TWI794864B - Plasma treatment device - Google Patents

Abstract

The present invention provides a plasma processing device capable of suppressing peeling off from the surface of an electrostatic chuck near the periphery of a film provided on an electrostatic chuck. The plasma processing apparatus of the embodiment is a plasma processing apparatus for processing a substrate having a substrate, a plurality of devices provided on one surface of the substrate, an organic film provided on one surface of the substrate and covering the plurality of devices, and a resist mask disposed on the other side of the substrate. The plasma processing apparatus includes an electrostatic chuck on which the side of the substrate on which the organic film is formed is placed. The above-mentioned electrostatic chuck has: a dielectric, which has a plurality of grooves opened on the surface; an electrode, which is arranged inside the above-mentioned dielectric; a film, which is arranged on the above-mentioned surface of the above-mentioned dielectric, covering the above-mentioned plurality of grooves The opening of the groove includes fluororesin; and the bonding part is provided between the above-mentioned thin film and the above-mentioned dielectric. When the dimension of the dielectric in the direction parallel to the surface is D1 (mm), and the dimension of the thin film in the direction parallel to the surface is D2 (mm), the following formula is satisfied. D2(mm)＜D1(mm)

Description

Plasma treatment device

Embodiments of the present invention relate to a plasma processing device.

There is a substrate that has a plate-shaped base such as a wafer, a plurality of devices provided on one side of the base (hereinafter referred to as the device side), and a resist mask formed on the other side of the base (hereinafter referred to as the back side). . The resist mask is provided, for example, to implant ions in specific areas on the backside of the substrate.

In such a substrate, after ion implantation, the resist mask formed on the back side of the substrate is removed by plasma treatment or the like. When performing plasma treatment, the substrate is placed on an electrostatic chuck. In this case, the back side of the substrate on which the resist mask to be removed is formed faces the plasma processing space, and the device side of the substrate is placed on the electrostatic chuck.

However, a plurality of devices are provided on the device side of the substrate. Therefore, a technique has been proposed in which a glass substrate is attached to the device surface side of the substrate in order to protect a plurality of devices. However, after attaching the glass substrate, it is difficult to attract the substrate to the electrostatic chuck. Therefore, a gap is generated between the electrostatic chuck and the substrate, preventing the electrostatic chuck from cooling the substrate. As a result, the adhesive layer to which the glass substrate is attached tends to deteriorate due to the heat during the plasma treatment. After the adhesive layer has deteriorated, it may become difficult to peel off the glass substrate, or when the glass substrate is peeled off, a part of the adhesive layer may remain on the device surface side of the substrate.

Also, a technique of attaching a sheet to the device surface side of the substrate has been proposed. Depending on the type of sheet, it is easier to attach a substrate to an electrostatic chuck than in the case of a glass substrate. However, the situation that a gap is easily generated between the electrostatic chuck and the substrate remains unchanged. Therefore, as in the case of the glass substrate, it may be difficult to peel off the sheet, or a part of the adhesive layer may remain on the device surface side of the substrate when the sheet is peeled off. Also, if a glass substrate or a sheet is attached to the substrate, an apparatus for attaching them to the substrate or an apparatus for removing them from the substrate is separately required. As a result, manufacturing cost increases.

Therefore, a method to replace the glass substrate and the protective device of the sheet is sought. The present inventors studied a method of providing an organic film covering a plurality of devices on the device surface side of the substrate instead of a glass substrate and a sheet. Since the thickness of the organic film can be thinned, it is easy to attach the substrate to the electrostatic chuck. Therefore, it is easy to cool the organic film by the electrostatic chuck. Therefore, the temperature rise of the organic film can be suppressed. Also, the formation of the organic film can be performed by existing techniques such as spin coating, and the removal of the organic film can also be performed by existing techniques such as plasma treatment or wet treatment. Therefore, the formation or removal of the organic film can be handled by existing devices.

However, it has been found that a part of the organic film remains on the surface of the electrostatic chuck when the substrate is separated from the electrostatic chuck after the plasma treatment is performed on the substrate supported by the electrostatic chuck. When the material of the organic film is attached to the surface of the electrostatic chuck, etc., a gap is easily generated between the electrostatic chuck and the substrate. Therefore, the cooling of the substrate by the electrostatic chuck is inhibited, or the adsorption force of the electrostatic chuck becomes weak.

Here, a technique of coating a modified fluororesin on the surface of an electrostatic chuck has been proposed (for example, refer to Patent Document 1). If the layer containing the modified fluororesin is formed on the surface of the electrostatic chuck, the adhesion of the organic film material to the surface of the electrostatic chuck can be suppressed. However, in the case of an electrostatic chuck for cooling a substrate, it is necessary to provide grooves for flowing cooling gas on the surface of the electrostatic chuck. When a modified fluororesin is applied to an electrostatic chuck having grooves on its surface, the grooves will be blocked by the modified fluororesin. As a result, cooling using cooling gas becomes difficult.

In this case, an electrostatic chuck in which a fluororesin film with an adhesive on only one side is attached to the surface can be considered. However, in this case, there is also a possibility that the adhesive and the like for bonding the thin film may be decomposed by the etchant. That is, there is a possibility that the vicinity of the peripheral edge of the film is peeled off from the surface of the electrostatic chuck. Therefore, it is desired to develop a plasma processing apparatus capable of suppressing peeling off from the surface of the electrostatic chuck near the peripheral end of the film provided on the electrostatic chuck. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2008-91353

[Problem to be solved by the invention]

The problem to be solved by the present invention is to provide a plasma processing device capable of suppressing peeling off from the surface of the electrostatic chuck near the peripheral end of the film provided on the electrostatic chuck. [Technical method to solve the problem]

A plasma processing apparatus according to an embodiment is a plasma processing apparatus for processing a substrate having a substrate, a plurality of devices provided on one surface of the substrate, an organic film provided on one surface of the substrate and covering the plurality of devices, and a resist mask disposed on the other side of the substrate. The plasma processing apparatus includes an electrostatic chuck on which the side of the substrate on which the organic film is formed is placed. The above-mentioned electrostatic chuck has: a dielectric, which has a plurality of grooves opened on the surface; an electrode, which is arranged inside the above-mentioned dielectric; a film, which is arranged on the above-mentioned surface of the above-mentioned dielectric, covering the above-mentioned plurality of grooves The opening of the groove includes fluororesin; and the bonding part is provided between the above-mentioned thin film and the above-mentioned dielectric. When the dimension of the dielectric in the direction parallel to the surface is D1 (mm), and the dimension of the thin film in the direction parallel to the surface is D2 (mm), the following formula is satisfied. D2(mm)＜D1(mm) [Effect of Invention]

According to an embodiment of the present invention, there is provided a plasma processing apparatus capable of suppressing peeling off from the surface of the electrostatic chuck near the peripheral end of the film provided on the electrostatic chuck.

Hereinafter, embodiments will be illustrated with reference to the drawings. In addition, in each figure, the same code|symbol is attached|subjected to the same component, and detailed description is omitted suitably.

(Substrate 100) First, the substrate 100 processed by the plasma processing apparatus 1 of this embodiment is illustrated. FIG. 1 is a schematic cross-sectional view of a substrate 100 . As shown in FIG. 1 , a substrate 101 , a device 102 , a resist mask 103 , and an organic film 104 can be disposed on a substrate 100 .

The base 101 may be a plate-shaped body. The base 101 can be a semiconductor substrate such as a wafer. The substrate 101 has a back surface 101a and a device surface 101b. A concave portion 101a1 is disposed on the back surface 101a of the base 101 . The concave portion 101a1 can be formed, for example, by grinding the back surface 101a of the substrate 101 . The concave portion 101a1 is not essential. However, if the concave portion 101a1 is provided, the thickness of the region of the substrate 101 where the plurality of devices 102 are formed can be reduced. Therefore, it is easy to implant ions or the like into the region where the device 102 is formed from the rear surface 101 a side of the substrate 101 .

A plurality of devices 102 are disposed on the device surface 101 b of the substrate 101 . The type, quantity, arrangement, etc. of the devices 102 are not particularly limited. Device 102 may be, for example, a power transistor with a backside electrode, or the like. Since the plurality of devices 102 can be formed by known semiconductor manufacturing processes, detailed descriptions of the manufacturing of the plurality of devices 102 are omitted.

The resist mask 103 may be disposed on the bottom surface of the concave portion 101a1. The resist mask 103 is provided for implanting ions or the like into a specific region of the bottom surface of the recess 101a1. For example, the resist mask 103 may be a so-called implant resist mask (Impla Resist mask) or the like. Since the resist mask 103 can be formed by, for example, a known photolithography method, the detailed description of the manufacture of the resist mask 103 is omitted.

In addition, the substrate 100 processed by the plasma processing apparatus 1 is the substrate 100 after ion implantation. Therefore, the surface of the resist mask 103 has a hardened layer formed by ion incident into the resist mask 103 in the ion implantation step.

The organic film 104 is disposed on the device surface 101b of the substrate 101 and covers the plurality of devices 102 . The organic film 104 is provided to protect the plurality of devices 102 . The thickness of the organic film 104 is not particularly limited. It is only necessary to cover the plurality of devices 102 with the organic film 104 . In particular, considering the ease of removal after use as a protective film and shortening the removal time, the thickness of the organic film 104 is preferably as thin as possible.

However, if the thickness of the organic film 104 is too thin, the particles 200 may reach the device 102 when the particles 200 are pressed against the organic film 104 described later (for example, refer to FIGS. 5 and 6 ). Generally speaking, since the thickness of the device 102 is about several hundreds of nm, the thickness of the organic film 104 can be set to, for example, 1 μm or more. More preferably, it is 3 μm or more and 10 μm or less. The organic film 104 may include photoresist or resin such as polyimide, for example. Since the organic film 104 can be formed by a known spin-coating method or the like, detailed descriptions related to manufacturing and the like are omitted. In addition, the thickness of the organic film 104 is the thickness t of the thickest part covering the device 102 (see FIG. 1 ). The thickness t may be confirmed by checking the cross section of the substrate 100 with, for example, a TEM (Transmission Electron Microscope) or a SEM (Scanning Electron Microscope: scanning electron microscope).

(plasma treatment device 1) Next, the plasma processing apparatus 1 of this embodiment is illustrated. In the following, as an example, a dual-frequency plasma processing apparatus having an inductively coupled electrode at the upper part and a capacitively coupled electrode at the lower part will be exemplified. However, the method of generating plasma is not limited to this. For example, the plasma processing device may be a plasma processing device using inductively coupled plasma (ICP: Inductively Coupled Plasma), or a plasma processing device using capacitively coupled plasma (CCP: Capacitively Coupled Plasma).

However, as described above, on the surface of the resist mask 103 to be removed, there is a hardened layer formed in the ion implantation step. Therefore, it is preferable to use ions to physically remove the hardened layer that is difficult to remove chemically by radicals or the like. In this case, if it is a dual-frequency plasma processing apparatus, the ion energy introduced into the substrate 100 can be controlled, and thus the hardened layer can be easily removed. Therefore, the plasma treatment device 1 is preferably a dual-frequency plasma treatment device. In addition, since the general operation of the plasma processing apparatus 1 and the process conditions for removing the resist mask 103 can be applied to known techniques, detailed descriptions thereof are omitted.

FIG. 2 is a schematic cross-sectional view illustrating the plasma processing apparatus 1 of this embodiment. As shown in FIG. 2 , a chamber 2 , a power supply unit 3 , a power supply unit 4 , a decompression unit 5 , a gas supply unit 6 , a mounting unit 7 and a controller 8 can be provided in the plasma processing apparatus 1 .

The controller 8 may have a computing unit such as a CPU (Central Processing Unit: Central Processing Unit) and a storage unit such as a memory. The controller 8 can be, for example, a computer. The controller 8 controls the operation of each element provided in the plasma processing apparatus 1 based on the control program stored in the memory unit. In addition, since known techniques can be applied to the control program for controlling the operation of each element, detailed description is omitted.

The chamber 2 has an airtight structure capable of maintaining a gas environment of relatively high pressure and reduced pressure. The chamber 2 has, for example, a substantially cylindrical shape. The chamber 2 can be formed of metal such as aluminum alloy, for example. Chamber 2 may be grounded.

A hole 2 a for carrying in and carrying out the substrate 100 may be provided on the side of the chamber 2 . A load lock chamber 21 may be connected to a portion of the chamber 2 provided with the hole 2a. A gate valve 22 may be disposed in the load lock chamber 21 . During the plasma treatment, the hole 2a is sealed airtight by the load lock chamber 21 . When loading and unloading the substrate 100 , the hole 2 a communicates with the load lock chamber 21 through the load lock chamber 21 .

The ceiling arrangement of the chamber 2 is airtight by the window 23 . The window 23 has a plate shape. The window 23 is permeable to electromagnetic fields. The window 23 is formed of a material that is not easily damaged during plasma treatment. The window 23 can be formed of a dielectric material such as quartz, for example.

A shielding body 24 may be provided inside the chamber 2 . Reaction products are generated during plasma treatment. The reaction products accumulate on the inner wall of the chamber 2, and the accumulated reaction products peel off and become pollutants such as particles. In addition, when the accumulation amount increases, the treatment rate will fluctuate due to the change of the treatment environment, or the product quality will become uneven. Therefore, clean it regularly or according to the accumulation of reaction products. In this case, although it is also possible to clean the inner wall of the chamber 2, etc., it takes effort, time, and expense.

Therefore, a shielding body 24 is provided inside the chamber 2 . The shielding body 24 has a cylindrical shape, and may be provided so as to cover, for example, the upper surface of the mounting portion 7 and the portion other than the surface of the window 23 . The shielding body 24 is formed of, for example, aluminum alloy, etc., and the surface may be subjected to aluminum oxide treatment or ceramic spraying treatment (aluminum oxide, yttrium, etc.). If the shielding body 24 is provided, the shielding body 24 can be replaced when cleaning. Therefore, the labor required for cleaning can be significantly reduced.

The power supply unit 3 generates plasma P in the inner space of the chamber 2 . The power supply unit 3 has, for example, an antenna 31 , an integrator 32 , and a power supply 33 .

The antenna 31 may be disposed outside the chamber 2 and above the window 23 . The antenna 31 is electrically connected to the power source 33 via the integrator 32 . The antenna 31 may have, for example, a plurality of coils and a plurality of capacitors for generating an electromagnetic field. The integrator 32 may include an integrating circuit or the like for integrating the impedance of the power source 33 side and the impedance of the plasma P side.

The power source 33 can be a high frequency power source. The power supply 33 applies, for example, high-frequency power having a frequency of about 100 KHz to 100 MHz to the antenna 31 . In this case, the power supply 33 applies high-frequency power having a frequency suitable for generating plasma P (for example, 13.56 MHz) to the antenna 31 . In addition, the power supply 33 may change the frequency of the output high-frequency power.

The power supply unit 4 is provided for so-called bias control. That is, the power supply unit 4 is provided to control ion energy introduced into the substrate 100 . As described above, a hardened layer is formed on the surface of the resist mask 103 . The hardness of the hardened layer is relatively hard, and it is difficult to remove it chemically by free radicals or the like. A power supply unit 4 is provided in the plasma processing apparatus 1 of this embodiment. Therefore, by controlling the energy of ions introduced into the substrate 100, the sputtering effect of ions is easily generated. Therefore, physical removal of the hardened layer is easily achieved.

The power supply unit 4 has, for example, a base 41 , an integrator 42 , and a power supply 43 . The base 41 is disposed at the bottom of the chamber 2 via the insulating member 41a. The base 41 is electrically connected to the power source 43 via the integrator 42 . Furthermore, an electrostatic chuck 71 can be disposed on the substrate 41 . The base 41 serves as an electrode to which high-frequency power is applied from the power source 43 , and serves as a support for supporting the electrostatic chuck 71 . In this case, the substrate 41 may have a cooling water flow path inside to cool the electrostatic chuck 71 . The base 41 can be formed of metal such as aluminum alloy, for example.

The integrator 42 is electrically connected between the base 41 and the power source 43 . The integrator 42 may have an integrating circuit for integrating the impedance of the power source 43 side and the impedance of the plasma P side.

The power source 43 can be a high frequency power source. The power source 43 applies high-frequency power having a frequency suitable for introducing ions (for example, 13.56 MHz or less) to the substrate 41 .

The decompression unit 5 decompresses the inside of the chamber 2 to a specific pressure. The decompression unit 5 can set the pressure inside the chamber 2 to 100 Pa or less, for example, when removing the resist mask 103 .

The decompression unit 5 includes, for example, an on-off valve 51 , a pump 52 , and a pressure controller 53 . The on-off valve 51 is connected to the hole 2 b provided on the side surface of the chamber 2 . The on-off valve 51 opens and closes the flow path between the chamber 2 and the pump 52 . The on-off valve 51 may be, for example, a poppet valve.

The pump 52 may be, for example, a turbo molecular pump (TMP: Turbo Molecular Pump) or the like.

The pressure controller 53 may be provided between the on-off valve 51 and the pump 52 . The pressure controller 53 controls so that the internal pressure of the chamber 2 becomes a predetermined pressure based on the output of the vacuum gauge etc. not shown which detects the internal pressure of the chamber 2. The pressure controller 53 may be, for example, an APC (Auto Pressure Controller: automatic pressure controller) or the like.

The gas supply unit 6 supplies the gas G to the inner space of the chamber 2 through a plurality of nozzles 2 c provided on the side surface of the chamber 2 . For example, a plurality of nozzles 2c may be arranged at approximately equal intervals around the central axis of the chamber 2 . In this way, the concentration unevenness of the gas G in the region where the plasma P is generated can be suppressed.

The gas supply unit 6 includes, for example, a gas source 61 , a gas controller 62 , and an on-off valve 63 . The gas source 61 supplies the gas G to the inside of the chamber 2 via the gas controller 62 and the on-off valve 63 . The gas source 61 can be, for example, a high-pressure gas storage bottle containing the gas G, or the like. Moreover, the gas source 61 may be factory piping etc., for example.

The gas G can generate free radicals that react with the resist mask 103 provided on the substrate 100 when excited and activated by the plasma P. The gas G can be, for example, oxygen, a mixed gas of oxygen and helium, and the like.

The gas controller 62 may be disposed between the gas source 61 and the chamber 2 . The gas controller 62 controls at least one of the flow rate and pressure of the gas G supplied from the gas source 61 . The gas controller 62 may be, for example, an MFC (Mass Flow Controller: mass flow controller) or the like.

The on-off valve 63 may be disposed between the gas controller 62 and the chamber 2 . The on-off valve 63 controls the start and end of the supply of the gas G. The on-off valve 63 can be, for example, a 2-port solenoid valve or the like. In addition, the gas controller 62 can be equipped with the function of the on-off valve 63 .

The mounting unit 7 includes, for example, an electrostatic chuck 71 , an insulating ring 72 , a shield ring 73 , a power supply unit 74 , and a cooling gas supply unit 75 . In addition, lift pins 76 for transferring the substrate 100 between a transfer device not shown and the electrostatic chuck 71 may be further provided on the mounting portion 7 (for example, refer to FIG. 6 ).

The side of the substrate 100 on which the organic film 104 is formed is placed on the electrostatic chuck 71 . The electrostatic chuck 71 detects electrostatic force to attract the substrate 100 . The electrostatic chuck 71 can also use Coulomb force or Johnsen-Rahbek force. Hereinafter, as an example, a case will be described in which the electrostatic chuck 71 uses Coulomb force.

In addition, the electrostatic chuck 71 cools the substrate 100 when removing the resist mask 103 so that the temperature of the substrate 100 does not become too high. That is, the electrostatic chuck 71 has the function of attracting the substrate 100 and the function of cooling the substrate 100 .

FIG. 3 is a schematic cross-sectional view illustrating the configuration of the electrostatic chuck 71 . FIG. 4 is a schematic top view of the electrostatic chuck 71 . As shown in FIG. 3 , the electrostatic chuck 71 is disposed on the substrate 41 . The electrostatic chuck 71 has, for example, a dielectric 71a, an electrode 71b, and a thin film 71c.

The thickness of the central area of the dielectric material 71a is thicker than the thickness of the peripheral area surrounding the central area, forming a stepped shape. The peripheral area of the dielectric material 71a can be attached to the base 41 using fastening members such as screws. The dielectric 71a can be formed of ceramics such as alumina. As shown in FIG. 3 and FIG. 4 , a plurality of grooves 71a1 are provided on the surface of the dielectric 71a. A plurality of grooves 71a1 open on the surface of the dielectric 71a. In this case, by dividing the plurality of trenches 71a1 into a plurality of groups, the trenches 71a1 included in one group can be communicated with each other. For example, as shown in FIG. 4 , the plurality of grooves 71a1 may be divided into three groups 71aa to 71ac. Furthermore, the grooves 71a1 included in the group 71aa can be connected to each other, the grooves 71a1 included in the group 71ab can be connected to each other, and the grooves 71a1 included in the group 71ac can be connected to each other.

In addition, a plurality of first holes 71a2 connected to a plurality of trenches 71a1 may be provided in the dielectric material 71a. The plurality of first holes 71a2 can be divided into an air supply hole 71a2a for supplying a cooling gas G1 described later to the plurality of grooves 71a1, and an exhaust hole 71a2b for discharging the cooling gas G1 supplied to the plurality of grooves 71a1. The cooling gas supply part 75 mentioned later can be connected to the gas supply hole 71a2a. An unshown exhaust pipe or the like can be connected to the exhaust hole 71a2b. For example, at least one air supply hole 71a2a and exhaust hole 71a2b may be connected in the groove 71a1 included in one group 71aa (71ab, 71ac).

The coolant G1 supplied to the plurality of grooves 71a1 through the air supply hole 71a2a flows through the inside of the plurality of grooves 71a1, and then is discharged to an unshown exhaust pipe or the like through the exhaust hole 71a2b. That is, the plurality of grooves 71 a 1 serve as flow paths of the cooling gas G1 supplied from the cooling gas supply unit 75 .

Also, a plurality of holes 71a3 (corresponding to an example of the second hole) penetrating in the thickness direction may be provided in the dielectric material 71a. A lift pin 76 may be provided in each of the plurality of holes 71a3 (for example, refer to FIG. 6 ). Also, a groove 71a1 connected to the hole 71a3, and an air supply hole 71a2a and an exhaust hole 71a2b connected to the groove 71a1 may be provided. A part of the cooling gas G1 supplied to the groove 71a1 through the gas supply hole 71a2a flows through the inside of the groove 71a1 and diffuses in the hole 71a3. Therefore, a portion of the cooling gas G1 directly contacts the portion of the organic film 104 that is opposed to the hole 71a3. Therefore, cooling efficiency can be improved.

The electrode 71b has a plate shape and is disposed inside the dielectric 71a. The electrode 71b may be unipolar or bipolar. For example, in the case of a bipolar type, two electrodes 71b may be arranged on the same plane. The electrode 71b can be formed of metal such as tungsten or molybdenum, for example.

The thin film 71c has a film shape and is provided on the surface of the dielectric 71a. The film 71c covers the openings of the plurality of grooves 71a1. The thin film 71c may contain, for example, a fluororesin. Furthermore, a joint portion 71c1 is provided between the film 71c and the dielectric 71a. The bonding portion 71c1 may be a layer formed by hardening an adhesive, an adhesive tape, or the like.

In this case, if the junction part 71c1 penetrates into the groove|channel 71a1, there exists a possibility that flow of a cooling gas may be obstructed. If the joint portion 71c1 is an adhesive tape, it is easy to prevent the joint portion 71c1 from intruding into the groove 71a1. Also, the sticking operation of the film 71c and the peeling operation of the film 71c are facilitated.

Also, if the sum of the thickness of the bonding portion 71c1 and the thickness of the thin film 71c is too large, the force of attracting the substrate 100 may become weak, or the cooling of the substrate 100 may be inhibited. Therefore, the total of the thickness of the bonding portion 71c1 and the thickness of the thin film 71c is preferably 100 μm or less.

Also, if the unevenness of the surface of the thin film 71c is too large, the gap between the thin film 71c and the substrate 100 (organic film 104) becomes large. Therefore, the force of attracting the substrate 100 becomes weak, or the cooling of the substrate 100 by the electrostatic chuck 71 is suppressed.

As mentioned above, since the thickness of the bonding portion 71c1 and the thickness of the film 71c are thinner, the unevenness on the surface of the dielectric 71a is transferred to the surface of the film 71c. Therefore, the arithmetic mean roughness Ra of the surface of the dielectric material 71a is preferably 0.3 μm or less. In this way, the irregularities on the surface of the thin film 71c can be reduced.

FIG. 5 is a schematic cross-sectional view illustrating an electrostatic chuck 171 of a comparative example. Although the dielectric 71a and the electrode 71b are provided in the electrostatic chuck 171, the thin film 71c is not provided. Therefore, the organic film 104 of the substrate 100 is in direct contact with the surface of the dielectric 71a.

As described above, the dielectric material 71a is formed of ceramics such as alumina. Therefore, in the case of holding the substrate 100 on the electrostatic chuck 171 without the thin film 71c, the substrate 100 is in contact with the dielectric 71a of the electrostatic chuck. Since the substrate 100 is in contact with the dielectric material 71a of the electrostatic chuck 171, fine particles including ceramics may be generated. Also, the substrate 100 and the dielectric 71a expand due to the heat of the plasma. Since the expansion coefficients of the substrate 100 and the dielectric 71a are different, friction may occur during expansion. Therefore, fine particles 200 including ceramics or the like may adhere to the surface of the dielectric material 71a. When the substrate 100 is attracted to the electrostatic chuck 171 with the particles 200 attached to the surface of the dielectric 71a, the particles 200 present on the surface of the dielectric 71a enter the interior of the organic film 104 as shown in FIG. 5 .

Also, the groove 71a1 of the dielectric 71a is generally formed by cutting. Therefore, there is a possibility that burrs are formed in the groove 71a1. Since the cooling gas G1 flows in the groove 71a1, burrs may peel off from the groove 71a1 and become particles 200 during the plasma treatment. Moreover, the cooling gas supply part 75 mentioned later supplies cooling gas G1 through the filter which is not shown in figure. However, there is a possibility that particles 200 leaked from the filter or particles 200 existing between the paths to the groove 71a1 after passing through the filter are included in the cooling gas G1. Therefore, there is a case where, in the electrostatic chuck 171 where the thin film 71c does not exist, the particles 200 existing inside the groove 71a1 enter the inside of the organic film 104 by the cooling gas G1.

In addition, a hole 71a3 for installing the lift pin 76 may be provided in the dielectric material 71a. When the cooling gas is supplied to the hole 71a3, the particles 200 existing on the inner wall of the hole 71a3 may enter the inside of the organic film 104 by the cooling gas.

In this case, if the particle diameter of the particle 200 is larger than the distance between the end of the device 102 and the surface of the organic film 104 , the particle 200 entering the interior of the organic film 104 reaches the device 102 . Therefore, there is a possibility that the device 102 may be damaged.

Fig. 6 is a schematic sectional view illustrating the function of the thin film 71c. As described above, the thin film 71c is provided on the surface of the dielectric 71a. Therefore, as shown in FIG. 6 , even if the particles 200 are attached to the surface of the dielectric 71 a, the thin film 71 c can prevent the particles 200 from entering the interior of the organic film 104 .

Also, as described above, the thin film 71c covers the openings of the plurality of grooves 71a1. Therefore, the particles 200 existing on the inner wall of the groove 71a1 can be suppressed from entering the inside of the organic film 104 by the cooling gas.

Fig. 7 is a graph for illustrating the effect of the thin film 71c. "A1" and "A2" in FIG. 7 indicate the number of particles 200 attached to the surface of the organic film 104 in the electrostatic chuck 171 of the comparative example. That is, it shows the number of particles 200 attached to the surface of the organic film 104 when the thin film 71c is not provided. "A2" refers to the case where the particle diameter of the particle 200 is 5 μm or more. That is, "A2" represents the number of particles 200 having a size that may cause damage to the device 102 described above. "A1" refers to the case where the particle diameter of the particle 200 is 0.3 μm or more and less than 5 μm. That is, “A1” represents the number of particles 200 of almost all sizes except particles 200 having a size that may cause damage to the device 102 .

"B1" represents the number of particles 200 attached to the surface of the organic film 104 in the electrostatic chuck 71 of the present embodiment. That is, it shows the number of particles 200 attached to the surface of the organic film 104 when the thin film 71c is provided. "B1" refers to the case where the particle 200 has a diameter of 0.3 μm or more and less than 5 μm. "B1" represents the number of particles 200 of almost all sizes except particles 200 having a size to the extent that damage to the device 102 may occur.

As can be seen from FIG. 7, if the openings of the plurality of grooves 71a1 are covered by the thin film 71c, the number of particles 200 of almost all sizes adhering to the surface of the organic film 104 can be reduced. That is, the particles 200 adhering to the organic film 104 can be suppressed. In addition, the particles 200 having a size that may cause damage to the device 102 can be prevented from adhering to the surface of the organic film 104 . That is, it is possible to prevent generation of particles having a size of 5 μm or more that may cause damage to the device 102 .

The inventors of the present invention conducted an experiment for confirmation: forming an organic film 104 on the surface of an aluminum substrate, and observing whether or not the indentation of the particles 200 occurred on the surface of the substrate. In addition, the plane size of the indentation refers to the scratch or dent of 5 μm×5 μm or more.

In the case of the electrostatic chuck 171 (the case where the thin film 71c is not provided), 67 indentations were generated. In the case of the electrostatic chuck 71 (the case where the thin film 71c is provided), no indentation occurs. This means that if the thin film 71c is provided on the surface of the electrostatic chuck 71, damage to the device 102 can be suppressed.

On the other hand, it has been found that when the substrate 100 is separated from the electrostatic chuck 71 after the plasma treatment, a part of the organic film 104 of the substrate 100 remains on the surface of the electrostatic chuck 71 (on the thin film 71c). The thin film 71c at this time is formed of polyimide.

If a part of the organic film 104 is attached to the thin film 71c provided on the surface of the dielectric 71a, it will hinder the adhesion between the electrostatic chuck 71 and the substrate 100, and inhibit the cooling of the electrostatic chuck 71 to the substrate 100, or the adsorption force of the electrostatic chuck 71. weaken.

The inventors of the present invention think that this is because the organic film 104 does not have an adhesive layer like a glass substrate or a sheet. That is, the inventors of the present invention believe that this is because the adhesion between the organic film 104 and the device 102 and the device surface 101b is weaker than the adhesion between the organic film 104 and the surface of the thin film 71c.

In the case of this embodiment, since the thin film 71c contains a fluororesin, the material of the organic film 104 is not easily adhered. In addition, when the resist mask 103 is removed, the thin film 71c is less likely to be decomposed or deteriorated by plasma.

In addition, etchant may intrude from a gap between the mask ring 73 and the substrate 100 described later. In this case, as shown in FIG. 3, if the dimension of the dielectric 71a in a direction parallel to its surface is set as D1 (mm), and the dimension of the film 71c in a direction parallel to its surface is set as D2 (mm), It is preferably "D2(mm)<D1(mm)". If so, the peripheral end surface of the junction part 71c1 is provided in the center side of the dielectric material 71a rather than the peripheral end surface of the dielectric material 71a. Therefore, the etchant entering from the gap between the mask ring 73 and the substrate 100 is less likely to reach the vicinity of the peripheral end of the bonding portion 71c1. Therefore, it is possible to prevent the vicinity of the peripheral end of the bonding portion 71c1 from being decomposed and the vicinity of the peripheral end of the thin film 71c to be peeled off from the surface of the dielectric 71a. According to the knowledge obtained by the present inventors, if the distance between the peripheral end surface of the dielectric 71a and the peripheral end surface of the film 71c is L (mm), it is preferably "0.5 mm≦L≦5 mm". This effectively prevents the vicinity of the peripheral end of the thin film 71c from peeling off from the surface of the dielectric 71a. In addition, the etchant is an active species of ions, free radicals, etc. generated from the gas G excited and activated by the plasma P.

Here, the organic film 104 is homogeneous to the resist mask 103 to be removed. Therefore, when the resist mask 103 is removed, the exposed portion of the organic film 104 (for example, the peripheral end surface of the organic film 104) may be decomposed by the etchant entering from the gap between the mask ring 73 and the substrate 100. . If the material of the decomposed organic film 104 adheres to the surface of the thin film 71c, the material of the adhered organic film 104 may become hard due to heat or the like. Also, as the number of processed substrates 100 increases, the amount of adhesion may increase over time. If there are hard deposits or large deposits on the surface of the electrostatic chuck 71 (thin film 71 c ), the deposits may interfere with the substrate 100 when the substrate 100 is placed on the electrostatic chuck 71 . If the attached matter interferes with the substrate 100 , the substrate 100 may be damaged, or the force of attracting the substrate 100 may be weakened, or the in-plane temperature distribution of the substrate 100 may be uneven.

Therefore, in the electrostatic chuck 71 of the present embodiment, when the dimension of the organic film 104 in the direction parallel to the surface is D3, "D2 (mm)<D3 (mm)" is satisfied. In this way, since the organic film 104 covers the thin film 71c when the substrate 100 is adsorbed, even if the vicinity of the periphery of the organic film 104 is decomposed, the material of the organic film 104 can be prevented from adhering to the surface of the thin film 71c. Therefore, it is possible to suppress damage to the substrate 100 due to the material of the attached organic film 104 , weakening of the force of attracting the substrate 100 , or uneven distribution of the temperature of the substrate 100 in the plane.

As described above, the particles 200 including ceramics and the like are generated by the contact between the electrostatic chuck and the substrate 100 . However, as described above, in order to reduce the unevenness of the surface of the dielectric material 71a, the surface of the dielectric material 71a is polished. Therefore, it is considered that the particles 200 including ceramics and the like are also generated when the dielectric 71a is formed. It is considered that the particles 200 including ceramics and the like generated when forming the dielectric 71a adhere to the surface of the dielectric 71a. Particles 200 including ceramics and the like adhered during the formation of the dielectric 71a are not completely removed in normal cleaning, and a part of them remains attached to the dielectric 71a.

For the problem that the particles 200 including ceramics etc. adhere to the dielectric 71a, the present inventors solved the problem by covering the surface of the dielectric 71a and the groove 71a1 with a thin film 71c. In this case, if "D2 (mm)<D3 (mm)" is satisfied in the state where the vicinity of the peripheral edge of the dielectric material 71a is not covered with the thin film 71c, the particles 200 including ceramics and the like adhere to the organic film 104 The danger near the end of the week.

In this embodiment, the vicinity of the peripheral end of the organic film 104 is not in contact with the electrostatic chuck 71 . Therefore, even if the particles 200 of 5 μm or larger adhere to the vicinity of the peripheral edge of the organic film 104 , it is considered that the particles 200 of 5 μm or larger do not enter the interior of the organic film 104 . However, during the transfer process of the substrate 100 after the plasma treatment and when the back surface 101a of the substrate 100 is processed in the next step, the organic film 104 may come into contact with the transfer arm or the electrostatic chuck of another device. That is, if the particles 200 of 5 μm or larger that may cause damage to the device 102 adhere to the vicinity of the peripheral edge of the organic film 104, there is a possibility of causing damage to the device. However, as shown in FIG. 7 , in the present embodiment, the adhesion of particles 200 of 5 μm or larger, which may cause damage to the device 102 , to the organic film 104 can be suppressed.

The mechanism by which the particles 200 of 5 μm or larger, which may cause damage to the device 102, do not adhere to the organic film 104 even if the vicinity of the peripheral end of the dielectric 71a is not covered with the thin film 71c is unclear. However, it can be considered as follows. Since the thin film 71c is attached to the surface of the dielectric 71a, there is a distance between the particles 200 including ceramics and the like attached near the periphery of the dielectric 71a and the organic film 104 of the substrate 100 . Therefore, it is considered that adhesion of the particles 200 to the organic film 104 can be suppressed.

Next, returning to FIG. 2 , other elements provided on the loading unit 7 will be described. As shown in FIG. 2 , the insulating ring 72 has a cylindrical shape and is disposed at the bottom of the chamber 2 . The insulating ring 72 covers the side of the base 41 . The insulating ring 72 can be formed of a dielectric material such as quartz, for example.

The mask ring 73 has a cylindrical shape and is disposed on the peripheral area of the dielectric material 71 a of the electrostatic chuck 71 . The shield ring 73 surrounds the central area of the electrostatic chuck 71 . By disposing the mask ring 73 in this way, the vicinity of the periphery of the dielectric 71a can be prevented from being exposed to the etchant. Therefore, the above-mentioned fastening member provided in the peripheral region of the dielectric material 71a can be suppressed from being damaged by the etchant.

The mask ring 73 can be formed of a dielectric material such as quartz, for example. In addition, if the mask ring 73 is provided, when the resist mask 103 is removed, the etchant can be prevented from reaching the peripheral end surface of the organic film 104 . Therefore, the material of the organic film 104 generated by the decomposition of the peripheral edge of the organic film 104 can be suppressed from adhering to the surface of the electrostatic chuck 71 .

The power supply unit 74 has, for example, a DC power supply 74a and a changeover switch 74b. The DC power source 74 a is electrically connected to the electrode 71 b of the electrostatic chuck 71 . When a voltage is applied to the electrode 71b from the DC power supply 74a, charges are generated on the surface of the electrode 71b on the substrate 100 side. Therefore, an electrostatic force is generated between the electrode 71 b and the substrate 100 , and the substrate 100 is attracted to the electrostatic chuck 71 by the generated electrostatic force.

The switching switch 74b is electrically connected between the DC power source 74a and the electrode 71b of the electrostatic chuck 71 . The adsorption and desorption of the substrate 100 are switched.

The cooling gas supply unit 75 supplies the cooling gas G1 to the groove 71a1 through the gas supply hole 71a2a provided in the dielectric material 71a. That is, the cooling gas supply unit 75 supplies cooling gas to the inside of the plurality of grooves 71a1 whose openings are covered with the film 71c.

The cooling gas supply unit 75 has, for example, a gas source 75a, a gas controller 75b, and an on-off valve 75c. The gas source 75a can be, for example, a high-pressure gas cylinder containing the cooling gas G1. In addition, the gas source 75a may be, for example, factory piping or the like. The cooling gas G1 may be, for example, helium or the like.

The gas controller 75b may be disposed between the gas source 75a and the electrostatic chuck 71 . The gas controller 75b controls at least one of the flow rate and pressure of the cooling gas G1 supplied from the gas source 75a. The gas controller 75b can be MFC etc., for example.

For example, the gas controller 75 b controls at least one of the flow rate and pressure of the cooling gas so that the surface temperature of the substrate 100 becomes 80° C. or lower when removing the resist mask 103 . For example, the gas controller 75 b can reduce the surface temperature of the substrate 100 to 80° C. or lower by reducing the temperature of the electrostatic chuck 71 to 45° C. or lower. For example, the gas controller 75b controls the supply flow rate of the cooling gas G1 in such a way that the detected value of the pressure of the space defined by the film 71c and the plurality of grooves 71a1 by a pressure gauge not shown in the figure becomes 400 Pa to 2000 Pa. In this way, the surface temperature of the substrate 100 can be kept at 80° C. or lower.

The on-off valve 75c may be provided between the gas controller 75b and the electrostatic chuck 71 . The on-off valve 75c controls the start and stop of supply of the cooling gas G1. The on-off valve 75c may be, for example, a 2-port solenoid valve or the like. In addition, the function of the on-off valve 75c may be provided to the gas controller 75b.

Here, as described above, the thin film 71c covers the openings of the plurality of grooves 71a1. Therefore, the cooling gas G1 supplied to the plurality of grooves 71a1 cools the substrate 100 through the film 71c. In this case, in order to enhance the cooling effect, it is preferable to set the temperature of the cooling gas G1 below normal temperature (for example, below 25° C.).

When the cooling gas G1 is supplied to the space defined by the thin film 71c and the plurality of grooves 71a1, the cooling gas G1 directly contacts the thin film 71c. Therefore, the heat transfer efficiency is better than cooling the thin film 71c through the dielectric 71a by the cooling gas G1.

For example, the cooling gas supply part 75 may further have the cooler 75d which cools the supplied cooling gas G1. The cooler 75 may be, for example, a heat exchanger or the like for cooling the cooling gas G1 so that the temperature of the cooling gas G1 may be -20° C. or lower. In addition, the liquefied cooling gas G1 may be vaporized to be used as the cooling gas G1. In this way, even if the cooler 75d is not provided, the cooling gas G1 at -20°C can be supplied to the electrostatic chuck 71 .

Moreover, in this embodiment, it can be divided into air supply hole 71a2a and exhaust hole 71a2b. In this way, not only can the generation of particles 200 with a particle size that may damage the device 102 be prevented, but also the air flow of the cooling gas G1 can be formed in the space defined by the thin film 71c and the plurality of grooves 71a1. Therefore, cooling efficiency improves.

Furthermore, the plasma processing apparatus 1 of this embodiment is particularly excellent in performing plasma processing on the substrate 100 having the concave portion 101a1 on the back surface 101a of the base 101 . In the case of the substrate 100 whose overall thickness of the base 101 is thin, the substrate 100 may be deflected because the rigidity of the substrate 100 is low. Therefore, a glass substrate or sheet with a thickness is used to supplement the rigidity.

The outer peripheral portion of the base 101 of the substrate 100 of the present embodiment is relatively thick. Therefore, the board|substrate 100 of this embodiment improves rigidity compared with the board|substrate 100 whose thickness of the base 101 is thinner as a whole. Therefore, the substrate 100 of this embodiment does not need to use a glass substrate or sheet to supplement rigidity. Therefore, the organic film 104 only needs to have a thickness capable of protecting the device 102 . That is, in the substrate 100 of this embodiment, the thickness of the organic film 104 can be made thinner than that of the glass substrate or sheet.

The thickness of the organic film 104 is very thin compared with a glass substrate or sheet. Therefore, the force with which the electrostatic chuck 71 attracts the substrate 100 of the present embodiment is greater than the force with which the electrostatic chuck 71 absorbs the substrate 100 protected by a glass substrate or a sheet. Therefore, even if the pressure of the space defined by the thin film 71c and the plurality of grooves 71a1 is greater than the pressure when the substrate 100 protected by a glass substrate or sheet is adsorbed, the substrate 100 of this embodiment will not be separated from the electrostatic chuck 71. . That is, even if the cooling gas G1 having a higher pressure than before is supplied to the space defined by the film 71c and the plurality of grooves 71a1, the film 71c does not expand due to the pressure of the cooling gas G1. As described above, the cooling gas G1 can be supplied at a higher pressure than before to the space defined by the thin film 71c and the plurality of grooves 71a1. Therefore, the cooling efficiency of the substrate 100 of this embodiment is better than that of the substrate 100 protected by a glass substrate or a sheet.

In addition, in this embodiment, the thickness of the organic film 104 can be set to 3 μm or more and 10 μm or less. By setting the thickness of the organic film 104 within the above range, the cooling gas G1 can be supplied at a higher pressure than before as described above. Therefore, the cooling efficiency is better than that of the substrate 100 protected by a glass substrate or sheet. Also, the thickness of the organic film 104 of the substrate 100 of the device 102 protected by the organic film is relatively thin. Therefore, heat conduction to the substrate 101 becomes better. Therefore, the cooling efficiency of the substrate 100 with the device 102 protected by the organic film 104 is better than that of the substrate 100 protected with a glass substrate or sheet.

The embodiments have been illustrated above. However, the present invention is not limited to those described. Regarding the above-mentioned embodiments, those skilled in the art may appropriately add, delete, or change the design of constituent elements, or add, omit, or change conditions of steps, as long as they have the characteristics of the present invention, they are also included in the scope of the present invention. . In addition, the respective requirements included in each of the above-mentioned embodiments can be combined as much as possible, and those obtained by combining them are also included in the scope of the present invention as long as they include the features of the present invention.

For example, the removal of the resist mask 103 has been described as an example of the plasma treatment, but it is not limited thereto. For example, the treatment of etching the back surface 101a of the base 101 of the substrate 100, or the treatment of forming a metal film or an insulating film on the back surface 101a of the base 101 is also included in the plasma treatment. For example, an opening may be provided in a portion of the film 71c facing the air supply hole 71a2a. In this way, the cooling efficiency of the substrate 100 is improved. For example, although the first hole 71a2 is divided into the air supply hole 71a2a and the exhaust hole 71a2b, it can be used without making a distinction. For example, during the plasma treatment, the gas G may be continuously supplied from the first hole 71a2, and exhausted from the first hole 71a2 after the plasma treatment is completed.

1: Plasma treatment device 2: chamber 2a: hole 2b: hole 2c: Nozzle 3: Power supply unit 4: Power supply unit 5: Decompression Department 6: Gas supply part 7: Loading part 8: Controller 21: Interlock chamber 22: Gate valve 23: window 24: Covering body 31: Antenna 32: Integrator 33: Power supply 41: Base 41a Insulation member 42:Integrator 43: Power 51: On-off valve 52: pump 53: Pressure controller 61: Gas source 62: Gas controller 63: On-off valve 71: Electrostatic Chuck 71a: dielectric 71a1: Trench 71a2: Hole 1 71a3: hole 71a2a: air hole 71a2b: Vent 71aa~71ac: group 71b: electrode 71c: Film 71c1: Joint 72: insulating ring 73:Mask ring 74: Power supply unit 74a: DC power supply 74b: toggle switch 75: Cooling gas supply part 75a: Gas source 75b: Gas controller 75c: On-off valve 75d: Cooler 76:Lift pin 100: Substrate 101: Base 101a: back 101a1: concave part 101b: device surface 102: device 103: Resist masking 104: Organic film 171: Electrostatic Chuck 200: Particles A1: Quantity A2: Quantity B1: Quantity D1: size D2: size D3: size G: gas G1: cooling gas P: Plasma t: thickness

Fig. 1 is a schematic cross-sectional view of a substrate. Fig. 2 is a schematic cross-sectional view illustrating the plasma processing apparatus of this embodiment. Fig. 3 is a schematic cross-sectional view illustrating the structure of the electrostatic chuck. Fig. 4 is a model top view of the electrostatic chuck. Fig. 5 is a schematic sectional view of an electrostatic chuck illustrating a comparative example. Fig. 6 is a schematic cross-sectional view illustrating the function of the thin film. Fig. 7 is a graph illustrating the effect of thin films.

41: Base

71: Electrostatic Chuck

71a: dielectric

71a1: Trench

71a2: Hole 1

71b: electrode

71c: Film

71c1: Joint

73:Mask ring

100: Substrate

101: Base

102: device

103: Resist masking

104: Organic film

D1: size

D2: size

D3: size

Claims (10)

A plasma processing device for processing a substrate, the substrate includes a substrate, a plurality of devices disposed on one side of the substrate, an organic film disposed on one side of the substrate and covering the plurality of devices, and a device disposed on the substrate The resist mask on the other side, and the plasma processing device includes: an electrostatic chuck, which places the side of the substrate on which the organic film is formed; the electrostatic chuck includes: a dielectric, which has a plurality of openings on the surface grooves; electrodes, which are provided inside the dielectric; thin films, which are provided on the surface of the dielectric, cover the openings of the plurality of grooves, and include fluororesin; and junctions, which are provided on Between the above-mentioned film and the above-mentioned dielectric; the dimension of the above-mentioned dielectric in the direction parallel to the above-mentioned surface is set as D1 (mm), and the dimension of the above-mentioned film in the direction parallel to the surface is set as D2 (mm) , satisfy the following formula: D2(mm)<D1(mm). The plasma processing device according to claim 1, wherein the thickness of the organic film is not less than 5 μm and not more than 10 μm. The plasma processing device according to claim 1, wherein when the dimension of the above-mentioned organic film in a direction parallel to the surface is set as D3, the following formula is satisfied: D2 (mm)<D3 (mm). The plasma processing device according to claim 2, wherein when the dimension of the above-mentioned organic film in a direction parallel to the surface is set as D3, the following formula is satisfied: D2 (mm)<D3 (mm). As for the plasma treatment device in any one of Claims 1 to 4, when the distance between the peripheral end surface of the above-mentioned dielectric material and the peripheral end surface of the above-mentioned thin film is set to L, the following formula is satisfied: 0.5mm≦L ≦5mm. The plasma processing apparatus according to any one of claims 1 to 4, wherein the sum of the thickness of the joint portion and the thickness of the thin film is 100 μm or less. The plasma processing apparatus according to claim 5, wherein the sum of the thickness of the joint portion and the thickness of the thin film is 100 μm or less. The plasma processing apparatus according to any one of claims 1 to 4, further comprising a cooling gas supply unit capable of supplying cooling gas to the interior of the plurality of grooves whose openings are covered with the thin film. The plasma processing apparatus according to claim 6, further comprising a cooling gas supply unit capable of supplying cooling gas to the interior of the plurality of grooves in which the openings are covered with the thin film. The plasma processing apparatus according to claim 7, further comprising a cooling gas supply unit capable of supplying cooling gas to the interior of the plurality of grooves in which the openings are covered with the thin film.

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