Dual-scan ion implant system with improved throughput

Abstract

A dual-scan ion implant system with improved throughput, according to one embodiment of the present invention, comprises: a first loadlock chamber assembly connected to one end of an EFEM; a second loadlock chamber assembly connected to the other end of the EFEM; a single vacuum transfer module (VTM) to which the first loadlock chamber assembly and the second loadlock chamber assembly are connected together; first and second dual-arm vacuum robots disposed inside the vacuum transfer module (VTM); a single process chamber connected to the vacuum transfer module (VTM), in which scanning is performed using an ion beam in a vacuum atmosphere; and first and second scan robots disposed inside the process chamber, wherein wafers are respectively transferred from the EFEM to the first loadlock chamber assembly, the second loadlock chamber assembly, the single vacuum transfer module (VTM), the single process chamber, and the first and second scan robots disposed inside the process chamber via different wafer scan transfer paths that do not overlap with each other, after which the first and second scan robots alternately perform ion beam scanning, and even if either one of the first and second scan robots fails to operate normally, the system is controlled such that the other scan robot continues normal operation.

Description

Dual-scan type ion implant system with improved throughput

[0001] The present invention relates to a dual-scan type ion implant system with improved throughput, and more specifically, to a dual-scan type ion implant system with improved throughput that resolves the problems of a conventional single-ion scan robot handling all the loading, unloading, and scanning for wafer replacement alone, which results in a significant decrease in wafer throughput because scanning cannot proceed at all during wafer replacement and transport, as well as the continuous waste of expensive ion beams during wafer replacement and transport and the reduced space utilization of a semiconductor manufacturing fab due to an increase in footprint.

[0002] Generally, the semiconductor device manufacturing process is performed by repeatedly carrying out oxidation, photolithography, diffusion, ion implantation, and metallization processes on a silicon wafer.

[0003] Among the aforementioned processes, the ion implantation process refers to the injection of charged impurities into a wafer at a desired amount and depth using a predetermined energy. In general, in semiconductor manufacturing, the ion implantation process refers to the injection of dopant ions into the surface of a silicon wafer.

[0004] The ion implanter used in the ion implantation process consists of the following four main parts.

[0005] These major parts can be divided into an ion source area, which is the region for extracting the ion beam; a terminal area, which includes a mass analyzer that classifies the extracted ion beam into desired masses and a beam line, which is the pathway through which the ion beam passes; and an end-station area, which transports the wafer and finally implants the ion beam. In the end-station area, the wafer is scanned within a processor chamber in a high-vacuum state, and the ion beam is implanted into the wafer.

[0006] The aforementioned ion implantation device is equipped with a single ion scan robot within the processor chamber, and since the single ion scan robot independently handles the entire process from sequentially introducing wafers one by one into the processor chamber to scanning (ion implantation) and removing them, it is also commonly referred to as a single-scan type ion implantation system.

[0007] Below, an example of such a single-scan type ion implant system is well illustrated in Korean Patent Registration No. 1311885 (hereinafter referred to as the 'prior art').

[0008] Referring to Fig. 1 of the prior art, the system has a configuration in which wafers (W) are brought in one by one from a wafer cassette (71) into a vacuum processing chamber (20) through an incoming dedicated load lock chamber (40A) and an opening / closing door (41A) installed on one side of the ion implant system, and the wafers (W) for which ion scanning is completed are then returned to the wafer cassette (72) through an outgoing dedicated load lock chamber (40B) and an opening / closing door (41B).

[0009] However, the conventional single-scan type ion implant system disclosed in the aforementioned prior art is equipped with only a single platen (hereinafter collectively referred to as a 'single ion scan robot') capable of tilting according to the ion implantation direction inside a vacuum processing chamber for performing ion implantation. Consequently, since the single ion scan robot must handle all the loading, unloading, and scanning for wafer replacement by itself, scanning cannot proceed at all during wafer transport, which not only significantly reduces wafer throughput but also causes serious problems such as the waste of expensive ion beams during wafer replacement / transport.

[0010] In addition, since the wafer is directly transferred from the vacuum load lock chamber to the vacuum processing chamber under atmospheric pressure, a time delay occurs as the vacuum atmosphere is re-established every time the load lock chamber is opened to transfer the wafer, which also became a factor in reducing throughput.

[0011] In addition, in order to increase the throughput of the ion implant process, the load lock chamber and vacuum processing chamber of the conventional single-scan type ion implant system configured as described above must all be expanded to multiple units, which increases the equipment footprint accordingly and ultimately leads to a problem where the space utilization of the semiconductor manufacturing fab is significantly reduced.

[0012] <Prior Art Literature>

[0013] Korean Patent Registration No. 1311885 (Registered September 17, 2013)

[0014] Accordingly, the present invention has been devised to resolve the above-mentioned problems. It aims to provide a dual-scan type ion implant system with improved throughput that resolves the issues of a conventional single-ion scan robot handling all the loading, unloading, and scanning for wafer replacement alone, which results in a significant decrease in wafer throughput because scanning cannot proceed at all during wafer replacement and transport, as well as the continuous waste of expensive ion beams during wafer replacement and transport and the reduced space utilization of a semiconductor manufacturing fab due to an increase in footprint.

[0015] According to one embodiment, the present invention for achieving the above-mentioned purpose comprises: a first load lock chamber assembly connected to one end of an EFEM; a second load lock chamber assembly connected to the other end of the EFEM; a single vacuum transfer module (VTM) in which the first load lock chamber assembly and the second load lock chamber assembly are connected together; first and second dual-arm vacuum robots disposed inside the vacuum transfer module (VTM); and a single process chamber to which the vacuum transfer module (VTM) is connected, wherein scanning by an ion beam is performed in a vacuum atmosphere. The invention includes first and second scan robots disposed inside the process chamber; wherein the first and second scan robots each receive a wafer from the EFEM through different wafer scan transfer paths that do not overlap with each other, and the first and second scan robots alternately perform ion beam scans, and are controlled so that even if one of the first and second scan robots fails to operate normally, the other one continues to operate normally.

[0016] In addition, according to one embodiment, the invention is characterized by configuring a first wafer scan transfer path that reciprocates the first load lock chamber assembly, the first dual arm vacuum robot, and the first scan robot, and configuring a second wafer scan transfer path that reciprocates the second wafer scan transfer path connecting the second load lock chamber assembly, the second dual arm vacuum robot, and the second scan robot.

[0017] In addition, according to one embodiment, the first wafer scan transfer path and the second wafer scan transfer path are characterized by forming a symmetrical straight line shape without overlapping each other.

[0018] In addition, according to one embodiment, the single vacuum transfer module (VTM) and the single process chamber are characterized by having widths in the left-right direction perpendicular to the first and second wafer scan transfer paths that are equal or similar to each other.

[0019] In addition, according to one embodiment, the partition between the single vacuum transfer module (VTM) and the single process chamber is characterized by having a vacuum atmosphere of the same pressure as it is connected to allow the wafer to reciprocate.

[0020] In addition, according to one embodiment, an ion beam is irradiated between the first and second scan robots inside the process chamber, and the first and second scan robots positioned on both sides of the ion beam irradiation area continuously scan the wafer while alternately exposing it to the ion beam irradiation area.

[0021] In addition, according to one embodiment, a single aligner for aligning the notch direction of a wafer is positioned between the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM).

[0022] In addition, according to one embodiment, first and second aligners for aligning the notch direction of a wafer are respectively disposed on the sides of the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM).

[0023] In addition, according to one embodiment, first and second aligners for aligning the notch direction of a wafer are respectively disposed above the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM).

[0024] In addition, according to one embodiment, the first load lock chamber assembly and the second load lock chamber assembly are each characterized by being divided into an upper chamber and a lower chamber for introducing or removing a wafer into or out of the first or second vacuum transfer module (VTM).

[0025] In addition, according to one embodiment, the first and second scan robots each comprise: an L1 axis vertically coupled to one side of a first link and rotating the first link by driving a first drive unit; an L2 axis in which a second link of the same length as the first link is superimposed on the upper part of the first link and vertically coupled to the other side of the first link and one side of the second link superimposed thereon, rotating the second link by driving a second drive unit; an R axis in which a support frame supporting a scan head is superimposed on the upper part of the other side of the second link and vertically coupled to the other side of the second link and the center of the support frame, rotating the support frame by driving a third drive unit; and a Y axis horizontally coupled to the support frame to support both sides of the scan head and rotating the scan head by driving a fourth drive unit. The invention includes an S-axis that adjusts the twist angle or orientation angle of a wafer by rotating a wafer chuck on which a wafer is placed by driving a fifth driving unit; wherein the first driving unit and the second driving unit drive in synchronization, and the first link rotates left and right with respect to the L1 axis, and the second link rotates left and right with respect to the L2 axis to move the scan head horizontally left and right.

[0026] In addition, according to one embodiment, the first load lock chamber assembly and the second load lock chamber assembly are each characterized by having a plurality of chambers arranged in a vertical or horizontal direction.

[0027] As described above, the present invention has the effect of significantly improving the wafer processing efficiency, i.e., throughput of the ion implantation process, by enabling nearly twice as many wafers to be processed in the same amount of time compared to a conventional single-scan system, as the first and second scan robots inside the process chamber each receive wafers from the EFEM through different wafer scan transfer paths that do not overlap with each other, and then the first and second scan robots alternately perform ion beam scans.

[0028] In addition, even if a problem occurs in either of the first or second scan robots, the ion implantation process can continue using the other without wasting the ion beam, thereby maintaining the throughput of the ion implantation process at a certain level and effectively resolving the problem of wasting expensive ion beams due to process interruptions.

[0029] In addition, the first and second dual-arm vacuum robots and the first and second scan robots are arranged adjacent to each other within a single vacuum transfer module (VTM) and a single process chamber to form the shortest wafer scan transfer path in a straight line, thus occupying nearly half the footprint compared to the case where two lines of a conventional single-scan scanning system are constructed, thereby improving the customer's Fab space utilization.

[0030] In addition, the improvement in Fab throughput and increased space utilization can lead to overall cost savings, including direct component repair costs and labor costs, as well as indirect costs such as electricity and utility costs. This ultimately contributes to improved price competitiveness in wafer production and the localization of implant equipment.

[0031] FIG. 1 is a plan view showing a conventional single-scan type ion implant system.

[0032] FIG. 2 is a plan view showing a dual-scan type ion implant system with improved throughput according to a first embodiment of the present invention.

[0033] FIG. 3 is a plan view showing a dual-scan type ion implant system with improved throughput according to a second embodiment of the present invention.

[0034] FIG. 4 is a plan view showing a dual-scan type ion implant system with improved throughput according to a third embodiment of the present invention.

[0035] FIG. 5 is a plan view showing a dual-scan type ion implant system with improved throughput according to a fourth embodiment of the present invention.

[0036] FIG. 6 is a plan view showing a dual-scan type ion implant system with improved throughput according to the fifth embodiment of the present invention.

[0037] FIG. 7 is a conceptual diagram illustrating a wafer beam scanning method of a first and second scan robot according to an embodiment of the present invention.

[0038] FIG. 8 is a schematic diagram illustrating the configuration of a first and second scanning robot according to an embodiment of the present invention.

[0039] FIGS. 9(a) and (b) are motion diagrams for explaining the operation of left and right scanning by synchronously driving the respective driving units of the L1 axis, L2 axis, and R axis of the first and second scan robots according to an embodiment of the present invention.

[0040] FIG. 10 (a) and (b) are motion diagrams for explaining the 45° tilt scan operation of the first and second scan robots according to an embodiment of the present invention.

[0041] FIG. 11 (a) and (b) are motion diagrams for explaining the operation of a scan head according to Y-axis (Tilt axis) driving in a first and second scan robot according to an embodiment of the present invention.

[0042] FIGS. 12 (a) and (b) are motion diagrams for explaining the adjustment of the twist angle or orientation angle of a wafer according to the S-axis driving of a scan head in a first and second scan robot according to an embodiment of the present invention.

[0043] FIG. 13 is a drawing illustrating the doping uniformity during high-angle tilt ion implantation of a wafer by first and second scan robots according to an embodiment of the present invention.

[0044] FIG. 14 is a conceptual diagram showing a dual scan process according to an embodiment of the present invention.

[0045] FIG. 15 is a diagram illustrating each step of a dual scan process according to an embodiment of the present invention, comprising: (a) a state where a left single scan starts and a right wafer is exchanged; (b) a state where a left single scan is completed and a right scan is waiting; (c) a state where a left wafer is exchanged and a right single scan starts; and (d) a state where a left scan is waiting and a right single scan is completed.

[0046] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “having,” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described herein, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0047] Unless otherwise defined in this specification, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains.

[0048] Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0049] Hereinafter, the configuration and operational relationship of a dual-scan type ion implant system according to one embodiment of the present invention will be examined in detail with reference to the attached drawings.

[0050] FIG. 2 is a plan view showing a dual-scan type ion implant system with improved throughput according to the first embodiment of the present invention.

[0051] Referring to FIG. 2, according to one embodiment, the present invention is largely composed of an EFEM (not shown), first and second load lock chamber assemblies (40-1) (40-2), a single vacuum transfer module (VTM, 50), first and second dual arm vacuum robots (60-1) (60-2), a single process chamber (10), and first and second scan robots (20-1) (20-2).

[0052] First, although not shown in the drawing, the Equipment Front End Module (EFEM) is a standard interface module of process equipment that supplies wafers (W) in a wafer cassette or wafer pod (FOUP, Front Opening Unified Pod) to a process chamber (10) in a semiconductor line. Typically, one side of the EFEM may be equipped with a plurality of load ports on which a plurality of wafer cassettes or wafer pods are placed, and may be positioned on one side of the process chamber (10).

[0053] Additionally, the first and second load lock chamber assemblies (40-1) (40-2) are connected to one end and the other end of the EFEM (not shown), respectively. The first and second load lock chamber assemblies (40-1) (40-2) function as intermediate modules for introducing a wafer (W) transferred from the EFEM in an atmospheric pressure atmosphere into the process chamber (10).

[0054] According to one embodiment, the first load lock chamber assembly (40-1) and the second load lock chamber assembly (40-2) may each be configured to be divided into an upper chamber (not shown) and a lower chamber (not shown) for bringing a wafer (W) into or out of a single vacuum transfer module (50).

[0055] Specifically, the upper chamber (not shown) is provided with a wafer receiving slot for receiving a wafer (W) into a single vacuum transfer module (50), and the wafer (W) is delivered to a first dual arm vacuum robot (60-1) inside the single vacuum transfer module (50) through the wafer receiving slot.

[0056] Likewise, the lower chamber (not shown) is provided with a wafer ejection slot for ejecting a wafer (W) from inside a single vacuum transfer module (50), and after the wafer ejection slot is opened, the wafer (W) with completed ion implantation (scan) is received from the first dual arm vacuum robot (60-1) inside the single vacuum transfer module (50).

[0057] In the above-described embodiment, the first load lock chamber assembly (40-1) and the second load lock chamber assembly (40-2) are vertically divided into an upper chamber and a lower chamber, respectively, for space efficiency on the wafer scan transfer path, and the present invention is not limited thereto.

[0058] Additionally, a single vacuum transfer module (VTM) is connected to the first load lock chamber assembly and the second load lock chamber assembly (40-1)(40-2). Here, the single vacuum transfer module (50) is provided between the first and second load lock chamber assemblies (40-1)(40-2) and the process chamber (10).

[0059] The single vacuum transfer module (50) above is an intermediate module that waits before the wafer (W) is introduced into the process chamber (10), and maintains a high vacuum corresponding to that of the process chamber (10) by communicating with the process chamber (10).

[0060] Additionally, the first and second dual arm vacuum robots (60-1) (60-2) are placed inside the vacuum transfer module (50).

[0061] The first and second dual-arm vacuum robots (60-1) (60-2) each have two arms (unmarked). Accordingly, using the two arms, the first and second dual-arm vacuum robots (60-1) (60-2) can perform a combined operation of simultaneously bringing in or taking out two wafers (W) with the first load lock chamber assembly and the second load lock chamber assembly (40-1) (40-2), or simultaneously bringing in or taking out two wafers (W) with the first and second scan robots (20-1) (20-2) inside the processor chamber (10).

[0062] Additionally, a single process chamber (10) is connected to the vacuum transfer module (50), and scanning by an ion beam is performed in a vacuum atmosphere.

[0063] The single process chamber (10) above is a processing space where scanning (ion implantation) of a wafer (W) by an ion beam takes place, and the process chamber (10) is maintained at a high vacuum to provide a clean ion implantation environment free of particles.

[0064] For example, an ion beam is irradiated to the center of the process chamber (10), and the shape of this ion beam may be a ribbon beam or a spot beam that is line-scanned in one direction of the electric and magnetic fields.

[0065] Accordingly, as shown in FIG. 2, an ion beam is incident on one side of the process chamber (10) into the process chamber (10) and meets the wafer (W) at a point (B, ion beam irradiation area) inside the process chamber (10) to perform a scan, and an ion beam dump (not shown) is provided on the opposite side of the process chamber (10) where the ion beam is incident.

[0066] In addition, the first and second scan robots (20-1) (20-2) are placed inside the process chamber (10).

[0067] Accordingly, according to the above configuration, the first load lock chamber assembly and the second load lock chamber assembly (40-1)(40-2), a single vacuum transfer module (50), a single process chamber (10), and the first and second scan robots (20-1)(20-2) inside the process chamber (10) each receive a wafer (W) through different wafer scan transfer paths (P1)(P2) that do not overlap with each other, and then the first and second scan robots (20-1)(20-2) continuously perform ion beam scans.

[0068] That is, first and second scan robots (20-1, 20-2) positioned on both sides of an ion beam irradiation area (B) inside a single process chamber perform continuous scanning while alternately exposing the wafer (W) to the ion beam irradiation area.

[0069] Accordingly, the present invention configures a first wafer scan transfer path (P1, a straight arrow shown on the left side of the drawing) that reciprocates the first load lock chamber assembly (40-1), the first dual arm vacuum robot (60-1), and the first scan robot (20-1) as shown in FIG. 2.

[0070] In addition, independently of the first wafer scan transfer path (P1), the present invention comprises a second wafer scan transfer path (P2, a straight arrow indicated on the right side of the drawing) that reciprocates the second load lock chamber assembly (40-2), the second dual arm vacuum robot (60-2), and the second scan robot (20-2).

[0071] Accordingly, the first wafer scan transfer path (P1) and the second wafer scan transfer path (P2) can be operated independently of each other and form a shortest distance wafer scan transfer path in the form of a parallel straight line without overlapping each other.

[0072] However, the first wafer scan transfer path (P1) and the second wafer scan transfer path (P2) do not necessarily have to be perfectly parallel or in a straight line shape to each other, and even when they form a symmetrical straight line shape to each other, a wafer scan transfer path approximately the shortest distance compared to the conventional one can be formed.

[0073] In particular, the configuration of the independent wafer scan transfer paths described above has the advantage that even if either of the first and second scan robots (20-1) (20-2) fails to operate normally, the other one can be controlled to continue operating normally.

[0074] In addition, according to one embodiment, the single vacuum transfer module (50) and the single process chamber (10) may be formed with equal widths in the left and right directions perpendicular to the first and second wafer scan transfer paths (P1) and (P2).

[0075] However, the single vacuum transfer module (50) and the single process chamber (10) mentioned above do not necessarily mean that their widths in the left and right directions are perfectly identical to each other; as long as they are identical or similar, they can form a straight-line wafer scan transfer path that is symmetrical to each other as described above, and also minimize the footprint.

[0076] In addition, according to one embodiment, the single vacuum transfer module (50) and the single process chamber (10) may have a vacuum atmosphere of the same pressure as they are connected to each other so that the wafer (W) can reciprocate.

[0077] In summary, the present invention comprises a single vacuum transfer module (VTM) and a single process chamber connected to form a first and second wafer scan transfer path having the shortest distance in a straight line, which is mutually independent, and also a first and second dual arm vacuum robot (60-1) (60-2) positioned inside the vacuum transfer module (50) to simultaneously process (in / out) two wafers (W), and a first and second scan robot (20-1) (20-2) positioned inside the single process chamber (10), thereby enabling the two wafers (W) to be scanned continuously without interruption by the first and second scan robots (20-1) (20-2).

[0078] According to one embodiment, an ion beam is irradiated in the area (B) between the first and second scan robots (20-1) (20-2) inside the process chamber (10), and the first and second scan robots (20-1) (20-2), positioned on both sides of the ion beam irradiation area (B), continuously scan two wafers (W) while alternately exposing them to the ion beam irradiation area (B).

[0079] That is, the first and second scan robots (20-1, 20-2) alternately perform a scanning operation to bring a wafer (W) into or out of the process chamber (10) under high vacuum, or to expose the brought-in wafer (W) to an ion beam.

[0080] Accordingly, unlike the case of the conventional single scan robot described above, the first and second scan robots (20-1, 20-2) of the present invention allow one of the robots to perform a scanning operation while the other robot is transporting the wafer (W) into or out of the process chamber (10). Therefore, when the scan is completed, the robot that finished transporting the wafer (W) can perform the scanning operation alternately and continuously, thereby preventing the disadvantage of the expensive ion beam being wasted because the conventional single scan robot could not scan while transporting the wafer (W).

[0081] Also, referring to FIG. 2, according to the first embodiment, a single aligner (70) for aligning the notch (see FIG. 12) direction of a wafer (W) is placed between the first and second dual-arm vacuum robots (60-1) (60-2) inside the single vacuum transfer module (50). By placing a single aligner (70) in this manner, the size and volume of the single vacuum transfer module can be reduced accordingly, and the advantage of reducing the vacuum attainment time required to re-establish a vacuum atmosphere each time the wafer (W) enters or exits can be obtained.

[0082] There is an advantage in reducing production costs due to the effect of simplifying the system.

[0083] Meanwhile, the aligner (70) may be configured to include a wafer chuck on which a wafer (W) is placed, although not specifically shown in the drawing; a servo motor provided below the wafer chuck to rotate the wafer (W) loaded on the wafer chuck by a certain angle in one direction or in the reverse direction; and a vision unit provided above the wafer chuck to image the notch (see FIG. 12) of the wafer (W) loaded on the wafer chuck.

[0084] The configuration of the above aligner (70) is not limited to a vision unit that captures an image as in the above-described embodiment, and according to other embodiments, it may be in a form that recognizes the outer edge and notch of a wafer (W) using a sensor (not shown) in place of the vision unit.

[0085] Accordingly, as seen in the configuration of the above-described embodiment, the present invention has a shortened straight-line wafer scan transfer path (P1, P2) and a spatially dense layout configuration of the first and second dual-arm vacuum robots (60-1) (60-2) inside a single vacuum transfer module (50), so the throughput of the ion implant process can be improved by nearly twofold compared to the conventional method, and furthermore, as the first and second scan robots (20-1) (20-2) perform continuous scans alternately, the waste of the ion beam can be eliminated, and the footprint of the system can be reduced by about half based on the same wafer processing performance.

[0086] FIG. 3 is a plan view showing a dual-scan type ion implant system with improved throughput according to a second embodiment of the present invention.

[0087] Referring to FIG. 3, the second embodiment of the present invention is configured differently from the configuration of the first embodiment, except for the chamber arrangement of the first and second load lock chamber assemblies (40-1) (40-2) (changing the arrangement from vertical to horizontal). That is, according to the second embodiment of the present invention, the first load lock chamber assembly and the second load lock chamber assembly (40-1) (40-2) are each divided into a left chamber and a right chamber for bringing a wafer (W) into or out of the first or second vacuum transfer module (50), and the left chamber and the right chamber have a horizontal layout configuration in which they are arranged in a horizontal direction.

[0088] FIG. 4 is a plan view showing a dual-scan type ion implant system with improved throughput according to a third embodiment of the present invention.

[0089] Referring to FIG. 4, the third embodiment of the present invention is configured differently from the configuration of the first embodiment, except that the arrangement of the aligner (70) within the vacuum transfer module (50) is changed (arrangement changed from vertical to horizontal). That is, according to the third embodiment of the present invention, the first and second aligners (70-1) (70-2) for aligning the notch direction (see FIG. 12) of the wafer (W) are respectively arranged on the sides of the first and second dual-arm vacuum robots (60-1) (60-2) inside the single vacuum transfer module (50), and the layout configuration is such that the first and second aligners are respectively arranged.

[0090] FIG. 5 is a plan view showing a dual-scan type ion implant system with improved throughput according to the fourth embodiment of the present invention.

[0091] Referring to FIG. 5, the fourth embodiment of the present invention is configured differently from the configuration of the third embodiment, except for the chamber arrangement of the first and second load lock chamber assemblies (40-1) (40-2) (changing the arrangement from vertical to horizontal). That is, according to the fourth embodiment of the present invention, the first load lock chamber assembly and the second load lock chamber assembly (40-1) (40-2) are each divided into a left chamber and a right chamber for bringing a wafer (W) into or out of a single vacuum transfer module (50), and the left chamber and the right chamber have a horizontal layout configuration in which they are arranged in a horizontal direction.

[0092] FIG. 6 is a plan view showing a dual-scan type ion implant system with improved throughput according to the fifth embodiment of the present invention.

[0093] Referring to FIG. 6, the fifth embodiment of the present invention is configured differently from the configuration of the first embodiment, except for the arrangement of the aligners within the vacuum transfer module (50). That is, according to the fifth embodiment of the present invention, the first and second aligners (70-1) (70-2) for aligning the notch direction of the wafer (W) are respectively arranged above the first and second dual-arm vacuum robots (60-1) (60-2) inside the single vacuum transfer module (50), and the layout configuration is provided.

[0094]

[0095] Meanwhile, FIG. 7 is a conceptual diagram illustrating a wafer beam scanning method of a first and second scan robot according to an embodiment of the present invention, FIG. 8 is a schematic diagram for explaining the configuration of a first and second scan robot according to an embodiment of the present invention, FIG. 9 (a) and (b) are motion diagrams for explaining the operation of left and right scanning by synchronously driving each driving unit of the L1 axis, L2 axis, and R axis of the first and second scan robots according to an embodiment of the present invention, FIG. 10 (a) and (b) are motion diagrams for explaining the 45° tilt scan operation of the first and second scan robots according to an embodiment of the present invention, FIG. 11 (a) and (b) are motion diagrams for explaining the operation of the scan head according to the Y-axis (Tilt axis) driving in the first and second scan robots according to an embodiment of the present invention, and FIG. 12 (a) and (b) are the twist angle or orientation angle of the wafer according to the S-axis driving of the scan head in the first and second scan robots according to an embodiment of the present invention Figure 13 is a plan view illustrating the doping uniformity during high-angle tilt ion implantation of a wafer by the first and second scan robots according to one embodiment of the present invention.

[0096] Hereinafter, the configuration and operational relationship of the first and second scan robots according to the present invention will be examined in more detail with reference to FIGS. 7 to 13 above as follows.

[0097] As illustrated in FIGS. 7 and 8, the first and second scan robots (20-1) (20-2) for ion implantation on a semiconductor wafer (W) according to one embodiment of the present invention perform left and right mechanical scanning in all directions within the horizontal plane through the movement of five drive axes consisting of L1 axis, L2 axis, R axis, Y axis (Tilt axis), and S axis with respect to the vertical scan ion beam.

[0098] First, as shown in FIG. 8, a first drive unit (110) is provided on the lower side of one side of the first link (100), and an L1 axis (120), which is the drive axis of the first drive unit (110), is vertically connected to one side of the first link (100). The L1 axis (120) becomes the reference axis of the first and second scan robots (20-1) (20-2) described above, and rotates the first link (100) left and right by the drive of the first drive unit (110).

[0099] And, a second link (200) is placed on top of the first link (100).

[0100] A second drive unit (210) is provided on the other side of the first link (100), and an L2 axis (220), which is the drive shaft of the second drive unit, protrudes upward and is vertically connected to one side of the second link (200). The L2 axis (220) rotates the second link (200) left and right by the driving of the second drive unit (210).

[0101] And, a support frame (300) that supports the scan head (400) is overlapped on the upper side of the other side of the second link (200).

[0102] A third drive unit (310) is provided on the other side of the second link (200), and the R-axis (320), which is the drive shaft of the third drive unit (310), protrudes upward and is vertically connected to the center of the support frame (300). The R-axis (320) rotates the support frame (300) left and right by the driving of the third drive unit (310).

[0103] Here, the first drive unit (110), the second drive unit (210), and the third drive unit (310) are driven in synchronization.

[0104] As illustrated in FIG. 9 (a) and (b), for a scan of 0°, as illustrated in FIG. 9 (b), the first link (100) rotates around the L1 axis (120) when the first drive unit (110) is driven from the initial state of FIG. 9 (a) as illustrated in FIG. 9 (b), and the second link (200), which has the same length as the first link, rotates around the L2 axis (220) when the second drive unit (210), which is synchronized with the first drive unit, is driven, thereby moving the scan head (400) horizontally left and right.

[0105] With reference to FIG. 9(b), the first link (100) rotates to the left with respect to the L1 axis (120) by the driving of the first driving unit (110), and at the same time, the second link (200) rotates to the left with respect to the L2 axis (220) by the driving of the second driving unit (210) synchronized with the first driving unit. Subsequently, the first link (100) rotates to the right with respect to the L1 axis (120) by the driving of the first driving unit (110), and at the same time, the second link (200) rotates to the right with respect to the L2 axis (220) by the driving of the second driving unit (210) synchronized with the first driving unit, thereby horizontally moving the scan head (400) to the left and right. At the same time, the scan head (400) rotates to the left and right with respect to the R axis (320) by the driving of the third driving unit (310) synchronized with the first driving unit (110). At this time, the R-axis (320) serves to adjust the incident angle of the ion beam to be constant during the left and right scanning process.

[0106] That is, the scan head (400) implements scalar motion that can scan in any designated horizontal direction through simultaneous rotation of the L1 axis (120), L2 axis (220), and R axis (320).

[0107] And, as illustrated in FIG. 10 (a) and (b), for a 45° tilt scan, the reference L1 axis (120) is rotated 45° from the initial state of 0° as illustrated in FIG. 10 (a). At this time, when the L1 axis (120) is rotated 45° by the drive of the first drive unit (110), the first link (100), the second link (200), and the scan head (400) are rotated at a 45° angle. Then, with the scan head (400) tilted 45°, the scan head (400) is moved horizontally left and right as illustrated in FIG. 10 (b). Here, the horizontal movement of the scan head (400) left and right is performed in the same manner as described in FIG. 9 (b).

[0108] That is, the scan head (400) implements scalar motion that can scan in any designated horizontal direction while tilted at 45°.

[0109] Meanwhile, the scan head (400) supported by the support frame (300) is connected to the Y-axis (Tilt axis, 420) which is connected horizontally.

[0110] As shown in FIG. 8, a fourth driving unit (410) is provided on one side of the support frame (300), and the Y-axis (420), which is the driving axis of the fourth driving unit (410), is horizontally connected to the support frame (300) to support both sides of the scan head (400) and rotate the scan head (400) by driving the fourth driving unit (410).

[0111] As shown in FIG. 11 (a) and (b), the Y-axis (420), which is rotated by the driving of the fourth driving unit (410), serves to rotate the scan head (400) to a wafer loading or unloading position, or to rotate the wafer (W) placed on the wafer chuck (401) of the scan head (400) to an ion implantation position or a beam profiling position.

[0112] As illustrated in FIG. 12 (a), the scan head (400) is configured to include a wafer chuck (401) that holds a wafer, an S-axis (402) that rotates the wafer chuck (401), and a fifth driving unit (403) that drives the S-axis (402).

[0113] And, as shown in Fig. 12 (b), the S-axis (402) is perpendicular to the Y-axis (420), and the wafer chuck (401) on which the wafer is placed is rotated by the driving of the fifth driving unit (403) to adjust the twist angle or orientation angle of the wafer (W).

[0114] Here, the first reason for adjusting the tilt angle and twist angle during ion implantation is that the beam incidence angle must be adjusted to a crystal direction where channeling is difficult in order to prevent beam channeling phenomena that occur depending on the semiconductor crystal direction, and the second reason is that ion implantation must be performed at various angles in semiconductors with a recent three-dimensional structure.

[0115] Accordingly, the present invention implements a scalar motion capable of scanning in any designated horizontal direction through the motion of the L1 axis (120) and the L2 axis (220), adjusts the incident angle of the ion beam to be constant during the left and right scanning process through the motion of the R axis (320), and adjusts the twist angle or orientation angle of the wafer (W) through the motion of the S axis (402).

[0116] FIG. 13 is a plan view illustrated to explain the doping uniformity during high-angle tilt ion implantation of a wafer by first and second scan robots according to one embodiment of the present invention.

[0117] As illustrated in FIG. 13, the first and second scanning robots (20-1) (20-2) scan the wafer (W) with a uniform ion beam density using an equidistant ion beam at all locations on the wafer (W) during 0° tilt ion implantation.

[0118] In addition, since the wafer (W) is scanned left and right with respect to the vertical ribbon beam or vertical scan beam even when tilted at a high angle, there is no difference in the beam path at any point on the wafer (W) regardless of the tilt angle, and as a result, the beam uniformity is maintained consistently during the wafer (W) scan, so that ions can be implanted uniformly at all locations on the wafer (W).

[0119] In this way, the present invention allows the wafer (W) to be scanned in any designated horizontal direction so that the ion beam is uniformly injected onto the wafer (W), and even when low-energy ion injection at a high tilt angle is performed, all parts of the wafer (W) are irradiated by an equidistant ion beam, thereby significantly improving the doping uniformity on the wafer (W).

[0120] In addition, the doping uniformity problem caused by the difference in distance of the ion beam path and the resulting change in ion beam size depending on the wafer (W) position in the existing scan direction is resolved, and the doping uniformity requirements of next-generation semiconductors can be satisfied.

[0121]

[0122] FIG. 14 is a conceptual diagram showing a dual scan process according to one embodiment of the present invention.

[0123] Referring to FIG. 14, the dual scan process of the dual scan type ion implant system of the present invention is schematically described as follows.

[0124] First, while wafer A (on the right in the diagram) that has entered the process chamber is performing a scan operation, wafer B (on the left in the diagram) also enters the process chamber.

[0125] At this time, wafer A reciprocates horizontally to repeatedly perform scans, while wafer B waits on the left side of the drawing until the scanning process of wafer A is completed.

[0126] In other words, while wafer A repeats horizontal scanning, wafer B remains in a waiting state, avoiding collisions while maintaining a distance of 'f' from the scan area. Conversely, while wafer B performs a scan, a newly entered unprocessed wafer remains in a waiting state on the right, avoiding collisions while maintaining a distance of 'f' from the scan area.

[0127] Subsequently, when the scanning process of wafer A is completed, wafer A is removed from the scanning area to be exchanged with an unprocessed wafer, and immediately wafer B, which was in a standby state, enters the scanning area, allowing the scanning process to continue continuously without interruption.

[0128] By controlling 'Scan Head A' and 'Scan Head B' to always repeat a fixed section so that wafers A and B entering from both sides can be processed consecutively without collision, scanning efficiency is maximized without wasting ion beams, and the throughput of the ion implantation process can be improved.

[0129] FIG. 15 is a diagram illustrating each step of a dual scan process according to an embodiment of the present invention, showing (a) a left single scan start and right wafer exchange state, (b) a left single scan completion and right scan waiting state, (c) a left wafer exchange and right single scan start state, and (d) a left scan waiting and right single scan completion state.

[0130] Referring to FIG. 15, the dual scan process according to the present invention is examined step-by-step as follows.

[0131] Step (a): Referring to FIG. 15(a), the first scan robot (20-1) on the left starts a single scan of an unprocessed wafer (W2) while reciprocating horizontally, and at this time, the second scan robot (20-2) on the right is in a wafer exchange state, receiving an unprocessed wafer (W3) while simultaneously transferring the scanned wafer (W1) to the second dual-arm vacuum robot (60-2). Here, since the second dual-arm vacuum robot (60-2) is equipped with two arms (not labeled) as described above, it can perform the operation of receiving the scanned wafer (W1) and providing the unprocessed wafer (W3) almost simultaneously. (Throughput is also improved by this.) In addition, in this state, another wafer (W4) is aligned at the aligner (70) and is prepared for supply to the process chamber (10).

[0132] Step (b): Referring to FIG. 15(b), the first scan robot (20-1) on the left completes scanning of the wafer (W2), and at this time, the second scan robot (20-2) on the right holds the unprocessed wafer (W3) and waits at a certain distance from the right side of the scan area in the drawing. Meanwhile, the unprocessed wafer (W4) that has finished alignment is held by the first dual arm vacuum robot (60-1) and waits for wafer exchange with the first scan robot (20-1) (exchanging W2 and W4).

[0133] Step (c): Referring to FIG. 15(c), the first scan robot (20-1) on the left transfers the scanned wafer (W2) to the first dual-arm vacuum robot (60-1) to perform a wafer exchange in which the aforementioned unprocessed wafer (W4) is supplied. At this time, the second scan robot (20-2) on the right starts scanning while holding the unprocessed wafer (W3). At this time, the unprocessed wafer (W3) is in a standby state and enters the scan area immediately after the previously scanned wafer (W2) is removed from the scan area, and scans begin immediately. Accordingly, as previously described, the present invention can prevent the waste of ion beams that occurred periodically during the wafer exchange process in a conventional single scan robot system.

[0134] Step (d): Referring to FIG. 15(d), the second scan robot (20-2) on the right completes scanning the wafer (W3), while the first scan robot (20-1) on the left waits holding the unprocessed wafer (W4). At this time, other unprocessed wafers (W5, W6) are prepared to enter the process chamber (10) for the scanning process by the first and second dual-arm vacuum robots (60-1)(60-2) or the aligner (70). (For reference, the number of wafers W1 to W6 is limited to six to briefly explain the process.)

[0135] Accordingly, by repeatedly performing the steps (a) to (d) described above, the present invention allows the scanning process to be performed continuously without wasting the ion beam, and the throughput of the ion scanning process is improved by about twofold, and the footprint of the semiconductor fab occupied by the system can also be reduced by about half.

[0136] That is, according to the present invention, while one of the first and second scan robots (20-1)(20-2) performs a scan operation, the other scan robot waits right next to the scan area after exchanging the scanned wafer and the unprocessed wafer, and then is alternately introduced into the scan area as soon as the scan is completed, thereby continuously performing the scan operation.

[0137] Accordingly, the dual scan type ion implant system with improved throughput according to the above configuration can process nearly twice as many wafers in the same amount of time compared to a conventional single scan system, thereby achieving the effect of significantly improving the wafer processing efficiency, i.e., throughput, of the ion implant process. This is achieved by receiving a wafer (W) through different wafer scan transfer paths (P1) and (P2) that do not overlap, from the EFEM (not shown) to the first load lock chamber assembly (60-1) and the second load lock chamber assembly (60-2), a single vacuum transfer module (50), a single process chamber (10), and the first and second scan robots (20-1) (20-2) inside the process chamber, respectively, and then having the first and second scan robots (20-1) (20-2) alternately perform ion beam scans.

[0138] In addition, even if a problem occurs in either of the first and second scan robots (20-1) (20-2), the ion implant process can be continued using the other one without wasting the ion beam, thereby maintaining the throughput of the ion implant process at a certain level and resolving the problem of wasting expensive ion beams due to the interruption of the process.

[0139] In addition, the first and second dual-arm vacuum robots (60-1) (60-2) and the first and second scan robots (20-1) (20-2) are arranged adjacent to each other to have the shortest wafer scan transfer path (P1, P2) in a straight line inside a single vacuum transfer module (VTM) (50) and a single process chamber (10), so that the footprint occupies almost half compared to the case where a conventional single-scan scanning system is built in two lines, thereby improving the space utilization of the customer's fab.

[0140] Furthermore, the present invention is not limited solely to the embodiment described above. Since the same effect can be achieved even when changing the detailed configuration, number, or arrangement structure of the device, it is hereby specified that those skilled in the art can add, delete, or modify various configurations within the scope of the technical concept of the present invention.

Claims

1. A first load lock chamber assembly connected to one end of the EFEM; A second load lock chamber assembly connected to the other end of the above EFEM; A single vacuum transfer module (VTM) in which the first load lock chamber assembly and the second load lock chamber assembly are connected together; First and second dual-arm vacuum robots positioned inside the above vacuum transfer module (VTM); A single process chamber to which the above vacuum transfer module (VTM) is connected and in which scanning by an ion beam is performed in a vacuum atmosphere; and It includes first and second scan robots disposed inside the process chamber; and After the first load lock chamber assembly and the second load lock chamber assembly, a single vacuum transfer module (VTM), a single process chamber, and the first and second scan robots inside the process chamber each receive a wafer through different wafer scan transfer paths that do not overlap with each other from the above EFEM, the first and second scan robots alternately perform ion beam scans, and Characterized by being controlled so that the other one continues to perform normal operation even if either of the first and second scan robots fails to operate normally. Dual-scan type ion implant system with improved throughput.

2. In Paragraph 1, Along with configuring a first wafer scan transfer path that reciprocates the first load lock chamber assembly, the first dual arm vacuum robot, and the first scan robot, Characterized by configuring a second wafer scan transfer path that reciprocates the second wafer scan transfer path connecting the second load lock chamber assembly, the second dual arm vacuum robot, and the second scan robot. Dual-scan type ion implant system with improved throughput.

3. In Paragraph 2, The first wafer scan transfer path and the second wafer scan transfer path are characterized by forming a symmetrical straight line shape without overlapping each other. Dual-scan type ion implant system with improved throughput.

4. In Paragraph 1, The single vacuum transfer module (VTM) and the single process chamber are characterized by having widths in the left-right direction perpendicular to the first and second wafer scan transfer paths that are equal or similar to each other. Dual-scan type ion implant system with improved throughput.

5. In Paragraph 1, The partition between the single vacuum transfer module (VTM) and the single process chamber is characterized by having a vacuum atmosphere of the same pressure as it is connected to allow the wafer to reciprocate. Dual-scan type ion implant system with improved throughput.

6. In Paragraph 1, An ion beam is irradiated between the first and second scan robots inside the process chamber, and the first and second scan robots positioned on both sides of the ion beam irradiation area continuously scan the wafer while alternately exposing it to the ion beam irradiation area. Dual-scan type ion implant system with improved throughput.

7. In Paragraph 1, Characterized by having a single aligner positioned between the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM) to align the notch direction of the wafer. Dual-scan type ion implant system with improved throughput.

8. In Paragraph 1, Characterized by having first and second aligners respectively positioned on the sides of the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM) to align the notch direction of the wafer. Dual-scan type ion implant system with improved throughput.

9. In Paragraph 1, Characterized by having first and second aligners respectively positioned above the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM) for aligning the notch direction of the wafer. Dual-scan type ion implant system with improved throughput.

10. In Paragraph 1, The first load lock chamber assembly and the second load lock chamber assembly are each, Characterized by being configured to be divided into an upper chamber and a lower chamber for introducing or removing a wafer into or out of a first or second vacuum transfer module (VTM). Dual-scan type ion implant system with improved throughput.

11. In Paragraph 1, The first and second scanning robots mentioned above are, respectively, An L1 axis vertically coupled to one side of a first link and rotating the first link by driving a first driving unit; An L2 axis having the same length as the first link is superimposed on the upper part of the first link, and vertically connected to the other side of the first link and one side of the second link superimposed thereon, thereby rotating the second link by driving a second driving unit; A support frame that supports a scan head is superimposed on the upper side of the other side of the second link, and an R-axis that rotates the support frame by driving a third drive unit is vertically coupled to the center of the other side of the second link; A Y-axis horizontally coupled to the support frame to support both sides of the scan head and rotating the scan head by driving the fourth drive unit; and It includes an S-axis that adjusts the twist angle or orientation angle of the wafer by rotating the wafer chuck on which the wafer is placed by driving the fifth drive unit. The first driving unit and the second driving unit drive in synchronization, and the first link rotates left and right around the L1 axis, and the second link rotates left and right around the L2 axis to move the scan head horizontally left and right. Dual-scan type ion implant system with improved throughput.

12. In Paragraph 1, The first load lock chamber assembly and the second load lock chamber assembly each have a plurality of chambers arranged in a vertical or horizontal direction, characterized in that Dual-scan type ion implant system with improved throughput.

Images