Wafer conveying unit and wafer conveying method

Abstract

The fault analysis unit of the present invention is a wafer transport unit that holds and transports a wafer while in a semiconductor fault analysis apparatus, and includes: a stage that fixes the wafer at a predetermined observation position; and a wafer chuck that holds the wafer and transports it to the observation position. The wafer chuck has a plurality of holding members (protrusions) arranged opposite to the side of the wafer, and holds the wafer by clamping the periphery of the wafer (W) by the plurality of holding members.

Description

Technical Field

[0001] One aspect of the present invention relates to a wafer transport unit and a wafer transport method that simultaneously holds and transports a wafer in a semiconductor fault analysis apparatus. Background Technology

[0002] In semiconductor fault analysis apparatus, there is a known mechanism that holds and transports a wafer at the same time (wafer transport mechanism) (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2010 / 0315617 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] As described above, wafer transport mechanisms include structures comprising wafer chucks for holding and transporting wafers. Previously, a method for securely holding wafers in the wafer chuck was to use tape to fix the wafers to the chuck. In recent years, to automatically perform fault analysis on multiple wafers, wafer transport robots have been used to move wafers from wafer cassettes to wafer chucks. However, when using such wafer transport robots, it is difficult to use tape to fix the wafers to the chuck. Therefore, there is a need to find a method other than tape to securely hold wafers during transport.

[0008] Furthermore, in semiconductor fault analysis apparatuses as described above, when the wafer is held in place by a wafer chuck or similar device, a special lens, called a solid-state immersion lens, with a hemispherical component mounted on its front end, is brought into close contact with the back side of the wafer to obtain a high-resolution image. For the solid-state immersion lens to be in close contact to analyze any chip within the wafer, the entire back side of the wafer must be exposed. Therefore, in structures where the solid-state immersion lens is brought into close contact with the wafer from the back side, a structure must be provided outside the back side of the wafer to securely hold the wafer during transport.

[0009] Furthermore, in the semiconductor fault analysis apparatus described above, the probe card's pins are touched down onto the wafer's pads from the wafer's surface side, and a bias voltage is applied to the wafer. However, if a fixing member is provided on the wafer's surface side to firmly hold the transported wafer, there is a possibility that the fixing member will obstruct the probe card's pins from touching down or cause the probe card's pins to break. Although, as described above, efforts are made to firmly hold the transported wafer using methods other than tape in the wafer transport mechanism, the position and thickness of the holding mechanism are limited in terms of realizing the various functions of the semiconductor fault analysis apparatus, and no suitable holding mechanism has been found.

[0010] One aspect of the present invention is made in view of the above-mentioned actual situation, and the object is to provide a wafer transport unit and a wafer transport method that can properly maintain a wafer in transit without hindering the functions of the semiconductor fault analysis device.

[0011] Technical means for solving problems

[0012] One aspect of the present invention is a wafer transport unit that transports a wafer while holding it in a semiconductor fault analysis apparatus, and includes: a fixing part that fixes the wafer at a predetermined observation position; and a transport part that transports the wafer to the observation position while holding it, the transport part having a plurality of holding members arranged opposite to the side of the wafer, and holding the wafer by clamping the periphery of the wafer by the plurality of holding members.

[0013] In one aspect of the wafer transport unit of the present invention, a transport section transports a wafer to an observation position where the wafer is fixed. Furthermore, the transport section clamps the periphery of the wafer using multiple holding members positioned opposite the side surfaces of the wafer. Thus, by employing a structure where the holding members of the transport section clamp the periphery of the wafer from the side surfaces, there is no need to provide new structures on the back and surface sides of the wafer for robustly holding it during transport. Therefore, the wafer during transport can be properly held without interfering with the functions of the semiconductor fault analysis apparatus.

[0014] Multiple retaining members may be configured to include at least three protrusions that abut against the periphery of the wafer. This allows for stable clamping of the wafer.

[0015] Multiple retaining members may be configured to include at least four protrusions. This allows for more stable clamping of the wafer.

[0016] Alternatively, the multiple holding members may have: a first holding member including one or more protrusions abutting against the periphery of the wafer; and a second holding member including one or more protrusions, wherein the direction in which the first holding member applies a force to the wafer is opposite to the direction in which the second holding member applies a force to the wafer. By setting the direction of the force applied to the wafer by the first holding member and the direction of the force applied to the wafer by the second holding member to be opposite, the wafer can be properly held by the first holding member and the second holding member.

[0017] The aforementioned wafer transport unit also includes a stop portion, which is configured such that by fixing only one of the first holding member and the second holding member, the separation distance between the first holding member and the second holding member can be changed, thereby releasing the clamping state of the wafer by the first holding member and the second holding member. According to this structure, the wafer clamping state can be appropriately released (wafer release) through a simple structure that only fixes the position of either the first holding member or the second holding member.

[0018] Alternatively, the conveying section may have: a base portion; a ring portion comprising: a first portion connected to the base portion via an elastic member; a pair of second portions continuous with the first portion, facing each other and extending in a first direction; and a third portion continuous with the front ends of the pair of second portions, and formed in a ring shape to divide a receiving space for accommodating the wafer; and a core portion continuous with the base portion and extending in the first direction between the pair of second portions. In the third portion of the ring portion, a first retaining member protruding toward the receiving space is provided; in the front end of the core portion, a second retaining member protruding toward the receiving space is provided; in the pair of second portions of the ring portion, holes are formed that can engage with a stop portion. The stop portion fixes the position of the ring portion by engaging with the holes, thereby fixing the position of the first retaining member. According to this structure, the wafer is appropriately clamped by the first and second retaining members protruding toward the receiving space. Furthermore, the ring is fixed by engaging with the stop portion through the holes in the pair of second portions of the ring, and the position of the first retaining member is also fixed. In this case, since the ring and the base portion are connected via an elastic member, and the elastic member extends, the base portion and the core portion connected to the base portion can be displaced even when the position of the ring is fixed. By displacing the core portion away from the receiving space while the position of the ring is fixed, the separation distance between the first retaining member provided on the ring portion and the second retaining member provided on the core portion increases, releasing the wafer clamping state achieved by the first retaining member and the second retaining member. As described above, with the above structure, proper clamping and release (release) of the wafer can be easily performed.

[0019] One aspect of the present invention is a wafer transport method in a semiconductor fault analysis apparatus that involves holding and transporting a wafer simultaneously. The method includes: a step of clamping the periphery of the wafer by means of a plurality of holding members configured to face the side of the wafer; and a step of transporting the wafer to a predetermined observation position while the periphery of the wafer is clamped by the plurality of holding members.

[0020] The effects of the invention

[0021] According to one aspect of the present invention, it is possible to properly maintain the wafer during transport without impairing the functions of the semiconductor fault analysis apparatus. Attached Figure Description

[0022] Figure 1 This is a diagram schematically illustrating a fault analysis apparatus according to an embodiment of the present invention.

[0023] Figure 2 It is a diagram illustrating the structure of the observation position on the wafer.

[0024] Figure 3 This diagram illustrates the view from the back of a wafer.

[0025] Figure 4 This diagram illustrates wafer replacement performed by a wafer handling robot.

[0026] Figure 5 This diagram illustrates the wafer holding and wafer release states achieved by the wafer chuck.

[0027] Figure 6 This is a diagram illustrating an example of the shape of a protrusion.

[0028] Figure 7 This is a schematic diagram illustrating an example of the contact structure between the wafer and the protrusion, and the contact structure between the wafer and the wafer holder.

[0029] Figure 8 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0030] Figure 9 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0031] Figure 10 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0032] Figure 11 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0033] Figure 12 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0034] Figure 13This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0035] Figure 14 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0036] Figure 15 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0037] Figure 16 This diagram illustrates the wafer transfer process performed by a wafer chuck.

[0038] Figure 17 This is a diagram schematically illustrating a comparative example of a wafer fixing method.

[0039] Figure 18 This is a schematic diagram illustrating a variation of a wafer chuck. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts are given the same reference numerals in each drawing, and repeated descriptions are omitted.

[0041] Figure 1 This diagram schematically illustrates the fault analysis apparatus 1 (semiconductor fault analysis apparatus) of this embodiment. Fault analysis apparatus 1 is an apparatus for inspecting wafer W (analyzing faults in wafer W). Multiple chips, which are semiconductor devices, are formed on wafer W. These semiconductor devices include logic devices, memory devices, analog devices, mixed-signal devices (combining digital and analog signals), discrete devices including power devices, optical devices including optical sensors or light-emitting elements, and passive components including capacitors or coils.

[0042] like Figure 1 As shown, the fault analysis device 1 includes: a fault analysis unit 10 (wafer transfer unit) and a controller 50. The controller 50 is a control unit that controls each structure of the fault analysis unit 10 (details are described later). The fault analysis unit 10 is as follows... Figure 1 and Figure 2 As shown, it has: a mounting stage 11 (fixed part), a pressure plate 13, a test head 14, a cable 15, a probe card 16, a performance board 40, a connector board 41, and a probe tower 42, and serves as an observation position for fault analysis of wafer W.

[0043] Figure 2 It is a diagram illustrating the structure of the observation position on the wafer. Figure 2 (a) indicates the state where the wafer W is not mounted on the stage 11. Figure 2(b) indicates the state where the wafer W is placed on the stage 11. The stage 11 is a fixing part that fixes the wafer in a specified observation position. The pressure plate 13 is a flat plate member that holds the probe card 16. The pressure plate 13 can move vertically via a Z-stage (not shown) provided at the lower part of the stage 11. The test head 14 is a structure that applies voltage to the pins 16a of the probe card 16 via the performance plate 40, cable 15, connector plate 41, and probe tower 42. The probe card 16 is a fixture for electrical inspection of the chip on the wafer W. The probe card 16 has pins 16a protruding toward the stage 11. Figure 2 As shown in (b), with the wafer W fixed on the stage 11, it is lowered by the pressure plate 13, and the pins 16a of the probe card 16 touch the pads on the chip formed on the surface of the wafer W. By applying an appropriate voltage with the test head 14, the fault state of the chip is reproduced, and fault analysis is performed on the chip being inspected.

[0044] Figure 3 This diagram illustrates the backside view of wafer W. In the fault analysis of wafer W at the wafer observation location, as shown... Figure 3 As shown in (a), the front end of the solid-state immersion lens 80 is placed in close contact with the back surface Wb of the wafer W to obtain a high-resolution image of the back surface Wb side of the wafer W. A plurality of wafer chucks 11a are formed on the stage 11. By forming the wafer chucks 11a, when performing inspection of the back surface Wb side, which is in a fault reproduction state caused by the aforementioned appropriate voltage application, the wafer W is properly fixed to the stage 11 by a vacuum chuck. Figure 3 As shown in (b), the wafer W is moved by the wafer chuck 12, and fault analysis is performed on any chip on the wafer W.

[0045] return Figure 1 The fault analysis unit 10 includes a wafer chuck 12 (transfer section), X stages 21, 21, and a Y stage 22, and serves as a structure for simultaneously holding and transferring the wafer W. The X stages 21, 21 are stages for moving the wafer chuck 12 holding the wafer W in the X direction (first direction). The Y stage 22 is a stage for moving the wafer chuck 12 holding the wafer W in the Y direction. The X and Y directions are directions along the wafer W's mounting surface on the wafer chuck 12 and intersect each other. Figure 1As shown, in this embodiment, the wafer chuck 12 moves along the X stages 21, 21 in the X direction, and the separation distance between the wafer chuck 12 and the mounting stage 11 of the fault analysis unit 10 changes. The X stages 21, 21 extend in the X direction in a mutually opposing manner. The Y stage 22 is mounted between the X stages 21, 21 and is movably arranged along the X stages 21, 21 in the X direction. The wafer chuck 12 is movably arranged along the Y stage 22 in the Y direction. According to this structure, the wafer chuck 12 moves in the X direction by moving the Y stage 22 along the X stages 21, 21.

[0046] The wafer chuck 12 is a transport unit that holds and transports the wafer W to the stage 11, which serves as the observation position. As described above, the wafer chuck 12 is movable in the X and Y directions (along the direction of the wafer W's mounting surface) via the X stages 21 and 22. The wafer chuck 12 will be transported by, for example, a wafer transport robot 60 (see...). Figure 4 The multiple wafers W that are automatically replaced are sequentially transported to the mounting stage 11.

[0047] Figure 4 This diagram illustrates the wafer replacement performed by the wafer transfer robot 60. Figure 4 The diagram illustrates a wafer transport robot 60 and a wafer cassette 70, serving as structures for wafer replacement. Figure 4 As shown, in the wafer cassette 70, multiple wafers W, the objects of fault analysis, are stacked in a state separated by separators and placed on each separator. The wafer transfer robot 60 uses its hand 61 to lift, pick up, and move a wafer W from the back of the wafer cassette 70, transferring it to the wafer chuck 12. At this time, the wafer transfer robot 60 can use the wafer holder 19 and wafer base 51 (described later) to... Figure 9 The wafer W is transferred to the wafer chuck 12. The wafer chuck 12 holds and transports the wafer W to the stage 11 via a holding member (described later). In the stage 11, when the fault analysis of wafer W is completed, the wafer W is moved to the vicinity of the wafer transport robot 60. Then, the wafer transport robot 60 removes the fault-analyzed wafer W from the wafer chuck 12, holds and transports the next wafer W stacked on the wafer cassette 70, and places it on the mounting surface of the wafer chuck 12. This is the wafer replacement performed by the wafer transport robot 60.

[0048] Near the wafer replacement area where the wafer transfer robot 60 and wafer cassette 70 are located, such as Figure 8 and Figure 9As shown, a wafer base 51 and a wafer holder 19 are provided. The wafer base 51 is a stage for holding the wafer W during wafer replacement. The wafer base 51 can be set at the same height as the stage 11 to allow the wafer W to slide and move. Alternatively, the structure can simply have the wafer holder 19 arranged in the stage 11, instead of including both the wafer base 51 and the wafer holder 19. The wafer holder 19 is configured to be able to move up and down, and the wafer W placed on the wafer base 51 is pushed up from the back side to facilitate the transfer of the wafer W to the wafer transport robot 60 (details are described later).

[0049] For the structure of holding the wafer W by the wafer chuck 12, refer to Figure 5 Please provide an explanation. Figure 5 This describes the wafer holding state achieved by the wafer chuck 12. Figure 5 (a) and wafer release state ( Figure 5 Figure (b) shows the wafer chuck 12. The wafer chuck 12 has a plurality of retaining members configured to face the side of the wafer W. These retaining members are configured with four protrusions 12x, 12x, 12y, and 12y. The protrusions 12x, 12x, 12y, and 12y are structures for clamping the wafer W. Specifically, the plurality of retaining members have: a first retaining member including two protrusions 12y, 12y that abut against the periphery of the wafer W, and a second retaining member including two protrusions 12x, 12x.

[0050] The wafer chuck 12 comprises a base portion 12a, a core portion 12b, elastic members 12c, and a ring portion 12d. The base portion 12a is connected to the Y-stage 22. The ring portion 12d comprises: a first portion 12k, which is connected to the base portion 12a via a pair of elastic members 12c, 12c; a pair of second portions 12e, 12e, which are connected to the first portion 12k and are opposite to each other and extend in the X direction (first direction); and a third portion 12g, which is connected to the front end of the pair of second portions 12e (the end in the X direction opposite to the side connected to the first portion 12k), and is formed in a ring shape to divide a roughly circular receiving space for accommodating (carrying) the wafer W.

[0051] In a pair of second parts 12e, 12e, a ratchet mechanism 18 (stop portion) is formed. (See reference...) Figure 9The ratchet mechanisms 18 and 18 engage with the holes 12f and 12f to fix the positions of the second portions 12e and 12e where the holes 12f and 12f are formed. The ratchet mechanism 18 is configured to fix the positions of the protrusions 12y and 12y, which serve as the first holding members, by fixing the positions of the second portions 12e and 12e. This allows the separation distance between the protrusions 12y and 12y and the protrusions 12x and 12x to change, thereby releasing the clamping state of the wafer W formed by the protrusions 12y and 12x and 12x (details are described later). In other words, when the ratchet mechanism 18 engages with the second portion 12e and the position of the ring 12d (that is, the position of the protrusions 12y and 12y) is fixed, as shown in the following description. Figure 10 As shown, by moving only the core 12b in the X direction (and in the direction separate from the wafer W), the distance between the protrusions 12y, 12y and the protrusions 12x, 12x is increased, and the protrusions 12x, 12x do not contact the wafer W, thus releasing the clamping state of the wafer W.

[0052] The elastic member 12c can be a spring member or rubber (such as a silicone rubber ring). The core 12b is connected to the base portion 12a and extends in the X direction (first direction) between a pair of second portions 12e, 12e. At the front end of the core 12b (the end in the X direction opposite to the side connected to the base portion 12a), protrusions 12x, 12x are provided as second holding members protruding toward the receiving space in which the wafer W is placed (accommodated). In addition, at the third portion 12g of the ring portion 12d, protrusions 12y, 12y are provided as first holding members protruding toward the receiving space in which the wafer W is placed (accommodated) in plan view. Figure 5 As shown in (a), the direction of the force exerted on the wafer W by the protrusions 12x, 12x, which are the second holding members for clamping the wafer W, is opposite to the direction of the force exerted on the wafer W by the protrusions 12y, 12y, which are the first holding members for clamping the wafer W, in the X direction. Although there is no particular limitation on the position of the protrusions 12x, 12x, 12y, 12y, for example, the position of the protrusions 12y, 12y in the Y direction is further outward than the position of the protrusions 12x, 12x.

[0053] like Figure 5 As shown in (a), in the wafer holding state, the wafer chuck 12 clamps the periphery of the wafer W through the protrusions 12x, 12x that serve as second holding members and the protrusions 12y, 12y that serve as first holding members, thereby holding the wafer W. Furthermore, as... Figure 5As shown in (b), in the wafer release state, the protrusions 12x, 12x that serve as the second holding member and the protrusions 12y, 12y that serve as the first holding member of the wafer chuck 12 do not contact the wafer W and do not clamp the wafer W.

[0054] For a detailed description of the structure of protrusion 12x (and protrusion 12y), please refer to... Figure 6 and Figure 7 Please provide an explanation. Figure 6 This is a diagram schematically illustrating an example of the shape of the protrusion 12x (and protrusion 12y) as a retaining member. Figure 6 (a) and Figure 6 The protrusions 12x shown in (b) are all shaped to hold the wafer W, and are designed to be more concave towards the center. Figure 6 The surface of the portion of the protrusion 12x shown in (a) that is inserted into the wafer W becomes a curved surface. On the other hand, Figure 6 The surface of the portion of the protrusion 12x shown in (b) that is sandwiched in the wafer W is not curved, but is formed as a valley with a central depression. Figure 6 The protrusion 12x shown in (c) is shaped to press the wafer W downwards.

[0055] Figure 7 This is an example schematically illustrating the contact structure between wafer W and protrusion 12x. Figure 7 (a) and Figure 7 (b)), and an example of the contact structure between the wafer W and the wafer holder 19 ( Figure 7 Figure (c) shows the process. As described later, when wafer W is removed from wafer chuck 12, wafer W is lifted from below via wafer holder 19. In this case, as... Figure 7 As shown in (a), the wafer W can slide up the inclined surface of the protrusion 12x of the wafer chuck 12. Even in cases where it is difficult to slide up as described above, it can be done as follows: Figure 7 As shown in (b), the protrusion 12x of the wafer chuck 12 deforms (in the direction in which the wafer W easily rises) as the wafer W rises, and the wafer W is appropriately removed from the wafer chuck 12. In this case, the protrusion 12x is made of a material with a certain degree of plasticity. Furthermore, it can be as follows... Figure 7 As shown in (c), a slope is provided in the wafer holder 19, which facilitates the movement of the wafer W by allowing the wafer W to slide, making it easy to remove the wafer W.

[0056] return Figure 1The controller 50 is a computer, physically comprising a RAM, ROM, or other memory, a CPU or other processor (arithmetic circuitry), a communication interface, a hard disk, and other storage units. Examples of controllers 50 include personal computers, cloud servers, and smart devices (smartphones, tablets, etc.). The controller 50 functions by executing programs stored in memory using the computer system's CPU. The controller 50 controls the X stage 21, Y stage 22, and Z stage (not shown). By controlling the X stage 21 and Y stage 22, the controller 50 switches between wafer holding and wafer releasing states and transports the wafer W.

[0057] Secondly, refer to Figures 8 to 16 This describes the wafer transfer process performed by the wafer chuck 12. Figures 8 to 16 Indicates a continuous process. Figures 8-11 This refers to the process of moving, for example, the fault-analyzed wafer W to the wafer replacement area (near the wafer transport robot 60). Figure 12 This indicates the wafer replacement process performed by the wafer transfer robot 60. Figures 13-16 This indicates the process of transferring the new wafer W to the mounting stage 11. Furthermore, in Figures 8 to 16 In the accompanying drawings, figures with the same numbers (a) to (c) (or (a) to (b)) indicate states with the same timing sequence. Furthermore, the following explanation will focus on the cases where the X direction represents the right direction of the figure (the direction from the stage 11 toward the wafer base 51) and the -X direction represents the left direction of the figure (the opposite direction to the direction from the stage 11 toward the wafer base 51).

[0058] like Figure 8 As shown in (a), currently, the wafer chuck 12 of the wafer W is kept moving in the -X direction by the control of the X stage 21 via the controller 50. Furthermore, as a prerequisite, the Y position of the ratchet mechanisms 18, 18 located near the wafer replacement section is aligned with the Y position of the holes 12f, 12f of the wafer chuck 12 by the control of the Y stage 22 via the controller 50. Figure 8 In the state shown in (a), the X positions of the holes 12f, 12f of the wafer chuck 12 do not reach the X positions of the ratchet mechanisms 18, 18. Figure 8 As shown in (b), a spring force is applied upward to the ratchet mechanism 18, but in the initial stage before the hole 12f reaches the ratchet mechanism 18, the upward force towards the ratchet mechanism 18 is suppressed by the back side of the second part 12e. Additionally, as... Figure 8 As shown in (c), in Figure 8 In state (a), a portion of the wafer W has been placed on a portion of the wafer base 51.

[0059] If, from this point, the wafer chuck 12 moves further in the -X direction, then as Figure 9 As shown in (a), the wafer W is placed on the wafer base 51 with the center of the wafer base 51 aligned with the center of the wafer W, and the ratchet mechanisms 18, 18 engage with the holes 12f, 12f of the wafer chuck 12 (see reference). Figure 9 (b) The ratchet mechanism 18, propelled upward through the hole 12f by the spring mechanism, hinders the movement (motion) of the ring 12d in the -X direction. With the ratchet mechanism 18 engaged with the hole 12f, the position of the ring 12d is fixed, and the position of the structure of the ring 12d (including protrusions 12y, 12y) does not change. Subsequently, if the wafer chuck 12 moves in the same direction, only the base portion 12a and the core portion 12b move in the same direction, and the position of the ring 12d does not change. This difference in position between the base portion 12a and the core portion 12b and the ring 12d is absorbed by the expansion and contraction of the elastic member 12c.

[0060] like Figure 10 As shown, if the base portion 12a and the core portion 12b move further in the same -X direction, the protrusions 12x, 12x at the front end of the core portion 12b separate from the wafer W, and the clamping state of the wafer W is released. Under the control of the X-stage 21 by the controller 50, the core portion 12b moves to a position where the open space is larger than the overhang inner diameter of the protrusions 12x, 12x, and then stops.

[0061] Next, as Figure 11 As shown in (c), the wafer holder 19 rises under the control of the controller 50, pushing the wafer W from the back side. As the wafer holder 19 rises, the wafer W slides along the inclined surface of the wafer holder 19, allowing the wafer W to be positioned where the center of the wafer holder 19 coincides with the center of the wafer W.

[0062] Next, as Figure 12 As shown in (c), with the wafer holder 19 raised, the wafer transport robot 60 is controlled by the controller 50 to remove (unload) the wafer W (wafer W1) after fault analysis, and then load the wafer W (wafer W2) before fault analysis. Furthermore, when loading wafer W2, the location of the notch on wafer W2 is determined by, for example, a notch sensor 43, and the tilt of wafer W2 is adjusted to set the correct angle. Figure 12 (a) shows the wafer chuck 12, wafer base 51, and wafer holder 19 in the state where the wafer W (wafer W1) has been removed.

[0063] Next, as Figure 13As shown in (c), the wafer holder 19 descends under the control of the controller 50, placing the wafer W on the wafer base 51. The wafer holder 19 is retracted to a position lower than the wafer base 51.

[0064] Next, as Figure 14 As shown in (a), the X stage 21 is controlled by the controller 50, and the base portion 12a and the core portion 12b move in the X direction, with the protrusions 12x, 12x contacting the periphery of the wafer W. Furthermore, in this state, the ring portion 12d engages with the holes 12f, 12f of the wafer chuck 12 via ratchet mechanisms 18, 18 (see reference). Figure 14 (b)), and movement regulation in the X direction.

[0065] Next, as Figure 15 As shown in (a), the base portion 12a and the core portion 12b move further in the X direction under the control of the X stage 21 via the controller 50, pressing the wafer W in the X direction through the protrusions 12x, 12x, and the periphery of the wafer W contacts the protrusions 12y, 12y of the ring portion 12d. Force is applied to the wafer W from both sides by the protrusions 12x, 12x and 12y, 12y, thereby clamping the wafer W and fixing it during transport. Furthermore, at this moment, a force in the X direction is applied to the ring portion 12d, such as... Figure 15 As shown in (b), the engagement between the ratchet mechanisms 18, 18 and the holes 12f, 12f of the wafer chuck 12 is released. That is, the ring 12d is released from the ratchet mechanism 18.

[0066] Then, with the wafer W held between the protrusions 12x, 12x, 12y, and 12y at its periphery, as follows: Figure 16 As shown in (a), the wafer chuck 12 moves in the X direction under the control of the X stage 21 by the controller 50. That is, the wafer chuck 12 separates from the wafer base 51 and moves toward the stage 11. The wafer W is clamped and held from the left and right (both sides) by the elastic member 12c provided at the root of the wafer chuck 12.

[0067] Secondly, regarding the effect of the fault analysis unit 10 in this embodiment, while referring to the structure of the comparative example (see Figure 17 The comparison is explained on one side.

[0068] As a wafer transport mechanism of the fault analysis unit 10, a structure is known that includes a wafer chuck 12 for loading and transporting wafers W. As a method for firmly holding wafer W in the wafer chuck 12, there are methods such as... Figure 17As shown in (a), the wafer W is fixed to the surface side of the wafer chuck 12 with tape 300. The tape 300 has a low height. Therefore, when the probe card 16's pin 16a touches the pad of the wafer W from the surface side of the wafer W, it is advantageous to be able to approach the chip point near the wafer edge. However, in recent years, in order to automatically perform fault analysis on multiple wafers W, there have been cases where wafers are moved from the wafer cassette 70 to the wafer chuck 12 by a wafer transport robot 60. However, when using this wafer transport robot 60, it is difficult to use the method of fixing the wafer W to the wafer chuck 12 with tape 300. Therefore, it is sought to use a structure other than tape 300 to firmly hold the wafer W during transport.

[0069] As a structure, it is considered to employ a fixture that firmly holds the wafer W during transport, for example, on the surface side of the wafer W. However, in, for example... Figure 17 As shown in (b), when using a taller fixing member 200a, there is a concern that the height of the fixing member 200a becomes higher than the height from the bottom surface of the probe card 16 to the front end of the needle 16a, making it impossible to achieve the aforementioned ground contact. Furthermore, in cases such as... Figure 17 As shown in (c), when using the lower-height fixture 200b, it does not fail to reach the ground as with fixture 200a, but there is a concern that interference may occur near the wafer edge due to the design of the probe card 16. As described above, in the wafer transport mechanism, there is an attempt to securely hold the transported wafer W using methods other than tape, but the position and thickness of the holding mechanism are limited in terms of realizing the various functions of the semiconductor fault analysis device, and no suitable holding mechanism has been found.

[0070] As a structure to solve the above-mentioned problems, the fault analysis unit 10 of this embodiment is a unit that holds and transports the wafer W in a semiconductor fault analysis apparatus, and includes: a stage 11 that fixes the wafer W at a predetermined observation position; and a wafer chuck 12 that holds and transports the wafer W to the observation position, and the wafer chuck 12 has a plurality of holding members (protrusions 12x, 12x, 12y, 12y) arranged opposite to the side of the wafer W, and holds the wafer W by clamping the periphery of the wafer W by the plurality of holding members.

[0071] In the fault analysis unit 10 of this embodiment, the wafer W is transported to the observation position where the wafer W is fixed by the wafer chuck 12. Then, the wafer chuck 12 clamps the periphery of the wafer W by a plurality of protrusions 12x, 12x, 12y, 12y that are configured to face the side surface of the wafer W. In this way, by adopting a structure in which the periphery of the wafer W is clamped from the side surface of the wafer W by the protrusions 12x, 12x, 12y, 12y of the wafer chuck 12, it is not necessary to provide a new structure for firmly holding the wafer W during transport on the back side and the surface side of the wafer. As a result, the wafer W during transport can be properly held without interfering with the functions of the semiconductor fault analysis device.

[0072] Multiple retaining members may be configured with at least four protrusions 12x, 12x, 12y, and 12y. This allows for more stable clamping of the wafer W.

[0073] Alternatively, the multiple holding members may have: a first holding member including multiple protrusions 12y, 12y that abut against the periphery of the wafer W; and a second holding member including multiple protrusions 12x, 12x, wherein the direction of the force applied to the wafer W by the first holding member is opposite to the direction of the force applied to the wafer W by the second holding member. By setting the direction of the force applied to the wafer W by the first holding member and the direction of the force applied to the wafer W by the second holding member to be opposite, the wafer W can be properly held by the first holding member and the second holding member.

[0074] The aforementioned fault analysis unit 10 further includes a ratchet mechanism 18, which is configured to release the wafer W from its clamping state by fixing only the position of the first holding member and changing the separation distance between the first holding member and the second holding member. According to this structure, the clamping state of the wafer W can be appropriately released (wafer W released) by a simple structure that only fixes the position of the first holding member.

[0075] Alternatively, the wafer chuck 12 may include: a base portion 12a, a ring portion 12d, and a core portion 12b. The ring portion 12d includes: a first portion 12k, which is connected to the base portion 12a via an elastic member 12c; a pair of second portions 12e, 12e, which are connected to the first portion 12k and extend in the X direction with one side facing each other; and a third portion 12g, which is connected to the front end of the pair of second portions 12e and is formed in a ring shape to divide the receiving space for receiving the wafer. The core portion 12b is connected to the base portion 12a. Furthermore, the ring 12d extends in the X direction between the pair of second portions 12e, 12e; in the third portion 12g of the ring 12d, protrusions 12y, 12y protruding toward the receiving space are provided; at the front end of the core 12b, protrusions 12x, 12x protruding toward the receiving space are provided; in the pair of second portions 12e of the ring 12d, a hole 12f is provided that can engage with a ratchet mechanism 18. The ratchet mechanism 18 fixes the position of the ring 12d and the position of the protrusions 12y, 12y by engaging with the hole 12f. According to this structure, the wafer W is properly clamped by the protrusions 12y, 12y and 12x, 12x protruding toward the receiving space. Moreover, the ring 12d is fixed and the position of the protrusions 12y, 12y is fixed by engaging with the ratchet mechanism 18 through the hole 12f of the pair of second portions 12e of the ring 12d. In this case, since the ring portion 12d and the base portion 12a are connected via the elastic member 12c, and the elastic member 12c extends, even when the position of the ring portion 12d is fixed, the base portion 12a and the core portion 12b connected to the base portion 12a can be displaced. By displacing the core portion 12b away from the receiving space while the position of the ring portion 12d is fixed, the separation distance between the protrusions 12y, 12y provided on the ring portion 12d and the protrusions 12x, 12x provided on the core portion 12b increases, releasing the wafer W clamping state achieved by the protrusions 12y, 12y and the protrusions 12x, 12x. As described above, with the above structure, proper clamping and release of the wafer W can be easily performed. Furthermore, the wafer clamping / releasing is achieved by the operation of the X-stage, eliminating the need for a separate clamping / releasing drive mechanism. This improves the reliability of the wafer loading / unloading system.

[0076] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, although the above embodiments were described with at least four protrusions as retaining members, the present invention may be as follows: Figure 18 As shown, there are three protrusions. That is to say, in Figure 18 (a) and Figure 18In the wafer chuck shown in (b), two protrusions 512x, 512x are provided at the front end of the core portion 512b, and one protrusion 512y is provided in the third portion 512g of the ring portion 512d. Although there is no particular limitation on the position of the protrusions 512x, 512x, 512y, for example, the position of the protrusions 512x, 512x in the Y direction is further outward than the position of the protrusion 512y.

[0077] Symbol Explanation

[0078] 10… Fault analysis unit (wafer transport unit); 11… Stage (fixing part); 12… Wafer chuck (transporting part); 12a… Base part; 12b… Core part; 12c… Elastic member; 12d… Ring part; 12e… Part 2; 12f… Hole part; 12g… Part 3; 12k… Part 1; 12x, 12x, 12y, 12y… Protrusions; 18… Ratchet mechanism (stop part); 19… Wafer holder; 21… X Stage; 22…Y stage; 40…performance board; 41…connector board; 42…probe tower; 43…notch sensor; 50…controller; 51…wafer base; 60…wafer transport robot; 61…hand; 70…wafer box; 80…solid immersion lens; 200a, 200b…fixtures; 300…tape; 512b…core; 512d…ring; 512x…protrusion; 512y…protrusion; W…wafer.

Claims

1. A wafer transport unit, wherein, It is a wafer transport unit in a semiconductor fault analysis device that simultaneously holds and moves the wafer. have: The fixing part, which fixes the wafer in the specified observation position; and The transport unit, while maintaining its position, transports the wafer to the observation location. The conveying part, The wafer has a plurality of holding members arranged opposite to the side surface of the wafer, which clamp the periphery of the wafer to hold the wafer. The device has an annular portion that divides a receiving space for accommodating the wafer, and the annular portion is provided with a plurality of retaining members that protrude toward the receiving space and contact only the periphery of the wafer and not the back side or surface of the wafer.

2. The wafer transport unit as described in claim 1, wherein, The plurality of retaining members are configured to include at least three protrusions that abut against the periphery of the wafer.

3. The wafer transport unit as described in claim 2, wherein, The plurality of retaining members comprises at least four of the aforementioned protrusions.

4. The wafer transport unit as described in any one of claims 1 to 3, wherein, The plurality of retaining members have: a first retaining member comprising one or more protrusions abutting against the periphery of the wafer; and a second retaining member comprising one or more of the protrusions. The direction in which the first holding member holding the wafer applies a force to the wafer is opposite to the direction in which the second holding member holding the wafer applies a force to the wafer.

5. The wafer transport unit as described in claim 4, wherein, It also includes a stop portion, which is configured such that by fixing only the position of either the first holding member or the second holding member, the separation distance between the first holding member and the second holding member can be changed, thereby releasing the clamping state of the first holding member and the second holding member on the wafer.

6. The wafer transport unit as described in claim 5, wherein, The conveying unit has: Base section; The ring portion includes: a first portion connected to the base portion via an elastic member; a pair of second portions continuous with the first portion, opposing each other and extending in a first direction; and a third portion continuous with the front ends of the pair of second portions, and formed in a ring shape to divide a receiving space for accommodating a wafer; and A core portion, which is continuous with the base portion and extends in a first direction between the pair of second portions. In the third portion of the ring, the first retaining member protruding toward the receiving space is provided. At the front end of the core, a second retaining member protruding toward the receiving space is provided. The pair of second portions of the ring portion have holes configured to engage with the stop portion. The stop portion engages with the hole portion to fix the position of the ring portion, thereby fixing the position of the first retaining member.

7. A wafer transport method, wherein, This refers to a wafer handling method in semiconductor fault analysis equipment that involves simultaneously moving and holding the wafer. Include: A process is provided for a conveying section having an annular portion that divides a receiving space for accommodating the wafer, wherein the annular portion is provided with a plurality of holding members that protrude toward the receiving space and contact only the periphery of the wafer and not the back side or surface of the wafer. The process of clamping the periphery of the wafer using the plurality of holding members arranged opposite to the side surface of the wafer; and The process of transporting the wafer to a predetermined observation position while the wafer is held in place by the plurality of holding members around its periphery.

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