High throughput load lock chamber

Abstract

An improved load lock chamber is provided. The load lock chamber comprises an exhaust port; a first compartment configured to receive a wafer to be loaded into and unloaded from the main vacuum chamber; and a second compartment, which is separated from the first compartment. The second compartment is configured to receive gas through the exhaust port. The load lock chamber also includes a flow attenuation path connecting the first compartment and the second compartment. The flow attenuation path is configured to direct gas from the second compartment to the first compartment and attenuate gas flow.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application No. 63 / 395,754, filed on August 5, 2022, and the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments provided herein disclose a particle beam inspection apparatus, and more particularly, disclose a particle beam inspection apparatus including an improved load lock chamber. Background Art

[0004] When manufacturing semiconductor integrated circuit (IC) chips, pattern defects or uninvited particles (residues) inevitably occur on wafers or masks during the manufacturing process, thereby reducing the yield to a great extent. For example, uninvited particles may be troublesome for patterns with smaller critical feature sizes, which have been adopted to meet the increasingly higher performance requirements of IC chips.

[0005] Pattern inspection tools with charged particle beams have been used to detect defects or uninvited particles. These tools typically employ a scanning electron microscope (SEM). In a SEM, a relatively high energy primary electron beam is decelerated, lands on a sample with a relatively low landing energy, and is focused to form a probe spot thereon. Due to this focused probe spot of primary electrons, secondary electrons will be generated from the surface. By scanning the probe spot across the sample surface and collecting the secondary electrons, the pattern inspection tool can obtain an image of the sample surface.

[0006] During operation of the inspection tool, the wafer is typically held in the main chamber by a wafer stage. The inspection tool may include a wafer positioning device for positioning the wafer stage and the wafer relative to the e-beam. This can be used to locate a target area, i.e., an area to be inspected, on the wafer within the operating range of the e-beam. During the inspection, the main chamber is maintained in a deep vacuum state. The inspection tool may also include a small vacuum chamber, referred to as a load lock chamber, which is connected to the large main chamber. The load lock chamber is used to transfer wafers between an atmospheric clean room environment and a main chamber in a deep vacuum state. Summary of the invention

[0007] Embodiments provided herein disclose a charged particle beam apparatus and, more particularly, disclose improved systems and methods for signal electronic detection.

[0008] One aspect of the present invention relates to a load lock chamber, the load lock chamber comprising an exhaust port, a first compartment and a second compartment, the first compartment being configured to receive a wafer for loading into and unloading from a main vacuum chamber, the second compartment being separated from the first compartment. The second compartment may be configured to receive gas through the exhaust port. The load lock chamber may also include a flow attenuation path connecting the first compartment and the second compartment, the flow attenuation path being configured to guide gas from the second compartment to the first compartment and attenuate gas flow.

[0009] Another aspect of the present disclosure relates to a load lock assembly, including a load lock chamber, a vacuum pump connected to the load lock chamber, and a gas supply connected to the load lock chamber through an exhaust port. The load lock chamber includes an exhaust port; a first compartment configured to receive wafers for loading into and unloading from a main vacuum chamber; and a second compartment separated from the first compartment. The second compartment can be configured to receive gas through the exhaust port. The load lock chamber can also include a flow attenuation path connecting the first compartment and the second compartment, the flow attenuation path configured to guide gas from the second compartment to the first compartment and attenuate gas flow.

[0010] Other advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which certain embodiments of the invention are set forth by way of illustration and example. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects of the present disclosure will become more apparent from the description of exemplary embodiments with reference to the accompanying drawings.

[0012] Figure 1A is a schematic diagram illustrating an exemplary charged particle beam inspection system according to an embodiment of the present disclosure.

[0013] Figure 1B is a diagram illustrating an embodiment according to the present disclosure Figure 1A Schematic diagram of an exemplary wafer loading sequence in a charged particle beam inspection system.

[0014] Figure 2A is a schematic diagram illustrating an exemplary charged particle beam inspection system having a conventional load lock chamber.

[0015] Figure 2B is a diagram showing the Figure 2A A schematic diagram of a conventional load lock chamber such as a load lock chamber in an exemplary charged particle beam inspection system is shown.

[0016] Figure 2C It shows that the technicians Figure 2A and Figure 2BIllustration of maintenance work performed under the load lock chamber shown.

[0017] Figure 3A is a schematic diagram illustrating an exemplary load lock chamber according to an embodiment of the present disclosure.

[0018] Figure 3B is a diagram illustrating an embodiment according to the present disclosure Figure 3A A schematic diagram of a cross-sectional view of an exemplary load lock chamber is shown. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, and unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Instead, they are merely examples of devices and methods consistent with various aspects of the present invention described in the appended claims.

[0020] Electronic devices consist of circuits formed on a silicon wafer called a substrate. Many circuits can be formed together on the same silicon wafer and are called an integrated circuit or IC. The size of these circuits has been greatly reduced so that more of them can fit on a substrate. For example, the IC chip in a smartphone can be as small as a thumbnail but can include more than 2 billion transistors, each less than 1 / 1000 the size of a human hair.

[0021] Manufacturing these ICs with so many tiny transistors is a complex, time-consuming, and expensive process that typically involves hundreds of individual steps. An error in even one step can result in a defect in the finished IC, rendering it useless. Therefore, one goal of the manufacturing process is to avoid such defects in order to maximize the number of functional ICs manufactured in the process, i.e., to increase the overall yield of the process.

[0022] An integral part of improving yield is monitoring the chip manufacturing process to ensure that it is producing sufficient numbers of functional integrated circuits. One way to monitor the process is to inspect the chip circuit structures at various stages of their formation. Inspection can be performed using a scanning electron microscope (SEM). The SEM can be used to image these very small structures, in effect taking a "photo" of the structure. The image can be used to determine if the structure was formed correctly and in the correct location. If the structure is defective, the process can be adjusted so that the defect is less likely to occur again.

[0023] While high process yields are desired in IC chip manufacturing facilities, it is also important to maintain high wafer throughput (defined as the number of wafers processed per hour). High process yields and high wafer throughput can be affected by the presence of defects, especially when the defects require operator intervention for a closer look. Therefore, high-throughput detection and identification of micron and nanometer-scale defects by inspection tools (such as SEM) is critical to maintaining high yields and low costs.

[0024] One aspect of the present disclosure includes an improved load lock system that increases overall inspection system throughput. The improved load lock system prepares wafers in a manner that speeds up the inspection process and reduces the chance of introducing uninvited particles when compared to conventional particle beam inspection systems.

[0025] For example, during the operation of the inspection tool, the wafer is usually held in the main chamber by the wafer stage. Maintain the main chamber in a deep vacuum state to allow particle beams (such as electrons) to travel unimpeded in the main chamber and prevent discharges (e.g., arc discharges) in the gun assembly. The inspection tool may also include a small vacuum chamber referred to as a load lock chamber, which is connected to the large main chamber. The load lock chamber is used to transfer the wafer between the atmospheric clean room environment and the main chamber in a deep vacuum state. In order to transfer the wafer to the main chamber for inspection, the wafer is first placed in the load lock chamber, and then the load lock chamber is decompressed to match the vacuum level of the main chamber. After the inspection, the wafer is placed in the load lock chamber again, and a ventilation operation is performed to restore the pressure of the load lock chamber to the atmospheric pressure level.

[0026] In conventional inspection systems, venting structures (e.g., gas supply, exhaust valve, exhaust diffuser, etc.) are placed on top of the load lock chamber to provide a strong downward exhaust flow within the load lock chamber. Thus, pumping-down structures (e.g., vacuum pump, plasma cleaner, residual gas analyzer, etc.) are placed below the load lock chamber. Pumping structures are usually complex and bulky, and are more prone to failure. However, the tight space below the load lock chamber poses great difficulties in installing, troubleshooting, or fixing pumping structures.

[0027] The improved load lock chamber has a redesigned internal structure that allows the exhaust port to be positioned on the side or bottom of the load lock chamber while still providing the desired downward exhaust flow within the load lock chamber. The improved load lock chamber also allows the pumping structure to be relocated to a location that is easy to access and facilitate maintenance work.

[0028] For clarity, the relative sizes of the components in the accompanying drawings may be exaggerated. In the following description of the accompanying drawings, the same or similar reference numerals refer to the same or similar components or entities, and only describe the differences relative to individual embodiments. As used herein, unless otherwise explicitly stated, the term "or" covers all possible combinations unless not feasible. For example, if it is stated that a component can include A or B, then unless otherwise explicitly stated or not feasible, the component can include A or B or A and B. As a second example, if it is stated that a component can include A, B or C, then unless otherwise explicitly stated or not feasible, the component can include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0029] Now, refer to Figure 1A , Figure 1A is a schematic diagram illustrating an exemplary charged particle beam inspection system 100 according to an embodiment of the present disclosure. Figure 1A As shown, the charged particle beam inspection system 100 includes a main chamber 10, a load lock chamber 20, an electron beam tool 40 and an equipment front end module (EFEM) 30. The electron beam tool 40 is located in the main chamber 10. Although the description and the drawings relate to electron beams, it should be appreciated that the embodiments are not intended to limit the present invention to specific charged particles. It should also be appreciated that the electron beam tool 40 can be a single beam tool utilizing a single electron beam or a multi-beam tool utilizing multiple electron beams.

[0030] The EFEM 30 includes a first loading port 30a and a second loading port 30b. The EFEM 30 may include one or more other loading ports. The first loading port 30a and the second loading port 30b may, for example, accommodate a front opening pod (FOUP) that contains wafers (e.g., semiconductor wafers or wafers made of one or more other materials) or samples to be inspected (wafers and samples are collectively referred to as "wafers" hereinafter). One or more robot arms (e.g., Figure 1B The robot arm (shown) transports the wafer to the load lock chamber 20.

[0031] although Figure 1A The load lock chamber 20 is shown to be located within the main chamber 10, but it should also be appreciated that Figure 2A As shown, the load lock chamber 20 may be located next to the main chamber 10 just outside the main chamber.

[0032] The load lock chamber 20 can be connected by a gate valve between the chambers (e.g. Figure 1B The load lock chamber 20 may include a sample holder (not shown) that may hold one or more wafers. The load lock chamber 20 may also include a mechanical transfer device (e.g., Figure 1BThe load lock chamber 20 may be connected to a load lock vacuum pump system (not shown) that removes gas molecules in the load lock chamber 20 to reach a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (such as Figure 1B The wafer is transported from the load lock chamber 20 to the main chamber 10 by a vacuum pump (not shown). The main chamber 10 is connected to a main chamber vacuum pump system (not shown), which removes gas molecules in the main chamber 10 to reach a second pressure lower than the first pressure. After reaching the second pressure, the wafer is inspected by the electron beam tool 40.

[0033] The controller 50 is electrically connected to the electron beam tool 40. The controller 50 may be a computer configured to perform various controls of the charged particle beam inspection system 100. Figure 1A 30, but it should be appreciated that the controller 50 may be part of the structure. Although the present disclosure provides an example of a main chamber 10 housing an electron beam inspection tool, it should be noted that aspects of the present disclosure in its broadest sense are not limited to chambers housing electron beam inspection tools. Rather, it should be appreciated that the aforementioned principles may also be applied to other tools operating at a second pressure.

[0034] Now, refer to Figure 1B , Figure 1B is a diagram illustrating an embodiment according to the present disclosure Figure 1A Schematic diagram of an exemplary wafer loading sequence in the charged particle beam inspection system 100 . Figure 1B is a two-dimensional view observed from the top of the inspection system 100. The X and Y axes represent two perpendicular directions defining the projection plane. In some embodiments, the charged particle beam inspection system 100 may include a robot arm 11 located in the EFEM 30 and a robot arm 12 located in the main chamber 10. In some embodiments, the EFEM 30 may also include a pre-aligner 60 configured to accurately position the wafer before transporting the wafer to the load lock chamber 20.

[0035] In some embodiments, the first load port 30a and the second load port 30b can receive, for example, a front opening wafer transport box (FOUP) that contains wafers. The robot arm 11 in the EFEM 30 can transport the wafer from any of the load ports to the pre-aligner 60 to assist in positioning. The pre-aligner 60 can use mechanical or optical alignment methods to position the wafer. After pre-alignment, the robot arm 11 can transport the wafer to the load lock chamber 20.

[0036] After the wafer is transported to the load lock chamber 20, a load lock vacuum pump (not shown) may remove gas molecules in the load lock chamber 20 to reach a first pressure lower than atmospheric pressure. After reaching the first pressure, the robot arm 12 may transport the wafer from the load lock chamber 20 to the wafer stage 80 of the electron beam tool 40 in the main chamber 10. The main chamber 10 is connected to a main chamber vacuum pump system (not shown) that removes gas molecules in the main chamber 10 to reach a second pressure lower than the first pressure. After reaching the second pressure, the wafer may be inspected by the electron beam tool.

[0037] In some embodiments, the main chamber 10 may include a docking station 70 configured to temporarily store wafers before inspection. For example, when the inspection of the first wafer is completed, the first wafer may be unloaded from the wafer stage 80, and then the robot arm 12 may transport the second wafer from the docking station 70 to the wafer stage 80. Thereafter, the robot arm 12 may transport the third wafer from the load lock chamber 20 to the docking station 70 to temporarily store the third wafer until the inspection of the second wafer is completed.

[0038] Now, refer to Figure 2A , Figure 2A is a schematic diagram illustrating an exemplary charged particle beam inspection system having a conventional load lock chamber. Figure 2A 1 is a three-dimensional projection diagram of the inspection system 100. The vertical axis (Z axis) represents the height from the ground. The inspection system 100 includes a load lock chamber 20, which is attached to the main chamber 10. The load lock chamber is used to transfer a wafer 250 between an atmospheric clean room environment and the main chamber 10 maintained in a deep vacuum state. The load lock chamber 20 can be connected to a pumping structure 220, which removes gas molecules in the load lock chamber 20 to achieve a vacuum state. The pumping structure 220 may include various vacuum pumps, such as a roughing pump and a turbomolecular pump (TMP). The pumping structure 220 may also include a vacuum definition tool, such as a plasma cleaner and a residual gas analyzer (RGA). The load lock chamber 20 may also be connected to an exhaust structure 210, which is configured to inject gas into the load lock chamber 20 to restore the pressure in the load lock chamber to an atmospheric pressure level. In a typical conventional particle beam inspection system, the exhaust structure 210 is installed on the top of the load lock chamber 20 , and the pumping structure 220 is installed below the load lock chamber 20 .

[0039] Now, refer to Figure 2B , Figure 2B2 is a schematic diagram illustrating an exemplary charged particle beam inspection system with a conventional load lock chamber. As explained above, in a conventional particle beam inspection system, an exhaust structure 210 is mounted on the top of the load lock chamber 20. The exhaust structure 210 may include a gas supply 211, an exhaust valve 212, and an exhaust port 213. The exhaust port 213 may be placed on the top seal of the load lock chamber 20 and is configured to inject gas from top to bottom into the load lock chamber 20. Injecting gas from the top of the load lock chamber provides a strong downward exhaust flow in the load lock chamber 20, which enables rapid upward ventilation operations to increase system throughput. The downward exhaust flow further reduces the chance of uninvited particle contamination because it suppresses the resuspension of particles that may be present at the bottom surface of the load lock chamber 20.

[0040] Similarly, in a conventional particle beam inspection system, a pumping structure 220 is installed below the load lock chamber 20. The pumping structure 220 may include a load lock valve 221 and a load lock turbomolecular pump 222. The pumping structure 220 may also include a load lock roughing valve and a load lock roughing pump (not shown). The pumping structure 220 may also include vacuum confinement tools, such as a plasma cleaner and a residual gas analyzer (not shown). The pumping structure 220 (such as a vacuum pump and a vacuum confinement tool) is typically complex and bulky, and is relatively prone to failure, thus requiring staff to perform maintenance work more frequently. For example, in practice, it is well known that the installation and maintenance of turbomolecular pumps requires a lot of manpower and material resources. However, the space below the load lock chamber 20 is typically very compact, which can cause various problems for staff (e.g., operators, technicians) who need to perform frequent maintenance work in a compact space. For example, Figure 2C The figure shows a technician performing maintenance work on the turbomolecular pump 222 in a tight space below the load lock chamber 20. This creates ergonomic problems and even physical dangers to the technician. In addition, due to improper operation and uncomfortable posture in the crowded space, the chance of damaging the parts is also higher.

[0041] Simply exchanging the positions of the exhaust structure 210 and the pumping structure 220 is not sufficient to solve the above problem. The internal structure of the conventional load lock chamber presents a downward exhaust flow, and thus the exhaust port (such as Figure 2B Moving the exhaust port 213 in the load lock chamber 20 to the bottom of the load lock chamber 20 may cause harmful flow-induced disturbances, such as wafer shedding. Further, as described above, downward gas flow is preferred due to its properties of inhibiting particle resuspension and contamination. In addition, if the exhaust port is placed on the bottom of the load lock chamber, the upward exhaust flow will agitate particles present in the load lock chamber, thereby causing contamination problems.

[0042] Now, refer to Figure 3A and Figure 3B , Figure 3A and Figure 3B is a schematic diagram illustrating an exemplary load lock chamber according to an embodiment of the present disclosure. In some embodiments, the load lock chamber 20 may include multiple internal compartments. One side of the load lock chamber 20 may be configured to hold wafers, while the other side of the load lock chamber is separated from the compartments in which the wafers are held by the internal structure covering the wafer below. Even if the exhaust port is located on the bottom of the load lock chamber, this separation can prevent the exhaust flow from directly impinging on the wafer. For example, as Figure 3A and Figure 3B As shown, the load lock chamber 20 may include a first compartment 310 and a second compartment 320. The first compartment 310 may be configured to receive a wafer 250 for transferring it to a main chamber (not shown) and transferring the wafer 250 from the main chamber. During the pumping operation and the ventilation operation, the wafer 250 is placed on a wafer holder 370. The second compartment 320 may include an exhaust port 312 on the bottom wall of the load lock chamber 20. The location of the exhaust port is flexible. For example, instead of the exhaust port 312 on the bottom wall, the load lock chamber 20 may have one or more side exhaust ports 313. In some embodiments, the exhaust port 312 and the side exhaust port 313 may coexist.

[0043] The first compartment 310 and the second compartment 320 may be separated by a baffle 350. In some embodiments, the baffle 350 may have a cantilever shape. The baffle 350 may be configured to cover the wafer 250 below to prevent direct impact from exhaust gas. In some embodiments, the second compartment 320 may be smaller than the first compartment 310. In some embodiments, the baffle 350 and the top seal 355 (e.g., the top wall of the load lock chamber) may form a flow attenuation path 330 connecting the first compartment 310 and the second compartment 320. The flow attenuation path 330 enables the exhaust gas in the second compartment 320 to flow to the first compartment 310. As Figure 3B As shown by a series of arrows (391 to 396) in FIG. 3 , for example, during a venting operation, gas is first injected into the second compartment 320 via the exhaust port 312, then flows upward within the second compartment 320, then flows across the entire baffle plate through the flow attenuation path 330, and then finally enters the first compartment 310 holding the wafer 250 via the opening 340. It should be appreciated that the opening 340 may have a variety of shapes as long as it permits gas to flow into the first compartment 310. For example, the opening 340 may be a slit formed between one end of the baffle plate 350 and the inner surface of the sidewall of the load lock chamber 20. In some embodiments, the opening 340 may be one or more holes placed on the baffle plate 350 along the sidewall of the load lock chamber 20.

[0044] Figure 3B The size of arrows 391 to 396 in FIG. 3 illustrates the decay of the gas flow velocity. Figure 3B As shown, when the gas enters the second compartment 320 (see arrows 391 and 392), the gas flow velocity is high. However, the high-speed exhaust gas travels through the flow attenuation path 330 across most of the load lock chamber (see arrows 393, 394, 395). When the gas reaches the wafer 250 in the first compartment 310 (see arrow 396), the gas flow velocity is greatly reduced. In some embodiments, the velocity reduction is greater than 95% relative to the initial velocity when the gas is discharged into the second compartment. In addition, the gas still flows downwardly in the first compartment 310 relative to the wafer 250. The slow velocity and downward direction combined reduce the flow disturbance around the wafer 250 and the chance of particle resuspension, thereby better protecting the wafer 250 and reducing particle contamination.

[0045] Further, it can be observed that the magnitude of the surface shear rate (Ustar) on the surface of the wafer 250 is lower in the improved load lock chamber. A lower surface shear rate is associated with a lower probability of particle deposition. Thus, a low Ustar value on the surface of the wafer 250 means a lower chance of particle deposition on the surface of the wafer 250 in the first compartment 310. Therefore, even if some particles are brought into the first compartment 310 with the exhaust flow, they are less likely to be deposited on the surface of the wafer 250. In addition, within the flow attenuation path 330 (e.g., on the top surface of the baffle 350 and / or the bottom surface of the top seal 355), the Ustar value is much larger, so any particles in the gas exhaust flow are more likely to remain in the flow attenuation path 330 rather than reach the wafer 250. The flow attenuation path 330 can effectively act as a particle filter.

[0046] In some embodiments, the load lock chamber 20 may further include a vacuum port 360, which may be connected to a vacuum pump (e.g., a turbomolecular pump or a roughing pump) for a pumping operation. Figure 2A The exhaust structure 210 in FIG. 2 is no longer placed on top of the load lock chamber 20, so the pumping structure (such as Figure 2A The pumping structure 220 in the embodiment of the present invention can be mounted above the load lock chamber 20. This allows for better access to the pumping structure, such as a turbomolecular pump or other vacuum confining tools for personnel performing installation or maintenance work. Thus, the improved load lock chamber can provide better access to high maintenance components, such as the pumping structure, while still providing the required downward exhaust flow to better protect the wafers and reduce particle contamination.

[0047] The embodiments may also be described using the following terms.

[0048] 1. A loading lock assembly comprising:

[0049] a load lock chamber having an exhaust port on one side or the bottom of the load lock chamber;

[0050] the load lock chamber having a first compartment and a second compartment, the first compartment being configured to receive wafers for loading into and unloading from a main vacuum chamber, and the second compartment being configured to receive gas from the exhaust port and direct the gas to a flow attenuation path, the flow attenuation path being configured to attenuate a gas flow;

[0051] The flow attenuation path is further configured such that the gas passing through the flow attenuation path enters the first compartment, so that the gas flows downward toward the bottom of the first compartment.

[0052] 2. The load lock chamber of clause 1, wherein the flow attenuation path is located above the first compartment.

[0053] 3. The load lock chamber according to clauses 1 to 2, further comprising a baffle separating the flow attenuation path from the first compartment.

[0054] 4. The load lock chamber of clause 3, wherein the baffle covers a portion of the first compartment, the wafer being configured to be placed in the portion.

[0055] 5. A load lock chamber according to clauses 3 to 4, wherein the baffle is a cantilever structure.

[0056] 6. A load lock chamber according to clauses 3 to 5, wherein the baffle separates the first compartment from the second compartment.

[0057] 7. The load lock chamber of clauses 1 to 6, further comprising an opening near the top of the first compartment, the opening configured to allow the gas to flow from the flow attenuation path into the first compartment.

[0058] 8. The load lock chamber of clause 7, wherein the opening is located adjacent a side of the load lock chamber that is positioned opposite the second compartment.

[0059] 9. A load lock chamber according to clauses 7 to 8, wherein the opening is in the shape of a slit.

[0060] 10. The load lock chamber of clauses 1 to 9, wherein the flow attenuation path is configured to induce a top-down gas flow within the first compartment.

[0061] 11. The load lock chamber of clauses 1 to 10, wherein the height of the flow attenuation path is less than the height of the first compartment.

[0062] 12. The load lock chamber of clauses 1 to 11, wherein the volume of the first compartment is greater than the volume of the second compartment.

[0063] 13. A load lock chamber comprising:

[0064] Exhaust port;

[0065] a first compartment configured to receive wafers for loading into and unloading from the main vacuum chamber;

[0066] a second compartment, spaced apart from the first compartment, the second compartment being configured to receive gas through the exhaust port; and

[0067] A flow attenuation path connects the first compartment and the second compartment, the flow attenuation path being configured to guide the gas from the second compartment to the first compartment and attenuate a gas flow.

[0068] 14. The load lock chamber of clause 13, wherein the exhaust port is located on a bottom wall of the load lock chamber.

[0069] 15. The load lock chamber of clause 13, wherein the exhaust port is located on a side wall of the load lock chamber.

[0070] 16. A load lock chamber according to clauses 13 to 15, wherein the flow attenuation path is located above the first compartment.

[0071] 17. The load lock chamber of clauses 13 to 16, further comprising a baffle separating the flow attenuation path from the first compartment.

[0072] 18. The load lock chamber of clause 17, wherein the baffle covers a portion of the first compartment, the wafer being configured to be placed in the portion.

[0073] 19. The load lock chamber according to clauses 17 to 18, wherein the baffle is a cantilever structure.

[0074] 20. The load lock chamber of clauses 17 to 19, wherein the baffle separates the first compartment from the second compartment.

[0075] 21. The load lock chamber of clauses 17 to 20, further comprising an opening near the top of the first compartment, the opening configured to allow the gas to flow from the flow attenuation path into the first compartment.

[0076] 22. The load lock chamber of clause 21, wherein the opening is located adjacent a side of the load lock chamber that is positioned opposite the second compartment.

[0077] 23. The load lock chamber according to clauses 21 to 22, wherein the opening is in the shape of a slit.

[0078] 24. A load lock chamber according to clauses 13 to 23, wherein the flow attenuation path induces a top-down gas flow within the first compartment.

[0079] 25. The load lock chamber of clauses 13 to 24, wherein the height of the flow attenuation path is less than the height of the first compartment.

[0080] 26. The load lock chamber of clauses 13 to 25, wherein the volume of the first compartment is greater than the volume of the second compartment.

[0081] 27. A loading lock assembly comprising:

[0082] Load lock chamber, including:

[0083] Exhaust port;

[0084] a first compartment configured to receive wafers for loading into and unloading from the main vacuum chamber;

[0085] a second compartment, spaced apart from the first compartment, the second compartment being configured to receive gas through the exhaust port; and

[0086] a flow attenuation path connecting the first compartment and the second compartment, the flow attenuation path being configured to guide the gas from the second compartment to the first compartment and attenuate a gas flow;

[0087] A vacuum pump, connected to the load lock chamber, and

[0088] A gas supply is connected to the load lock chamber through the exhaust port.

[0089] 28. The load lock assembly of clause 27, wherein the exhaust port is located on a bottom wall of the load lock chamber.

[0090] 29. The load lock assembly of clause 27, wherein the exhaust port is located on a side wall of the load lock chamber.

[0091] 30. The load lock assembly according to clauses 27 to 29, wherein the load lock chamber further comprises a vacuum port located on a top wall of the load lock chamber.

[0092] 31. The load lock assembly of clauses 27 to 30, wherein the vacuum pump is located above the load lock chamber.

[0093] 32. A load lock assembly according to clauses 27 to 31, wherein the vacuum pump comprises a roughing pump or a turbomolecular pump.

[0094] Although the disclosed embodiments have been explained with respect to the preferred embodiments thereof, it should be understood that other modifications and variations may be made without departing from the spirit and scope of the subject matter as hereinafter claimed.

Claims

1. A load lock chamber comprising: Exhaust port; a first compartment configured to receive wafers for loading into and unloading from the main vacuum chamber; a second compartment, spaced apart from the first compartment, the second compartment being configured to receive gas through the exhaust port; as well as A flow attenuation path connects the first compartment and the second compartment, the flow attenuation path being configured to guide the gas from the second compartment to the first compartment and attenuate a gas flow. 2 . The load lock chamber of claim 1 , wherein the exhaust port is located on a bottom wall of the load lock chamber. 3 . The load lock chamber of claim 1 , wherein the exhaust port is located on a side wall of the load lock chamber. The load lock chamber of claim 1 , wherein the flow attenuation path is located above the first compartment. 5 . The load lock chamber of claim 1 , further comprising a baffle separating the flow attenuation path from the first compartment. 6 . The load lock chamber of claim 5 , wherein the baffle covers a portion of the first compartment, the wafer being configured to be placed in the portion. The load lock chamber of claim 5 , wherein the baffle is a cantilever structure.

8. The load lock chamber of claim 5, wherein the baffle separates the first compartment from the second compartment. 9 . The load lock chamber of claim 5 , further comprising an opening near the top of the first compartment, the opening configured to allow the gas to flow from the flow attenuation path into the first compartment. 10 . The load lock chamber of claim 9 , wherein the opening is located near a side of the load lock chamber that is located opposite to the second compartment. The load lock chamber of claim 9 , wherein the opening is in the shape of a slit.

12. The load lock chamber of claim 1, wherein the flow attenuation path induces a top-down gas flow within the first compartment.

13. The load lock chamber of claim 1, wherein a height of the flow attenuation path is less than a height of the first compartment.

14. The load lock chamber of claim 1, wherein a volume of the first compartment is greater than a volume of the second compartment.

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