KR20090055146A - Apparatus for cleaning substrate with plasma - Google Patents

Abstract

A substrate cleaning apparatus is provided to shorten a process time by forming plasma in a side surface and a rear surface of a substrate at the same time. A substrate cleaning apparatus cleans a rear surface and a side surface of a substrate by generating plasma in the side surface and the rear surface of the substrate while gripping a top surface of the substrate. The substrate cleaning apparatus includes a vacuum chamber(10), an electrostatic chuck(20), a moving chuck(30), a top insulator(40), a substrate holder(50), a bottom insulator(60), a top gas supply path(80), and an RF application part(90). A lift pin(100) penetrates the moving chuck, is driven top and bottom, and receives the substrate from outside. A cooling medium is circulated inside the electrostatic chuck. A top cooling path(24) cools the electrostatic chuck.

Description

Substrate cleaning device {APPARATUS FOR CLEANING SUBSTRATE WITH PLASMA}

The present invention relates to a substrate cleaning apparatus capable of cleaning particles generated during substrate processing such as etching and deposition using plasma.

Particles, such as fine dust and water, in the production stage of an integrated circuit manufactured by developing and etching a circuit pattern on the wafer surface, must be actively removed because they damage the formation of the circuit pattern.

In general, particles generated by external factors can be prevented in advance through the cleanliness of the process atmosphere through a clean facility, but particles of internal factors generated in the manufacturing process cannot be prevented in advance. Therefore, the wafer undergoes several steps of cleaning in the process of moving from process to process.

As is well known, wet cleaning is known as wet cleaning in which a particle or surface is removed by immersion in a solvent or a rinse, and dry cleaning in which the surface is etched and removed by plasma.

The wet cleaning is effectively used to remove the photoresist layer applied to the wafer surface, but it is difficult to manage the process and the operating cost such as the cost of the cleaning liquid is expensive, and the process time is long, so that the productivity is not good. Therefore, at present, a dry cleaning method using plasma is widely used.

Such dry cleaning apparatuses include a method of etching and removing a photoresist layer or the like applied to a wafer surface, and a bevel etching method of removing particles deposited on upper and lower edges of a wafer seated on a stage.

However, such a dry cleaning device does not clean the back of the wafer. However, the particles present on the back side of the wafer cause problems with the horizontality of the wafer while the wafer is placed on the stage. When the wafer mounted on the stage is not parallel to the stage surface, a fatal problem occurs that the uniform processing on the substrate is not performed in a subsequent process such as exposure.

The problem to be solved by the present invention is to provide a substrate cleaning apparatus capable of simultaneously or sequentially cleaning not only the side surface but also the rear surface of the substrate using plasma.

In the substrate cleaning apparatus of the present invention for solving the above technical problem, plasma is generated on the side and bottom surfaces of the substrate while the upper surface of the substrate is gripped to clean the bottom and side surfaces of the substrate.

Specifically, the cleaning apparatus of the present invention includes a vacuum chamber capable of maintaining an interior in a vacuum state; An electrostatic chuck disposed on an upper side of the vacuum chamber and contacting the upper surface of the substrate to expose the edge of the substrate; A mobile chuck disposed below the vacuum chamber and provided to be driven in an up and down direction; An upper insulator disposed on the side of the electrostatic chuck and spaced apart from the side surface of the electrostatic chuck at a predetermined interval; A substrate holder disposed on a side of the moving chuck and surrounding the substrate such that the bottom and side surfaces of the substrate fixed to the electrostatic chuck are exposed; A lower insulator disposed outside the substrate holder and opposed to the upper insulator; An upper gas supply path formed in the electrostatic chuck to supply a process gas to a space between the side surface of the electrostatic chuck and the upper insulator; A lower gas supply path formed in the moving chuck and supplying a process gas to a space between the substrate and the moving chuck; And an RF applying means formed at any one of the electrostatic chuck or the mobile chuck to apply RF power.

In addition, the substrate cleaning apparatus of the present invention is formed to penetrate the moving chuck, and is further easily loaded and unloaded into the substrate cleaning apparatus further including a lift pin which is driven in the vertical direction and receives the substrate charged from the outside. It is preferable because it can be done.

Meanwhile, in the electrostatic chuck of the present invention, the side surface thereof is stepped by the thickness of the upper insulator so that the electrostatic chuck, the upper insulator, the substrate holder and the lower insulator are in close contact with each other to form a donut-shaped space for cleaning the edge of the substrate. It is desirable to be able to provide a space in which side plasma can be formed.

At this time, the substrate holder, it is preferable that the portion facing the side of the substrate is formed with a chamfered chamfer.

On the other hand, it is preferable that the cooling medium is further circulated inside the electrostatic chuck to further provide an upper cooling flow path for cooling the electrostatic chuck, since the temperature of the wafer gripped by the electrostatic chuck can be adjusted.

In addition, it is preferable to further include a lower cooling flow path through which a cooling medium is circulated to cool the moving chuck inside the moving chuck, since the temperature rise of the moving chuck due to the back plasma can be suppressed.

In addition, the electrostatic chuck of the present invention is preferably disposed so as to be driven in the vertical direction, since it is advantageous to form a space for forming a back plasma for cleaning the back surface of the substrate.

In addition, it is preferable that a baffle is further provided between the lower insulator and the side wall of the vacuum chamber, and the baffle may be disposed to be capable of driving in the vertical direction.

According to the present invention, plasma can be simultaneously formed on the side and the back side of the substrate, thereby simultaneously cleaning the edge and the back side of the substrate, while also significantly reducing the process time.

Hereinafter, with reference to the accompanying drawings will be described in detail a specific embodiment of the present invention.

As shown in FIG. 1, the substrate cleaning apparatus 1 according to the present embodiment includes a vacuum chamber 10, an electrostatic chuck 20, a moving chuck 30, an upper insulator 40, and a substrate holder 50. , A lower insulator 60, an upper gas supply path 70, a lower gas supply path 80, and an RF application means 90.

First, the vacuum chamber 10 forms the overall shape of the substrate cleaning apparatus 1 according to the present embodiment, and has a structure capable of maintaining the internal space in a vacuum state. Therefore, each seam of the vacuum chamber 10 is sealed, and a gate valve 14 is also formed at the substrate entrance 12 through which the substrate enters and exits. It has a structure that can In addition, the vacuum chamber 10 is provided with a pumping system 18 to discharge the gas in the chamber interior space to create a vacuum state, a venting system for injecting gas to make the pressure inside the chamber to atmospheric pressure (not shown in the drawing) ) Is also provided.

In addition, an insulating member may be further provided on an inner wall of the vacuum chamber 10 according to the present embodiment. That is, by applying an insulating member such as ceramic on the inner wall surface of the vacuum chamber 10 to prevent damage to the inner wall of the chamber by plasma, and to reduce the time required for pumping by reducing the volume inside the chamber. There is this.

Next, the electrostatic chuck 20 is disposed above the inside of the vacuum chamber 10, and is a component that contacts the upper surface of the substrate W to expose the substrate edge and fixes the substrate. Since the substrate cleaning apparatus 1 according to the present embodiment cleans not only the edge of the substrate W but also the back of the substrate, the back and edge portions of the substrate should be exposed. Therefore, the electrostatic chuck 20 contacts the upper surface of the substrate and lifts the substrate so that the edge of the substrate W is exposed, so that the rear surface of the substrate W is exposed. In addition, as shown in FIGS. 1 and 2, side surfaces of the electrostatic chuck 20 of the present exemplary embodiment are formed to be stepped by the thickness of the upper insulator 40 so that the edge of the substrate and the upper edge portion thereof are exposed.

Here, the electrostatic chuck 20 of the present embodiment grips the substrate W using electrostatic power, and thus does not damage circuits or the like formed on the upper surface of the substrate. Therefore, the DC voltage for generating the electrostatic force is applied to the electrostatic chuck 20.

The electrostatic chuck 20 may be driven in the vertical direction. As shown in FIG. 1, the electrostatic chuck 20 is driven up and down inside the chamber by using the electrostatic chuck driving unit 22 disposed above the vacuum chamber 10. When the electrostatic chuck 20 is driven in this manner, it is advantageous to secure a minimum space for generating the side plasma and the back plasma.

On the other hand, the circuit pattern protection layer (not shown) made of a material having a hardness smaller than that of the circuit pattern formed on the surface of the substrate to protect the circuit pattern formed on the surface of the electrostatic chuck (20) This may be further provided. The circuit pattern protective layer may be formed on all or a portion of the electrostatic chuck in contact with the upper surface of the substrate, and may be made of, for example, a material such as a polyimide film.

In addition, an insulating member may be further provided to protect the exposed portion of the electrostatic chuck 20, that is, the side surface and the stepped surface. As shown in FIG. 1, the exposed portion of the electrostatic chuck 20 may be damaged by a plasma, thereby forming and protecting an insulating member separately.

Next, the moving chuck 30 is disposed below the vacuum chamber 10 and is a component provided to be driven in the vertical direction. The moving chuck 30 is disposed in parallel with the electrostatic chuck 20 described above, and as shown in FIG. 1, the moving chuck 30 is movably disposed in a vertical direction by a moving chuck driving part 32 installed at a lower portion of the chamber. By moving the chuck 30 up and down, a suitable space for forming the back plasma can be secured. Of course, when the electrostatic chuck 20 has a structure capable of driving up and down, the moving chuck 30 may not be driven up and down.

Next, the upper insulator 40 is a component disposed on the side of the electrostatic chuck 20 spaced apart from the side surface of the electrostatic chuck at a predetermined interval. As shown in FIG. 2, the upper insulator 40 is disposed to face the side of the electrostatic chuck 20 at a predetermined interval, and provides a space for forming the side plasma for cleaning the edge of the substrate. The upper insulator 40 has a ring shape as a whole. Meanwhile, an outer insulator surrounding the upper insulator 40 may be further provided.

The substrate holder 50 is disposed on the side of the moving chuck 30 and surrounds the substrate so that the bottom and side surfaces of the substrate W fixed to the electrostatic chuck 20 are exposed. That is, the substrate holder 50 is disposed in contact with the side surface of the moving chuck 30, as shown in FIGS. 1 and 2, and the side surface of the substrate in a state where the substrate W is gripped by the electrostatic chuck 20. The lower surface and the side surface of the substrate are exposed to expose the lower surface. The substrate holder 50 approaches the upper insulator 40 described above to form a space for forming the side plasma together with the upper insulator.

As shown in FIGS. 1 and 2, the substrate holder 50 may be formed such that a portion of the substrate W facing the side surface of the substrate W has a smooth curved shape, or may be formed of a chamfered bevel. It may also be made of a general angled corner. This is to adjust the shape of the plasma sheath for cleaning the edge of the substrate, in addition to the shape of the substrate holder 50 can be variously changed. By changing the shape of the substrate holder 50 in this manner, the etching rate of the edge portion of the substrate W can be changed.

Next, as shown in FIGS. 1 and 2, the lower insulator 60 is disposed outside the substrate holder 50, and is a component facing the upper insulator 40. The lower insulator 60 is in close contact with the upper insulator 50 during the substrate cleaning process to help form the side plasma stably.

Next, an upper gas supply path 70 is formed in the electrostatic chuck 20 to supply process gas to a space between the side surface of the electrostatic chuck 20 and the upper insulator 40. As shown in FIGS. 1 and 2, the upper gas supply path 70 penetrates through the interior of the electrostatic chuck 20, and an end thereof is a space between the upper insulator 40 and the electrostatic chuck 20. Communicating. Therefore, the process gas supplied from the outside is supplied to the space between the electrostatic chuck 20 side and the upper insulator 40 so that the side plasma is generated. One end of the upper gas supply passage 70 is connected to an external process gas supply source 62, as shown in FIG.

Next, the lower gas supply path 80 is formed on the moving chuck 30 to supply process gas to the space between the substrate W and the moving chuck 30. That is, the lower gas supply path 80 is formed through the moving chuck 30, as shown in FIG. 1, and supplies process gas to the space between the substrate W and the moving chuck 30. The back plasma for etching the back surface of the substrate is formed by the supplied process gas. Of course, as shown in FIG. 1, the lower gas supply path 80 may also be formed in the substrate holder 50 to supply the process gas to the side plasma formation space. One end of the lower gas supply path 80 is connected to a process gas supply source 82 provided outside to receive the process gas.

Meanwhile, the lower gas supply path 80 may have a multilayer structure as shown in FIG. 4. In the case of having a multilayer structure as described above, the process gas is uniformly diffused while passing through each layer, thereby providing the process gas uniformly in the direction of the substrate.

Next, as shown in FIG. 1, the RF applying means 90 is connected to the electrostatic chuck 20 to apply RF power. Although FIG. 1 shows that the RF applying means 90 is connected to the electrostatic chuck 20, the RF applying means may be connected to the mobile chuck to apply RF power to the mobile chuck. The mobile chuck is grounded when RF power is applied to the electrostatic chuck, and the electrostatic chuck is grounded when RF power is applied to the mobile chuck.

On the other hand, the substrate cleaning apparatus 1 according to the present embodiment is preferably further provided with a lift pin (100). As shown in FIG. 1, the lift pin 100 is formed to penetrate the moving chuck 30 and is driven in an up and down direction to receive a substrate charged from the outside. The lift pins 100 are connected to the lift pin assembly 102 and driven simultaneously, and the lower surface of the substrate loaded by the end effector (not shown) while the substrate W is loaded into the vacuum chamber 10. It receives the substrate from the end effector. Then, the substrate W is transferred to the electrostatic chuck 20.

In addition, in the process of unloading the substrate, the substrate W is supported from the electrostatic chuck by supporting the lower portion of the substrate W gripped by the electrostatic chuck 20. The substrate is then delivered to the end effector entering through the substrate entrance 12. Therefore, the loading and unloading process of the substrate is smoothly performed by the lift pin 100.

An upper cooling passage 24 may be further formed in the electrostatic chuck 20. As shown in FIG. 1, the upper cooling channel 24 is formed inside the electrostatic chuck 20 so that the cooling medium is circulated and cools the substrate W gripped by the electrostatic chuck during the process. do.

In addition, a lower cooling passage 34 may be further provided inside the moving chuck 30 to cool the moving chuck by circulating a cooling medium. The lower cooling passage 34 functions to cool the moving chuck 30 heated by the plasma in the process.

Next, a baffle 110 may be further provided between the lower insulator 60 and the sidewall of the vacuum chamber 10. The baffle 110 serves to increase the uniformity of the process by uniformly flowing the process gas and the like discharged to the gas outlet 16 formed under the vacuum chamber 10. The baffle 110 may be arranged to be driven in the vertical direction for the sake of completeness of the process. This is because the process conditions can be changed by adjusting the height of the baffle 110.

Hereinafter, a process of simultaneously cleaning the side and bottom surfaces of the substrate using the substrate cleaning apparatus 1 according to the present embodiment will be described.

First, the substrate is brought into the vacuum chamber 10 using the end effector. Then the lift pin 100 is raised to receive the substrate from the end effector. The end effector then retracts out of the vacuum chamber, closing the gate valve 14 and adjusting the pressure inside the chamber to suit process conditions.

Then, the lift pin 100 is raised or the electrostatic chuck 20 is lowered to bring the electrostatic chuck 20 and the substrate W into contact with each other, and a DC power is applied to the electrostatic chuck 20 to generate a constant power. Let's do it. The substrate is then fixed to the electrostatic chuck by the electrostatic force. When the substrate is fixed to the electrostatic chuck 20, the lift pin 100 is lowered.

In the state where the substrate W is gripped by the electrostatic chuck 20, the distance between the electrostatic chuck 20 and the moving chuck 30 is adjusted so that a space suitable for generating plasma is formed on the side and the back side of the substrate. And the process gas is supplied to the side surface and the back side of the substrate through the upper gas supply path 70 and the lower gas supply path 80. When RF power is applied to the electrostatic chuck 20 in this state, as shown in FIG. 3, the side plasma P1 and the back plasma P2 are generated to simultaneously clean the side and the back surface of the substrate.

Here, the side plasma P1 is a plasma formed in the space formed by the side surface of the electrostatic chuck 20, the upper insulator 40, and the substrate holder 50, as shown in FIG. 3. The side surface and the edge portion of the substrate W are cleaned by P1.

Also, as shown in FIG. 3, the back plasma P2 is a plasma formed in the space between the back surface of the substrate W and the moving chuck 30. The back is cleaned.

When the cleaning process is completed, the substrate is taken out of the vacuum chamber in the reverse order of the above-described substrate loading.

1 is a cross-sectional view showing the structure of a substrate cleaning apparatus according to an embodiment of the present invention.

2 is an enlarged view of a portion of a substrate cleaner according to an embodiment of the present invention.

3 is a state diagram in which plasma is generated in a substrate cleaning apparatus according to an embodiment of the present invention.

4 is a cross-sectional view showing the structure of a moving chuck according to an embodiment of the present invention.

Claims (9)

A substrate cleaning apparatus for cleaning a lower surface and a side surface of a substrate by generating plasma on the side surfaces and the lower surface of the substrate while the upper surface of the substrate is gripped. The method of claim 1, wherein the substrate cleaning apparatus, A vacuum chamber capable of keeping the interior in a vacuum state; An electrostatic chuck disposed on an upper side of the vacuum chamber and contacting the upper surface of the substrate to expose the edge of the substrate; A mobile chuck disposed below the vacuum chamber and provided to be driven in an up and down direction; An upper insulator disposed on the side of the electrostatic chuck and spaced apart from the side surface of the electrostatic chuck at a predetermined interval; A substrate holder disposed on a side of the moving chuck and surrounding the substrate such that the bottom and side surfaces of the substrate fixed to the electrostatic chuck are exposed; A lower insulator disposed outside the substrate holder and opposed to the upper insulator; An upper gas supply path formed in the electrostatic chuck to supply a process gas to a space between the side surface of the electrostatic chuck and the upper insulator; A lower gas supply path formed in the moving chuck to supply process gas to a space between the substrate and the moving chuck; And an RF applying means formed at one of the electrostatic chuck or the mobile chuck to apply RF power. The method of claim 2, And a lift pin formed through the moving chuck and driven in an up and down direction to receive a substrate loaded from the outside. The method of claim 2, wherein the electrostatic chuck, The side surface of the substrate cleaning apparatus characterized in that the step is formed by the thickness of the upper insulator so that the electrostatic chuck, the upper insulator, the substrate holder and the lower insulator are in close contact to form a donut-shaped space. The method of claim 2, The inside of the electrostatic chuck substrate cooling apparatus further comprises an upper cooling passage for circulating a cooling medium to cool the electrostatic chuck. The method of claim 2, The inside of the moving chuck substrate cooling apparatus further comprises a lower cooling passage for circulating a cooling medium to cool the moving chuck. The method of claim 2, And the electrostatic chuck is arranged to be driven in an up and down direction. The method of claim 2, And a baffle between the lower insulator and the sidewall of the vacuum chamber. The method of claim 8, The baffle is substrate cleaning apparatus, characterized in that the drive is arranged in the vertical direction.

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