DOOR OPENING DEVICE

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 63/723,670, filed Nov. 22, 2024 and titled DOOR OPENING DEVICE, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates generally to the field of semiconductor processing methods, and associated structures and apparatus, and to the field of device and integrated circuit manufacture. More particularly the present disclosure generally relates to a door opening device for opening a door of a wafer cassette.

BACKGROUND

Wafer cassettes are used in clean room environments to transport wafers to and from clean room apparatuses, such as vertical batch furnaces. An example of such a wafer cassette is the Front Opening Unified Pod, or FOUP, which is used to transport 300 mm wafers.

A wafer cassette may be docked at a wall separating two environments in order to transfer wafers between the two environments. A door opening device may be provided in the wall so as to allow the wafer cassette to be opened while avoiding gas flow between the two environments, which may have different gas compositions and/or contaminant level restrictions.

A door opening device may include a purge gas supply for providing a purge gas during a door opening process. There is a need to avoid transfer of particles by the purge gas flow to wafers in the wafer cassette or to other areas which are required to be kept substantially free of contaminants.

Any discussion, including discussion of problems and solutions, set forth in this section, has been included in this disclosure solely for the purpose of providing a context for the present disclosure, and should not be taken as an admission that any or all of the discussion was known at the time the invention was made or otherwise constitutes prior art.

BRIEF SUMMARY

This summary introduces a selection of concepts in a simplified form, which are described in further detail below. This summary is not intended to necessarily identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to a first aspect of the present invention, there is provided a device for opening a cassette for storing a plurality of wafers, the device comprising a housing containing an inner volume, the inner volume comprising a first door position and a second door position adjacent to the first door position; a docking port in the housing for coupling to a cassette; a door opener configured to couple to a door of the cassette and to translate the door within the housing between the first door position and the second door position; and a purge gas diffuser located adjacent to the first door position such that the first door position is between the second door position and the purge gas diffuser, wherein the purge gas diffuser is configured to provide a flow of purge gas to the inner volume towards the second door position.

By using a diffuser to provide the purge gas, the flow of purge gas may be substantially uniform. This can help to avoid turbulent flow in the inner volume, which may help to prevent particle contamination on wafers in the wafer cassette due to pickup of particles by fast flowing gas jets.

The first door position and the second door position may be spaced apart in a direction perpendicular to a wafer translation direction, the wafer translation direction being a direction in which wafers can be removed from the wafer cassette via the docking port.

The device may comprise a closable opening spaced apart from the docking port in a the wafer translation direction, configured such that when the cassette door is in the second door position, wafers can be transferred from the cassette through the closable opening.

The purge gas diffuser may comprise a purge gas inlet and a porous filter connected to the inlet configured to diffuse a purge gas.

The porous filter may extend in a vertical direction.

The porous filter may extend over at least 50% of a height of the docking port.

The porous filter may substantially span a height of the docking port.

The purge gas diffuser may be configured to provide an outflow of purge gas which is substantially uniformly distributed over a length of the diffuser.

The device may comprise a first gas outlet for exhausting gas from the inner volume.

The first gas outlet may be located on an opposite side of the second door position to the first door position.

The device may comprise a pressure relief outlet located in a wall of the housing overlapping with the second door position.

The housing may comprise a first inner volume encompassing the first door position and the second door position, and a second inner volume located adjacent to the second door position and not in the direction of the first door position, wherein the first gas outlet is located in the first inner volume.

The first inner volume may be at least partially separated from the second inner volume by a wall.

The device may comprise a second gas outlet located in the second inner volume.

The first gas outlet and the second gas outlet may be spaced apart in a vertical direction.

One or more of the gas outlets may comprise a venturi valve.

The door opener may comprise a mechanism for translating the door opener between the first door position and the second door position, and the mechanism may be at least partially located in the second inner volume.

According to a second aspect of the present invention, there is provided a semiconductor processing apparatus comprising a wafer handling chamber, a process chamber adjacent to the wafer handling chamber, and a cassette handling chamber adjacent to the wafer handling chamber, wherein the semiconductor processing apparatus comprises a wall for separating the wafer handling chamber from the cassette handling chamber and the wall comprises a device according to the first aspect.

According to a third aspect of the present invention there is provided a method of operating a device according to the first aspect, the method comprising the steps of providing a cassette at the docking port; causing the door opener to couple to a door of the cassette; causing the door opener to move the door of the cassette in a direction perpendicular to a plane of the door; causing the door opener to move the door of the cassette in a direction parallel to a plane of the door; wherein, while the door opener is moving, a purge gas is flowed through the purge gas diffuser into the inner volume.

The device may comprise a pressure relief outlet and the method may comprise monitoring a pressure in the inner volume and, if the pressure approaches a threshold value, opening the pressure relief valve so as to prevent the pressure in the inner volume from increasing above the threshold value.

The device may comprise a pressure relief valve for exhausting gas from the inner volume, and a mass flow controller for controlling an amount of purge gas flowing into the purge gas diffuser, and the method may comprise controlling the amount of purge gas flowing into the purge gas diffuser while the pressure relief valve is open so as to control a pressure difference between the inner volume and an environment outside the device.

According to a fourth aspect of the present invention, there is provided a device for opening a cassette for storing a plurality of wafers, the device comprising a housing containing an inner volume, the inner volume comprising a first door position and a second door position adjacent to the first door position; a docking port in the housing for coupling to a cassette; a door opener configured to couple to a door of the cassette and to translate the door within the housing between the first door position and the second door position; and a first gas outlet for exhausting gas from the inner volume, the first gas outlet being located on an opposite side of the second door position to the first door position.

The housing may comprise a first inner volume encompassing the first door position and the second door position, and a second inner volume located adjacent to the second door position and not in the direction of the first door position, wherein the first gas outlet is located in the first inner volume.

The first inner volume may be at least partially separated from the second inner volume by a wall.

The device may comprise a second gas outlet located in the second inner volume.

The first gas outlet and the second gas outlet may be spaced apart in a vertical direction.

One or more of the gas outlets may comprise a venturi valve.

The door opener may comprise a mechanism for translating the door opener between the first door position and the second door position, and the mechanism may be at least partially located in the second inner volume.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view of a device according to embodiments of the present invention, the cross-section being taken in a plane perpendicular to direction C shown in FIG. 4, with a door of the device in a first door position.

FIG. 2 is a schematic cross-sectional view of a device according to embodiments of the present invention, the cross-section being taken in a plane perpendicular to direction C shown in FIG. 4, with a door of the device in a second door position.

FIG. 3 is a schematic cross-sectional view of a device according to embodiments of the present invention, the cross-section being taken in a plane perpendicular to direction C shown in FIG. 4, illustrating the first and second door positions.

FIG. 4 is a schematic perspective view of a device according to embodiments of the present invention.

FIG. 5 is a schematic cross-sectional view of a device according to embodiments of the present invention, the cross-section being taken in a plane perpendicular to direction C shown in FIG. 6, with a door of the device in a first door position, the device including a first first gas outlet.

FIG. 6 is a schematic perspective view of a device according to embodiments of the present invention including a first outlet valve and second outlet valve.

FIG. 7 is a schematic perspective view of a device according to embodiments of the present invention including a mass flow controller.

FIG. 8 is a schematic plan view of a semiconductor processing apparatus according to embodiments of the present invention.

FIG. 9 is a flow chart of a method according to embodiments of the present invention.

It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure.

DETAILED DESCRIPTION

The description of exemplary embodiments of methods and compositions provided below is merely exemplary and is intended for purposes of illustration only. The following description is not intended to limit the scope of the disclosure or the claims. Moreover, recitation of multiple embodiments having indicated features or steps is not intended to exclude other embodiments having additional features or steps or other embodiments incorporating different combinations of the stated features or steps.

Where in the present disclosure two or more elements are referred to as being “in fluid communication”, it is meant that a fluid such as a gas or liquid or mixture thereof can flow between the elements, in one or both directions. The fluid communication may be achieved, for example, by means of a gas line, tube, pipe, inlet, outlet, or any combination thereof. The fluid communication may be interruptible; for example, a valve or other flow control element may be present.

In this disclosure, any two numbers of a variable can constitute a workable range of the variable, and any ranges indicated may include or exclude the endpoints. Additionally, any values of variables indicated (regardless of whether they are indicated with “about” or not) may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments. Further, in this disclosure, the terms “including,” “constituted by” and “having” can refer independently to “typically or broadly comprising,” “comprising,” “consisting essentially of,” or “consisting of” in some embodiments. In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments. In some cases, percentages indicate herein can be relative or absolute percentages.

A number of example materials are given throughout the embodiments of the current disclosure, it should be noted that the chemical formulas given for each of the example materials should not be construed as limiting and that the non-limiting example materials given should not be limited by a given example stoichiometry.

In the specification, it will be understood that the term “on” or “over” may be used to describe a relative location relationship. Another element, film or layer may be directly on a mentioned layer, or another layer (an intermediate layer) or element may be intervened therebetween, or a layer may be disposed on a mentioned layer but not completely cover a surface of the mentioned layer. Therefore, unless the term “directly” is separately used, the term “on” or “over” will be construed to be a relative concept. Similarly to this, it will be understood the term “under”, “underlying”, or “below” will be construed to be relative concepts.

Referring to FIG. 1, FIG. 2, FIG. 3, and FIG. 4, a device 101 according to embodiments of the present invention for opening a wafer cassette 102 is shown. The wafer cassette 102 may comprise a cassette body 103 defining a cassette interior 104 for accommodating wafers and may have a cassette opening 105 which is closeable with a door 106 or lid. Wafers may be inserted and removed from the wafer cassette 102 through the cassette opening 105 in a wafer translation direction A. The device 101 comprises a housing 107 containing an inner volume 108. The inner volume 108 comprises a first door position 109 and a second door position 110 adjacent to the first door position 109. The housing 107 comprises a docking port 111 in the housing 107 for coupling to a wafer cassette 102. The device 101 comprises a door opener 112 configured to couple to a door 106 of the wafer cassette 102 and to translate the door 106 within the housing 107 between the first door position 109 and the second door position 110. The housing 107 may be defined by a wall 113 and the docking port 111 may comprise an opening in the wall 113. The device 101 may be part of or located or integrated in a separation wall separating a wafer handling chamber from a cassette handling chamber (FIG. 8).

Referring in particular to FIG. 1, the first door position 109 may be a position in which the door 106 is spaced apart from the wafer cassette 102 in the wafer translation direction only. The first door position 109 may be a position in which the door 106 is still attached to the wafer cassette 102. The door opener 112 may be configured to couple to the door 106 while the door is attached to the wafer cassette 102 and to translate the door 106 in the wafer translation direction so as to space the door 106 apart from the wafer cassette 102 in the wafer translation direction, prior to translating the door 106 from the first door position 109 to the second door position 110. The door opener 112 may comprise one or more vacuum nozzles 114 for attaching to the cassette door 106 in order to move the cassette door 106.

Referring in particular to FIG. 2, the second door position 110 may be a position in which the door 106 is spaced apart from the wafer cassette 102 in the wafer translation direction and in a second direction perpendicular B to the wafer translation direction. The second direction may be vertical or horizontal. FIG. 3 shows the device 101 without the door 106, illustrating simultaneously the first door position 109 and second door position 110.

Referring again to FIG. 1, FIG. 2, FIG. 3, and FIG. 4, the device 101 comprises a purge gas diffuser 115 configured to provide a flow of purge gas to the inner volume 108 towards the second door position 110. The purge gas diffuser 115 is located adjacent to the first door position 109 such that the first door position 109 is between the second door position 110 and the purge gas diffuser 115.

By diffusing a purge gas into the inner volume 108 using the purge gas diffuser 115, a purge gas flow in the inner volume 108 can be provided which is more uniform. This can help to prevent high velocity flow and recirculation of gas, reducing the likelihood of particles being blown from the inner volume 108 into the wafer cassette 102.

The device 101 may comprise a closable opening 118 spaced apart from the docking port 111 in the wafer translation direction. The closable opening 118 is configured such that when the cassette door 106 is in the second door position 110, wafers can be transferred from the wafer cassette 102 through the closable opening 118. The door opener 112 may be configured to couple to the door 106 and to a lid 119 for closing off the closable opening 118 and to translate the door 106 and the lid 119 simultaneously so as to open the wafer cassette 102 and the closable opening 118 simultaneously. The docking port 111 may provide an interface with a cassette handling chamber (FIG. 8) and the closable opening 118 may provide an interface with a wafer handling chamber (FIG. 8). The gas environment in the wafer handling chamber may be different to the gas environment of the cassette handling chamber. For example, the gas environment in the wafer handling chamber may have a contaminant level which is much lower than that of the cassette handling chamber. The pressure in the inner volume 108 of the device may be different to the pressure in the cassette handling chamber, for example the pressure in inner volume may be greater than a pressure in the cassette handling chamber. When opening a door 106 of a wafer cassette 102, due to the greater pressure in the inner volume 108, gas may enter the wafer cassette 102 at high speed, and may carry contaminants onto the wafers. In some embodiments, the device 101 comprises a pressure relief valve 120 which may be opened during a door opening process so as to reduce a gas inflow into the wafer cassette 102 from the inner volume 108. The pressure relief valve 120 may be located on a wall of the housing 107 which is opposite, in the wafer translation direction, to a wall of the housing in which the docking port 111 is formed. The pressure relief valve 120 may be located on a wall of the housing 107 which partially overlaps the second door position 110, when viewed in the wafer translation direction.

The device 101 may comprise a pressure sensor 116 for sensing a pressure in the inner volume 108. The pressure sensor 116 may be located at an opposite end of the device 101 to the purge gas diffuser 115.

The purge gas diffuser 115 may be configured to output a diffuse flow of gas, which is less prone to turbulent flow. Referring in particular to FIG. 4, the purge gas diffuser 115 may comprise a purge gas inlet 117 and a porous filter 121 connected to the inlet at a first end of the filter 121. The filter may be, for example, a high-efficiency particulate air (HEPA) filter. The filter 121 may be generally cylindrical in shape. The filter 121 may have a cap 124 at a second end 123 of the filter 121 opposite to the first end 122, to prevent gas flowing out of the filter 121 at the second end 123. A gas may flow through the purge gas inlet 117 and subsequently through microchannels within the filter 121, causing relatively uniform distribution of flow throughout the filter 121 volume. The gas may eventually exit the filter 121 substantially uniformly over a surface of the filter 121.

The filter 121 may extend in a third direction C which is perpendicular to the wafer translation direction and the second direction. Thus the purge gas diffuser 115 may be configured to provide an outflow of purge gas which is substantially uniformly distributed over a length of the diffuser. For example, in embodiments wherein the first door position 109 and the second door position 110 are spaced apart in a horizontal direction, the filter 121 may extend in the vertical direction. The filter 121 may be substantially cylindrical. In some embodiments, the filter 121 may extend over at least 50% of a height (when extending in the vertical direction) or width (when extending in the horizontal direction) of the docking port 111. The filter 121 may substantially span a height or width of the docking port 111.

The purge gas diffuser 115 may be positioned adjacent to the docking port 111. Part of the gas flow provided by the purge gas diffuser 115 may, in some embodiments, flow into a wafer cassette 102 provided at the docking port 111. The likelihood of purge gas flowing from the purge gas diffuser 115 to the second inner volume 127 (FIG. 6) where particles may be generated and then back to the wafer cassette 102 is low due to the uniform, rather than turbulent or circulating, nature of the gas flow from the purge gas diffuser 115.

Referring to FIG. 5 and FIG. 6, a device 101 according to embodiments of the present invention may comprise a first gas outlet 125 for exhausting gas from the inner volume 108. The first gas outlet 125 may provide an outlet for purge gas flowing from the purge gas diffuser 115. The first gas outlet 125 may be located in the housing 107 on an opposite side of the second door position 110 to the first door position 109. That is, the second door position 110 may be located between the first door position 109 and the first gas outlet 125.

The device 101 may comprise, in the housing 107, a first inner volume 126 and a second inner volume 127. The first inner volume 126 may encompass the first door position 109 and the second door position 110. The second inner volume 127 may be located adjacent to the second door position 110 in a direction perpendicular to the wafer translation direction and not towards the first door position 109. For example, in embodiments wherein the first door position 109 and the second door position are spaced apart in a horizontal direction, the second inner volume 127 may be located vertically above or below the second door position 110. The first gas outlet 125 may be located in the first inner volume 126. The device 101 may comprise a second gas outlet 128 located in the second inner volume 127.

The second inner volume 127 may contain a mechanism 129 for translating the door opener 112 between the first door position 109 and the second door position 110, and the mechanism 129 may be at least partially located in the second inner volume 127. Since the mechanism 129 contains moving parts, for example a spindle, it may generate particles which may contaminate wafers. By providing a first gas outlet 125 in the first inner volume 126 and a second gas outlet 128 in the second inner volume 127, gas flow which may entrain particles generated by the mechanism 129 may be exhausted close to the mechanism 129 itself, reducing the chance of such particles moving towards the first inner volume 126 (which may be desired to be kept free of particles) or contaminating wafers in the wafer cassette 102. By providing the purge gas diffuser 115 configured to provide a diffuse flow of gas towards the second door position 110 in combination with the first gas outlet 125 and the second gas outlet 128, a relatively uniform flow of purge gas, rather than turbulent or recirculating flow, may be provided to the housing 107 from the purge gas diffuser 115 towards the first gas outlet 125 and second gas outlet 128, reducing the chance of particles contaminating wafers in the wafer cassette 102.

The first gas outlet 125 may be spaced apart from the second gas outlet 128 in a vertical direction. The second gas outlet 128 is therefore not visible in FIG. 3 which is a cross-section of the device 101 in a vertical plane. The first gas outlet 125 may be spaced apart from the second gas outlet 128 in a direction which is substantially parallel to a direction in which the purge gas diffuser 115 extends. The first gas outlet 125 may be spaced apart from the second gas outlet 128 in a third direction C which is perpendicular to the wafer transfer direction and to the second direction.

The first inner volume 126 may be at least partially separated from the second inner volume 127 by a wall 130. The device 101 may comprise more than one gas outlet in the first inner volume 126 and/or in the second inner volume 127. Each gas outlet may comprise a venturi valve or other pneumatic valve.

In some embodiments, the pressure relief valve 120 may be located in the second inner volume 127. This can help to avoid transport of particles from the second inner volume 127 to the first inner volume 126 during evacuation of gas through the pressure relief valve 120.

The device 101 may comprise a controller 131 configured to control opening/closing of any of the pressure relief valve 120 and the first gas outlet 125 and second gas outlet 128. The controller 131 may be configured to receive pressure measurements from a pressure sensor 116 and to control opening/closing of the pressure relief valve 120 depending on the received pressure measurements. The controller 131 may be configured to control a movement of the door opener 112. The controller 131 may comprise a memory and a processor. The memory may store instructions for carrying out a method according to embodiments of the present invention of operating the device 101. The controller 131 may be configured to load such instructions from the memory into the processor and thereby to carry out the method according to embodiments of the present invention.

Referring to FIG. 7, in some embodiments, the device 101 comprises a mass flow controller at the purge gas inlet 117 for controlling a gas flow rate into the purge gas diffuser 115 and thus into the inner volume 108. By controlling the flow rate of purge gas into the inner volume 108, a pressure difference between the inner volume 108 and an environment with which the pressure relief valve 120 connects the inner volume 108 can be controlled. This may be beneficial, for example, in reducing a rate of gas inflow into the inner volume 108. The controller 131 may be configured to control the amount of purge gas flowing into the purge gas diffuser using the mass flow controller while the pressure relief valve is open so as to control a pressure difference between the inner volume and an environment outside the device. The pressure difference may be controlled to be less than a threshold value.

Referring to FIG. 8, a semiconductor processing apparatus 801 according to embodiments of the present invention comprises a wafer handling chamber 802, a process chamber 803 adjacent to the wafer handling chamber 802, and a cassette handling chamber 804 adjacent to the wafer handling chamber 802. The process chamber 803 may be located vertically above the wafer handling chamber 802. The semiconductor processing apparatus 801 comprises a separation wall 805 for separating the wafer handling chamber 802 from the cassette handling chamber 804. The separation wall 805 comprises a device 101 according to embodiments of the present invention for opening a wafer cassette. The device 101 may be configured such that the docking port 111 is located so as to provide an interface with the cassette handling chamber 804 and the closable opening 118 is located so as to provide an interface with the wafer handling chamber 802.

The cassette handling chamber 804 may comprise a set of cassette storage positions 806 at which a wafer cassette lid may be placed. The cassette handling chamber 804 may comprise a cassette handling robot 807 configured to transfer a cassette from a cassette storage position 806 to the docking port 111 of the device 101. The cassette handling chamber 804 may comprise a port 808 for introducing a wafer cassette lid into the cassette handling chamber 804 from outside the semiconductor processing apparatus 801.

The wafer handling chamber 802 may comprise a wafer handling robot 809 configured to transfer wafers from a wafer cassette lid docked at the device 101, through the docking port 111 and the closable opening 118, to a wafer support 810 which may be a single wafer support or may be a wafer boat for supporting a plurality of wafers.

Referring to FIG. 9, embodiments of the present invention provide a method of operating a device for opening a wafer cassette as described hereinbefore. The method may comprise the steps of providing a cassette at the docking port (step S1); causing the door opener to couple to a door of the cassette (step S2); causing the door opener to move the door of the cassette in a direction perpendicular to a plane of the door (step S3); causing the door opener to move the door of the cassette parallel to a plane of the door (step S4). While the door opener is moving in steps S3 and S4, a purge gas is flowed through the purge gas diffuser into the inner volume.

In step S1, the wafer cassette may be provided to the docking port by a cassette handling robot in the cassette handling chamber. In step S2, coupling the door opener to the door of the cassette may comprise moving the door opener to a position which overlaps the door of the cassette and engaging a coupling mechanism, which may be for example a vacuum nozzle arrangement for suctioning the door to the door opener. In steps S3 and S4, a purge gas may be flowed into the purge gas inlet and through the purge gas diffuser so as to provide a uniform flow of gas into the inner volume.

The method may comprise monitoring a pressure in the inner volume and, if the pressure approaches a threshold value, opening a pressure relief valve so as to prevent the pressure from increasing above the threshold value. This pressure control may help to prevent fast inrush of gas into the FOUP which may be a cause of particle pickup and contamination on the wafers.

The device may comprise a pressure relief valve for exhausting gas from the inner volume, and a mass flow controller for controlling an amount of purge gas flowing into the purge gas diffuser, and the method may comprise controlling the amount of purge gas flowing into the purge gas diffuser while the pressure relief valve is open so as to minimise a pressure difference between the inner volume and an environment outside the device.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.