JP6778920B2 - Plasma processing equipment and plasma processing method - Google Patents

Description

The present invention relates to a plasma processing apparatus and a plasma processing method, and more particularly to a plasma processing apparatus and a plasma processing method for processing a substrate held by a transport carrier.

As a method for dicing a substrate, plasma dicing is known in which a substrate on which a resist mask is formed is subjected to plasma etching and divided into individual chips. Patent Document 1 describes a stage (hereinafter, may be simply referred to as a stage) in a state where the substrate is attached to a transport carrier including a frame and a holding sheet covering the opening thereof in order to improve the handleability of the substrate in transport or the like. There is), and it teaches to perform plasma processing.

Japanese Unexamined Patent Publication No. 2009-94436

When the substrate is mounted on the stage while being held by the transport carrier and plasma processing is performed, the transport carrier is usually attracted to the stage by an electrostatic adsorption mechanism called an electrostatic chuck. The electrostatic adsorption mechanism applies a voltage to an electrode for electrostatic adsorption (Electrostatic Chuck) (hereinafter referred to as an ESC electrode) arranged inside the stage, and Coulomb force acting between the ESC electrode and the transport carrier and Johnson.・ The transport carrier is attracted to the stage by the rabek force. The stage is cooled. By performing the plasma treatment in a state where the transport carriers are adsorbed on the cooled stage, the transport carriers during the plasma treatment can be effectively cooled.

In recent years, electronic devices have become smaller and thinner, and the thickness of IC chips and the like mounted on electronic devices has become smaller. Along with this, the thickness of the substrate for forming the IC chip or the like to be diced is also reduced, and the substrate is easily bent.

In addition, the holding sheet that holds the substrate is also small in thickness and easily bends. Therefore, the transport carrier that holds the substrate may be placed on the stage with the holding sheet wrinkled. Wrinkles are not eliminated even if the carrier is adsorbed on the stage by the electrostatic adsorption mechanism. If the plasma treatment is performed with wrinkles remaining on the holding sheet, abnormal discharge may occur at the wrinkled portion or the temperature of the wrinkled portion may rise, making it difficult to perform the plasma treatment normally.

One aspect of the present invention is a plasma processing apparatus that performs plasma processing on a substrate held by a transport carrier, wherein the transport carrier includes a holding sheet and a frame arranged on an outer peripheral portion of the holding sheet. The substrate is held by the holding sheet, and the plasma processing apparatus is arranged inside the reaction chamber, a reaction chamber, a plasma generating portion for generating plasma in the reaction chamber, and the transport carrier. A coolable stage for the purpose, an electrostatic adsorption mechanism provided with an electrode portion provided inside the stage, and a control device for controlling the plasma generating portion and the electrostatic adsorption mechanism, and the electrode portion is provided. The electrostatic adsorption mechanism is the same as that of the bipolar mode in which the first electrode and the second electrode are provided and voltages having different polarities are applied to the first electrode and the second electrode, and the first electrode and the second electrode. The control device includes two operation modes, a unipolar mode in which a voltage of polarity is applied, and the control device operates the electrostatic adsorption mechanism in the bipolar mode to move the transport carrier mounted on the stage to the stage. The present invention relates to a plasma processing apparatus that drives the plasma generating unit to generate plasma, and then controls the operation mode of the electrostatic adsorption mechanism to be switched from the bipolar mode to the unipolar mode. ..

Another aspect of the present invention is a plasma processing method in which a transfer carrier holding a substrate is mounted on a coolable stage provided in a plasma processing device to perform plasma processing on the substrate, and the transfer is performed. The carrier includes a holding sheet and a frame arranged on the outer peripheral portion of the holding sheet, and the substrate is held by the holding sheet, and a step of mounting the transport carrier at a mounting position on the stage and a step of mounting the transport carrier. The step of applying a voltage to the electrode portion of the electrostatic adsorption mechanism provided inside the stage and the step of etching the substrate with plasma are provided, and the step of applying the voltage to the electrode portion is the electrode. The step of etching the substrate is started in a bipolar mode in which voltages having different polarities are applied to the first electrode and the second electrode of the part, and the operation mode of the electrode part is set in a state where the plasma is generated. The present invention relates to a plasma processing method including an operation of switching from the bipolar mode to a unipolar mode in which a voltage of the same polarity is applied to the first electrode and the second electrode.

According to the present invention, the yield of a product is improved when the substrate held by the transport carrier is plasma-treated.

It is the top view (a) which shows typically the transport carrier which held the substrate which concerns on one Embodiment of this invention, and is the sectional view (b) in line BB. It is a conceptual diagram of the plasma processing apparatus which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the relationship between the ESC electrode and the DC power source which concerns on one Embodiment of this invention. It is a conceptual graph which took the time after the support part which concerns on one Embodiment of this invention start descent on the horizontal axis, and has the voltage applied to the ESC electrode on the vertical axis. It is explanatory drawing which shows the bending of the holding sheet which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the state from the start of lowering of the support part which concerns on one Embodiment of this invention until the transport carrier is mounted on a stage ((a)-(d)). It is a conceptual diagram which shows the state of the elevating operation performed from the start of lowering of the support part which concerns on one Embodiment of this invention until the transport carrier is mounted on a stage ((a)-(d)). It is a conceptual diagram which shows a part of the operation of the plasma processing apparatus which concerns on one Embodiment of this invention ((a)-(e)). Conceptual graphs ((a) and (b)) in which the time from when power is applied to the antenna from the first high-frequency power source according to the embodiment of the present invention is taken on the horizontal axis and the voltage applied to the ESC electrode is taken on the vertical axis. ), Which is a conceptual graph (c) in which the horizontal axis is similarly taken and the electric power input to the antenna is taken on the vertical axis. It is a conceptual graph which took the time after the support part which concerns on another Embodiment of this invention start descent on the horizontal axis, and the voltage applied to the ESC electrode on the vertical axis. It is a conceptual graph which took the time after the support part which concerns on still another Embodiment of this invention start descent on the horizontal axis, and has the voltage applied to the ESC electrode on the vertical axis.

Hereinafter, the present invention will be described in detail with reference to the drawings showing one embodiment of the present invention.
FIG. 1 (a) is a top view schematically showing a transport carrier 10 according to an embodiment of the present invention, and FIG. 1 (b) is a B-show of the transport carrier 10 (a) in a no-load state. It is sectional drawing in line B. Note that FIG. 1 illustrates the case where both the frame 2 and the substrate 1 are circular, but the present invention is not limited to this.

As shown in FIG. 1A, the transport carrier 10 includes a substrate 1, a frame 2, and a holding sheet 3. The outer peripheral portion 3c of the holding sheet 3 is fixed to the frame 2. The substrate 1 is attached to the holding sheet 3 and held by the transport carrier. The outer peripheral portion 3c is an overlapping portion of the holding sheet 3 with the frame 2. In FIGS. 1A and 1B, hatching is inserted in the outer peripheral portion 3c for convenience.

The substrate 1 is a processing object for plasma processing such as plasma dicing. In the substrate 1, a circuit layer such as a semiconductor circuit, an electronic component element, or a MEMS is formed on one surface of a substrate main body (for example, Si, GaAs, SiC), and then the substrate main body is on the opposite side of the circuit layer. It is manufactured by grinding the back surface of the part to reduce the thickness. The thickness of the substrate 1 is usually very thin, about 25 to 150 μm. Therefore, the substrate 1 itself has almost no self-supporting property (rigidity). When the thickness of the substrate 1 becomes thin, warpage or bending may occur due to the difference in internal stress between the circuit layer portion and the substrate main body portion. When warpage or bending occurs, it becomes difficult to convey or cool the substrate 1 when performing plasma treatment.

Therefore, the outer peripheral portion 3c of the holding sheet 3 is fixed to the substantially flat frame 2 in a state where tension is applied, and the substrate 1 is attached to the holding sheet 3. The holding sheet 3 is made of a resin having a thickness of about 50 to 150 μm, and has a rigidity sufficient to hold the substrate 1. Further, an adhesive layer is formed on one surface of the holding sheet 3, and the substrate 1 is attached to the adhesive layer. As a result, the transport carrier 10 can hold the substrate 1, the holding sheet 3, and the frame 2 in substantially the same plane. Therefore, when plasma processing is performed on the substrate 1, handling such as transportation of the substrate 1 and cooling during the plasma processing becomes easy.

However, when the substrate 1 is attached to the holding sheet 3 whose outer peripheral portion 3c is fixed to the frame 2, the holding sheet 3 may bend (see FIG. 1B). In addition, in FIG. 1B, in order to make the explanation easy to understand, the bending is emphasized.

The following four cases can be considered as the cause of the holding sheet 3 bending.
The first case is a case where the holding sheet 3 is bent due to the distortion of the frame 2. The frame 2 is originally designed to be flat, but the flatness may be low due to variations and tolerances in manufacturing the frame 2, repeated use in the production process, and the like. When the frame 2 having a low flatness is used, the holding sheet 3 fixed to the frame 2 is bent.

The second case is a case where the holding sheet 3 is bent due to the shape of the substrate 1. The transport carrier 10 holds the substrate 1 substantially flat by the tension of the holding sheet 3. For example, when the substrate 1 has a notch such as an orientation flat (orifura), the tension of the holding sheet 3 is uniform on the substrate 1. Do not join. In this case, wrinkles are generated on the holding sheet 3 near the orientation flat, which causes the holding sheet 3 to bend.

The third case is a case where the holding sheet 3 is bent due to gravity. The transport carrier 10 holds the substrate 1 substantially flat due to the tension of the holding sheet 3, but the holding sheet 3 is stretched or the frame 2 is distorted due to the weight of the substrate 1 and the holding sheet 3 to hold the substrate 1. The sheet 3 is bent.

The fourth case is a case where the holding sheet 3 is bent due to the stress of the substrate 1. A stress that warps the substrate 1 is applied to the substrate 1. On the other hand, the holding sheet 3 resists this stress due to the adhesive force to which the substrate 1 is attached and the tension of the holding sheet 3, suppresses the warp of the substrate 1, and keeps the substrate 1 flat. At this time, if the stress of the substrate 1 is larger, the holding sheet 3 is transferred to the substrate 1.
The warp cannot be suppressed, the holding sheet 3 is stretched, and the holding sheet 3 is bent.

Electrostatic adsorption electrodes (ESC electrodes) are roughly classified into two types: unipolar type and bipolar type. When a voltage is applied to the ESC electrode, an attractive force is generated between the ESC electrode and the holding sheet 3, and the transfer carrier 10 can be attracted to the stage 111.

The unipolar ESC electrode consists of at least one electrode, and a voltage of the same polarity is applied to all the electrodes. The electrostatic adsorption mechanism including the unipolar ESC electrode utilizes Coulomb force as the adsorption mechanism. By applying a voltage to all the electrodes, a charge due to dielectric polarization is induced on the surface of the stage 111 made of a dielectric material, and the transport carrier 10 placed on the stage 111 is charged. As a result, a Coulomb force acts between the electric charge induced on the surface of the stage 111 and the charged transport carrier 10, and the transport carrier 10 is adsorbed on the stage 111. In order to charge the transport carrier 10, plasma may be generated in the reaction chamber (vacuum chamber 103) and the transport carrier 10 may be exposed to the generated plasma.

On the other hand, the bipolar ESC electrode includes a positive electrode and a negative electrode, and voltages having different polarities are applied to the positive electrode and the negative electrode. As the bipolar ESC electrode, for example, a comb-shaped electrode 20 as shown in FIG. 3 is used. As shown in FIG. 3, a voltage of V1 is applied to the positive electrode, and a voltage of −V1 is applied to the negative electrode.

As the adsorption mechanism of the electrostatic adsorption mechanism provided with the bipolar ESC electrode, there are a case where a Coulomb force is used and a case where a Johnson-Labeck force is used. Depending on the adsorption mechanism, the structure of the electrode and the material (for example, ceramics) constituting the electrode are appropriately selected. In any of the adsorption mechanisms, by applying voltages having different polarities to the positive electrode and the negative electrode, an adsorption force is generated between the ESC electrode and the transfer carrier 10, and the transfer carrier 10 can be attracted to the stage 111. .. In the case of the bipolar type, unlike the case of the unipolar type, it is not necessary to charge the transport carrier 10 for adsorption.

The bipolar electrode can function as a unipolar electrode depending on the method of applying voltage to the positive electrode and the negative electrode. Specifically, it can be used as a unipolar ESC electrode by applying a voltage having the same polarity to the positive electrode and the negative electrode. Hereinafter, the case where voltages having different polarities are applied to the positive electrode and the negative electrode of the bipolar electrode is referred to as a bipolar mode, and the case where voltages having the same polarity are applied to the positive electrode and the negative electrode are referred to as a unipolar mode.

In the unipolar mode, a voltage of the same polarity is applied to the positive electrode and the negative electrode, and Coulomb force is used as an adsorption mechanism. Unlike the case of the bipolar mode, the transport carrier cannot be adsorbed only by applying a voltage to the positive electrode and the negative electrode. In the unipolar mode, in order to adsorb the transport carrier 10, it is necessary to charge the transport carrier 10. Therefore, when adsorbing in the unipolar mode, plasma is generated in the vacuum chamber 103, and the transport carrier 10 is charged by exposing the transport carrier 10 to the plasma. As a result, the transport carrier 10 is attracted to the stage 111. The unipolar and bipolar ESC electrodes have been described above, but the transport carrier 10 can be adsorbed on the stage regardless of which type is used.

As described above, when the transport carrier 10 in which the holding sheet 3 is in a bent state is mounted on the stage, wrinkles may occur on the holding sheet 3 and the substrate 1 itself. Such wrinkles may occur in a region of the holding sheet 3 that is not in contact with the substrate 1, or may occur in a region of the holding sheet 3 that is in contact with the substrate 1. In the latter case, wrinkles may occur on the substrate 1 itself attached to the holding sheet 3.

Further, usually, the stage is cooled to, for example, 15 ° C. or lower in order to prevent the transport carrier 10 from being heated by plasma irradiation and receiving thermal damage. By cooling the stage, the transport carrier 10 mounted on the stage is also cooled, and thermal damage to the transport carrier is suppressed. However, when the holding sheet 3 comes into contact with the cooled stage, the holding sheet 3 may shrink. Since the outer peripheral portion 3c of the holding sheet 3 is fixed to the frame 2, the shrinkage of the holding sheet 3 can be one of the causes of wrinkles on the holding sheet 3.

When the wrinkled transport carrier was attracted to the stage by the electrostatic adsorption mechanism, at least a part of the wrinkles generated on the holding sheet 3 could not come into contact with the stage, and a part of the holding sheet was lifted from the stage. Adsorbed in the state. When such a raised portion is generated in a region of the holding sheet 3 in contact with the substrate 1, if plasma treatment is performed as it is, etching becomes non-uniform between the raised portion and other portions, resulting in a processed shape. Variations and unprocessed parts occur. Further, regardless of the region where the raised portion of the holding sheet 3 is generated, a local temperature rise may occur or an abnormal discharge may occur in the raised portion. There is a concern that the substrate 1, the holding sheet 3, and the ESC electrode may be damaged due to the temperature rise or abnormal discharge. Further, in the pick-up process after the plasma treatment, wrinkles on the holding sheet 3 make it difficult to accurately recognize the chip, which may cause a pick-up error. Further, in the subsequent visual inspection process, it may not be possible to accurately distinguish between a non-defective product and a defective product.

In the present invention, when the holding sheet 3 is adsorbed on the stage, the holding sheet 3 is adsorbed on the stage without wrinkles by varying the voltage applied to the ESC electrode.

(Plasma processing equipment)
First, the plasma processing apparatus 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 schematically shows a cross section of the plasma processing apparatus 100 according to the embodiment of the present invention.

The plasma processing apparatus 100 includes a stage 111. The transport carrier 10 is mounted on the stage 111 so that the surface (adhesive surface 3a) of the holding sheet 3 holding the substrate 1 faces upward. Above the stage 111, a cover 124 having a window portion 124W for covering at least a part of the frame 2 and the holding sheet 3 and exposing at least a part of the substrate 1 is arranged.

The stage 111 and the cover 124 are arranged in the reaction chamber (vacuum chamber) 103. The top of the vacuum chamber 103 is closed by a dielectric member 108, and an antenna 109 as an upper electrode is arranged above the dielectric member 108. The antenna 109 is electrically connected to the first high frequency power supply 110A. The stage 111 is arranged on the bottom side in the vacuum chamber 103.

A gas introduction port 103a is connected to the vacuum chamber 103. A process gas source 112 and an ashing gas source 113, which are supply sources of plasma generating gas, are connected to the gas introduction port 103a by pipes, respectively. Further, the vacuum chamber 103 is provided with an exhaust port 103b, and the exhaust port 103b is connected to a decompression mechanism 114 including a vacuum pump for exhausting the gas in the vacuum chamber 103 to reduce the pressure. The plasma generating unit includes an antenna 109, a process gas source 112, and a first high-frequency power supply 110A.

The stage 111 includes a substantially circular electrode layer 115, a metal layer 116, a base 117 that supports the electrode layer 115 and the metal layer 116, and an outer peripheral portion 118 that surrounds the electrode layer 115, the metal layer 116, and the base 117, respectively. To be equipped. Inside the electrode layer 115, an electrode portion (hereinafter referred to as an ESC electrode) 119 constituting an electrostatic adsorption mechanism and a high frequency electrode 120 electrically connected to a second high frequency power supply 110B are arranged. A DC power supply 126 is electrically connected to the ESC electrode 119. The electrostatic adsorption mechanism is composed of an ESC electrode 119 and a DC power supply 126.

The metal layer 116 is made of, for example, aluminum or the like having an alumite coating formed on its surface. A refrigerant flow path 127 is formed in the metal layer 116. The refrigerant flow path 127 cools the stage 111. By cooling the stage 111, the transport carrier 10 mounted on the stage 111 is cooled, and the cover 124 in which a part of the transport carrier 10 comes into contact with the stage 111 is also cooled. The refrigerant in the refrigerant flow path 127 is circulated by the refrigerant circulation device 125.

A plurality of support portions 122 penetrating the stage 111 are arranged near the outer periphery of the stage 111. The support portion 122 is driven up and down by the elevating mechanism 123A. When the support portion 122 is in the delivery position above the stage 111, the transport carrier 10 is transported into the vacuum chamber 103 by a transfer mechanism (not shown) and delivered to the support portion 122. At this time, the support portion 122 supports the frame 2 of the transport carrier 10. More preferably, the support portion 122 supports the overlapping portion of the transport carrier 10 between the frame 2 and the holding sheet 3 (the outer peripheral portion 3c of the holding sheet 3). The transport carrier 10 is mounted at a predetermined position on the stage 111 by lowering the upper end surface 122a of the support portion 122 to the same level as or lower than the stage 111.

A plurality of elevating rods 121 are connected to one end of the cover 124 to allow the cover 124 to be elevated and lowered. The elevating rod 121 is elevated and driven by the elevating mechanism 123B. The elevating operation of the elevating mechanism 123B can be performed independently of the elevating mechanism 123A.

The control device 128 includes a first high frequency power supply 110A, a second high frequency power supply 110B, a process gas source 112, an ashing gas source 113, a decompression mechanism 114, a refrigerant circulation device 125, an elevating mechanism 123A, an elevating mechanism 123B, and an electrostatic adsorption mechanism. It controls the operation of the elements constituting the plasma processing device 100.

(flame)
The frame 2 is a frame having an opening having an area equal to or larger than the entire substrate 1, and has a predetermined width and a substantially constant thin thickness. The frame 2 has a rigidity sufficient to hold and convey the holding sheet 3 and the substrate 1.

The shape of the opening of the frame 2 is not particularly limited, but may be a polygon such as a circle, a rectangle, or a hexagon. The frame 2 may be provided with a notch 2a, a corner cut 2b, or the like for positioning. Examples of the material of the frame 2 include metals such as aluminum and stainless steel, and resins. One surface 3a of the outer peripheral portion 3c of the holding sheet 3 is attached to one surface of the frame 2.

(Holding sheet)
The holding sheet 3 includes, for example, a surface having an adhesive (adhesive surface 3a) and a surface not having an adhesive (non-adhesive surface 3b). The adhesive surface 3a side of the outer peripheral portion 3c is attached to one surface of the frame 2. Further, the substrate 1 is attached to the portion of the adhesive surface 3a exposed from the opening of the frame 2. The adhesive surface 3a is preferably composed of an adhesive component whose adhesive strength is reduced by irradiation with ultraviolet rays. This is because the individualized substrate (chip) is easily peeled off from the adhesive surface 3a by performing ultraviolet irradiation after dicing, and it is easy to pick up. For example, the holding sheet 3 may be composed of a UV-curable acrylic pressure-sensitive adhesive (adhesive surface 3a) and a polyolefin-made base material (non-adhesive surface 3b). In this case, the thickness of the UV curable acrylic pressure-sensitive adhesive is preferably 5 to 20 μm, and the thickness of the polyolefin base material is preferably 50 to 150 μm.

The holding sheet 3 may have conductivity. In the case of a unipolar ESC electrode or an ESC electrode operating in a unipolar mode, a high adsorption force can be obtained with respect to the stage 111 regardless of the presence or absence of conductivity of the holding sheet 3. On the other hand, in the case of the ESC electrode operating in the bipolar mode, if the holding sheet 3 has poor conductivity, the adsorption force to the stage 111 becomes weak. Therefore, the conductive holding sheet 3 is particularly useful when the bipolar ESC electrode is operated in the bipolar mode. As a result, when the bipolar ESC electrode is operated in the bipolar mode, it is possible to increase the suction force with respect to the stage 111.

(substrate)
The substrate 1 is an object of plasma treatment and is not particularly limited. The material of the substrate 1 is not particularly limited. For example, it may be a semiconductor, a dielectric, a metal, or a laminate thereof. Examples of the semiconductor include silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN), and silicon carbide (SiC). Examples of the dielectric include silicon dioxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), polyimide, lithium tantalate (LiTaO ₃ ), lithium niobate (LiNbO ₃ ), and the like. The size is not particularly limited, and for example, the maximum diameter is about 50 mm to 300 mm and the thickness is about 25 to 150 μm. Further, the shape of the substrate 1 is not particularly limited, and is, for example, circular or square. The substrate 1 may be provided with notches (none of which are shown) such as an orientation flat (orifura) and a notch.

Further, a resist mask is formed in a desired shape on the surface of the substrate 1 that is not attached to the holding sheet 3 (not shown). The portion where the resist mask is formed is protected from etching by plasma. The portion from which the resist mask is not formed can be etched by plasma from the front surface to the back surface.

(Electrostatic adsorption mechanism)
The electrostatic adsorption mechanism applies a voltage from the DC power supply 126 to the ESC electrode 119 arranged inside the stage 111 (electrode layer 115), and acts as a Coulomb force or a Johnson-Labeck force between the stage 111 and the transport carrier 10. The transport carrier 10 is attracted to the stage 111. The ESC electrode 119 is arranged so that the center thereof and the center of the stage 111 substantially coincide with each other. The center of the ESC electrode 119 can be regarded as the center of the perfect circle when the smallest perfect circle in which the entire ESC electrode 119 fits is drawn.

The ESC electrode 119 may be a bipolar type or a unipolar type. Further, the bipolar ESC electrode 119 may be operated in the bipolar mode or the unipolar mode. When the ESC electrode 119 operates in the unipolar type or the unipolar mode, the transport carrier 10 is attracted to the stage 111 by operating the DC power supply 126 and the first high frequency power supply 110A. Specifically, the first high-frequency power supply 110A is operated to generate plasma in the vacuum chamber 103 to charge the surface of the transport carrier 10, and the DC power supply 126 is operated to operate the unipolar or unipolar mode. By applying a voltage to the ESC electrode 119, an attractive force is generated between the transport carrier 10 and the stage 111.

When the ESC electrode 119 is a bipolar type and operates in the bipolar mode, the transport carrier 10 is attracted to the stage 111 by operating the DC power supply 126. Specifically, by operating the DC power supply 126 and applying voltages having different polarities to the positive electrode and the negative electrode of the ESC electrode 119, an adsorption force is generated between the transport carrier 10 and the stage 111. Hereinafter, the present embodiment will be described by taking the case where the ESC electrode 119 is a bipolar type as an example, but the present invention is not limited thereto.

FIG. 3 conceptually shows the relationship between the bipolar ESC electrode 119 and the DC power supply 126. The ESC electrode 119 is, for example, a comb-shaped electrode as shown in FIG. In FIG. 3, a voltage of V1 is applied to the positive electrode, and a voltage of −V1 is applied to the negative electrode. The shape of the ESC electrode 119 is not limited to this, and may be appropriately selected.

When a voltage is applied to the ESC electrode 119, an operation of increasing or decreasing the absolute value of the applied voltage is included. That is, the voltage applied to the ESC electrode is temporarily increased or decreased. The increase / decrease of the voltage includes, for example, a pattern in which the voltage V _n , the voltage W _n , and the voltage V _{n + 1} are sequentially switched n times (n ≧ 1). The absolute value of the voltage W _n is smaller than the absolute value of the voltage V _{n and} the absolute value of the voltage V _{n + 1} (| V _n |> | W _n |, | V _{n + 1} |> | W _n |) and is zero. Also good (| W _n | ≧ 0). The absolute value of the voltage V _{n + 1} may be the same as the absolute value of the voltage V _{n + 1 or} may be large (| V _n | ≤ | V _{n + 1} |).

When the voltage applied to the ESC electrode is increased or decreased, the holding sheet 3 is adsorbed to the stage 111, weakly adsorbed (further desorbed), and strongly adsorbed again. In this process, the wrinkles on the holding sheet 3 are eliminated. That is, the wrinkles are loosened by temporarily releasing the holding sheet 3 that has been adsorbed on the stage 111 in a wrinkled state from the adsorption. When a higher voltage is applied again, the holding sheet 3 is adsorbed in a state where the wrinkles are eliminated. By performing this adsorption and release, that is, application of a high voltage (V) and application (or no application) of a low voltage (W), wrinkles can be more easily eliminated.

The elimination (alleviation) of wrinkles will be described in detail below.
When a high voltage (V) is applied to the ESC electrode 119, an attractive force is generated at the contact portion of the holding sheet 3 with the stage 111. At this time, due to the suction force acting on the contact portion of the holding sheet 3 with the stage 111, wrinkles in the vicinity of the contact portion of the holding sheet 3 with the stage 111 are stretched, and the contact portion of the holding sheet 3 with the stage 111 is formed. Expanding. Next, a low voltage (W) is applied (or not applied) to the ESC electrode 119. As a result, the suction force of the holding sheet 3 on the stage 111 is relaxed. At this time, the suction force is relaxed, but the holding sheet 3 maintains a shape in which the contact portion with the stage 111 is enlarged. Next, when a high voltage (V) is applied to the ESC electrode 119 again, an attractive force acts on the enlarged contact portion, wrinkles in the vicinity of the enlarged contact portion are stretched, and the holding sheet 3 with the stage 111 The contact area expands further. By repeating the above, the wrinkles of the holding sheet 3 are alleviated.

It is preferable that the high voltage (V) first applied to the ESC electrode 119 has an absolute value smaller than or the same voltage as the high voltage (V) applied next. This is because if the absolute value of the high voltage (V) first applied to the ESC electrode 119 is large, the effect of smoothing wrinkles may not appear easily. That is, by first applying a voltage having a small absolute value as the high voltage (V) applied to the ESC electrode 119 and repeating weak adsorption and relaxation, the contact portion of the holding sheet 3 with the stage 111 is gradually expanded. , It is preferable to eliminate wrinkles. The high voltage (V) may be gradually increased.

The voltage may be increased or decreased a plurality of times. The number of times to increase or decrease is not particularly limited, and may be, for example, 2 to 5 times. It should be noted that performing the voltage increase / decrease once includes, for example, a pattern of V _n → W _n → V _{n + 1} . Performing the voltage increase / decrease twice means, for example, including a pattern of V _n → W _n → V _{n + 1} → W _{n + 1} → V _{n + 2} . It suffices to include an operation of increasing or decreasing the voltage at least once between the time when the voltage is applied to the ESC electrode 119 and the time when the plasma treatment is performed. For example, the voltage may be applied to the ESC electrode 119 so that at least the pattern of V _n → W _n → V _{n + 1} is included between the time when the voltage is applied to the ESC electrode 119 and the time when the plasma treatment is performed.

After the voltage increase / decrease operation is performed a predetermined number of times, the applied voltage is adjusted so that the ESC electrode 119 becomes a predetermined voltage, and plasma processing is performed. The predetermined voltage, that is, the voltage of the ESC electrode 119 when the plasma processing is performed is not particularly limited, and may be higher than, for example, V _n . Hereinafter, the application of voltage to the ESC electrode 119 is variablely applied so as to include at least one operation of increasing or decreasing the voltage (in other words, including at least _one pattern of V _n → W _n → V _{n + 1} ). Called I.

Hereinafter, the present embodiment will be described in detail. The present invention is not limited to the present embodiment, and various modifications can be made.

(First Embodiment)
In the present embodiment, the variable application I is performed in the pattern shown in FIG. That is, the voltage of the ESC electrode is changed from V1 (V ₁ ) → 0V (W ₁ ) → V ₁ (V ₂ ) → 0 V (W ₂ ) → V 1 (V ₃ ) → 0 V (W ₃ ) → V 1 (V ₄ ) ( Increase or decrease as n = 4). This pattern is performed, for example, by repeatedly turning on (ON) and off (OFF) the DC power supply 126 (see FIG. 6B). FIG. 4 is a conceptual graph in which the time from the start of descent of the support portion 122 is on the horizontal axis and the voltage applied to the ESC electrode 119 is on the vertical axis.

In FIG. 4, the descent start is the time when the support portion 122 supporting the transport carrier 10 starts to descend. The landing start is when the most bent portion (flexed portion) of the holding sheet held by the transport carrier 10 comes into contact with the stage 111. The landing is completed when the upper end surface of the support portion 122 descends to the same level as or lower than the stage 111, and (at least a part of) the outer peripheral portion 3c of the holding sheet 3 comes into contact with the stage 111.

Whether or not the bent portion of the holding sheet 3 comes into contact with the stage 111 is determined, for example, by the distance D at which the upper end surface 122a of the supporting portion 122 is lowered. The deflection Tc (see below) of the holding sheet 3 held by the transport carrier 10 is measured in advance, and the support portion 122 when the distance T between the upper end surface 122a of the support portion 122 and the stage 111 becomes Tc. The descent distance D of is grasped. Then, the time when the descent distance of the support portion 122 becomes D is regarded as the time when the bent portion of the holding sheet 3 held by the transport carrier 10 first comes into contact with the stage 111.

The deflection Tc is obtained, for example, as follows. As shown in FIG. 6, the transport carrier 10 is placed on the upper end surface 122a of the support portion 122 that is raised so that the holding sheet 3 does not come into contact with the stage 111. At this time, in the cross section passing through the center of the transport carrier 10, the shortest distance between the straight line L1 passing through the surface 3b of the outer peripheral portion 3c and the tangent line L2 of the surface 3b at the portion where the holding sheet 3 is most bent is defined as the bending Tc. ..

The deflection Tc does not necessarily have to be measured in the vacuum chamber 103 or the plasma processing apparatus 100. For example, the measurement may be performed in advance by a non-contact optical measuring device or the like before the processing by the plasma processing device 100. In FIG. 5, in order to make the explanation easy to understand, the deflection Tc is emphasized. When the diameter of the frame 2 is about 300 mm, the diameter of the substrate 1 is about 150 mm, the thickness of the substrate 1 is about 100 μm, and the thickness of the holding sheet is about 110 μm, the deflection Tc is, for example, about 50 μm to 800 μm.

In FIG. 4, the voltage applied to the ESC electrode is once set to 0 (V) (W _n = 0). Voltage W _n is the absolute value thereof is as small than the absolute value and the absolute value of the voltage V _{n + 1} of the voltage V _n, is not particularly limited. For example, the voltage W _n may have a polarity opposite to the polarity of the voltage V _n and / or the voltage V _{n + 1} . Of these, in that it is possible to suppress the residual adsorption, it is preferable that the voltage W _n is 0 (V).

The variable application I will be described with reference to FIGS. 6A and 6B. 6A and 6B conceptually show a state from when the support portion 122 supporting the transport carrier 10 starts to descend until the transport carrier 10 is mounted on the stage 111. For the sake of clarity, FIGS. 6A and 6B show the ESC electrode 119 to which the voltage is applied with hatching. It should be noted that also in FIGS. 6A and 6B, the deflection is emphasized for the sake of explanation.

As shown in FIG. 6A (a), first, the support portion 122 supporting the transport carrier 10 begins to descend. At this time, the distance T between the upper end surface 122a of the support portion 122 and the stage is larger than the deflection Tc (T> Tc). The support portion 122 continues to descend, and the flexible portion of the holding sheet 3 comes into contact with the stage 111 (FIG. 6A (b), T = Tc). After that, the support portion 122 continues to descend (FIG. 6A (c)), and the landing of the holding sheet 3 is completed (FIG. 6A (d)).

After the landing of the holding sheet 3 is completed (FIGS. 6A (d)), the variable application I is performed (FIGS. 6B (a)-(d)). The variable application I is performed in a state where at least a part of the outer peripheral portion 3c of the holding sheet 3 is in contact with the stage 111. At this time, the entire outer peripheral portion 3c may be in contact with the stage 111. A constant voltage (for example, V1) may be applied to the ESC electrode 119 before the landing of the holding sheet 3 is completed (T> 0), that is, between FIGS. 6A and 6A to 6C.

When the holding sheet 3 is in contact with the stage 111 with wrinkles, when the voltage V1 is applied, the holding sheet 3 is attracted to the stage 111 as it is. Next, when a voltage W1 lower than V1 is applied to the ESC electrode, the suction force between the contact portion and the stage 111 becomes small. Therefore, the wrinkles generated in the contact portion of the holding sheet 3 with the stage 111 are temporarily loosened. After that, when the voltage V1 is applied again, the holding sheet 3 is adsorbed in a state where the wrinkles are eliminated. By repeating the variable application I, wrinkles are more likely to be eliminated. After that, the substrate 1 is uniformly etched by performing plasma treatment with a predetermined voltage applied to the ESC electrode.

Hereinafter, the operation of the plasma processing apparatus will be specifically described with reference to FIG. 7. In addition, also in FIG. 7, for the sake of explanation, the bending is emphasized.

In the vacuum chamber 103, a plurality of support portions 122 stand by in an elevated state in order to support the transfer carrier 10. The cover 124 also stands by at a raised position (FIG. 7 (a)). The transport carrier 10 is transported into the vacuum chamber 103 by a transfer mechanism (not shown) and delivered to a plurality of support portions 122 (FIG. 7 (b)).

The transport carrier 10 is placed on the upper end surface 122a of the support portion 122 so that the surface (adhesive surface 3a) holding the substrate 1 of the holding sheet 3 faces upward. The frame 2 may be mounted on the upper end surface 122a of the support portion 122 via the outer peripheral portion 3c of the holding sheet 3, or the frame 2 may be directly mounted on the upper end surface 122a of the support portion 122. .. From the viewpoint of suppressing peeling between the frame 2 and the holding sheet 3 during the ascending / descending operation of the supporting portion 122, the transport carrier 10 is attached to the upper end surface 122a of the supporting portion 122 via the outer peripheral portion 3c of the holding sheet 3. It is preferable to be placed.

Next, the support portion 122 descends (FIG. 7 (c)). Further, as the support portion 122 continues to descend, the outer peripheral portion 3c of the holding sheet 3 comes into contact with the stage 111, and the transport carrier 10 is mounted at a predetermined position on the stage 111 (FIG. 7 (d)). When the upper end surface 122a of the support portion 122 is lowered to the same level as or lower than the stage 111, it can be determined that the outer peripheral portion 3c of the holding sheet 3 is in contact with the stage 111.

After FIG. 7D, variable application I is performed (see FIG. 6B). After the variable application I is completed, the elevating mechanism 123B drives the elevating rod 121 to lower the cover 124 to a predetermined position (FIG. 7 (e)).

When the ESC electrode 119 is unipolar, the transfer carrier 10 is placed on the upper end surface 122a of the support portion 122 by the transfer mechanism, and after the transfer mechanism exits the vacuum chamber 103, a voltage is applied to the ESC electrode 119. In the meantime, low power (for example, 500 W or less) is applied to the antenna 109 from the first high frequency power supply 110A to generate plasma in the vacuum chamber 103. As a result, the surface of the transport carrier 10 is charged, and at the same time a voltage is applied to the ESC electrode 119, the transport carrier 10 can be adsorbed on the stage 111.

When the cover 124 is placed in a predetermined lowered position, the portion of the frame 2 and the holding sheet 3 that does not hold the substrate 1 is covered by the cover 124 without contacting the cover 124, and the substrate 1 is a window of the cover 124. It is exposed from the part 124W.

The cover 124 is, for example, a donut shape having a substantially circular outer contour, and has a constant width and a thin thickness. The inner diameter of the cover 124 (diameter of the window portion 124W) is smaller than the inner diameter of the frame 2, and the outer diameter of the cover 124 is larger than the outer diameter of the frame 2. Therefore, when the transport carrier 10 is mounted at a predetermined position on the stage and the cover 124 is lowered, the cover 124 can cover at least a part of the frame 2 and the holding sheet 3. At least a part of the substrate 1 is exposed from the window portion 124W. At this time, the cover 124 does not come into contact with any of the frame 2, the holding sheet 3, and the substrate 1. The cover 124 is made of, for example, a dielectric such as ceramics (for example, alumina, aluminum nitride, etc.) or quartz, or a metal such as aluminum or aluminum whose surface is anodized.

When the support portion 122 and the cover 124 are arranged at predetermined positions, the process gas is introduced into the vacuum chamber 103 from the process gas source 112 through the gas introduction port 103a. On the other hand, the depressurizing mechanism 114 exhausts the gas in the vacuum chamber 103 from the exhaust port 103b and maintains the inside of the vacuum chamber 103 at a predetermined pressure.

Subsequently, high-frequency power is applied to the antenna 109 from the first high-frequency power source 110A to generate plasma P in the vacuum chamber 103. The generated plasma P is composed of ions, electrons, radicals and the like. Next, high-frequency power is applied from the second high-frequency power source 110B to the high-frequency electrode 120 to start plasma processing on the substrate 1. The incident energy of the ions on the substrate 1 can be controlled by the bias voltage applied from the second high frequency power supply 110B to the high frequency electrode 120. The surface to the back surface of the exposed portion from the resist mask formed on the substrate 1 is removed by a physicochemical reaction with the generated plasma P, and the substrate 1 is fragmented.

The conditions for plasma processing are set according to the material of the substrate 1 and the like. For example, when the substrate 1 is Si, the substrate 1 is etched by generating plasma P of a fluorine-containing gas such as sulfur hexafluoride (SF ₆ ) in the vacuum chamber 103. In this case, for example, the pressure of the vacuum chamber 103 is controlled to 10 to 50 Pa by the depressurizing mechanism 114 while supplying SF ₆ gas at 100 to 800 sccm from the process gas source 112. The antenna 109 is supplied with high-frequency power having a frequency of 1000 to 5000 W and a frequency of 13.56 MHz, and the high-frequency electrode 120 is supplied with high-frequency power having a frequency of 50 to 1000 W and a frequency of 13.56 MHz. At that time, in order to suppress the temperature rise of the transport carrier 10 due to the plasma treatment, the temperature of the refrigerant circulated in the stage 111 is set from −20 to 20 ° C. by the refrigerant circulation device 125. As a result, the temperature of the transport carrier 10 during the plasma treatment can be suppressed to 100 ° C. or lower.

It is desirable that the surface of the substrate 1 exposed from the resist mask during the etching process is vertically etched. In this case, for example, the etching step of a fluorine-based gas such as SF ₆ by plasma and the step of depositing a protective film by plasma of fluorocarbon gas such as perfluorocyclobutane (C ₄ F ₈ ) may be alternately repeated. ..

After generating the plasma P, the operation mode of the ESC electrode 119 may be switched from the bipolar mode to the unipolar mode. When the operation mode of the ESC electrode 119 is the bipolar mode, the surface of the substrate 1 above the positive electrode of the ESC electrode 119 (positive electrode side surface) and the surface of the substrate 1 above the negative electrode of the ESC electrode 119 (negative electrode side surface) , The potential is slightly different. Further, since the Coulomb force is stronger on the positive electrode side than on the negative electrode side, there is a slight difference in the adsorption force.

Therefore, when the plasma treatment is started in the bipolar mode, the temperature of the substrate 1 differs between the positive electrode side surface and the negative electrode side surface of the ESC electrode 119 due to the difference in the adsorption force to the stage 111. Further, there may be a difference in the effective bias voltage applied to the substrate 1 between the positive electrode side surface and the negative electrode side surface. Furthermore, there may be a difference in the degree of etching between the positive electrode side surface and the negative electrode side surface. For these reasons, it may be difficult to perform uniform plasma treatment on the substrate 1.

Switching from bipolar mode to unipolar mode is the same as the voltage of the other, for example, by reversing the polarity of the voltage applied to one of the positive electrode or the negative electrode, or by changing the voltage applied to one of the positive electrode or the negative electrode. It is done by making it.

When switching from the bipolar mode to the unipolar mode, the suction force of the transport carrier 10 to the stage 111 may be momentarily weakened, resulting in insufficient cooling of the transport carrier 10. Therefore, it is preferable that the switching from the bipolar mode to the unipolar mode is performed while a low power (for example, 500 W or less) is applied to the antenna 109 from the first high frequency power supply 110A.

In other words, first, the operation mode of the ESC electrode 119 is switched from the bipolar mode to the unipolar mode while applying low power from the first high frequency power supply 110A to the antenna 109 to generate low power plasma. After this switching is completed, it is preferable to apply high power from the first high frequency power supply 110A to the antenna 109 to perform plasma processing (see FIG. 8C). When the power input to the antenna 109 is low, the energy of the generated plasma is weak, so that the heat transferred from the plasma to the carrier 10 is small. Therefore, there is little need to strongly adsorb the transport carrier 10 to the stage 111 to cool it. Therefore, when switching from the bipolar mode to the unipolar mode, problems due to insufficient cooling of the transport carrier 10 are less likely to occur.

The voltage applied to each ESC electrode 119 may be increased after switching to the unipolar mode and before starting the plasma processing. 8 (a) and 8 (b) are conceptual, with the time from when power is applied to the antenna 109 from the first high frequency power supply 110A on the horizontal axis and the voltage applied to each ESC electrode 119 on the vertical axis. The graph is shown. As shown in FIGS. 8A and 8B, after switching to the unipolar mode, the voltage applied to each ESC electrode 119 is gradually increased to + V2 to attract the transfer carrier 10 to the stage 111. High enough. After that, high power is applied to the antenna 109 from the first high frequency power supply 110A to start plasma processing.

Specifically, for example, the positive electrode voltage (+ V1) in the bipolar mode is 1500 V, the negative electrode voltage (−V1) is -1500 V, and the input power (low power) of the antenna 109 is 500 W. Next, the negative electrode voltage (−V1) is changed from -1500V to 1500V to switch from the bipolar mode to the unipolar mode. After that, both the positive electrode voltage (+ V1) and the negative electrode voltage (-V1) are gradually increased to 3000 V (+ V2). Finally, the power input (high power) to the antenna 109 is increased to 2000 W to 5000 W, and plasma processing is performed. As a result, the transport carrier 10 is strongly adsorbed on the stage 111 even during plasma processing, and the transport carrier 10 is reliably cooled, while suppressing the occurrence of problems associated with switching from the bipolar mode to the unipolar mode. Can be done.

After individualization, ashing is executed. A process gas for ashing (for example, oxygen gas or a mixed gas of oxygen gas and a gas containing fluorine) is introduced into the vacuum chamber 103 from the ashing gas source 113. On the other hand, exhaust is performed by the depressurizing mechanism 114 to maintain the inside of the vacuum chamber 103 at a predetermined pressure. Oxygen plasma is generated in the vacuum chamber 103 by inputting high-frequency power from the first high-frequency power supply 110A, and the resist mask on the surface of the substrate 1 (chip) exposed from the window portion 124W of the cover 124 is completely removed. Will be done.

Finally, the transport carrier 10 holding the individualized substrate 1 is carried out from the plasma processing device 100. The removal of the substrate 1 may be performed in the reverse procedure of the procedure for mounting the substrate 1 shown in FIG. 7 on the stage 111. That is, after raising the cover 124 to a predetermined position, the voltage applied to the ESC electrode 119 is set to zero to release the adsorption of the transport carrier 10 to the stage 111, and the support portion 122 is raised. When the electric charge at the time of plasma processing remains in the transport carrier 10 and the transport carrier 10 is residually adsorbed on the stage 111, if necessary, before or during the rise of the support portion 122, from the first high frequency power supply 110A, for example, A weak high-frequency power of about 200 W may be applied to generate a weak plasma to eliminate the charge of the transport carrier 10.

(Second Embodiment)
The present embodiment is the same as the first embodiment except that the pattern for making the voltage V _{n + 1} larger than the voltage V _n is included. In other words, in the present embodiment, the absolute value of the high voltage (V _{n + 1} ) applied after the low voltage (W _n ) is set to the high voltage (V _n ) applied before the low voltage (W _n ) as the increase / decrease operation is repeated. Make it larger than. FIG. 9 shows the pattern of variable application I. 9, the voltage of the ESC _{electrodes, V1 (V 1) → 0V} (W 1) → V2 of (V 2, V2> V1) → 0V (W 2) → V3 (V 3, V3> V2) → 0V (W ₃ ) → V 3 (V ₄ ) (n = 4). In this pattern, for example, after turning off (OFF) the DC power supply 126, adjusting the DC power supply 126 so as to apply a voltage higher than the voltage before turning off, and then turning on (ON) the DC power supply 126. It is done by repeating it once.

FIG. 9 is a conceptual graph in which the time from the start of descent of the support portion 122 is on the horizontal axis and the voltage applied to the ESC electrode 119 is on the vertical axis. As shown in FIG. 9, by including a pattern in which the applied voltage is gradually increased, wrinkles are further eliminated and adsorbed. When the voltage applied to the ESC electrode 119 is high, the attraction force of the holding sheet 3 to the stage 111 increases. The wrinkles that could not be eliminated when adsorbed with a weak voltage can be removed by applying a large voltage to the ESC electrode 119 after the adsorption is released (or weakened), so that the holding sheet 3 exerts a large adsorption force. It will be resolved.

(Third Embodiment)
The present embodiment is the same as the first embodiment except that the pattern for reversing the polarities of the voltage V _n and the voltage V _{n + 1} is included. In other words, in the present embodiment, when the increase / decrease operation is repeated, the polarity of the high voltage (V _{n + 1} ) applied after the low voltage (W _n ) is changed to the polarity of the high voltage (V _n ) applied before that. And reverse. FIG. 10 shows the pattern of variable application I. In FIG. 10, the voltage of the ESC electrode is changed from V1 (V ₁ ) → 0V (W ₁ ) → −V1 (V ₂ ) → 0V (W ₂ ) → V 1 (V ₃ ) → 0 V (W ₃ ) → V 1 (V). ₄ ) Increase or decrease (n = 4). This pattern is performed, for example, by repeating the on (ON) and off (OFF) of the DC power supply 126 twice using a polarity reversal switch. FIG. 10 is a conceptual graph in which the time from the start of descent of the support portion 122 is on the horizontal axis and the voltage applied to the ESC electrode 119 is on the vertical axis.

By reversing the polarity of the applied voltage, the portion of the ESC electrode of the substrate 1 corresponding to the positive electrode and the portion corresponding to the negative electrode are exchanged. Therefore, the residual adsorption is reduced, and the wrinkles of the holding sheet 3 become more loose when the DC power supply 126 is turned off. Therefore, the wrinkles of the holding sheet 3 can be more easily eliminated.

The plasma processing apparatus of the present invention is useful as an apparatus for plasma processing a substrate held by a transport carrier.

1: Substrate 2: Frame, 2a: Notch, 2b: Corner cut, 3: Holding sheet, 3a: Adhesive surface, 3b: Non-adhesive surface, 3c: Outer peripheral part, 10: Transport carrier, 100: Plasma processing device, 103 : Vacuum chamber, 103a: Gas inlet, 103b: Exhaust port, 108: Dielectric member, 109: Antenna (plasma source), 110A: First high frequency power supply, 110B: Second high frequency power supply, 111: Stage, 112: Process Gas source (gas supply means), 113: Ashing gas source, 114: Decompression mechanism, 115: Electrode layer, 116: Metal layer, 117: Base, 118: Outer circumference, 119: ESC electrode, 120: High frequency electrode, 121 : Lifting rod, 122: Support part, 122a: Upper end surface, 123A, 123B: Lifting mechanism, 124: Cover, 124W: Window part, 125: Gas refrigerant circulation device, 126: DC power supply, 127: Gasoline flow path, 128: Control apparatus

Claims (2)

A plasma processing device that performs plasma processing on a substrate held by a transport carrier.
The transport carrier includes a holding sheet and a frame arranged on the outer peripheral portion of the holding sheet.
The substrate is held by the holding sheet and
The plasma processing device is
Reaction room and
A plasma generating part that generates plasma in the reaction chamber and
A coolable stage located inside the reaction chamber for mounting the transport carrier,
An electrostatic adsorption mechanism provided with an electrode portion provided inside the stage, and
A control device for controlling the plasma generating unit and the electrostatic adsorption mechanism is provided.
The electrode portion includes a first electrode and a second electrode.
The electrostatic adsorption mechanism includes a bipolar mode in which voltages having different polarities are applied to the first electrode and the second electrode, and a unipolar mode in which voltages having the same polarity are applied to the first electrode and the second electrode. It has two operation modes,
The control device is
The electrostatic adsorption mechanism is operated in the bipolar mode to attract the transport carrier mounted on the stage to the stage, and then the plasma generation unit is driven to generate plasma, and then the electrostatic attraction is performed. The operation mode of the suction mechanism is controlled to be switched from the bipolar mode to the unipolar mode .
After switching the operation mode of the electrostatic adsorption mechanism from the bipolar mode to the unipolar mode, the electrostatic adsorption mechanism increases the absolute value of the voltage applied to the first electrode and the second electrode. A plasma processing device that controls . A plasma processing method in which a transport carrier on which a substrate is held is mounted on a coolable stage provided in a plasma processing apparatus to perform plasma processing on the substrate.
The transport carrier includes a holding sheet and a frame arranged on the outer peripheral portion of the holding sheet.
The substrate is held by the holding sheet and
The process of mounting the transport carrier at the mounting position on the stage and
A step of applying a voltage to the electrode portion of the electrostatic adsorption mechanism provided inside the stage, and
A step of etching the substrate by plasma is provided.
The step of applying a voltage to the electrode portion is
It is started in a bipolar mode in which voltages having different polarities are applied to the first electrode and the second electrode of the electrode portion.
The step of etching the substrate is
An operation of switching the operation mode of the electrode portion from the bipolar mode to a unipolar mode in which a voltage of the same polarity is applied to the first electrode and the second electrode while the plasma is being generated .
An operation of switching the operation mode to the unipolar mode and then increasing the absolute value of the voltage applied to the first electrode and the second electrode is included.
Plasma processing method.

Images