KR102874818B1 - Dual scan type ion implant system with improved throughput - Google Patents

Abstract

According to one embodiment of the present invention, a dual scan type ion implant system with improved throughput 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) to 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); a single process chamber to which the vacuum transfer module (VTM) is connected and in which scanning is performed by an ion beam in a vacuum atmosphere; And first and second scan robots disposed inside the process chamber; and characterized in that after receiving a wafer from the EFEM through different wafer scan transfer paths that do not overlap with each other through the first load lock chamber assembly and the second load lock chamber assembly, the single vacuum transfer module (VTM), the single process chamber, and the first and second scan robots inside the process chamber, the first and second scan robots alternately perform an ion beam scan, and if either one of the first and second scan robots does not operate normally, the other one continues to operate normally.

Description

Dual scan type ion implant system with improved throughput

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 solves the problems of a conventional single ion scan robot handling all of the wafer replacement transport and scanning by itself, so that scanning is not performed at all between wafer replacement and return, which significantly reduces wafer processing efficiency (throughput), and expensive ion beams are continuously wasted between wafer replacement and return, and the space utilization of a semiconductor manufacturing fab is reduced due to an increase in footprint.

Typically, the semiconductor device manufacturing process is performed by repeatedly performing oxidation processes, photolithography processes, diffusion processes, ion implantation processes, and metal processes on a silicon wafer.

Among the above processes, the ion implantation process refers to implanting a desired amount of charged impurities into the wafer at a desired depth with a predetermined energy. Typically, in semiconductor manufacturing, the ion implantation process involves implanting dopant ions into the surface of a silicon wafer.

The ion implanter used in the ion implantation process is largely composed of the following four main parts.

These main parts can be divided into an ion source region, which is an region that extracts an ion beam, a terminal region that includes a mass analyzer that classifies the extracted ion beam into a desired mass and a beam line, which is a passage through which the ion beam passes, and an end station region that transports the wafer and ultimately injects the ion beam. In the end station region, the wafer is scanned in a high-vacuum processor chamber to inject the ion beam into the wafer.

The above-described ion implantation device is typically referred to as a single-scan type ion implant system because it is equipped with one ion scan robot inside a processor chamber, and the one ion scan robot sequentially loads wafers into the processor chamber one by one, scans them (ion implants), and then loads them out.

Below, an example of such a single scan type ion implant system is well described in Korean Patent Registration No. 1311885 (hereinafter referred to as “prior document”).

Referring to FIG. 1 of the above-mentioned prior art document, the ion implant system has a configuration in which wafers (W) are loaded one by one into a vacuum processing chamber (20) from a wafer cassette (71) through a dedicated load lock chamber (40A) for loading and an opening/closing door (41A) installed on one side of the system, and the wafers (W) for which the ion scan is completed are then loaded and removed into a wafer cassette (72) through a dedicated load lock chamber (40B) for loading and an opening/closing door (41B).

However, the conventional single-scan type ion implant system disclosed in the above-mentioned prior art document is equipped with only a single platen (hereinafter collectively referred to as a “single ion scan robot”) capable of tilting in accordance with the ion implantation direction inside a vacuum processing chamber for performing ion implantation. Accordingly, the single ion scan robot must handle all of the wafer replacement, loading/unloading, return, and scanning by itself, so that scanning cannot be performed at all between wafer returns, which not only significantly reduces wafer processing efficiency (throughput), but also has the serious problem of expensive ion beams being wasted between wafer replacement/return.

In addition, since the wafer is directly transferred to the vacuum processing chamber through the vacuum load lock chamber under atmospheric pressure, a time delay occurs each time the load lock chamber is opened to transfer the wafer due to the need to re-establish the vacuum atmosphere, which also becomes a factor in reducing the throughput.

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 in multiples, which increases the equipment footprint and ultimately leads to a problem of significantly reducing the space utilization of the semiconductor manufacturing fab.

Korean Patent Registration No. 1311885 (registered on September 17, 2013)

Accordingly, the present invention has been devised to solve the above-mentioned problems, and the purpose of the present invention is to provide a dual scan type ion implant system with improved throughput, which solves the problems of not only that the conventional single ion scan robot handles all of the wafer replacement, return, and scanning by itself, so that scanning is not performed at all between wafer replacement and return, and thus the wafer processing efficiency (throughput) is greatly reduced, and that expensive ion beams are continuously wasted between wafer replacement and return, and that the space utilization of the semiconductor manufacturing fab is reduced due to the increased footprint.

In order to achieve the above object, the present invention, according to one embodiment, 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) to 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); a single process chamber to which the vacuum transfer module (VTM) is connected and in which scanning is performed by an ion beam in a vacuum atmosphere; And first and second scan robots disposed inside the process chamber; and characterized in that after receiving a wafer from the EFEM through different wafer scan transfer paths that do not overlap with each other through the first load lock chamber assembly and the second load lock chamber assembly, the single vacuum transfer module (VTM), the single process chamber, and the first and second scan robots inside the process chamber, the first and second scan robots alternately perform an ion beam scan, and if either one of the first and second scan robots does not operate normally, the other one continues to operate normally.

In addition, according to one embodiment, a first wafer scan transfer path reciprocating the first load lock chamber assembly, the first dual-arm vacuum robot, and the first scan robot is configured, and a second wafer scan transfer path reciprocating the second wafer scan transfer path connecting the second load lock chamber assembly, the second dual-arm vacuum robot, and the second scan robot is configured.

Additionally, according to one embodiment, the first wafer scan transfer path and the second wafer scan transfer path are characterized in that they form a symmetrical straight line shape without overlapping each other.

Additionally, according to one embodiment, the single vacuum transfer module (VTM) and the single process chamber are characterized in that the widths in the left and right directions perpendicular to the first and second wafer scan transfer paths are formed to be equal to or similar to each other.

Additionally, 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 the partition wall so as to be in communication with the wafer so that the wafer can be reciprocated.

Also, according to one embodiment, an ion beam is irradiated between first and second scan robots inside the process chamber, and the first and second scan robots arranged on both sides of the ion beam irradiation area continuously scan the wafer while alternately exposing the wafer to the ion beam irradiation area.

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

Additionally, according to one embodiment, the first and second dual-arm vacuum robots inside the single vacuum transfer module (VTM) are characterized in that first and second aligners are respectively disposed on the sides for aligning the notch direction of the wafer.

Additionally, according to one embodiment, the single vacuum transfer module (VTM) is characterized in that first and second aligners are respectively positioned above the first and second dual-arm vacuum robots for aligning the notch direction of the wafer.

Additionally, according to one embodiment, the first load lock chamber assembly and the second load lock chamber assembly are characterized in that they are each divided into an upper chamber and a lower chamber for loading or unloading wafers into or from the first or second vacuum transfer module (VTM).

In addition, according to one embodiment, the first and second scan robots each include: an L1 axis vertically coupled to one side of the first link and rotating the first link by driving a first driving unit; an L2 axis vertically coupled to the other side of the first link and one side of the second link overlapping the first link, wherein a second link having the same length as the first link is overlaid on the first link, and rotating the second link by driving a second driving unit; an R axis vertically coupled to the other side of the second link and the center of the support frame, wherein a support frame supporting a scan head is overlaid on the other side of the second link, and rotating the support frame by driving a third driving unit; a Y axis horizontally coupled to the support frame, supporting both sides of the scan head, and rotating the scan head by driving a fourth driving unit; And an S-axis for adjusting the twist angle or orientation angle of the wafer by rotating the wafer chuck on which the wafer is placed by the driving of the fifth driving unit; wherein the first driving unit and the second driving unit are driven in synchronization, and the first link rotates left and right based on the L1 axis, and the second link rotates left and right based on the L2 axis to horizontally move the scan head left and right.

Additionally, 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 direction or a horizontal direction.

As described above, the present invention has the effect of significantly improving the wafer processing efficiency, i.e., throughput, of the ion implant process by having the first and second scan robots alternately perform ion beam scanning, as the wafers are transferred from the EFEM through different non-overlapping wafer scan transfer paths, the first and second load lock chamber assemblies, the single vacuum transfer module (VTM), the single process chamber, and the first and second scan robots inside the process chamber. As a result, the first and second scan robots can process almost twice as many wafers in the same amount of time as a conventional single-scan system.

In addition, even if a problem occurs in either of the first and second scan robots, the ion implant process can be continued using the other one without wasting ion beams, thereby maintaining the throughput of the ion implant process at a certain level and solving the problem of expensive ion beams being wasted due to process interruption.

In addition, since the first and second dual-arm vacuum robots and the first and second scan robots are arranged adjacent to each other to have the shortest wafer scan transfer path in a straight line within a single vacuum transfer module (VTM) and a single process chamber, the footprint is almost half that of a two-line conventional single-scan scanning system, which has the effect of improving the utilization of the customer's fab space.

In addition, with the improvement of fab throughput and increased space utilization, it is expected that the overall cost reduction will be achieved, including direct component repair costs, labor costs, and indirect power and utility costs. This will ultimately have the effect of contributing to the improvement of price competitiveness in wafer production and the localization of implant equipment.

Figure 1 is a plan view showing a conventional single scan type ion implant system.
Figure 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.
Figure 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.
Figure 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.
Figure 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.
Figure 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.
Figure 7 is a conceptual diagram illustrating a wafer beam scanning method of the first and second scan robots according to one embodiment of the present invention.
Figure 8 is a schematic diagram for explaining the configuration of the first and second scan robots according to one embodiment of the present invention.
Figures 9 (a) and (b) are motion diagrams for explaining the operation of scanning left and right 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 one 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 one embodiment of the present invention.
Figures 11 (a) and (b) are motion diagrams for explaining the operation of the scan head according to the Y-axis (Tilt axis) drive in the first and second scan robots according to one embodiment of the present invention.
(a) and (b) of FIG. 12 are motion diagrams for explaining the adjustment of 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 one embodiment of the present invention.
FIG. 13 is a diagram illustrating 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.
Figure 14 is a conceptual diagram showing a dual scan process according to one embodiment of the present invention.
FIG. 15 is a drawing illustrating each step of a dual scan process according to one embodiment of the present invention, (a) left single scan start and right wafer exchange state, (b) left single scan completion and right scan standby state, (c) left wafer exchange and right single scan start state, (d) left scan standby and right single scan completion state.

The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" or "has" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in this specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined herein, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

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

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.

Referring to FIG. 2, the present invention, according to one embodiment, is largely configured to include 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).

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 FOUP (Front Opening Unified Pod) to a process chamber (10) in a typical semiconductor line. Typically, one side of the EFEM is equipped with a plurality of load ports on which a plurality of wafer cassettes or wafer FOUPs are placed, and can be placed on one side of the process chamber (10).

In addition, 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).

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

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

Likewise, the lower chamber (not shown) is provided with a wafer removal slot for removing a wafer (W) from inside a single vacuum transfer module (50), and after the wafer removal slot is opened, a wafer (W) on which ion implantation (scanning) has been completed is received from the first dual-arm vacuum robot (60-1) inside the single vacuum transfer module (50).

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, to improve space efficiency on the wafer scan transfer path, but the present invention is not limited thereto.

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).

The above first vacuum transfer module (50) is an intermediate module that waits before the wafer (W) is introduced into the process chamber (10), and maintains a high vacuum corresponding to the process chamber (10) by being connected to the process chamber (10).

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

The first and second dual-arm vacuum robots (60-1) (60-2) above each have two arms (no sign). Accordingly, by using the two arms, the first and second dual-arm vacuum robots (60-1) (60-2) can perform a composite operation of simultaneously loading or unloading two wafers (W) with the first load lock chamber assembly and the second load lock chamber assembly (40-1) (40-2), or simultaneously loading or unloading two wafers (W) with the first and second scan robots (20-1) (20-2) inside the processor chamber (10).

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

The above single process chamber (10) is a processing space where scanning (ion implantation) of a wafer (W) using an ion beam is performed, and the process chamber (10) is maintained in a high vacuum to ensure a clean ion implantation environment free of particles.

For example, an ion beam is irradiated to the central portion of the process chamber (10), and the shape of this ion beam may be a ribbon beam or a spot beam line-scanned in one direction of the electric field and the magnetic field.

Accordingly, as shown in FIG. 2, an ion beam is incident on one side of the process chamber (10) and scans the wafer (W) by meeting it at a point (B, ion beam irradiation area) inside the process chamber (10), and an ion beam dump (not shown) is provided on the opposite side of the process chamber (10) where the ion beam is incident.

Additionally, the first and second scan robots (20-1) (20-2) are placed inside the process chamber (10).

Accordingly, according to the above-described configuration, the first load lock chamber assembly and the second load lock chamber assembly (40-1)(40-2), the single vacuum transfer module (50), the single process chamber (10), and the first and second scan robots (20-1)(20-2) inside the process chamber (10) receive the wafer (W) through different non-overlapping wafer scan transfer paths (P1)(P2) from the EFEM (not shown), and then the first and second scan robots (20-1)(20-2) continuously perform ion beam scanning.

That is, the first and second scan robots (20-1, 20-2) arranged on both sides of the 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.

Accordingly, the present invention configures a first wafer scan transfer path (P1, a straight arrow indicated 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 illustrated in FIG. 2.

In addition, independently of the first wafer scan transfer path (P1), the present invention configures a second wafer scan transfer path (P2, a straight arrow shown 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).

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 a straight line shape that is parallel to each other without overlapping.

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

In particular, the configuration of the above-described independent wafer scan transfer path has the advantage that even if one of the first and second scan robots (20-1) (20-2) fails to operate normally, the other one can be controlled to continue to perform normal operation.

Additionally, according to one embodiment, the single vacuum transfer module (50) and the single process chamber (10) may be formed to have the same width in the left and right directions perpendicular to the first and second wafer scan transfer paths (P1) (P2).

However, the single vacuum transfer module (50) and the single process chamber (10) do not necessarily have to have the same width in the left and right directions, and if they are the same or similar to each other, a wafer scan transfer path in a symmetrical straight line shape can be formed as described above, and the footprint can be minimized.

Additionally, according to one embodiment, the single vacuum transfer module (50) and the single process chamber (10) may be connected to each other to allow the wafer to reciprocate, thereby having a vacuum atmosphere of the same pressure.

In short, the present invention comprises a single vacuum transfer module (VTM) and a single process chamber that are connected to each other to form first and second wafer scan transfer paths that are independent of each other and have a straight-line shortest distance, and further, first and second dual-arm vacuum robots (60-1) (60-2) are arranged inside the vacuum transfer module (50) so that two wafers (W) can be processed (loaded in/loaded out) simultaneously, and first and second scan robots (20-1) (20-2) are arranged inside the single process chamber (10), so that two wafers (W) can be scanned continuously without interruption by the first and second scan robots (20-1) (20-2).

According to one embodiment, an ion beam is irradiated to an 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) arranged 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).

That is, the first and second scan robots (20-1, 20-2) alternately perform a scanning operation of loading or unloading a wafer (W) into or out of a process chamber (10) under high vacuum or exposing the loaded wafer (W) to an ion beam.

Accordingly, unlike the conventional single scan robot discussed above, the first and second scan robots (20-1, 20-2) of the present invention can perform a scanning operation while one of the first and second scan robots (20-1, 20-2) is transporting the wafer (W) into or out of the process chamber (10). Therefore, when the scan is completed, the robot that has completed the transport takes turns performing the scanning again, thereby preventing the disadvantage of expensive ion beams being wasted because the conventional single scan robot cannot scan while transporting the wafer.

Also, referring to FIG. 2, according to the first embodiment, a single aligner (70) is disposed between the first and second dual-arm vacuum robots (60-1) (60-2) inside the single vacuum transfer module (50) to align the direction of the notch (see FIG. 12) of the wafer (W). When a single aligner (70) is disposed in this manner, the size and volume of the single vacuum transfer module can be reduced accordingly, and the advantage of reducing the vacuum arrival time for re-forming a vacuum atmosphere each time the wafer enters and exits can be obtained.

The advantage is that the production cost is reduced due to the system being simplified.

Meanwhile, the aligner (70) may be configured to include, although not shown in the drawing, a wafer chuck on which a wafer (W) is mounted; 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 the opposite direction; and a vision unit provided above the vacuum chamber to capture an image of a notch (see FIG. 12) of the wafer (W) loaded on the wafer chuck.

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 another embodiment, the vision unit may be replaced with a sensor (not shown) that recognizes the outer edge and notch of the wafer (W).

Therefore, 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 arrangement of the first and second dual-arm vacuum robots (60-1) (60-2) inside a single vacuum transfer module (50), so that the throughput of the ion implant process can be improved by almost two times compared to the conventional one, and in addition, since the first and second scan robots (20-1) (20-2) alternately perform continuous scans, waste of ion beams can be eliminated, and the footprint of the system can be reduced by about half based on the same wafer processing performance.

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.

Referring to FIG. 3, the second embodiment of the present invention is configured differently from the first embodiment in that only the chamber arrangement of the first and second load lock chamber assemblies (40-1) (40-2) is changed 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 loading or unloading a wafer (W) into or from 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.

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.

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

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.

Referring to FIG. 5, the fourth embodiment of the present invention is configured differently from the third embodiment in that only the chamber arrangement of the first and second load lock chamber assemblies (40-1) (40-2) is changed 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 loading or unloading 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 horizontally arranged.

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

Referring to FIG. 6, the fifth embodiment of the present invention is configured differently from the first embodiment only in the arrangement of the aligner 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) within the single vacuum transfer module (50).

Meanwhile, FIG. 7 is a conceptual diagram illustrating a wafer beam scanning method of the first and second scan robots according to an embodiment of the present invention, FIG. 8 is a schematic diagram for explaining the configuration of the first and second scan robots according to an embodiment of the present invention, (a) and (b) of FIG. 9 are motion diagrams for explaining the operation of the L1-axis, L2-axis, and R-axis driving units of the first and second scan robots according to an embodiment of the present invention to be synchronously driven and scan left and right, (a) and (b) of FIG. 10 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, (a) and (b) of FIG. 11 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 (a) and (b) of FIG. 12 are motion diagrams for explaining the twist angle or the S-axis driving of the scan head in the first and second scan robots according to an embodiment of the present invention. This is a motion diagram for explaining orientation angle adjustment, and FIG. 13 is a plan view for explaining 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.

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 the above-mentioned FIGS. 7 to 13.

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

First, as illustrated in Fig. 8, a first driving unit (110) is provided on one lower side of the first link (100), and the L1 axis (120), which is a driving shaft of the first driving unit (110), is vertically coupled to one side of the first link (100). The L1 axis (120) becomes a 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 driving the first driving unit (110).

And, a second link (200) is covered on the upper part of the first link (100).

A second driving unit (210) is provided on the other side of the first link (100), and the L2 axis (220), which is the driving shaft of the second driving unit, protrudes upward and is vertically coupled 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 driving unit (210).

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

A third driving unit (310) is provided on the other side of the second link (200), and the R-axis (320), which is the driving shaft of the third driving 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 driving the third driving unit (310).

Here, the first driving unit (110), the second driving unit (210), and the third driving unit (310) operate in synchronization.

As shown in (a) and (b) of FIG. 9, in the case of a 0° scan, in the initial state of FIG. 9(a), as shown in FIG. 9(b), the first link (100) rotates about the L1 axis (120) when the first driving unit (110) drives, and the second link (200) having the same length as the first link rotates about the L2 axis (220) when the second driving unit (210) synchronized with the first driving unit drives, thereby horizontally moving the scan head (400) left and right.

Referring to FIG. 9(b), to explain in more detail, by the driving of the first driving unit (110), the first link (100) rotates to the left with respect to the L1 axis (120), and at the same time, by the driving of the second driving unit (210) synchronized with the first driving unit, the second link (200) rotates to the left with respect to the L2 axis (220), and then, by the driving of the first driving unit (110), the first link (100) rotates to the right with respect to the L1 axis (120), and at the same time, by the driving of the second driving unit (210) synchronized with the first driving unit, the second link (200) rotates to the right with respect to the L2 axis (220), thereby horizontally moving the scan head (400) left and right. At the same time, by the driving of the third driving unit (310) synchronized with the first driving unit (110), the scan head (400) rotates left and right with respect to the R axis (320). At this time, the R axis (320) plays a role in adjusting the incident angle of the ion beam to be constant during the left and right scan process.

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

And, in the case of a 45° tilt scan as shown in (a) and (b) of FIG. 10, the L1 axis (120), which serves as a reference, is rotated 45° from the initial state of 0° as shown in FIG. 10(a). At this time, when the L1 axis (120) is rotated 45° by the driving of the first driving unit (110), the first link (100), the second link (200), and the scan head (400) are rotated at an angle of 45°. And, in a state where the scan head (400) is tilted 45°, the scan head (400) is horizontally moved left and right as shown in FIG. 10(b). Here, the left and right horizontal movement of the scan head (400) is performed in the same manner as described in FIG. 9(b).

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

Meanwhile, the scan head (400) supported on the support frame (300) is coupled to the Y-axis (Tilt axis, 420) that is coupled horizontally.

As illustrated 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 shaft of the fourth driving unit (410), is horizontally coupled 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).

As shown in (a) and (b) of FIG. 11, the Y-axis (420) that rotates by the driving of the fourth driving unit (410) serves to rotate the scan head (400) to the wafer load or unload position or to rotate the wafer placed on the wafer chuck of the scan head to the ion implantation position or beam profiling position.

As shown in (a) of Fig. 12, 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).

And, as shown in (b) of FIG. 12, 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.

Here, the first reason why the tilt angle and twist angle must be adjusted during ion implantation is that the beam incidence angle must be adjusted toward the crystal direction where channeling is difficult in order to prevent beam channeling phenomenon that occurs depending on the semiconductor crystal direction, and the second reason is that ion implantation must be performed at various angles in recent three-dimensional semiconductor structures.

Accordingly, the present invention implements a scalar motion that can scan in any designated direction in the 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 through the motion of the S axis (402).

FIG. 13 is a plan view illustrating 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.

As illustrated in Fig. 13, the first and second scan robots (20-1) (20-2) scan the wafer with uniform ion beam density by equidistant ion beams at all locations on the wafer during 0° tilt ion implantation.

In addition, since the wafer 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 regardless of the tilt angle, and thus the beam uniformity is maintained constant during the wafer scan, allowing ions to be injected uniformly at all locations on the wafer.

In this way, the present invention can scan the wafer in any designated horizontal direction so that the ion beam is uniformly injected onto the wafer, and even when low-energy ions are injected at a high tilt angle, all areas on the wafer are irradiated with an equidistant ion beam, thereby significantly improving the doping uniformity on the wafer.

In addition, it is possible to solve the doping uniformity problem caused by the difference in the distance of the ion beam path and the change in the ion beam size according to the wafer position in the existing scan direction, and also to satisfy the doping uniformity requirements of next-generation semiconductors.

Figure 14 is a conceptual diagram showing a dual scan process according to one embodiment of the present invention.

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.

First, while wafer A (right in the drawing) enters the process chamber and performs a scan operation, wafer B (left in the drawing) also enters the process chamber.

At this time, wafer A is scanned repeatedly in a horizontal direction, and wafer B waits on the left side of the drawing until the scanning process of wafer A is completed.

That is, while wafer A repeats horizontal scanning, wafer B waits to avoid collision while maintaining a distance of 'f' from the scan area. Conversely, while wafer B performs scanning, the newly entered unprocessed wafer waits to avoid collision on the right while maintaining a distance of 'e' from the scan area.

Afterwards, when the scanning process of wafer A is completed, wafer A is removed from the scan area to be exchanged with an unprocessed wafer, and immediately wafer B, which was in a waiting state, enters the scan area to continue the scanning process continuously without interruption.

In this way, 'Scan Head A' and 'Scan Head B' are controlled to always repeat a set section so that the A wafer and B wafer entering from both sides can prevent collision and be processed consecutively, thereby maximizing the scanning efficiency without wasting the ion beam and improving the throughput of the ion implant process.

FIG. 15 is a drawing illustrating each step of a dual scan process according to one 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 standby state, (c) a left wafer exchange and right single scan start state, and (d) a left scan standby and right single scan completion state.

Referring to Figure 15, the dual scan process according to the present invention is examined step by step as follows.

Step (a): Referring to FIG. 15a, the first scan robot (20-1) on the left starts a single scan of an unprocessed wafer (W2) by horizontally reciprocating, and at this time, the second scan robot (20-2) on the right is in a wafer exchange state in which it transfers the scanned wafer (W1) to the second dual-arm vacuum robot (60-2) and simultaneously receives the unprocessed wafer (W3). Here, since the second dual-arm vacuum robot (60-2) has two arms (no symbol) as described above, it can perform the operations of receiving the scanned wafer (W1) and providing the unprocessed wafer (W3) almost simultaneously (this also improves throughput). In addition, in this state, another wafer (W4) is aligned in the aligner (70) and prepares to be supplied to the process chamber (10).

Step (b): Referring to FIG. 15b, 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 scan area on the right side of the drawing. Meanwhile, the unprocessed wafer (W4) that has completed alignment is held by the first dual-arm vacuum robot (60-1) and waits for wafer exchange (exchanging W2 and W4) with the first scan robot (20-1).

Step (c): Referring to FIG. 15c, the wafer (W2) that has been scanned is transferred to the first dual-arm vacuum robot (60-1) on the left while the wafer exchange is performed to receive the unprocessed wafer (W4) described above, and 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) leaves the scan area and starts scanning immediately. Accordingly, as described above, the present invention can prevent waste of ion beams that occurred periodically during the wafer exchange process in a conventional single scan robot system.

Step (d): Referring to FIG. 15d, the second scan robot (20-2) on the right completes scanning of the wafer (W3), and at this time, the first scan robot (20-1) on the left waits while holding the unprocessed wafer (W4). In addition, at this time, other unprocessed wafers (W5, W6) prepare 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 expressed by limiting the number to six in order to briefly explain the process.)

Accordingly, the present invention can continuously perform the scanning process without wasting the ion beam by repeatedly performing the above-described steps (a) to (d), and the throughput of the ion scanning process can be improved by about two times, and the footprint of the semiconductor fab occupied by the system can also be reduced by about half.

That is, according to the present invention, while one of the first and second scan robots (20-1) (20-2) performs a scanning operation, the other scan robot exchanges a scanned wafer with an unprocessed wafer, then waits right next to the scanning area, and then, as soon as the scanning is completed, alternately enters the scanning area to continuously perform the scanning operation.

Therefore, the dual scan type ion implant system with improved throughput of the present invention by the above-described configuration receives wafers from an EFEM (not shown) through different wafer scan transfer paths (P1)(P2) that do not overlap with each other through a first load lock chamber assembly (60-1) and a second load lock chamber assembly (60-2), a single vacuum transfer module (50), a single process chamber (10), and first and second scan robots (20-1)(20-2) inside the process chamber, and then the first and second scan robots (20-1)(20-2) alternately perform ion beam scans, thereby processing almost twice as many wafers in the same amount of time as a conventional single scan type system, thereby obtaining the effect of significantly improving the wafer processing efficiency, i.e., throughput, of the ion implant process.

In addition, even if a problem occurs in either of the first and second scan robots, the ion implant process can be continued using the other one without wasting ion beams, thereby maintaining the throughput of the ion implant process at a certain level and solving the problem of expensive ion beams being wasted due to process interruption.

In addition, since the first and second dual-arm vacuum robots and the first and second scan robots are arranged adjacent to each other to have the shortest wafer scan transfer path in a straight line within a single vacuum transfer module (VTM) and a single process chamber, the footprint is approximately half that of a two-line conventional single-scan scanning system, thereby improving the utilization of the customer's fab space.

In addition, the present invention is not limited to the above-described embodiment, and the same effect can be created even when the detailed configuration, number, and arrangement structure of the device are changed. Therefore, it is stated that a person having ordinary skill in the art can add, delete, and modify various configurations within the scope of the technical idea of the present invention.

10: Process chamber
20-1, 20-2: 1st and 2nd scan robots
30: EFEM (Equipment Front End Module)
40-1, 40-2: First and second load lock chamber assemblies
41, 42: Upper chamber, lower chamber
50: Single Vacuum Transfer Module (VTM)
60-1, 60-2: First and second vacuum robots
70, 70-1, 70-2: Aligner
P1, P2: First and second wafer scan transfer paths
W: Wafer
S: Wafer rotation axis (Rotation axis, Twist axis)
B: Ion beam irradiation area

Claims (12)

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 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);
A single process chamber to which the vacuum transfer module (VTM) is connected and scanning is performed by an ion beam in a vacuum atmosphere; and
comprising first and second scan robots disposed inside the process chamber;
After receiving a wafer from the EFEM through a first load lock chamber assembly and a second load lock chamber assembly, a single vacuum transfer module (VTM), a single process chamber, and first and second scan robots inside the process chamber through different non-overlapping wafer scan transfer paths, the first and second scan robots alternately perform an ion beam scan,
Characterized in that even if one of the first and second scan robots fails to operate normally, the other one is controlled to continue to operate normally.
Dual scan type ion implant system with improved throughput. In the first paragraph,
In addition to 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,
A second wafer scan transfer path is characterized by forming a second wafer scan transfer path that reciprocates 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. In the second paragraph,
The first wafer scan transfer path and the second wafer scan transfer path are characterized in that they form a symmetrical straight line shape without overlapping each other.
Dual scan type ion implant system with improved throughput. In the first paragraph,
The single vacuum transfer module (VTM) and the single process chamber are characterized in that the widths in the left and right directions perpendicular to the first and second wafer scan transfer paths are formed to be equal or similar to each other.
Dual scan type ion implant system with improved throughput. In the first paragraph,
The partition between the single vacuum transfer module (VTM) and the single process chamber is characterized in that it has a vacuum atmosphere of the same pressure as the partition wall so that the wafer can be reciprocated.
Dual scan type ion implant system with improved throughput. In the first paragraph,
An ion beam is irradiated between the first and second scan robots inside the process chamber, and the first and second scan robots arranged 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. In the first paragraph,
Characterized in that a single aligner is placed between the first and second dual-arm vacuum robots within the single vacuum transfer module (VTM) for aligning the notch direction of the wafer.
Dual scan type ion implant system with improved throughput. In the first paragraph,
Characterized in that the first and second aligners are respectively arranged on the sides of 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. In the first paragraph,
Characterized in that first and second aligners are 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. In the first paragraph,
The first load lock chamber assembly and the second load lock chamber assembly are each,
Characterized in that it is divided into an upper chamber and a lower chamber for loading or unloading wafers into or from the first or second vacuum transfer module (VTM).
Dual scan type ion implant system with improved throughput. In the first paragraph,
The first and second scanning robots are respectively,
An L1 axis vertically coupled to one side of the first link and rotating the first link by driving the first driving unit;
A second link having the same length as the first link is overlaid on the upper portion of the first link, and an L2 axis vertically coupled to the other side of the first link and one side of the second link overlaid thereon, and rotating the second link by driving of a second driving unit;
A support frame that supports a scan head is covered on the upper side of the other side of the second link, and an R-axis that is vertically connected to the other side of the second link and the center of the support frame and rotates the support frame by driving of a third driving unit;
A Y-axis that is horizontally connected to the support frame to support both sides of the scan head and rotates the scan head by driving the fourth driving unit; and
An S-axis for adjusting the twist angle or orientation angle of the wafer by rotating the wafer chuck on which the wafer is placed by the driving of the fifth driving unit;
The first driving unit and the second driving unit are driven in synchronization, and the first link rotates left and right based on the L1 axis, and the second link rotates left and right based on the L2 axis to horizontally move the scan head left and right.
Dual scan type ion implant system with improved throughput. In the first paragraph,
The first load lock chamber assembly and the second load lock chamber assembly are each characterized in that they have a plurality of chambers arranged in a vertical direction or a horizontal direction.
Dual scan type ion implant system with improved throughput.