in which the second ring member is disposed is formed in the inner peripheral portion of the third ring member. With this configuration, the second ring member can be easily disposed in the concave portion provided in the third ring member.

[0012] In the substrate processing apparatus according to the above aspect, preferably, the second ring member is formed of quartz (SiO2). With this configuration, the combined capacitance in the region where the second ring member is disposed in plan view can be easily reduced.

[0013] In the substrate processing apparatus according to the above-described one aspect, preferably, a gas supply unit for supplying a processing gas of a compound containing carbon and fluorine is further provided in a processing chamber provided with a base. With this configuration, in the case of performing dry etching using a processing gas of a compound containing carbon and fluorine (CF-based processing gas), it is possible to suppress the deposition of products caused by plasma on the side surface of the electrostatic chuck.

Effect of the Invention

[0014] According to the present invention, as described above, it is possible to provide a substrate processing apparatus capable of suppressing the deposition of products caused by plasma on the side surface of the electrostatic chuck.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] The substrate processing apparatus 100 of the present embodiment will be described with reference to FIG. 1.

[0018] (Substrate Processing Apparatus) The substrate processing apparatus 100 is a plasma processing apparatus that forms plasma in a processing chamber 10 and performs plasma processing on a substrate 1. The substrate 1 is, for example, a semiconductor wafer formed of a material such as silicon oxide, silicon, quartz glass, borosilicate glass, silicon carbide, gallium arsenide, or sapphire.

[0019] In this embodiment, in FIGS. 1 and 2, the vertical direction is defined as the Z direction, the upward direction is the Z1 direction, and the downward direction is the Z2 direction. Also, the radial direction centered on the center of the substrate 1 in plan view is defined as the R direction, the direction outward from the center is the R1 direction, and the direction toward the center is the R2 direction. Further, the circumferential direction centered on the center of the substrate 1 is defined as the θ direction, the counterclockwise direction is the θ1 direction, and the clockwise direction is the θ2 direction.

[0020] The substrate processing apparatus 100 includes a processing chamber 10, a substrate placement unit 20, a gas supply device 30, a plasma generation device 40, an exhaust device 50, a high-frequency power supply 60, and a protection member 70.

[0021] The processing chamber 10 has a closed space and houses the substrate placement unit 20 therein. The processing chamber 10 is composed of an upper chamber 11 and a lower chamber 12 having an internally communicating space.

[0022] The substrate placement unit 20 has a placement surface 20a on which the substrate 1 is placed. The substrate placement unit 20 has a disk shape and includes a base 21, an electrostatic chuck 22 installed on the base 21, and an annular member 23 surrounding the periphery of the electrostatic chuck 22. The substrate placement unit 20 is provided so as to be movable up and down within the processing chamber 10 by an elevating cylinder 25. The base 21 has high-frequency power applied thereto. The base 21 is formed of aluminum. The electrostatic chuck 22 is formed of aluminum oxide (alumina). The electrostatic chuck 22 is connected to an electrostatic adsorption power supply (not shown) that applies a voltage for electrostatic adsorption. When a voltage is applied to the electrostatic chuck 22, the substrate 1 is adsorbed to the placement surface 20a, which is the upper surface of the electrostatic chuck 22, by electrostatic induction. Note that the substrate placement unit 20 is provided with internal piping (not shown), and a chiller device (not shown) that introduces a predetermined refrigerant into this internal piping and circulates the refrigerant while controlling the temperature of the refrigerant (for example, controlling it to 40°C) is attached. Thereby, during the execution of plasma processing, the substrate placement unit 20 is cooled. Also, during the execution of plasma processing, an inert gas such as He gas as a cooling gas is supplied from a predetermined cooling gas supply pipe (not shown) to the back surface of the substrate 1 via the electrostatic chuck 22, and the substrate 1 is cooled.

[0023] When the substrate mounting portion 20 is in the lowered position (see solid line) by the elevating cylinder 25, the substrate mounting portion 20 is spaced below the protection member 70. When the substrate mounting portion 20 is moved to the raised position (see two-dot chain line) by the elevating cylinder 25, the upper surface of the annular member 23 contacts the lower surface of the protection member 70, and the protection member 70 covers the peripheral portion of the substrate 1 from above. Note that the protection member 70 may be moved up and down with respect to the substrate mounting portion 20.

[0024] As shown in FIG. 2, the annular member 23 includes a ring member 23a and a quartz ring member 23b. The ring member 23a is formed in an annular shape so as to surround the electrostatic chuck 22 in plan view. Also, the ring member 23a is a single continuous member over the entire circumference. Further, the ring member 23a is disposed below the ring member 71. That is, the ring member 23a is disposed on the base side with respect to the ring member 71. The ring member 23a is disposed so as to cover the upper part of the quartz ring member 23b. Also, the ring member 23a is formed of aluminum oxide (alumina). Further, a recess 231a in which the quartz ring member 23b is disposed is formed in the inner peripheral portion of the ring member 23a. Note that the ring member 23a is an example of the "third ring member" in the claims.

[0025] The quartz ring member 23b is formed of quartz (SiO2) (dielectric constant: about 3.9). That is, the quartz ring member 23b is formed of a material having a lower dielectric constant than that of the ring member 23a (aluminum oxide (alumina) (dielectric constant: about 10)). Also, the quartz ring member 23b is formed in an annular shape so as to surround the electrostatic chuck 22 in plan view. Also, the quartz ring member 23b is a single continuous member over the entire circumference. Further, the quartz ring member 23b is disposed so as to overlap the ring member 71 in plan view. Also, the quartz ring member 23b is disposed below the substrate 1. That is, the quartz ring member 23b is disposed on the side opposite to the ring member 71 with respect to the substrate 1. Note that the quartz ring member 23b is an example of the "second ring member" in the claims.

[0026] Further, the quartz ring member 23b is disposed in the concave portion 231a of the ring member 23a. That is, the outer side in the radial direction and the upper side of the quartz ring member 23b are covered by the ring member 23a. Also, the lower side of the quartz ring member 23b is in contact with the base 21. Further, the inner side in the radial direction of the quartz ring member 23b faces the base 21 and the electrostatic chuck 22 with a gap therebetween. Also, the width of the quartz ring member 23b in the radial direction of the substrate 1 has a length L2. For example, the length L2 is 5 mm or more and 60 mm or less. Also, the length L2 is larger than the length L1 of the width by which the ring member 71 covers the peripheral portion of the substrate 1. Also, in the region A1 of the ring member 71 on the inner side (R2 direction side) rather than the outer side (R1 direction side) in the radial direction of the quartz ring member 23b, as a result of being able to reduce the combined capacitance in the vertical direction (Z direction) of the ring member 71, the ring member 23a, and the quartz ring member 23b by the quartz ring member 23b, the bias potential can be made less effective. For this reason, plasma is difficult to be drawn in. For this reason, in the region A1 of the ring member 71, it is possible to suppress the generation of particles due to the reaction product generated by reacting with radicals in the plasma on the surface of the ring member 71 being etched by the collision of ions in the plasma. Also, since the quartz ring member 23b can suppress the drawing in of plasma to the region A1 of the ring member 71, more plasma can be drawn into the substrate 1 inside the region A1, so that plasma processing of the substrate 1 can be efficiently performed. That is, it is possible to effectively improve the etching rate of the substrate 1.

[0027] Further, the upper surface of the quartz ring member 23b is disposed at a position above the interface between the base 21 and the electrostatic chuck 22 in the vertical direction. Note that the upper surface of the quartz ring member 23b may be disposed at a position substantially the same as or below the interface between the base 21 and the electrostatic chuck 22 in the vertical direction. Also, the quartz ring member 23b has a thickness of length L4 in the vertical direction (Z direction). For example, the length L4, which is the thickness of the quartz ring member 23b, is 2 mm or more and 6 mm or less. Preferably, the length L4 is 4 mm or more and 6 mm or less.

[0028] The gas supply device 30 supplies a processing gas (etching gas) into the processing chamber 10. The gas supply device 30 includes a C4F8 gas supply unit 31 that supplies C4F8 gas as the etching gas, and a C2F6 gas supply unit 32 that supplies C2F6 gas as the etching gas. Each gas supply unit is connected into the processing chamber 10 from the upper surface of the upper chamber 11 by a branched supply pipe 33 for gas supply. Through the supply pipe 33, C4F8 gas and C2F6 gas are supplied into the processing chamber 10. That is, the gas supply device 30 supplies a processing gas (CF-based processing gas) of a compound containing carbon and fluorine into the processing chamber 10 provided with the base 21. Note that the gas supply device 30 is an example of the "gas supply unit" in the claims.

[0029] The plasma generation device 40 is a device that generates inductively coupled plasma (ICP) by the processing gas supplied into the processing chamber 10. The plasma generation device 40 includes a spiral coil 41 provided on the outer periphery of the upper chamber 11, and a high-frequency power supply 42 that supplies high-frequency power to the coil 41. By supplying high-frequency power to the coil 41 by the high-frequency power supply 42, the processing gas supplied into the upper chamber 11 is turned into plasma.

[0030] The exhaust device 50 reduces the pressure inside the processing chamber 10. The exhaust device 50 includes a vacuum pump 51 that exhausts the gas inside the processing chamber 10, and an exhaust pipe 52 that connects the vacuum pump 51 to the inside of the processing chamber 10. Through the exhaust pipe 52, the vacuum pump 51 exhausts the gas inside the processing chamber 10, bringing the inside of the processing chamber 10 to a predetermined pressure state close to vacuum.

[0031] The high-frequency power supply 60 supplies high-frequency power for the bias potential to the substrate mounting portion 20. The high-frequency power supply 60 supplies high-frequency power to the base 21 of the substrate mounting portion 20, thereby applying a bias potential between the substrate mounting portion 20 (base 21) and the plasma.

[0032] The protection member 70 is disposed above the substrate mounting portion 20 inside the processing chamber 10. The protection member 70 has an annular shape and a flat plate shape. The protection member 70 is supported by a plurality of columns 73 rising from an annular base portion.

[0033] As shown in FIG. 2, the protection member 70 includes an annular ring member 71 and an annular support member 72 that detachably supports the outer peripheral end of the ring member 71. The ring member 71 is formed in an annular shape so as to cover the peripheral portion of the substrate 1 placed on the electrostatic chuck 22 from above in plan view. The ring member 71 is a single continuous member over the entire circumference. Also, the ring member 71 is disposed spaced apart upward from the upper surface of the substrate 1. Specifically, the ring member 71 is disposed spaced apart by a length L3 on the side opposite to the electrostatic chuck 22 with respect to the substrate 1. For example, the length L3 is 0.2 mm or more and 1.2 mm or less. Preferably, the length L3 is about 0.3 mm. Note that the ring member 71 is an example of the "first ring member" in the claims.

[0034] The ring member 71 is formed of aluminum oxide (alumina). Also, the ring member 71 is formed so as to cover the peripheral portion of the substrate 1 with a width of length L1 in plan view. For example, the length L1 is 1 mm or more and 10 mm or less. Also, the inner peripheral side end face of the ring member 71 is formed in a curved surface shape.

[0035] The support member 72 supports the ring member 71 from below. The support member 72 is formed in an annular shape. Further, the outer peripheral side of the support member 72 is supported by a plurality of support columns 73 (see FIG. 1).

[0036] In the substrate processing apparatus 100, in order to deeply etch the substrate 1 (for example, about 10 μm to 100 μm), the substrate 1 may be etched for a long time (for example, about 1 hour to 2 hours). In this case, when the plasma acts on places other than the substrate 1, products are more likely to deposit on places other than the substrate 1 as the processing time becomes longer. For example, when plasma processing is performed using a CF-based gas, when the plasma acts on a member made of aluminum oxide (alumina), aluminum fluoride (AlF) is generated and deposited by mixing with the CF-based deposit. And when removing the CF-based deposit mixed with the deposited aluminum fluoride by plasma processing with oxygen gas (cleaning processing in the processing chamber 10), a long time (for example, 2 hours or more) is required. Also, when products are deposited on the electrostatic chuck 22 that adsorbs the substrate 1, if not removed, problems such as a gap being generated in the adsorption of the next substrate 1 to be processed and leakage of the gas for cooling (for example, He gas) are likely to occur.

[0037] Therefore, in the substrate processing apparatus 100 of the present embodiment, in order to prevent the plasma from acting on places other than the substrate 1 and causing problems, as described above, an annular ring member 71 is formed so as to cover the peripheral edge portion in a plan view of the substrate 1 placed on the electrostatic chuck 22 from above and is disposed at a distance above the substrate 1, a quartz ring member 23b that is disposed so as to overlap the ring member 71 in a plan view, is disposed below the substrate 1, and is formed in an annular shape so as to surround the electrostatic chuck 22 in a plan view, and a ring member 23a that is formed in an annular shape so as to surround the electrostatic chuck 22 in a plan view, is disposed below the ring member 71, and covers the upper part of the quartz ring member 23b are provided. And the quartz ring member 23b is formed of a material having a lower dielectric constant than the ring member 23a.

[0038] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0039] In this embodiment, as described above, a ring member 71 is formed in an annular shape so as to cover the peripheral portion of the substrate 1 placed on the electrostatic chuck 22 in a plan view from above, and is disposed spaced apart upward from the substrate 1, a quartz ring member 23b is disposed so as to overlap the ring member 71 in a plan view, is disposed below the substrate 1, and is formed in an annular shape so as to surround the electrostatic chuck 22 in a plan view, and a ring member 23a is formed in an annular shape so as to surround the electrostatic chuck 22 in a plan view, is disposed below the ring member 71, and covers the upper part of the quartz ring member 23b. Further, the quartz ring member 23b is formed of a material having a lower dielectric constant than that of the ring member 23a. Thereby, since the peripheral portion of the substrate 1 can be covered by the ring member 71, even when there is a gap on the outer periphery of the electrostatic chuck 22 on which the substrate 1 is placed, it is possible to suppress the plasma from entering the gap. Further, since the quartz ring member 23b surrounding the electrostatic chuck 22 can reduce the gap on the outer periphery of the electrostatic chuck 22, it is also possible to suppress the plasma from entering the gap thereby. Further, by forming the quartz ring member 23b of a material having a relatively low dielectric constant, the combined capacitance of the region where the quartz ring member 23b is disposed in a plan view can be reduced. As a result, the bias potential acting on the region where the quartz ring member 23b is disposed can be made less effective. Thereby, it is possible to suppress the plasma from being attracted to the quartz ring member 23b, so that it is possible to suppress the plasma from entering the gap between the quartz ring member 23b and the electrostatic chuck 22. As a result of these, it is possible to suppress the deposition of products caused by the plasma on the side surface of the electrostatic chuck 22. Thereby, due to the deposition of products on the electrostatic chuck 22, it is possible to suppress the occurrence of adsorption abnormalities of the substrate 1 such as the weakening of the adsorption force of the substrate 1 pushed from below by the deposits and the leakage of He gas on the back surface of the substrate 1 which is the cooling gas of the substrate 1. Further, it is possible to suppress the increase in the time for removing the products deposited on the side surface of the electrostatic chuck 22 by cleaning the inside of the processing chamber 10 by dry etching during substrate processing. As a result, when continuously processing a plurality of substrates 1, it is possible to suppress the decrease in processing efficiency.Also, regarding the ring member 71 that overlaps with the quartz ring member 23b, the bias potential can be made less effective, so the action of the plasma can be suppressed. As a result, it is possible to suppress the generation of particles due to the etching of the reaction products generated by reacting with the radicals in the plasma on the surface of the ring member 71 by the collision of the ions in the plasma. Thereby, it is possible to suppress the scattering of the products resulting from the plasma from the ring member 71 to the substrate 1. Further, since the bias potential in the region where the quartz ring member 23b is arranged in plan view is less effective, the bias potential can be made more effective on the substrate 1 side, so the processing rate such as etching on the substrate 1 can be improved.

[0040] Also, in the present embodiment, as described above, the ring member 71 is formed so as to cover the peripheral edge portion of the substrate 1 with a width of 1 mm or more and 10 mm or less in plan view. Thereby, by covering the peripheral edge portion of the substrate 1 by 1 mm or more with the ring member 71, the gap outside the electrostatic chuck 22 on which the substrate 1 is placed can be effectively covered, so that the entry of plasma into the gap on the side surface of the electrostatic chuck 22 can be effectively suppressed. Further, by covering the peripheral edge portion of the substrate 1 by 10 mm or less with the ring member 71, it is possible to suppress the width of covering the peripheral edge portion of the substrate 1 from becoming too large, so that it is possible to suppress the processing area of the substrate 1 from becoming excessively small.

[0041] Also, in the present embodiment, as described above, a recess 231a in which the quartz ring member 23b is arranged is formed in the inner peripheral portion of the ring member 23a. Thereby, the quartz ring member 23b can be easily arranged in the recess 231a provided in the ring member 23a.

[0042] Also, in the present embodiment, as described above, the quartz ring member 23b is formed of quartz. Thereby, the combined capacitance in the region where the quartz ring member 23b is arranged in plan view can be easily reduced.

[0043] In addition, in the present embodiment, as described above, a gas supply device 30 for supplying a processing gas of a compound containing carbon and fluorine is provided in the processing chamber 10 provided with the base 21. Thereby, in the case of dry etching using a processing gas (CF-based processing gas) of a compound containing carbon and fluorine, it is possible to suppress the deposition of products caused by plasma on the side surface of the electrostatic chuck 22.

[0044] (Example) Next, an experiment (example) conducted to confirm the effect of plasma processing by the substrate processing apparatus of the present embodiment will be described.

[0045] In the experiments (Examples 1 and 2), using the same substrate processing apparatus 100, the same etching process was performed while varying the width of the ring member 71 covering the peripheral edge of the substrate 1, and the leakage amount of the cooling gas (He gas) and the like were measured, and the presence or absence of deposits on the electrostatic chuck 22 was confirmed. Further, in Comparative Examples 1 to 3, the etching process was performed with a configuration in which the ring member 71 was not provided, and the leakage amount of the cooling gas (He gas) and the like were measured, and the presence or absence of deposits on the electrostatic chuck 22 was confirmed.

[0046] In Examples 1 and 2, an annular member 23 surrounding the electrostatic chuck 22 was provided. Further, in Examples 1 and 2, as the annular member 23, a ring member 23a and a quartz ring member 23b were provided. Further, in Examples 1 and 2, a ring member 71 was provided so as to cover the peripheral edge of the substrate 1 from above.

[0047] Under the conditions shown in Table 1, an etching process of a silicon oxide film obtained by thermally oxidizing a silicon wafer as the substrate 1 was performed.

Table 1

[0048] Further, after the etching process under the conditions shown in Table 2, the inside of the processing chamber 10 was subjected to a cleaning process by dry etching.

Table 2

[0049] In Examples 1 and 2 and Comparative Examples 1 to 3, the results shown in Table 3 were obtained. [Table 3]

[0050] (Example 1) In Example 1, the width of the ring member 71 covering the peripheral edge of the substrate 1 was set to 4 mm. In Example 1, as shown in Table 3, in the treatment of the first substrate 1, the He leak rate before treatment was 5.15 (Pa / min), and the He flow rate on the back surface before treatment was within the appropriate range (normal). Also, the treatment ended normally. Also, there was no deposit on the edge of the back surface of the substrate after treatment. Also, the He leak rate before treatment of the second substrate 1 after the cleaning treatment was 4.55 (Pa / min), and the He flow rate on the back surface before treatment was within the appropriate range (normal). Note that in Example 1, the treatment of the second substrate 1 was not performed. Also, in Example 1, after the cleaning treatment (only the state of substrate adsorption was confirmed without treating the second one), there was no deposit on the electrostatic chuck 22 in the processing chamber 10.

[0051] (Example 2) In Example 2, the width of the ring member 71 covering the peripheral edge of the substrate 1 was set to 2 mm. In Example 2, as shown in Table 3, in the process of the first substrate 1, the He leak rate before the process was 4.75 (Pa / min), and the He flow rate on the back surface before the process was within the appropriate range (normal). Also, the process ended normally. Further, there was no deposit on the edge of the back surface of the substrate after the process. Also, the He leak rate before the process of the second substrate 1 after the cleaning process was 3.56 (Pa / min), and the He flow rate on the back surface before the process was within the appropriate range (normal). Note that in Example 2, the process of the second substrate 1 was not performed. Also, in Example 2, after the cleaning process, there was no deposit on the electrostatic chuck 22 in the process chamber 10. Also, in Example 2, while sandwiching a cleaning process during the additional etching process of the silicon oxide film of the substrate 1, four substrates 1 were continuously processed. The process of each substrate ended normally, and there was no deposit on the edge of the back surface of the substrate after the process. Also, after the cleaning process after the process of the fourth substrate 1, there was no deposit on the electrostatic chuck 22 in the process chamber 10.

[0052] (Comparative Example 1) In Comparative Example 1, the ring member 71 was not provided, and an annular member 23 surrounding the periphery of the electrostatic chuck 22 was provided. Also, in Comparative Example 1, the quartz ring member 23b was not provided. In Comparative Example 1, as shown in Table 3, in the process of the first substrate 1, the He leak rate before the process was 6.73 (Pa / min), and the He flow rate on the back surface before the process was within the appropriate range (normal). Also, the process ended normally. Further, there was a deposit on the edge of the back surface of the substrate after the process. Also, the He leak rate before the process of the second substrate 1 after the cleaning process exceeded 60 (Pa / min), and an adsorption abnormality of the substrate 1 occurred. Also, the He flow rate on the back surface before the process exceeded the upper limit of the appropriate range. Note that in Comparative Example 1, the process of the second substrate 1 was not performed. Also, in Comparative Example 1, after the cleaning process (only the substrate adsorption state was confirmed without processing the second one), there was a deposit on the electrostatic chuck 22 in the process chamber 10.

[0053] (Comparative Example 2) In Comparative Example 2, in the same configuration as in Comparative Example 1, the cleaning processing time was twice that of Comparative Example 1. In Comparative Example 2, as shown in Table 3, in the processing of the first substrate 1, the He leak amount before processing was 4.75 (Pa / min), and the He flow rate on the back surface before processing was within the appropriate range (normal). Also, an abnormality occurred at 118 minutes from the start and the processing stopped. The He flow rate on the back surface at the time of the abnormality exceeded the upper limit of the appropriate range. Also, there were deposits (deposits) on the edge of the back surface of the substrate after the abnormal stop. Also, the He leak amount before processing of the second substrate 1 after the cleaning process exceeded 60 (Pa / min), and an adsorption abnormality of the substrate 1 occurred. Also, the He flow rate on the back surface before processing exceeded the upper limit of the appropriate range. Note that in Comparative Example 2, the processing of the second substrate 1 was not performed. Also, in Comparative Example 2, after the cleaning process (after only confirming the substrate adsorption state without processing the second sheet), there were deposits (deposits) on the electrostatic chuck 22 in the processing chamber 10.

[0054] (Comparative Example 3) In Comparative Example 3, the ring member 71 was not provided, and an annular member 23 surrounding the periphery of the electrostatic chuck 22 was provided. Also, in Comparative Example 3, a quartz ring member 23b was provided. In Comparative Example 3, as shown in Table 3, in the processing of the first substrate 1, the He leak amount before processing was 6.34 (Pa / min), and the He flow rate on the back surface before processing was within the appropriate range (normal). Also, the processing was completed normally. Also, there were deposits (deposits) on the edge of the back surface of the substrate after processing. Also, the He leak amount before processing of the second substrate 1 after the cleaning process was 5.35 (Pa / min), and the He flow rate on the back surface before processing was within the appropriate range (normal). Note that in Comparative Example 3, the processing of the second substrate 1 was not performed. Also, in Comparative Example 3, after the cleaning process (after only confirming the substrate adsorption state without processing the second sheet), there were no deposits (deposits) on the electrostatic chuck 22 in the processing chamber 10.

[0055] Next, the results of the experiment for measuring the etching rate of the silicon oxide film on the substrate 1 will be described. In Examples 3 and 4, using the same substrate processing apparatus 100, the same etching process was performed while varying the width of the ring member 71 covering the peripheral portion of the substrate 1, and the etching rate was measured. In Comparative Examples 4 and 5, the etching process was performed with a configuration in which the ring member 71 was not provided, and the etching rate was measured.

[0056] In Examples 3 and 4 and Comparative Examples 4 and 5, the results shown in Table 4 were obtained.

Table 4

[0057] (Example 3) In Example 3, similar to Example 1, the width of the ring member 71 covering the peripheral portion of the substrate 1 was set to 4 mm. In Example 3, the etching rate was 0.539 (μm / min), and it can be seen that the etching rate is higher compared to Comparative Examples 4 and 5.

[0058] (Example 4) In Example 4, similar to Example 2, the width of the ring member 71 covering the peripheral portion of the substrate 1 was set to 2 mm. In Example 4, the etching rate was 0.546 (μm / min), and it can be seen that the etching rate is higher compared to Comparative Examples 4 and 5.

[0059] (Comparative Example 4) In Example 4 (should be Comparative Example 4), similar to Comparative Example 1, the ring member 71 was not provided, and an annular member 23 surrounding the periphery of the electrostatic chuck 22 was provided. Also, in Comparative Example 4, the quartz ring member 23b was not provided. In Comparative Example 4, the etching rate was 0.504 (μm / min).

[0060] (Comparative Example 5) In Example 5, similar to Comparative Example 3, the ring member 71 was not provided, and an annular member 23 surrounding the periphery of the electrostatic chuck 22 was provided. Further, in Comparative Example 5, a quartz ring member 23b was provided. In Comparative Example 5, the etching rate was 0.513 (μm / min).

[0061] From the results of Examples 3 and 4 and Comparative Examples 4 and 5, by the combination of the ring member 71 (first ring member), the quartz ring member 23b (second ring member), and the ring member 23a (third ring member), the combined capacitance in the region where the quartz ring member 23b is disposed (the region corresponding to L2 in FIG. 2) can be made smaller than in the prior art (only the third ring member). Therefore, the application of the bias potential can be reduced, and ions can be concentrated on the substrate 1 accordingly. As a result, it is possible to improve the etching rate of the silicon oxide film on the substrate 1.

[0062] (Modification example) It should be noted that the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims rather than the description of the above embodiments, and further includes all changes (modification examples) within the meaning and scope equivalent to the scope of claims.

[0063] For example, in the above embodiment, an example of the configuration in which the ring member 71 (first ring member) covering the upper part of the peripheral edge of the substrate is a single continuous member over the entire circumference has been shown, but the present invention is not limited to this. In the present invention, the first ring member may be configured by combining a plurality of arc-shaped members.

[0064] Also, in the above embodiment, an example of the configuration in which the quartz ring member 23b (second ring member) disposed on the outer periphery of the electrostatic chuck 22 is a single continuous member over the entire circumference has been shown, but the present invention is not limited to this. In the present invention, the second ring member may be configured by combining a plurality of arc-shaped members.

[0065] In the above-described embodiment, an example of the configuration in which the ring member 23a (third ring member) disposed on the outer periphery of the electrostatic chuck 22 is a single continuous member over the entire circumference has been shown. However, the present invention is not limited to this. In the present invention, the third ring member may be configured by combining a plurality of arc-shaped members.

[0066] In the above-described embodiment, an example of the configuration in which the quartz ring member 23b (second ring member) is formed of quartz has been shown. However, the present invention is not limited to this. In the present invention, the second ring member may be formed of a material other than quartz as long as it has a lower dielectric constant than the first ring member.

[0067] In the above-described embodiment, an example of the configuration in which the ring member 71 (first ring member) covering the upper part of the peripheral edge of the substrate is formed of aluminum oxide (alumina) has been shown. However, the present invention is not limited to this. In the present invention, the first ring member may be formed of a material other than aluminum oxide (alumina). For example, the first ring member may be formed of quartz.

[0068] In the above-described embodiment, an example of the configuration in which plasma treatment is performed using a CF-based processing gas has been shown. However, the present invention is not limited to this. In the present invention, plasma treatment may be performed using a processing gas other than CF-based. For example, plasma treatment may be performed using a processing gas such as a hydrofluorocarbon gas or a chlorofluorocarbon gas.

[0069] In the above-described embodiment, an example of the configuration in which a silicon oxide film is etched has been shown. However, the present invention is not limited to this. In the present invention, a silicon oxide film, a silicon nitride film, or a glass substrate or a quartz substrate formed on a silicon wafer may be etched.

[0070] In the above-described embodiment, an example of a configuration in which the quartz ring member 23b (second ring member) is brought into contact with the concave portion of the ring member 23a (third ring member) and arranged so that there is no gap in the vertical direction has been shown. However, the present invention is not limited to this. In the present invention, the second ring member may be arranged so as to be separated from the third ring member in the vertical direction, and a space may be provided between the second ring member and the third ring member. Thereby, the space between the second ring member and the third ring member becomes an ambient gas, and it is possible to further lower the dielectric constant. However, when a space is provided, discharge is likely to occur in the space. Therefore, it is preferable to fill and arrange an insulator (second ring member) having a low dielectric constant.

[0071] [Aspect] It is understood by those skilled in the art that the above-exemplified embodiment is a specific example of the following aspects.

[0072] (Item 1) A processing chamber, A susceptor disposed in the processing chamber and to which high-frequency power is applied, An electrostatic chuck disposed on the susceptor and on which a substrate to be plasma-processed is placed, A first ring member formed in an annular shape so as to cover the peripheral portion of the substrate placed on the electrostatic chuck in a plan view from above, and disposed at a distance above the substrate, A second ring member disposed so as to overlap the first ring member in a plan view, disposed below the substrate, and formed in an annular shape so as to surround the electrostatic chuck in a plan view, A third ring member formed in an annular shape so as to surround the electrostatic chuck in a plan view, disposed below the first ring member, and covering the upper part of the second ring member, A substrate processing apparatus, wherein the second ring member is formed of a material having a lower dielectric constant than the third ring member.

[0073] (Item 2) The substrate processing apparatus according to item 1, wherein the first ring member is formed so as to cover a peripheral portion of the substrate with a width of 1 mm or more and 10 mm or less in a plan view.

[0074] (Item 3) The substrate processing apparatus according to item 1 or 2, wherein a recess in which the second ring member is disposed is formed in an inner peripheral portion of the third ring member.

[0075] (Item 4) The substrate processing apparatus according to any one of items 1 to 3, wherein the second ring member is formed of quartz.

[0076] (Item 5) The substrate processing apparatus according to any one of items 1 to 4, further comprising a gas supply unit that supplies a processing gas of a compound containing carbon and fluorine into a processing chamber provided with the base.

Explanation of reference numerals

[0077] 1: Substrate, 10: Processing chamber, 20: Substrate mounting portion, 21: Base, 22: Electrostatic chuck, 23a: Ring member (third ring member), 23b: Quartz ring member (second ring member), 30: Gas supply device (gas supply unit), 70: Protection member, 71: Ring member (first ring member), 100 Substrate processing apparatus, 231a: Recess

Claims

1. a processing chamber; a base disposed in the processing chamber and to which high frequency power is applied; an electrostatic chuck disposed on the base and on which a substrate to be plasma-processed is placed; a first ring member that is formed in an annular shape so as to cover from above a peripheral portion of the substrate placed on the electrostatic chuck in a plan view and that is disposed above and spaced apart from the substrate; a second ring member disposed below the substrate and formed in an annular shape so as to surround the electrostatic chuck in a plan view, the second ring member being disposed so as to overlap with the first ring member in a plan view, a third ring member that is formed in an annular shape so as to surround the electrostatic chuck in a plan view, that is disposed below the first ring member, and that covers an upper portion of the second ring member, The second ring member is formed of a material having a lower dielectric constant than the third ring member.

2. The substrate processing apparatus according to claim 1 , wherein the first ring member is formed to cover a peripheral portion of the substrate with a width of 1 mm to 10 mm in plan view.

3. The substrate processing apparatus according to claim 1 , wherein the third ring member has an inner periphery formed with a recess in which the second ring member is disposed.

4. The substrate processing apparatus according to claim 1 , wherein the second ring member is made of quartz.

5. The substrate processing apparatus according to claim 1 , further comprising a gas supply unit that supplies a process gas of a compound containing carbon and fluorine into a process chamber in which the base is provided.

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