Chamber sealing member

A reaction chamber including an upper region for processing a substrate, a lower region for loading a substrate, a susceptor movable within the reaction chamber, a first sealing member positioned on a perimeter of the susceptor, a second sealing member positioned between the upper region and the lower region, wherein the first and second sealing members are selectively engaged with one another to limit communication between the upper region and the lower region.

BACKGROUND

Thin film deposition reaction chambers are generally manufactured with a single chamber or a dual chamber. In the dual chamber arrangement, the two chambers may be oriented with one chamber vertically above the second chamber. The upper chamber is used for the processing of the substrate, while the lower chamber is used for substrate loading and unloading. A regularly occurring issue in dual chamber reactors is deposition particles coating the lower chamber walls and requiring more frequent chamber cleaning.

It can also be difficult to heat a substrate being processed in a substrate processing tool. Variation in substrate heating may lead to within-substrate temperature variations. Such within-substrate temperature variations may lead to within-substrate processing non-uniformities. In some settings, substrates exhibiting such non-uniformities may produce defective devices. Further, deposition product may be deposited in the lower processing chamber, leading to reduced temperatures in the reaction chamber and therefore increased power consumption to overcome the inadequate heating. Additionally, the build-up of deposition product in the chamber can lead to premature chamber cleaning requirements and increased costs.

SUMMARY

Aspects of this document relate to reaction chambers for processing substrates. In one aspect, a reaction chamber including an upper region for processing a substrate, a lower region for loading a substrate, a susceptor movable within the reaction chamber, a first sealing member positioned on a perimeter of the susceptor, a second sealing member positioned between the upper region and the lower region, wherein the first and second sealing members are selectively engaged with one another to limit communication between the upper region and the lower region.

In an implementation, the first sealing member may be removably positioned on the susceptor. The second sealing member may be removably positioned between the upper region and the lower region. The reaction chamber may further include a gap between a perimeter of the susceptor and the first sealing member. The gap may decrease when the reaction chamber is at a processing temperature. The first sealing member may travel vertically with the susceptor. The reaction chamber may further include a showerhead in the upper region, wherein the second sealing member is secured between the showerhead and the first sealing member. A processing gas may travel between the first sealing member and the second sealing member when the susceptor is in a processing position.

The first sealing member and the second sealing member may be composed of quartz. The sealing member may be self-centering on the susceptor. The first sealing member may further include at least one protrusion extending upward. The second sealing member may further include at least one protrusion extending downward. The first sealing member at least one protrusion and the second sealing member at least one protrusion may be nested together when the susceptor is in a processing position. A tortuous path may be defined between the first sealing member and the second sealing member. The first sealing member and the second sealing member at least one protrusions may each further include three protrusions.

The second sealing member may be flexible and the first sealing member may deflect the second sealing member when the susceptor is in a processing position. The second sealing member may be secured to the reaction chamber within the lower region. The second sealing member may further include a plurality of notches. The second sealing member may further include a plurality of radially aligned slits. The second sealing member may further include two second sealing members with radially aligned slits positioned offset from each other.

In another aspect, a reaction chamber isolation device includes a first sealing member movable within a reaction chamber and positionable on a susceptor, a second sealing member positionable within the reaction chamber between an upper region and a lower region, and wherein the first and second sealing members are selectively engageable with one another to limit communication between the upper region and the lower region.

In an implementation, the first sealing member may further include at least one protrusion extending upward and the second sealing member may further include at least one protrusion extending downward. The first sealing member at least one protrusion and the second sealing member at least one protrusion may be nested together when the susceptor is in a processing position. A tortuous path may be defined between the first sealing member and the second sealing member. The second sealing member is flexible and the first sealing member deflects the second sealing member when the susceptor is in a processing position.

DETAILED DESCRIPTION

The present aspects and implementations may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware or software components configured to perform the specified functions and achieve the various results. For example, the present aspects may employ various sensors, detectors, flow control devices, heaters, and the like, which may carry out a variety of functions. In addition, the present aspects and implementations may be practiced in conjunction with any number of processing methods, and the apparatus and systems described may employ any number of processing methods, and the apparatus and systems described are merely examples of applications of the invention.

FIGS. 1 and 2illustrate views of a reaction chamber20in a loading/unloading position and a processing position, respectively. Reaction chamber20may include an upper region22and a lower region24, which may be separated by an interface plate26. In general, processing occurs within the upper region22while substrate loading and unloading occurs within lower region24. A susceptor28includes a substrate mounting surface30and is connected to a vertically movable elevator32for displacing the susceptor between the substrate loading position and the substrate processing position. A substrate34may be positioned on substrate mounting surface30and may be located in a processing region36when positioned susceptor28is moved upwards in the direction of arrows38as shown inFIG. 2with a showerhead40defining an upper surface of the processing region. As will be discussed in greater detail below, a first sealing member42may be positioned on and removable from susceptor28, while a second sealing member44may be positioned between upper region22and lower region24. Specifically, the second sealing member44may be positioned to rest at least partially on interface plate26or may connected to the interface plate or any other suitable portion of reaction chamber20without departing from the spirit and scope of the present disclosure.

Referring now toFIGS. 3 and 4, susceptor28is shown with the first sealing member42and the second sealing member44attached and detached, respectively. Susceptor28includes an outer surface46and a ledge48extending outward of the outer surface46. Ledge48may be positioned generally near a lower surface50of the susceptor and is arranged to receive first sealing member42thereon. First sealing member42includes a lower portion52and an upper portion54, with the lower portion being positioned generally radially inward of the upper portion54in one implementation, although any suitable arrangements may be utilized. Lower portion52may include a bottom surface56arranged to rest on ledge48of the susceptor28when the first sealing member is being used to separate the upper region22and the lower region24. Upper portion54may include an upper surface58which assists with sealing by forming a portion of a tortuous path as will be discussed below in greater detail. Further, lower portion52may include an inner surface60and an outer surface62, while upper portion54may include an inner surface64and an outer surface66. Accordingly, upper portion54functions as a protrusion by extending upward from lower portion52as part of the first sealing member42.

Second sealing member44may include an outer mounting ring68having a bottom surface70, with the outer mounting ring68partially defining a channel72. Bottom surface70is generally in contact with interface plate26when the second sealing member44is being used to provide separation between the upper region22and the lower region24. Outer ring68may also include a plurality of notches74which can be used to insure constant and consistent alignment with the other components in the reaction chamber. The second sealing member44may also include an outer protrusion76and an inner protrusion78generally extending downward. The outer protrusion76may include an outer surface80and an inner surface82, while inner protrusion78may include an outer surface84and an inner surface86. In this arrangement, outer surface80of outer protrusion76further defines channel72in second sealing member44, while outer surface84of inner protrusion78and inner surface82of outer protrusion76at least partially define a channel88for receiving upper portion54of the first sealing member42when the susceptor28travels upwards into the processing position. In one implementation, inner protrusion78and outer protrusion76may extend downward beyond bottom surface70since the bottom surface is positioned on an interface plate within the reaction chamber. In another implementation, the inner protrusion78may extend downwards a shorter distance than outer protrusion76. A person of skill in the art will immediately appreciate that a number of changes can be made to the sealing members without departing from the spirit and scope of the disclosure.

FIG. 5illustrates an enlarged sectional view of the first sealing member42nested within a portion of second sealing member44when susceptor28is moved upwards into a processing position. Specifically, upper portion54of first sealing member42is shown positioned within channel88formed at least partially between outer protrusion76, inner protrusion78, and a wall90. A gas path indicated by arrows92is generally less susceptible to transmitting gases from within the upper region22to the lower region24due to the tortuous path created by the first and second sealing members. The gas must travel through the tortuous path defined by a gap94formed between inner surfaces60and64of first sealing member42and an outer surface46of susceptor28, through channel88with upper portion54positioned therein, and finally into the lower region24. The width and lengths of the tortuous path may be optimized to permit a variable amount of communication between the upper and lower regions, or no communication between the upper and lower regions depending on the processing requirements.

Both the first sealing member42and the second sealing member44may be composed of quartz, rutile, yttria, zirconia, Inconel, titanium, beryllium-copper, or any other suitable material. In some implementations, the first and second sealing members may increase or decrease in size depending on the temperature within reaction chamber20. For example, when first sealing member42is composed of quartz, the first sealing member42tends to expand or grow when the temperature within the reaction chamber increases and particularly when the temperature increases near 400 degrees C. Further, when the first sealing member42grows, gap94may be decreased and the first sealing member42provides a self-centering function on the susceptor28.

Referring now toFIG. 6, another aspect of the first sealing member42and the second sealing member44are shown in section with the first sealing member42formed integral with susceptor28. Specifically, a middle protrusion96is included in second sealing member44in addition to protrusions98,100, and102extending upward from susceptor28. In this arrangement, ledge48of the first aspect has been replaced with three protrusions98,100, and102which are nested within channels88formed between each of the various protrusions extending downward from the second sealing member44. In this arrangement, gas path92requires following a tortuous path through a plurality of channels88having protrusions98,100, and102therein to further restrict the gas flow path. Accordingly, even less gas flow communication is obtained between upper region22and lower region24when additional protrusions are included in the tortuous path. Thus it is seen that any number of protrusions may be utilized in the first and second sealing members depending on the restrictions of gas flow required by the tool or process. Further, the distances between the protrusions and open spaces there between may be optimized as may be necessary. Finally, the protrusions in the first sealing member42may be formed as part of a separate removable piece or may be formed integral with the susceptor, while the protrusions of the second sealing member44may be formed as a separate removable piece or may be formed integral to the reaction chamber20or an interface plate as may be appropriate.

Referring now toFIGS. 7-15, another aspect chamber sealing device is shown, although the remaining components are the same and/or similar. A first sealing member104is removably positionable on ledge48of susceptor28, while a second sealing member106is generally positioned within lower region24and removably attached to interface plate26. Specifically, second sealing member106may be removably secured to the interface plate26with a mounting plate108and a plurality of bolts110. The second sealing member106may be secured with the mounting plate at an outer perimeter112of a spring sealing member114in either lower region24or upper region22. The spring sealing member114may also include an inner perimeter116which may be deflected by first sealing member104when the susceptor28is moved in the direction associated with arrows38until a processing position is reached.

Referring toFIGS. 9 and 11, spring sealing members114are shown with notches118on the outer perimeter112of the spring sealing member. In one implementation, 24 notches are included and a bolt is used to secure the spring sealing member to the mounting plate108at each of the notches and between the interface plate26and the mounting plate108. As also seen inFIG. 11, a plurality of slits120may be included around the inner perimeter116of the spring sealing member114to provide a minimal and controlled transfer rate between the upper and lower regions of the reaction chamber. In one implementation, the slits120may be radially aligned along the inner perimeter116and may include approximately 100 slits, or any other suitable number. It will be appreciated by a person of skill in the art that any suitable number of notches or slits may be utilized so long as the spring sealing member is properly secured and the gas flow rate between the upper region and the lower region is controlled.

FIGS. 7,8and10illustrate views of spring sealing member114in an unbiased position (FIG. 7) and a biased or deflected position (FIGS. 8 and 10). In the biased or deflected views, spring sealing member114is resiliently bent upwards by a top surface122of the first sealing member104. Specifically, top surface122is positioned on a flat portion of shelf124separated from ledge48by spacing portion126. In this arrangement, spring sealing member114is bent upwards by contact at top surface122and thereby limits communication between the upper region and the lower region. The area between a flow control ring128, spring sealing member114, susceptor28, and gap94may collect some portion of a processing or purge gas, but this may ultimately be dissipated by vacuum measures, purging, or the disconnection between the first and second sealing members when the substrate is unloaded.

Referring now toFIGS. 11-15, two spring sealing members114are positioned one on top of the other as particularly shown inFIG. 12. Specifically, two spring sealing members114are positioned between mounting plate108and interface plate26, with bolts110maintaining the relationship between the components.FIGS. 13 and 14illustrate the arrangement of the two spring sealing members114with slits120in each sealing member being aligned offset from one another such that slits120on an upper spring sealing member are positioned between slits120in the lower spring sealing member. In this arrangement, gas flow in the under region is prevented from flowing into the lower region when susceptor28is in a processing position as discussed with respect toFIGS. 7-10, with the exception of slits120. For example, the orientation of two spring sealing members114as seen inFIG. 14may permit gas flow from the upper region through the upper spring sealing member at slits120and then through slits120in the lower spring sealing member. In this arrangement, a tortuous path is again formed whereby a limited and controlled amount of gas flow may communicate between the upper region and the lower region as the process may require. The dual spring sealing member arrangement functions similar to a single spring sealing member as discussed above and only limits and/or prevents gas flow between the upper and lower regions when susceptor28and first sealing member104are moved upwards in the direction associated with arrow38and the susceptor is in a processing position. A person of ordinary skill in the art will immediately appreciate that any number of slits120may be utilized depending on the desired communication between the upper and lower regions without departing from the spirit and scope of the present disclosure.

Throughout the description, any gas flow communication has been passing from the upper region22to the lower region24in a controlled and/or limited fashion. Nevertheless, it is within the spirit and scope of this disclosure to provide gas flow from the lower region to the upper region. For example, a purge, an inert, or other gas flow within the lower region may be provided at a pressure which is greater than the gas flow pressure in the upper region. In this instance, the higher pressure in the lower region would then permit gas flow from the lower region to communicate into the upper region through the various tortuous paths described and defined above. This arrangement may be useful to decrease purge times by limiting resonance within pockets and gaps in the upper region or reduce particle build-up in the lower region. Regardless, the various sealing members gas flow communication may be selectively tuned to control the amount and direction of the gas flow between the upper and lower regions.

In operation, the first sealing member42or104is positioned on susceptor28and may particularly be positioned on a ledge48if applicable. The second sealing member44or106is then positioned generally between the upper and lower regions, or in contact with an interface plate26, either above in the case of second sealing member44or below in the case of second sealing member106. With the first and second sealing members in position, the susceptor28is lowered to the substrate loading position where a substrate is positioned on lift pins. Next, the susceptor is moved upwards in the direction associated with arrows38until the first sealing member forms a tortuous path with the second sealing member. In some implementations, the first and second sealing members contact one another when the susceptor is in a processing position, while in other implementations a small gap remains between the first and second sealing members, but is generally incorporated into the tortuous path. Regardless of which aspect or implementation is utilized, gas flow between the upper and lower regions is controlled and/or minimized when the susceptor is in a processing position. After the process is completed, the susceptor is lowered into the lower region and regular communication between the upper and lower regions may again be established until another substrate is loaded on the susceptor and the susceptor is moved into the processing position once again.