JP7214021B2 - PLASMA PROCESSING APPARATUS AND OBJECT CONVEYING METHOD - Google Patents

Description

The present disclosure relates to a plasma processing apparatus and a method of transporting an object to be processed.

2. Description of the Related Art Conventionally, a plasma processing apparatus is known that performs plasma processing on an object to be processed such as a semiconductor wafer using plasma. Such a plasma processing apparatus has, for example, a mounting table for mounting an object to be processed in a processing container capable of forming a vacuum space. Lifter pins are housed inside the mounting table. In the plasma processing apparatus, when an object to be processed that has been subjected to plasma processing is transported, a drive mechanism causes a lifter pin to protrude from the mounting table, and the lifter pin lifts the object to be processed from the mounting surface of the mounting table. Further, in the plasma processing apparatus, plasma processing may be performed while the mounting table is cooled to a temperature of 0° C. or less.

JP 2016-207840 A JP 2017-103388 A

The present disclosure provides a technique capable of reducing adhesion of reaction products to the mounting surface of the mounting table.

A plasma processing apparatus according to an aspect of the present disclosure includes a mounting table having a mounting surface on which an object to be processed to be plasma-processed is mounted; and a lifting mechanism for controlling the lifting mechanism to move the mounting surface of the mounting table and the processing target during the period from the end of plasma processing to the processing target to the start of transportation of the processing target. The object to be processed is held at a position separated from the substrate by a distance that suppresses the intrusion of the reaction product, and the object to be processed is held by controlling the elevating mechanism when the transport of the object to be processed is started. and an elevation control unit for raising the object to be processed from the position where the object to be processed is positioned.

According to the present disclosure, it is possible to reduce adhesion of reaction products to the mounting surface of the mounting table.

FIG. 1 is a schematic cross-sectional view showing the configuration of a plasma processing apparatus according to one embodiment. FIG. 2 is a block diagram showing an example of a schematic configuration of a controller that controls the plasma processing apparatus according to one embodiment. FIG. 3 is a diagram showing an example of the relationship between the distance between the mounting surface of the mounting table and the wafer and the length of the range of reaction products entering the mounting surface measured with reference to the edge of the wafer; is. FIG. 4 is a diagram showing an example of a state in which the wafer is lifted from the mounting surface of the mounting table. FIG. 5 is a flowchart showing an example of the flow of wafer transfer processing according to one embodiment.

Various embodiments are described in detail below with reference to the drawings. In addition, suppose that the same code|symbol is attached|subjected to the part which is the same or equivalent in each drawing.

2. Description of the Related Art Conventionally, a plasma processing apparatus is known that performs plasma processing on an object to be processed such as a semiconductor wafer using plasma. Such a plasma processing apparatus has, for example, a mounting table for mounting an object to be processed in a processing container capable of forming a vacuum space. Lifter pins are housed inside the mounting table. In the plasma processing apparatus, when an object to be processed that has been subjected to plasma processing is transported, a drive mechanism causes a lifter pin to protrude from the mounting table, and the lifter pin lifts the object to be processed from the mounting surface of the mounting table. Further, in the plasma processing apparatus, plasma processing may be performed while the mounting table is cooled to a temperature of 0° C. or less.

By the way, in a plasma processing apparatus, when an object to be processed is subjected to plasma processing, a reaction product is generated, which adheres and accumulates on the inner wall of the processing chamber and the like. A part of the reaction product deposited on the inner wall of the processing container may volatilize from the reaction product, float in the processing container as gas, and adhere to the mounting surface of the mounting table again. For example, in a plasma processing apparatus, when an object to be processed which has been subjected to plasma processing is transported, the object to be processed is lifted from the mounting surface of the mounting table by lifter pins, so that the reaction product is removed from the mounting surface of the mounting table. and the object to be processed, and adhere to the mounting surface of the mounting table. In particular, when the plasma processing is performed while the mounting table is cooled to a temperature of 0° C. or less, the reaction products floating as volatile gases are likely to condense, so that the reaction products may adhere to the mounting surface of the mounting table. Easier to adhere. Adherence of reaction products to the mounting surface of the mounting table is not preferable because it causes abnormalities such as poor adsorption of the object to be processed to the mounting surface of the mounting table.

[Configuration of plasma processing apparatus]
FIG. 1 is a schematic cross-sectional view showing the configuration of a plasma processing apparatus 10 according to one embodiment. The plasma processing apparatus 10 has a processing container 1 that is airtight and electrically grounded. The processing container 1 is cylindrical and made of, for example, aluminum. The processing vessel 1 defines a processing space in which plasma is generated. A mounting table 2 for horizontally supporting a semiconductor wafer (hereinafter simply referred to as "wafer") W, which is a workpiece (work-piece), is provided in the processing container 1 . The mounting table 2 includes a substrate (base) 2 a and an electrostatic chuck (ESC: Electrostatic chuck) 6 . The base material 2a is made of a conductive metal such as aluminum, and functions as a lower electrode. The electrostatic chuck 6 has a function of electrostatically attracting the wafer W. As shown in FIG. The mounting table 2 is supported by the support table 4 . The support base 4 is supported by a support member 3 made of, for example, quartz. A focus ring 5 made of, for example, single-crystal silicon is provided on the outer circumference of the upper portion of the mounting table 2 . Furthermore, a cylindrical inner wall member 3a made of quartz or the like is provided in the processing container 1 so as to surround the mounting table 2 and the support table 4 .

A first RF power supply 10a is connected to the substrate 2a through a first matching box 11a, and a second RF power supply 10b is connected through a second matching box 11b. The first RF power supply 10a is for plasma generation, and is configured to supply high-frequency power of a predetermined frequency to the substrate 2a of the mounting table 2 from the first RF power supply 10a. The second RF power supply 10b is for attracting ions (bias), and from this second RF power supply 10b, high-frequency power with a predetermined frequency lower than that of the first RF power supply 10a is applied to the base of the mounting table 2. It is configured to be supplied to the material 2a. Thus, the mounting table 2 is configured to be able to apply voltage. On the other hand, a shower head 16 functioning as an upper electrode is provided above the mounting table 2 so as to face the mounting table 2 in parallel. The shower head 16 and the mounting table 2 function as a pair of electrodes (upper electrode and lower electrode).

The electrostatic chuck 6 has a disk shape with a flat upper surface, and the upper surface serves as a mounting surface 6e on which the wafer W is mounted. The electrostatic chuck 6 is constructed by interposing an electrode 6a between the insulators 6b, and a DC power source 12 is connected to the electrode 6a. When a DC voltage is applied to the electrode 6a from the DC power source 12, the wafer W is attracted by Coulomb force.

A coolant channel 2d is formed inside the mounting table 2, and a coolant inlet pipe 2b and a coolant outlet pipe 2c are connected to the coolant channel 2d. By circulating an appropriate coolant such as cooling water in the coolant passage 2d, the mounting table 2 can be controlled at a predetermined temperature. Further, a gas supply pipe 30 for supplying cold heat transfer gas (backside gas) such as helium gas is provided to the rear surface of the wafer W so as to pass through the mounting table 2 and the like. , is connected to a gas supply source (not shown). With these configurations, the wafer W attracted and held on the upper surface of the mounting table 2 by the electrostatic chuck 6 is controlled to a predetermined temperature.

The mounting table 2 is provided with a plurality of, for example, three pin through holes 200 (only one is shown in FIG. 1). are arranged. The lifter pins 61 are connected to the lifting mechanism 62 . The elevating mechanism 62 elevates the lifter pins 61 so that the lifter pins 61 can freely appear and retract with respect to the mounting surface 6 e of the mounting table 2 . When the lifter pins 61 are lifted, the tips of the lifter pins 61 protrude from the mounting surface 6e of the mounting table 2, and the wafer W is held above the mounting surface 6e of the mounting table 2. FIG. On the other hand, when the lifter pins 61 are lowered, the tips of the lifter pins 61 are accommodated in the pin through holes 200 and the wafer W is mounted on the mounting surface 6 e of the mounting table 2 . In this way, the lifting mechanism 62 lifts and lowers the wafer W with respect to the mounting surface 6 e of the mounting table 2 with the lifter pins 61 . Further, the lifting mechanism 62 holds the wafer W above the mounting surface 6 e of the mounting table 2 with the lifter pins 61 in a state where the lifter pins 61 are raised.

The shower head 16 described above is provided on the top wall portion of the processing vessel 1 . The shower head 16 includes a main body 16 a and an upper top plate 16 b that serves as an electrode plate, and is supported above the processing vessel 1 via an insulating member 95 . The body portion 16a is made of a conductive material such as aluminum whose surface is anodized, and is configured to detachably support the upper top plate 16b on the lower portion thereof.

A gas diffusion chamber 16c is provided inside the body portion 16a. Further, the main body portion 16a has a large number of gas communication holes 16d formed in the bottom thereof so as to be positioned below the gas diffusion chamber 16c. Further, the upper top plate 16b is provided with a gas introduction hole 16e that penetrates the upper top plate 16b in the thickness direction so as to overlap the above-described gas flow hole 16d. With such a configuration, the processing gas supplied to the gas diffusion chamber 16c is dispersed and supplied into the processing chamber 1 through the gas communication hole 16d and the gas introduction hole 16e in the form of a shower.

A gas introduction port 16g for introducing a processing gas into the gas diffusion chamber 16c is formed in the body portion 16a. One end of the gas supply pipe 15a is connected to the gas introduction port 16g. A processing gas supply source (gas supply unit) 15 for supplying a processing gas is connected to the other end of the gas supply pipe 15a. The gas supply pipe 15a is provided with a mass flow controller (MFC) 15b and an on-off valve V2 in order from the upstream side. A processing gas for plasma etching is supplied from the processing gas supply source 15 to the gas diffusion chamber 16c through the gas supply pipe 15a. A processing gas is supplied from the gas diffusion chamber 16c into the processing container 1 in a shower-like manner through the gas communication hole 16d and the gas introduction hole 16e.

A variable DC power supply 72 is electrically connected to the shower head 16 as the upper electrode described above via a low-pass filter (LPF) 71 . The variable DC power supply 72 is configured so that power supply can be turned on/off by an on/off switch 73 . The current/voltage of the variable DC power supply 72 and the on/off of the on/off switch 73 are controlled by the controller 100, which will be described later. As will be described later, when high-frequency waves are applied to the mounting table 2 from the first RF power supply 10a and the second RF power supply 10b and plasma is generated in the processing space, the control unit 100 turns on the power supply as necessary. - The off switch 73 is turned on, and a predetermined DC voltage is applied to the shower head 16 as the upper electrode.

A cylindrical ground conductor 1a is provided to extend from the side wall of the processing container 1 above the height position of the shower head 16 . The cylindrical ground conductor 1a has a top wall on its top.

An exhaust port 81 is formed at the bottom of the processing container 1 . A first exhaust device 83 is connected to the exhaust port 81 via an exhaust pipe 82 . The first evacuation device 83 has a vacuum pump, and is configured to be able to reduce the pressure inside the processing container 1 to a predetermined degree of vacuum by operating the vacuum pump. On the other hand, a loading/unloading port 84 for the wafer W is provided on the side wall inside the processing container 1 , and the loading/unloading port 84 is provided with a gate valve 85 for opening and closing the loading/unloading port 84 .

A deposit shield 86 is provided along the inner wall surface inside the side portion of the processing container 1 . The deposit shield 86 prevents etching by-products (depot) from adhering to the processing chamber 1 . A conductive member (GND block) 89 connected to the ground so as to control the potential is provided at a position of the deposition shield 86 substantially at the same height as the wafer W, thereby preventing abnormal discharge. A deposit shield 87 extending along the inner wall member 3 a is provided at the lower end of the deposit shield 86 . The deposit shields 86 and 87 are detachable.

The operation of the plasma processing apparatus 10 configured as described above is centrally controlled by the control unit 100 . The controller 100 is, for example, a computer, and controls each part of the plasma processing apparatus 10 .

FIG. 2 is a block diagram showing an example of a schematic configuration of a controller 100 that controls the plasma processing apparatus 10 according to one embodiment. The control unit 100 has a process controller 110 , a user interface 120 and a storage unit 130 .

The process controller 110 has a CPU (Central Processing Unit) and controls each part of the plasma processing apparatus 10 .

The user interface 120 includes a keyboard for inputting commands for the process manager to manage the plasma processing apparatus 10, a display for visualizing and displaying the operating status of the plasma processing apparatus 10, and the like.

The storage unit 130 stores a control program (software) for realizing various processes executed in the plasma processing apparatus 10 under the control of the process controller 110, and recipes in which process condition data and the like are stored. . For example, the storage unit 130 stores intrusion range information 131 . Recipes such as control programs and processing condition data should be stored in computer-readable computer recording media (for example, hard disks, optical disks such as DVDs, flexible disks, semiconductor memories, etc.). is also possible. Alternatively, recipes such as control programs and processing condition data can be transmitted from other devices, for example, via a dedicated line, and used online.

The penetration range information 131 includes the distance between the mounting surface 6e of the mounting table 2 and the wafer W and the mounting surface 6e measured with the edge of the wafer W as a reference for each processing condition of plasma processing on the wafer W. It is data showing the relationship between the penetration range of the reaction product and the length of the penetration range. FIG. 3 shows the relationship between the distance between the mounting surface 6e of the mounting table 2 and the wafer W, and the length of the range of penetration of reaction products into the mounting surface 6e measured with reference to the edge of the wafer W. It is a figure which shows an example. 3, for example, by changing the distance between the mounting surface 6e of the mounting table 2 and the wafer W, the length of the range of penetration of the reaction product into the mounting surface 6e with reference to the edge of the wafer W is determined. These are the results of measurements. In the measurement of FIG. 3, a measurement sample was prepared by simulating the mounting table 2 and the wafer W by flat plates facing each other vertically, and the length of the range of penetration of the reaction product to the surface of the lower flat plate was placed. It was measured as the length of the penetration range of the reaction product to the surface 6e. In FIG. 3, the distance between the mounting surface 6e of the mounting table 2 and the wafer W and the edge of the wafer W are measured for each processing condition (processing conditions A to C) of the plasma processing for the wafer W. The relation with the length of the penetration range of the reaction product to the placed mounting surface 6e is shown. The processing conditions for the plasma processing on the wafer W include conditions such as the type of processing gas used for the plasma processing and the temperature of the mounting table 2 . In one embodiment, the process gas used for plasma processing is, for example, a fluorocarbon gas or a hydrofluorocarbon gas. Moreover, the plasma processing of the wafer W is performed, for example, while the mounting table 2 is cooled to a temperature of 0° C. or less.

As shown in FIG. 3, regardless of the difference in the processing conditions of the plasma processing for the wafer W, the larger the distance between the mounting surface 6e of the mounting table 2 and the wafer W, the more the reaction products on the mounting surface 6e. length of penetration range increases. Further, the length of the range of penetration of the reaction product into the mounting surface 6e of the mounting table 2 changes with respect to the distance between the mounting surface 6e of the mounting table 2 and the wafer W for each processing condition of the plasma processing of the wafer W. The degree to which it does varies.

As described above, in the plasma processing apparatus 10, the length of the range in which the reaction product enters the mounting surface 6e changes according to the distance between the mounting surface 6e of the mounting table 2 and the wafer W. FIG. Further, the degree of change in the length of the range of reaction products entering the mounting surface 6e varies depending on the processing conditions of the plasma processing of the wafer W. FIG.

Therefore, for example, by experiment or the like, the distance between the mounting surface 6e of the mounting table 2 and the wafer W and the mounting distance measured with reference to the edge of the wafer W are set for each processing condition of the plasma processing of the wafer W. The relationship with the length of the penetration range of the reaction product to the surface 6e is obtained in advance. The distance between the mounting surface 6e of the mounting table 2 and the wafer W and the generation of reaction to the mounting surface 6e measured with reference to the edge of the wafer W are determined for each processing condition of the plasma processing of the wafer W. The relationship with the length of the intrusion range of the object is stored in the intrusion range information 131 . For example, the intrusion range information 131 indicates the amount of penetration of the reaction product into the mounting surface 6e of the mounting table 2 with respect to the distance between the mounting surface 6e of the mounting table 2 and the wafer W for each processing condition of plasma processing on the wafer W. This is a table that associates range lengths.

Returning to the description of FIG. The process controller 110 has an internal memory for storing programs and data, reads a control program stored in the storage unit 130, and executes processing of the read control program. The process controller 110 functions as various processing units by executing control programs. For example, the process controller 110 has a calculator 111 and an elevation controller 112 .

By the way, in the plasma processing apparatus 10 , when the wafer W is plasma-processed, a reaction product is generated, which adheres and accumulates on the inner wall of the processing chamber 1 or the like. Some of the reaction products deposited on the inner wall of the processing container 1 may volatilize from the reaction products, float in the processing container 1 as gas, and adhere to the mounting surface 6e of the mounting table 2 again. For example, in the plasma processing apparatus 10 , the wafer W is lifted from the mounting surface 6 e of the mounting table 2 by the lifter pins 61 when the wafer W subjected to the plasma processing is transported. Therefore, in the plasma processing apparatus 10, reaction products floating in the processing chamber 1 enter the gap between the mounting surface 6e of the mounting table 2 and the wafer W, and adhere to the mounting surface 6e of the mounting table 2. I have something to do. Adhesion of the reaction product to the mounting surface 6e of the mounting table 2 causes abnormalities such as poor adsorption of the wafer to the mounting surface 6e of the mounting table 2, which is not preferable.

FIG. 4 is a diagram showing an example of a state in which the wafer W is lifted from the mounting surface 6e of the mounting table 2. As shown in FIG. As shown in FIG. 4 , in the plasma processing apparatus 10 , the lifter pins 61 lift the wafer W from the mounting surface 6 e of the mounting table 2 when the wafer W subjected to the plasma processing is transported. Thereby, a gap is formed between the mounting surface 6e of the mounting table 2 and the wafer W. As shown in FIG. Some of the reaction products deposited on the inner wall of the processing container 1 float inside the processing container 1 as volatile gases, enter between the mounting surface 6e of the mounting table 2 and the wafer W, and enter the mounting table 2. may adhere as a reaction product 161 to the mounting surface 6e. In particular, when the plasma processing is performed while the mounting table 2 is cooled to a temperature of 0° C. or lower, the reaction products 161 floating on the mounting table 2 are likely to condense as volatile gas. It becomes easy to adhere to the placement surface 6e. For example, in the plasma processing apparatus 10 , if the reaction product 161 adheres excessively to the mounting surface 6 e of the mounting table 2 , an abnormality such as poor adhesion of the wafer to the mounting surface 6 e of the mounting table 2 is caused.

Therefore, in the plasma processing apparatus 10, during the period from the end of the plasma processing to the wafer W to the start of the transfer of the wafer W, the reaction product is prevented from entering the mounting surface 6e of the mounting table 2 and the wafer W. The lifting mechanism 62 is controlled so as to maintain the restraining interval.

Returning to the description of FIG. Calculation unit 111 refers to penetration range information 131 to determine the length of the penetration range of the reaction product corresponding to the processing conditions of the executed plasma processing. A distance between the placement surface 6e and the wafer W is calculated. For example, the calculation unit 111 calculates the distance between the mounting surface 6 e of the mounting table 2 and the wafer W by referring to the penetration range information 131 stored in advance in the storage unit 130 . For example, it is assumed that the penetration range information 131 stores the relationship between the interval and the penetration range of the reaction product shown in FIG. do. In this case, the calculation unit 111 refers to the penetration range information 131, for example, and sets the predetermined allowable length of the penetration range corresponding to the processing condition A of the executed plasma processing to “2 mm” or less. Then, the distance "0.20 mm" between the mounting surface 6e of the mounting table 2 and the wafer W is calculated. The predetermined allowable length is determined based on at least the difference between the outer diameter of the mounting surface 6e of the mounting table 2 and the outer diameter of the wafer W. FIG. For example, when the outer diameter of the mounting surface 6e of the mounting table 2 is 296 mm and the outer diameter of the wafer W is 300 mm, the predetermined allowable length is equal to the outer diameter of the mounting surface 6e of the mounting table 2. It is determined to be "2 mm" which is 1/2 of the difference from the outer diameter of the wafer W (300-296=4 mm). Further, in determining the allowable length, the dimensional error of the outer diameter of the mounting surface 6e of the mounting table 2, the dimensional error of the outer diameter of the wafer W, and the like may be taken into consideration. Further, the calculation of the distance between the mounting surface 6e of the mounting table 2 and the wafer W may be performed during the period from the completion of the plasma processing of the wafer W to the start of transfer of the wafer W. It may be performed before the plasma processing on the wafer W is completed.

The elevation control unit 112 controls the elevation mechanism 62 to raise the mounting surface 6e of the mounting table 2 and the wafer W during the period from the completion of the plasma processing of the wafer W to the start of the transfer of the wafer W. The wafer W is held at a position separated by a distance that suppresses entry of reaction products. For example, the lift control unit 112 controls the lift mechanism 62 to lift the mounting surface 6e of the mounting table 2 and the wafer W during the period from the end of the plasma processing of the wafer W to the start of transfer of the wafer W. are separated from each other by the distance calculated by the calculator 111 . The transfer of the wafer W is started, for example, at the timing when the transfer arm receives an instruction to start transfer of the plasma-processed wafer W and arrives at the plasma processing apparatus 10 (processing container 1).

Then, when the transfer of the wafer W is started, the elevation control unit 112 controls the elevation mechanism 62 to raise the wafer W from the position where the wafer W is held. That is, the elevation control unit 112 moves the wafer W from the position where the wafer W is held to the transfer arm at the timing when the transfer arm receives the command to start transferring the plasma-processed wafer W and reaches the processing container 1 . The wafer W is lifted to a position for delivering the wafer W.

As a result, in the plasma processing apparatus 10, when the plasma-treated wafer W is transported, the reaction products are prevented from entering the gap between the mounting surface 6e of the mounting table 2 and the wafer W. Therefore, adhesion of reaction products to the mounting surface 6e of the mounting table 2 can be reduced.

[Flow of control]
Next, a transfer process of the wafer W using the plasma processing apparatus 10 according to one embodiment will be described. FIG. 5 is a flow chart showing an example of the flow of the wafer W transfer process according to one embodiment. This transfer processing of the wafer W is executed at the timing when the plasma processing of the wafer W is finished, for example. In one embodiment, it is assumed that the plasma processing on the wafer W is performed while the mounting table 2 is cooled to a temperature of 0° C. or less.

As shown in FIG. 5, when the plasma processing of the wafer W is completed (S101), a command to start transporting the plasma-processed wafer W is issued (S102). 10 (processing container 1) is started (S103).

Calculation unit 111 refers to penetration range information 131 to determine the length of the penetration range of the reaction product corresponding to the processing conditions of the executed plasma processing. The distance between the placement surface 6e and the wafer W is calculated (S104).

The elevation control unit 112 controls the elevation mechanism 62 to hold the wafer W at a position where the mounting surface 6e of the mounting table 2 and the wafer W are separated by the distance calculated by the calculation unit 111 (S105).

The elevation control unit 112 moves the mounting surface 6e of the mounting table 2 and the wafer W by the distance calculated by the calculation unit 111 until the transfer arm reaches the plasma processing apparatus 10 (processing container 1) (S106; No). It waits while the wafer W is held at the separated position. In other words, the elevation control unit 112 prevents reaction products from entering the mounting surface 6e of the mounting table 2 and the wafer W during the period from the end of the plasma processing of the wafer W to the start of transportation of the wafer W. The lifting mechanism 62 is controlled so as to maintain the restraining interval.

On the other hand, when the transfer arm reaches the plasma processing apparatus 10 (processing container 1) (S107; Yes), the elevation control unit 112 moves the wafer from the position where the wafer W is held to the position for transferring the wafer W to the transfer arm. W is increased (S108).

After that, the transfer of the wafer W by the transfer arm is started (S109). That is, the transfer arm is carried into the processing container 1 and the wafer W is transferred to the transfer arm by lowering the wafer W by the elevation control unit 112 . Then, the transfer arm transfers the transferred wafer W out of the processing container 1 .

As described above, the plasma processing apparatus 10 according to one embodiment has the mounting table 2 , the elevating mechanism 62 and the elevating controller 112 . The mounting table 2 has a mounting surface 6e on which a wafer W to be plasma-processed is mounted. The elevating mechanism 62 elevates the wafer W with respect to the mounting surface 6 e of the mounting table 2 . The elevation control unit 112 controls the elevation control unit 112 so that the mounting surface 6e of the mounting table 2 and the wafer W are aligned during the period from the end of the plasma processing of the wafer W to the start of the transfer of the wafer W. The wafer W is held at a position separated by a distance that suppresses entry of reaction products. Then, when the transfer of the wafer W is started, the elevation control unit 112 controls the elevation mechanism 62 to raise the wafer W from the position where the wafer W is held. Thereby, the plasma processing apparatus 10 can reduce adhesion of reaction products to the mounting surface 6 e of the mounting table 2 . In particular, the plasma processing apparatus 10 does not react to the gap between the mounting surface 6e of the mounting table 2 and the wafer W even when the plasma processing is performed with the mounting table 2 cooled to a temperature of 0° C. or lower. Intrusion of products can be suppressed to reduce adhesion of reaction products.

Although various embodiments have been described above, the technology disclosed herein is not limited to the above-described embodiments, and can be modified in various ways. For example, the plasma processing apparatus 10 described above is a capacitively coupled plasma processing apparatus 10, but may be employed in any plasma processing apparatus 10. FIG. For example, the plasma processing apparatus 10 may be any type of plasma processing apparatus 10, such as an inductively coupled plasma processing apparatus 10, or a plasma processing apparatus 10 that excites a gas by surface waves such as microwaves.

Further, in the above-described embodiment, an example has been described in which the wafer W is held at a position separated from the mounting surface 6e of the mounting table 2 and the wafer W by a distance that suppresses the intrusion of reaction products, but the present invention is limited to this. not a thing For example, the plasma processing apparatus 10 causes the mounting surface 6e of the mounting table 2 and the wafer W to react with each other while supplying an inert gas to a gap formed between the mounting surface 6e of the mounting table 2 and the wafer W. The wafer W may be held at a position separated by a distance that suppresses entry of the product. As a result, the plasma processing apparatus 10 suppresses the penetration of reaction products into the gap between the mounting surface 6e of the mounting table 2 and the wafer W by the inert gas, thereby further reducing the adhesion of the reaction products. can be done. Inert gas is, for example, N2 gas, O2 gas, or rare gas. The inert gas is supplied, for example, by using a gas supply pipe 30 for supplying a cold heat transfer gas (backside gas) such as helium gas to the back surface of the wafer W. FIG.

Further, the plasma processing apparatus 10 may perform dry cleaning to remove reaction products deposited on the inner wall of the processing chamber 1 by plasma processing after the wafer W is transferred out of the processing chamber 1 by the transfer arm. . As a result, the plasma processing apparatus 10 can suppress the component released into the processing chamber 1 as a volatile gas from the reaction products deposited on the inner wall of the processing chamber 1 or the like, and the wafer W is not mounted. Adhesion of reaction products to the mounting surface 6e of the mounting table 2 can be reduced.

Further, the plasma processing apparatus 10 may mount a dummy wafer, which is not to be subjected to plasma processing, on the mounting surface 6e of the mounting table 2 after the wafer W is transferred out of the processing chamber 1 by the transfer arm. As a result, the plasma processing apparatus 10 can protect the mounting surface 6e of the mounting table 2 with the dummy wafer and further reduce adhesion of reaction products to the mounting surface 6e of the mounting table 2. FIG. The time during which the dummy wafer is continued to be placed is the time from the end of the plasma processing until the components volatilized from the reaction products deposited on the inner wall of the processing chamber 1 and emitted into the processing chamber 1 are exhausted. It will be decided as appropriate in consideration of time.

As described above, the following additional remarks will be disclosed with respect to each of the above-described embodiments.

(Appendix 1)
a mounting table having a mounting surface on which an object to be processed to be plasma-processed is mounted;
an elevating mechanism for elevating the object to be processed with respect to the mounting surface of the mounting table;
During a period from the end of plasma processing of the object to be processed to the start of transportation of the object to be processed, reaction is generated between the mounting surface of the mounting table and the object to be processed by controlling the elevating mechanism. The object to be processed is held at a position separated by a distance for suppressing the intrusion of objects, and when the transport of the object to be processed is started, the elevating mechanism is controlled to move the object to be processed from the position where the object to be processed is held. a lifting control unit for lifting the object to be processed;
A plasma processing apparatus comprising:

(Appendix 2)
1. The plasma processing apparatus according to claim 1, wherein the plasma processing on the object to be processed is performed in a state in which the mounting table is cooled to a temperature of 0° C. or less.

(Appendix 3)
For each processing condition of the plasma processing, the distance between the mounting surface of the mounting table and the object to be processed, and the distance to the mounting surface of the mounting table measured with reference to the edge of the object to be processed a storage unit that stores penetration range information indicating a relationship with the length of the penetration range of the reaction product;
a mounting surface of the mounting table in which the length of the penetration range of the reaction product corresponding to the processing conditions of the executed plasma processing is equal to or less than a predetermined allowable length by referring to the penetration range information; a calculation unit that calculates the distance between the object to be processed;
further having
The elevating control unit controls the elevating mechanism to lift the mounting surface of the mounting table and the object during a period from the end of the plasma processing of the object to be processed to the start of transportation of the object to be processed. 3. The plasma processing apparatus according to appendix 1 or 2, wherein the object to be processed is held at a position separated from the object to be processed by the calculated distance.

(Appendix 4)
The plasma according to appendix 3, wherein the predetermined allowable length is determined at least based on a difference between an outer diameter of the mounting surface of the mounting table and an outer diameter of the object to be processed. processing equipment.

(Appendix 5)
The elevation control unit holds the object to be processed at the position while supplying an inert gas to a gap formed between the mounting surface of the mounting table and the object to be processed. The plasma processing apparatus according to any one of Appendices 1 to 4.

(Appendix 6)
during a period from the end of the plasma processing to the object to be processed mounted on the mounting surface of the mounting table to the start of transportation of the object to be processed, the mounting surface of the mounting table to the to-be-processed object; holding the object to be processed at a position separated from the mounting surface of the mounting table and the object to be processed by a distance that suppresses the intrusion of the reaction product by controlling an elevating mechanism that moves the object up and down;
When the transport of the object to be processed is started, the elevating mechanism is controlled to raise the object to be processed from the position where the object to be processed is held;
A method of transporting an object to be processed, characterized in that the processing is executed by a computer.

1 processing container 2 mounting table 6 electrostatic chuck 6e mounting surface 10 plasma processing device 61 lifter pin 62 lifting mechanism 100 control unit 111 calculation unit 112 lifting control unit 130 storage unit 131 penetration range information W wafer

Claims (9)

a mounting table having a mounting surface on which the object to be processed is mounted;
an elevating mechanism for elevating the object to be processed with respect to the mounting surface;
has
The elevating mechanism holds the object to be processed at a position where the placement surface and the object to be processed are spaced apart by a distance that suppresses the intrusion of deposits.
processing equipment. The interval for suppressing the invasion of the adhering matter is based on the interval between the mounting surface and the object to be processed and the edge of the object to be processed for each processing condition of plasma processing on the object to be processed. 2. The processing apparatus according to claim 1, which is set based on intrusion range information indicating a relationship with a measured length of an intrusion range of said deposit on said mounting surface. The space for suppressing the intrusion of the adhering matter is the mounting surface of the mounting table such that the length of the intrusion range of the adhering matter corresponding to the processing conditions of the executed plasma processing is equal to or less than a predetermined allowable length. and the object to be processed. 4. The processing apparatus according to claim 3, wherein said predetermined allowable length is determined based on at least a difference between an outer diameter of said mounting surface and an outer diameter of said object to be processed. 5. The processing apparatus according to any one of claims 1 to 4 , wherein said elevating mechanism holds said object to be processed at said position after finishing the plasma processing on said object to be processed. 6. The processing apparatus according to any one of claims 1 to 5 , wherein said position is lower than other positions for transferring said plasma-processed object to a transfer apparatus. The processing apparatus according to any one of claims 1 to 6 , wherein the plasma processing of the object to be processed is performed with the mounting table being cooled to a temperature of 0°C or less. The apparatus according to any one of claims 1 to 7 , wherein the elevating mechanism holds the object to be processed at the position while an inert gas is supplied to a gap formed between the mounting surface and the object to be processed. A processing apparatus according to any one of the preceding claims. During a period from the completion of plasma processing of the object placed on the mounting surface of the mounting table until the start of transportation of the object to be processed, the object to be processed is moved up and down with respect to the mounting surface. holding the object to be processed at a position separated from the mounting surface by a distance that suppresses the intrusion of adhering matter, by controlling an elevating mechanism for
A method of transporting an object to be processed.

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