KR20210066346A - Sealing structure for rotary vaccum process chamber - Google Patents

Abstract

The present invention relates to a sealing structure for a rotary vacuum process chamber used in a semiconductor manufacturing process, and more specifically, to a sealing structure for a rotary vacuum process chamber, which is configured such that an upper chamber and a lower chamber are divided and mutually rotated. The complex sealing structure is applied to a vacuum process chamber, which is divided into an upper chamber and a lower chamber coupled with each other to rotate relative to each other. The complex sealing structure includes: a solid seal provided on an outermost side of the vacuum process chamber; and a magnetic fluid seal provided between the solid seal and an inner space of the vacuum process chamber. According to the complex sealing structure described above, it is advantageously applied particularly to a rotary vacuum process chamber by blocking fine particles generated during the operation using the magnetic fluid seal while realizing a high vacuum by the solid seal, thereby improving the process yield and overcoming the process limitations related to the degree of vacuum.

Description

Sealing structure of rotary vacuum process chamber {SEALING STRUCTURE FOR ROTARY VACCUM PROCESS CHAMBER}

The present invention relates to a sealing structure of a vacuum process chamber used in a semiconductor manufacturing process, and more particularly, to a sealing structure of a rotary vacuum process chamber in which an upper chamber and a lower chamber are divided and rotated with each other.

In the semiconductor manufacturing process, various types of vacuum process chambers are used to process substrates. Typically, an atomic layer deposition apparatus for controlling thin films used in semiconductor devices in atomic units is used according to the trend of high integration of semiconductor devices. In addition, an atomic layer etching (ALE) apparatus, a chemical vapor deposition (CVD) apparatus, etc. are being used.

Meanwhile, in terms of productivity of the semiconductor manufacturing process, such a vacuum process chamber may be divided into a time division type and a space division type. In a temporal process chamber, a large amount of substrates to be processed are accommodated in a single chamber and processed simultaneously over several days, but there is a problem in that the yield is significantly reduced due to non-uniform gases or temperature gradients. In order to replace this, the concept of a spatially divided process chamber in which the interior of the process chamber is spatially divided according to process conditions is newly emerging.

More specifically, the concept of a temporal ALD process chamber is a process chamber that implements the time-division ALD method, which is an original ALD process developed in the early 1970s, and after placing the base material or substrate to form a thin film in the process space. In order to form a chemical adsorption reaction on the surface of the substrate, it is a method of forming an ALD thin film by repeatedly performing the process of supplying (pulse) and purging (purge) of the reactive gas without overlapping time. The problem with the time-shared process chamber is that the actual thin film formation process time is only 1 to 2% of the total process time, and most of the time is spent discharging the input reaction gas. For this reason, because of the inherently slow process characteristics of the time-division type ALD process chamber, it is the biggest reason that the mass production process consists of a batch type that processes 50 to 100 substrates at once in a large amount. The concept of a spatial ALD process chamber was first applied to a patent by Suntola and Antson in the United States in 1977. Each reaction gas is continuously separated from each other in the process space without dividing the process time. It is supplied and a thin film is formed on the surface as the substrate passes through the separated regions. At this time, the spatially separated reactive gases must be completely separated from each other by a blocking gas to prevent mixing with each other. Since a thin film is formed in the process space over the entire process time, the productivity of the process chamber is improved.

There are various methods for the space division type process chamber, an example of which is an atomic layer deposition apparatus according to Korean Patent No. 10-1301471, in which an upper chamber and a lower chamber are divided and provided in a mutually rotating form. It is disclosed as provided in. The space division type process chamber according to the patent is divided into an upper chamber and a lower chamber, and the lower chamber rotates along the rail, so that the upper chamber and the lower chamber rotate relative to each other. In this case, despite the relative rotational displacement between the upper chamber and the lower chamber in a horizontal plane, the coupling part of the lower chamber outside the upper chamber is sealed by a magnetic fluid sealing part in order to maintain the inside of the process chamber in a vacuum.

In the case of the rotary vacuum process chamber according to the Republic of Korea Patent No. 10-1301471, it is expected to have high productivity and good yield under certain process conditions. However, the divided upper chamber and lower chamber are simply magnetic fluid sealing. In the process requiring high vacuum, the product yield is significantly lowered, limiting its application because there is a constant risk of contamination of the process chamber due to the inflow of magnetic fluid from the sealing part during the initial process of forming a vacuum inside the process chamber. There is a situation.

Patent No. 10-1301471

An object of the present invention is to provide a complex sealing structure that is applied to a rotary vacuum process chamber used in a substrate processing process such as a semiconductor, and that can effectively prevent contamination inside the process chamber while implementing a high vacuum. will be.

The subject matter of the present invention related to the above-mentioned problem is the same as described in the claims as follows.

The composite sealing structure according to the present invention is a composite sealing structure applied to a vacuum process chamber divided into an upper chamber and a lower chamber coupled in a relatively rotational manner, comprising: a solid seal provided at the outermost side of the vacuum process chamber; and a magnetic fluid seal provided between the solid seal and the inner space of the vacuum process chamber.

The upper chamber may be coupled such that an outer wall thereof is accommodated in the lower chamber. In this case, the solid seal is provided between the outer wall of the upper chamber and the inner wall of the lower chamber, and the magnetic fluid seal is the upper chamber of the upper chamber. It may be provided between the lower surface and the upper surface of the lower chamber.

A friction reducing coating may be provided on the surface of the solid seal. In this case, the friction reducing coating may be PTFE.

Optionally, the composite sealing structure may further include a bypass for the magnetic fluid seal.

In this case, the lower chamber has one or more ring-shaped trenches formed in the circumferential direction from the upper surface edge to fill the magnetic fluid, and the upper chamber has a tip inserted and accommodated in the trench, The bypass may be formed in the tip.

Optionally, the bypass of the composite sealing structure may further include a valve for opening and closing it.

The solid seal may be an O-ring seal, a lip seal, or a polygonal seal.

The lower chamber is provided with one or more ring-shaped trenches formed in the circumferential direction from the edge of the upper surface so that the magnetic fluid can be filled, and the trench located closest to the inner space of the vacuum process chamber is a buffer trench that is not filled with the magnetic fluid. may be provided.

The vacuum process chamber may constitute a part of an ALD, ALE, or CVD apparatus.

As described above, according to the complex sealing structure according to the present invention, high vacuum is realized by the solid seal and fine particles generated in the operation process are blocked using the magnetic fluid seal, which is particularly advantageously applied to the rotary vacuum process chamber. At the same time, it is possible to effectively overcome the process limitations related to the degree of vacuum.

1 is a block diagram of an ALD apparatus equipped with a process chamber to which a complex sealing structure of the present invention is applied.
2 is a cross-sectional view of a composite sealing structure for a rotary vacuum process chamber according to a first embodiment of the present invention;
3 is a cross-sectional view of a composite sealing structure for a rotary vacuum process chamber according to a second embodiment of the present invention;

Hereinafter, the present invention will be described in detail through examples. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention. Accordingly, since the configuration of the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent all the technical spirit of the present invention, various equivalents that can be substituted for them at the time of filing of the present invention It should be understood that there may be variations and variations. On the other hand, the same or similar reference numbers are given to the same or equivalent in the drawings, and in the entire specification, when it is said that a certain part "includes" a certain element, unless otherwise specifically stated, other elements It does not exclude, but means that other components may be further included.

1 shows a schematic configuration diagram of an ALD apparatus 1 to which a rotary vacuum process chamber 10 according to an embodiment of the present invention is applied. 2 is a cross-sectional view of a composite sealing structure 500 for the rotary vacuum process chamber 10 according to the first embodiment of the present invention.

First, in FIG. 1 , the process chamber 10 provided in the ALD apparatus 1 is exemplified as the process chamber 10 to which the complex sealing structure 500 of the present invention is applied, but a process chamber used for substrate processing in a semiconductor process. As (10), if the process chamber 10 requiring a high vacuum is applied without any particular limitation, the type of device equipped with the vacuum process chamber 10 is irrespective of, for example, a CVD device, an ALE (Atomic Layer Etching) device, etc. It can also be applied to other types of semiconductor processing equipment.

In addition, the process chamber 10 to which the complex sealing structure 500 of the present invention is applied is a space division type process chamber 10 in which the inner space is spatially divided according to process conditions. The process of the ALD apparatus 1 of FIG. 1 . As exemplified by the chamber 10, in particular, it is intended that the upper chamber 100 and the lower chamber 200 are divided into a structure in which both are combined in a relatively rotating manner. Accordingly, in the case of the present invention, the divided upper chamber 100 and the lower chamber 200 have a mutually rotatable structure and a higher degree of vacuum is a fundamental task.

Meanwhile, in the process chamber 10 of FIG. 1 , the relative rotational operation of the upper chamber 100 and the lower chamber 200 is similar to the process chamber provided in the ALD apparatus according to Korean Patent No. 10-1301471, the lower chamber ( 200) is supported by a rail (not shown) provided thereunder and is illustrated as being rotated by a driving means such as a driving gear 300 (refer to FIG. 2). In a state in which the upper chamber 100 and the lower chamber 200 are vertically coupled, an empty space therein constitutes a process area PC, and a workpiece to be processed, such as a wafer, is supplied to the process area PC. do. Meanwhile, in the embodiment, the process region PC is exemplified as being formed substantially at the same height as the gap regions PA and PB, but for example, the process region PC has a step difference from the gap regions PA and PB. It may be designed to be formed in a high position. When the process region PC is formed with a step higher than the gap regions PA and PB, the magnetic fluid used in the magnetic fluid seal 520 constituting a part of the composite sealing structure 500 of the present invention ( The possibility that 522 is introduced into the process region PC can be further reduced, which is advantageous.

Since each of the upper chamber 100 and the lower chamber 200 has a donut shape in the embodiment of FIG. 1 , a compound sealing structure described for the outside of the donut-shaped process chamber 10 in the embodiments of the present invention below It goes without saying that 500 may be applied to the inside of the donut-shaped process chamber 10 in the same way.

Referring to FIG. 2 , the composite sealing structure 500 according to the present invention includes a solid seal 510 ; It is characterized in that the magnetic fluid seal 520 is provided as a pair. In this case, the solid seal 510 is provided on the outermost side of the process chamber 10 as a main sealing part for primarily shielding the process region (PC) from the external region, and the magnetic fluid seal 520 is the solid seal ( As an auxiliary sealing part for the 510 , it is provided between the process region PC corresponding to the inner space of the vacuum process chamber 10 and the solid seal 510 .

The solid seal 510 is a main sealing part for primarily shielding the process area PC from the outside. The solid seal 510 is provided on the outermost side of the process chamber 10 as a solid seal to enable high vacuum formation in the process region PC. To this end, the solid seal 510 is provided as an elastic member to enable rotation between the upper chamber 100 and the lower chamber 200 while exhibiting airtightness by closely adhering to the contact portion between the upper chamber 100 and the lower chamber 200 . can be The solid seal 510 may be provided in the form of, for example, an O-ring seal, a lip seal, or a polygonal seal.

Optionally, the surface of the solid seal 510 is preferably provided with a friction reducing coating. It is advantageous in terms of airtightness that the gap between the upper chamber 100 and the lower chamber 200 is sealed by pressing the solid seal 510 as much as possible, but in this case, the rotational operation between the upper chamber 100 and the lower chamber 200 is It may be disturbed due to frictional force due to excessive adhesion by the solid seal 510 . The friction-reducing coating is provided for smooth rotational operation by alleviating this frictional force, and may be typically made of PTFE.

The magnetic fluid seal 520 is provided between the solid seal 510 and the process area PC corresponding to the inner space of the vacuum process chamber 10 as an auxiliary sealing part for the solid seal 510 to provide a vacuum process. It serves to prevent the inflow of fine particles generated during the rotational operation of the chamber 10 . Specifically, the magnetic fluid seal 520 is composed of a liquid magnetic fluid 522 and a permanent magnet 524 for preventing separation by applying a magnetic force to the magnetic fluid 522, and the liquid magnetic fluid 522 is In the process of relative rotation between the upper chamber 100 and the lower chamber 200, fine particles generated from the solid seal 510, etc. are prevented from flowing into the process area PC through the gap areas PA and PB. .

As described above, in the double composite sealing structure 500 of the solid seal 510 and the magnetic fluid seal 520, the installation sequence is sequentially installed from the outside in the process chamber 10 direction in consideration of the roles shared by each. On the other hand, the specific form in which the solid seal 510 and the magnetic fluid seal 520 constituting the double complex sealing structure 500 are installed at the contact surface between the upper chamber 100 and the lower chamber 200 is designed in consideration of sealing properties. It is preferable to be determined based on the shape and coupling structure of the upper chamber 100 and the lower chamber 200, but from the viewpoint of maximizing the operation and role of the solid seal 510 and the magnetic fluid seal 520, respectively. . Specifically, the shape of the upper chamber 100 and the lower chamber 200 may be advantageous in terms of hermeticity to be coupled in such a way that the outer wall of the upper chamber 100 is accommodated in the lower chamber 200 as in the embodiment.

In this case, the solid seal 510 is provided between the outer wall of the upper chamber 100 and the inner wall of the lower chamber 200 , a part of which is accommodated in the mounting groove 110 provided in the outer wall of the upper chamber 100 . and the remaining exposed portion is elastically pressed and adhered to the inner wall of the lower chamber 200 to secure high vacuum airtightness to the inside of the process chamber 10 . The mounting groove 110 and the solid seal 510 may be provided in plurality.

In addition, in the coupling structure between the upper chamber 100 and the lower chamber 200 according to the embodiment, the magnetic fluid seal 520 is provided between the lower surface of the upper chamber 100 and the lower surface of the lower chamber 200 , The fluid 522 is accommodated in one or more trenches 210 (trench) provided in the lower chamber 200, and the permanent magnet 524 is mounted on the other side of the trench 210 at the bottom of the lower chamber 200. is installed The trench 210 for accommodating the magnetic fluid 522 is ring-shaped and may be provided in plurality of one or more so that the airtightness by the magnetic fluid seal 520 can be increased. The upper chamber 100 has a tip 120 inserted and accommodated in the trench 210 is formed, and this tip 120 promotes a binding force between the upper chamber 100 and the lower chamber 200 to guide the rotational operation. At the same time, airtightness in the process chamber 10 is better secured together with the magnetic fluid 522 filled and accommodated in the trench 210 to a predetermined height. The liquid magnetic fluid 522 is filled in the trench 210 to an appropriate height, and is stably accommodated in the trench 210 by the magnetic force applied from the permanent magnet 524 installed on the outer bottom surface of the lower chamber 200. can

In this case, the plurality of trenches 210 provided in the lower chamber 200 are basically provided with the intention of accommodating the magnetic fluid 522, but optionally the trenches 210 located closest to the inner process region PC. The magnetic fluid 522 may be provided as a buffer trench 220 not filled (buffer). The buffer trench 220 serves to prevent or minimize the inflow of the magnetic fluid stored in the outer trench 210 into the process region PC by any chance due to a slight pressure difference occurring during the initial vacuum forming process or the chamber operation process. do.

Optionally, the composite sealing structure 500 may optionally further include a bypass 600 for the magnetic fluid seal 520 . The bypass 600 is provided for the purpose of preventing the magnetic fluid 522 from contaminating the common area, thereby reducing the product yield. see. Specifically, in the composite sealing structure 500 according to the present invention, the magnetic fluid seal 520 is an auxiliary sealing part, and in particular, the solid seal 510 is formed during the rotation between the upper chamber 100 and the lower chamber 200. Although it is provided to prevent fine particles generated by wear from being introduced into the process region by the vacuum suction force, the magnetic fluid 522 causes the magnetic fluid 522 to enter the process chamber due to a sudden pressure difference in the initial process of forming a high degree of vacuum inside the process chamber 10 . (10) There is a possibility of inadvertently flowing into the internal process area (PC). In this case, the bypass 600 prevents the magnetic fluid 522 from flowing into the process region PC by buffering the sudden pressure difference in the initial vacuum forming process. This bypass 600 is provided for the purpose of minimizing the transmission of high vacuum negative pressure to the magnetic fluid seal 520 , and the method may be implemented in various ways.

In the embodiment of FIG. 2 in relation to the provision form of the bypass 600 , the bypass 600 is provided in a form in which a hole 122 is machined in the tip 120 (tip) inserted and received in the trench 210 . is exemplified to be In this case, the machining position of the hole 122 with respect to the tip 120 is determined to be placed on the surface of the magnetic fluid 522 in a state accommodated in the trench 210 . The upper chamber 100 and the lower chamber 200 are generated between the gap regions PA and PB and the process regions PC (PC) during the initial vacuum formation process by the bypass 600 in the form of the hole 122 . Since the abrupt pressure difference is effectively buffered, the magnetic fluid 522 accommodated in the trench 210 may be effectively prevented from being sucked into the process region PC.

In the embodiment of FIG. 3 as another embodiment of the form of providing the bypass 600 , the bypass 600 is provided as a detour line 124 in the form of a conduit formed in the body of the upper chamber 100 . can be In particular, the bypass 600 in the form of the detour line 124 of FIG. 3 may selectively further include valves 612 and 614 for opening and closing them. In the case of the bypass 600 in the form of the hole 122 of FIG. 2 , since it is always in an open state during the operation of the process chamber 10 , there is still a possibility that fine particles may be introduced through this, although it is insignificant. The bypass 600 in the form of the tour line 124 can be opened and closed by the valves 612 and 614 during the initial vacuum formation process, thereby fundamentally solving this problem. That is, pumping is performed for vacuum formation in a state in which the two valves 612 and 614 are opened only during the initial vacuum formation that needs to buffer the pressure difference, and when the initial vacuum formation process is completed, the two valves 612, 612, 614) completely blocks the possibility of influx of fine particles generated during the operation process.

As described above, according to the composite sealing structure 500 according to the present invention, a high vacuum is realized by the solid seal 510 and fine particles generated in the operation process are blocked using the magnetic fluid seal 520 , so that in particular a rotary vacuum It is advantageously applied to the process chamber 10 to improve the process yield and at the same time effectively overcome the process limitations related to the degree of vacuum.

The above description relates to specific embodiments of the present invention. As described above, the embodiments according to the present invention are disclosed for the purpose of explanation and are not to be construed as limiting the scope of the present invention, and those of ordinary skill in the art will not depart from the essence of the present invention. It should be understood that various changes and modifications are possible. Accordingly, all such modifications and variations are to be understood as falling within the scope of the invention disclosed in the claims or equivalents thereof.

1: ALD device
10: vacuum process chamber
100: upper chamber
110: mounting groove
120: tip
122: Hall
124: Detour line
200: lower chamber
210: trench
220: buffer trench
300: drive gear
500: composite sealing structure
510: solid seal (O-ring seal)
520: magnetic fluid seal
522: magnetic fluid
524: permanent magnet
600: bypass
612, 614: valve

Claims (10)

A complex sealing structure applied to a vacuum process chamber divided into an upper chamber and a lower chamber coupled in a relatively rotational manner, comprising: a solid seal provided at the outermost side of the vacuum process chamber; and a magnetic fluid seal provided between the solid seal and the inner space of the vacuum process chamber. According to claim 1, wherein the outer wall of the upper chamber is coupled to be accommodated in the lower chamber, the solid seal is provided between the outer wall of the upper chamber and the inner wall of the lower chamber, the magnetic fluid seal is the upper chamber A composite sealing structure for a rotary vacuum process chamber, characterized in that it is provided between the lower surface of the chamber and the upper surface of the lower chamber. [2] The composite sealing structure for a rotary vacuum process chamber according to claim 1, wherein a friction-reducing coating is provided on the surface of the solid seal. The composite sealing structure for a rotary vacuum process chamber according to claim 3, wherein the friction reducing coating is PTFE. The composite sealing structure for a rotary vacuum process chamber according to claim 1, further comprising a bypass for the magnetic fluid seal. According to claim 5, wherein the lower chamber is provided with at least one ring-shaped trench (trench) formed in the circumferential direction from the upper surface edge to fill the magnetic fluid, the upper chamber has a tip inserted and received in the trench (tip) and, wherein the bypass is formed in the tip, a composite sealing structure for a rotary vacuum process chamber. The complex sealing structure for a rotary vacuum process chamber according to claim 5, further comprising a valve for opening and closing the bypass. The composite sealing structure according to claim 1, wherein the solid seal is an O-ring seal lip seal or a polygonal seal. According to claim 1, wherein the lower chamber is provided with one or more ring-shaped trenches formed in the circumferential direction from the upper surface edge so that the magnetic fluid can be filled, the trench located closest to the inner space of the vacuum process chamber is a magnetic fluid A composite sealing structure for a rotary vacuum process chamber, characterized in that it is provided as an unfilled buffer trench. The composite sealing structure for a rotary vacuum process chamber according to claim 1, wherein the vacuum process chamber forms a part of an ALD, ALE or CVD apparatus.

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