Systems, apparatus, and methods for an improved load port

Embodiments provide systems, apparatus, and methods for an improved load port that includes a frame supporting a dock and a carrier opener; an elevator operable to raise and lower the carrier opener; an isolation compartment within which the elevator is operable to move, the isolation compartment including a volume isolated from a volume of an equipment front end module (EFEM); and a purge supply within the isolation compartment operable to purge the isolation compartment of reactive gas trapped within the isolation compartment. Numerous additional aspects are disclosed.

FIELD

The present application relates to electronic device manufacturing systems, and more specifically to systems, apparatus, and methods for an improved load port for such systems.

BACKGROUND

Oxygen from a cleanroom can have deleterious effects on substrates (e.g., semiconductor wafers) such as oxidation. Thus, substrates are typically stored in sealed carriers and/or kept in a non-reactive gas (e.g., nitrogen) environment. Electronic device processing systems use load ports coupled to equipment front end modules (EFEMs) or factory interfaces between the cleanroom and the processing tools. Operators or material handling systems can load substrate carriers onto the load ports so the substrates can be loaded into and removed from the processing systems. The cleanrooms have oxygen environments for the operators while the EFEM for the processing systems typically have nitrogen environments to protect the substrates. Ideally, the EFEM provides a barrier to keep oxygen out of the processing system but in some cases, the load port may contribute to oxygen contamination. Thus, what is needed are systems, apparatus, and methods for an improved load port.

SUMMARY

In some embodiments, a load port system is provided. The system includes a frame supporting a dock and a carrier opener; an elevator operable to raise and lower the carrier opener; an isolation compartment within which the elevator is operable to move, the isolation compartment including a volume isolated from a volume of an equipment front end module (EFEM); and a purge supply within the isolation compartment operable to purge the isolation compartment of reactive gas trapped within the isolation compartment.

In some other embodiments, a load port is provided. The load port includes an isolation compartment for an elevator defined by a housing and a frame, the isolation compartment including a volume isolated from a volume of an equipment front end module (EFEM) couplable to the load port; and a purge supply within the isolation compartment operable to purge the isolation compartment of reactive gas trapped within the isolation compartment.

In yet other embodiments, a method for purging an equipment front end module (EFEM) system is provided. The method includes flooding an EFEM with a gas non-reactive to substrates to be passed through the EFEM system; and purging an isolation compartment of a load port coupled to the EFEM of reactive gas trapped within the isolation compartment using a non-reactive gas supply disposed within the isolation compartment.

Still other features, aspects, and advantages of embodiments will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the embodiments. Embodiments of may also be capable of other and different applications, and its several details may be modified in various respects, all without departing from the spirit and scope of the disclosed embodiments. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. The drawings are not necessarily drawn to scale. The description is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claims.

DETAILED DESCRIPTION

Embodiments described herein provide systems, apparatus, and methods for an improved load port to an equipment front end module (EFEM) for an electronic device manufacturing system. An EFEM typically provides an enclosed environment filled with a gas (e.g., nitrogen) that is not reactive with substrates to be loaded into a processing tool. The EFEM includes a robot that enables transfer of substrates between the cleanroom environment (e.g., from within sealed substrate carriers via a load port) and the interior of the processing system. In use, the EFEM is ideally maintained in a positive pressure, nitrogen-only environment. However, an airtight seal is not continuously maintained between the cleanroom and the EFEM. For example, during maintenance, oxygen is introduced into the EFEM to allow personnel to safely enter. Afterward, the EFEM is again flooded with nitrogen to force out remaining oxygen.

The inventors have determined that conventional load ports coupled to EFEMs can trap oxygen which can remain in an isolation compartment of the load port and the oxygen can slowly leak out into the EFEM, particularly when the carrier opener of the load port is opened and lowered during substrate transfer from a docked substrate carrier. The isolation compartment is an enclosed volume within the lower portion of the load port within which an elevator translates up and down to lower and raise the carrier opener of the load port when opening a substrate carrier. The isolation compartment is in fluid communication with the EFEM and the movement of the elevator can push trapped oxygen out of the isolation compartment into the EFEM. In addition, slow leaking of oxygen from the isolation compartment of the load port after the EFEM has been flooded with nitrogen is particularly problematic because the oxygen, which is reactive with substrate materials, can contaminate substrates moved though the EFEM. Embodiments solve this problem by providing a dedicated nitrogen purge supply within the isolation compartment of the load port that is operative to force out the trapped oxygen so the oxygen can be removed when the EFEM is flooded with nitrogen. In some embodiments, a fan within the isolation compartment is used to force oxygen out of the load port, with or without the dedicated nitrogen purge supply. In some embodiments, a fan within the EFEM is used to pull oxygen out of the load port, with or without the dedicated nitrogen purge supply.

Turning toFIGS. 1A and 1B, block diagrams of an example electronic device processing system100according to some embodiments is shown.FIG. 1Bdepicts the same system100asFIG. 1Abut includes a vertical dashed line101demarcating the boundary between an oxygen (e.g., reactive) environment and a nitrogen (e.g., non-reactive) environment. The system100includes a substrate processing tool102coupled to an EFEM104. The EFEM104is coupled to a load port105which includes a frame106supporting a docking tray108, an carrier opener110, an elevator112, and an isolation compartment114surrounded by a load port housing116. The load port housing116also encloses a control components board supporting a controller118, and an isolation compartment purge supply120.

The docking tray108is adapted to receive a substrate carrier122(e.g., a front opening unified pod (FOUP)). The substrate carrier122is accessed via the carrier opener110which is lowered out of the way via the elevator112that moves the carrier opener110up and down in the EFEM104, carried by an elevator arm124that extends from the elevator112in the isolation compartment114. The isolation compartment114contains the elevator112. Note that the volume enclosed by load port housing116, i.e., the isolation compartment114, is in fluid communication with the EFEM104due to an opening (SeeFIG. 3, 302) for moving elements that extend through the frame106.

As illustrated by the vertical dashed line101inFIG. 1B, elements on the left side of the system100may be maintained in an oxygen environment, e.g., a cleanroom, while elements on the right side of the system100are ideally maintained in a non-reactive gas (e.g., nitrogen) environment. A gas is selected to be non-reactive relative to the substrate.

In operation, the EFEM104is initially flooded with nitrogen to force out oxygen. However, oxygen gets trapped in the isolation compartment114and is purged using the dedicated isolation compartment purge supply120disposed within the isolation compartment114. Alternatively or additionally, isolation compartment114(i.e., the volume enclosed by the load port housing116) is purged using a fan disposed within the load port housing116or is drawn out using a fan or vacuum source within the EFEM104adjacent the isolation compartment114. Once the oxygen has been flushed out of the EFEM104, a substrate carrier122can be docked at the load port105to deliver or receive substrates to or from the substrate processing tool102. The carrier opener110is lowered via elevator112. The substrates are inserted into or removed from the substrate carrier122via a robot (not shown) and then the carrier opener110is raised to reseal the substrate carrier122. Shown in phantom inFIGS. 1A and 1B, the controller118(including a programed processor and memory storing processor executable instructions) within the load port housing116can be coupled to each of the active components to control operation thereof.

In some embodiments, the purge supply120within the isolation compartment114is disposed at a lower end of the isolation compartment114and arranged to force trapped reactive gas up out of the isolation compartment114. In some embodiments, the purge supply120within the isolation compartment114is disposed at an upper end of the isolation compartment114and arranged to force trapped reactive gas down out of the isolation compartment114. In some embodiments, the isolation compartment114includes a vent opening disposed at an end of the isolation compartment114opposite the purge supply120. The vent opening can include a one-way check valve to allow gas out of the isolation compartment but not back in. In some embodiments, the purge supply120can be replaced with a fan disposed in any of the arrangements described above for the purge supply120.

FIGS. 2A and 2Bdepict front isometric views of an example embodiment of a load port105. Note that inFIG. 2A, the load port housing116is installed and inFIG. 2B, the load port housing116has been removed. Also note that inFIGS. 2A & 2B, as well as inFIGS. 3 and 4, the same reference numeral is used to reference the same component even when a different view of the component is shown. InFIG. 2B, the control components board202mentioned above with respect toFIGS. 1A and 1B, is visible.

FIG. 3depicts a back isometric view andFIG. 4depicts a back plan view of the example embodiment of a load port105. The opening302to the isolation compartment114is clearly shown in these drawings. The volume within the isolation compartment114is partially isolated from the volume within the EFEM104(FIG. 1) but due to the opening302for the elevator arm124, the isolation compartment114is in fluid communication with the EFEM104. Note that the opening302is minimized in order minimize particle migration into the EFEM104environment. Thus, there are two volumes separated by opening302, the EFEM104environment and the isolation compartment114volume. Because there is only a small opening302connecting the two volumes, reactive gas is trapped inside the isolation compartment114volume unless a purge supply120is introduced. If trapped oxygen is not purged from the isolation compartment114, oxygen leaks out into the volume within the EFEM104, particularly when the elevator112moves through the isolation compartment114to lower or raise the carrier opener110.

In some embodiments, the isolation compartment purge supply120provides a non-reactive gas (e.g., nitrogen) at a rate within the range of approximately 10 to approximately 100 lpm and at a pressure within the range of approximately 0.5 in WC to approximately 3 in WC. Other ranges are possible. In some embodiments, an EFEM purge supply (not shown) provides a non-reactive gas (e.g., nitrogen) at a rate within the range of approximately 20 lpm to approximately 1000 lpm and at a pressure within the range of approximately 0.5 in WC to approximately 3 in WC. Other ranges are possible. In alternative embodiments that include a fan, a fan can be selected that moves of approximately 10 to approximately 100 lpm of gas.

Turning now toFIG. 5, a flowchart depicting an example method500of embodiments is provided. Initially, the substrate processing tool102side of the system100(i.e., the EFEM104) is flooded with a non-reactive gas (e.g., nitrogen) to force out oxygen (502). Concurrently or after a delay, oxygen trapped in the isolation compartment114is purged using the dedicated isolation compartment purge supply120(504). Alternatively or additionally, a fan is used to purge the isolation compartment114of any trapped oxygen. After the oxygen has been flushed out of the isolation compartment114and the EFEM104, a substrate carrier122can be docked at the load port105(506). Alternatively, a substrate carrier122can be docked at the load port105and then the isolation compartment114and the EFEM104are purged before opening the substrate carrier122. The carrier opener110opens the substrate carrier122and is then lowered via elevator112with the door of the substrate carrier122(508). Substrates are inserted into or removed from the substrate carrier122and then the carrier opener110is raised to reseal the substrate carrier122(510).

Numerous embodiments are described in this disclosure, and are presented for illustrative purposes only. The described embodiments are not, and are not intended to be, limiting in any sense. The presently disclosed embodiments are widely applicable to numerous other embodiments, as is readily apparent from the disclosure. One of ordinary skill in the art will recognize that the disclosed embodiments may be practiced with various modifications and alterations, such as structural, logical, software, and electrical modifications. Although particular features of the disclosed embodiments may be described with reference to one or more particular embodiments and/or drawings, it should be understood that such features are not limited to usage in the one or more particular embodiments or drawings with reference to which they are described, unless expressly specified otherwise.

The present disclosure is neither a literal description of all embodiments nor a listing of features of the embodiments that must be present in all embodiments. The present disclosure provides, to one of ordinary skill in the art, an enabling description of several embodiments. Some of these embodiments may not be claimed in the present application, but may nevertheless be claimed in one or more continuing applications that claim the benefit of priority of the present application.

The foregoing description discloses only example embodiments. Modifications of the above-disclosed apparatus, systems and methods which fall within the scope of the claims will be readily apparent to those of ordinary skill in the art. Accordingly, while the embodiments have been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the intended spirit and scope, as defined by the following claims.