Chip detection scanning electron microscope

Abstract

The application discloses a chip detection scanning electron microscope, which comprises a shell, a scanning electron microscope device and a sample stage are arranged in the shell vertically, a focused ion beam device is also arranged in the shell obliquely, the sample stage comprises a base and a first platform which is swingably arranged on the base, a deflection device for driving the first platform to deflect is arranged on the base, a connecting seat is arranged on the base, a second platform is swingably arranged on the connecting seat and located above the first platform, and a driving mechanism is further arranged on the connecting seat. Compared with the prior art, the chip detection scanning electron microscope utilizes the deflection of the original sample stage (i.e. the first platform) of the equipment to realize the deflection driving of the second platform, the deflection of the first platform can be performed multiple times to realize the deflection of the second platform with a larger amplitude, and the chip detection scene is expanded, for example, the detection and observation of the chip with a larger angle can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chip detection, in particular, to a chip detection scanning electron microscope. BACKGROUND

[0002] A scanning electron microscope (SEM) is a high-resolution imaging device that uses a focused electron beam to scan the surface of a sample and obtains microstructure information of the sample surface by detecting signals such as secondary electrons and backscattered electrons generated by the interaction between electrons and the sample.

[0003] In the field of chip failure analysis, a scanning electron microscope plays a crucial role. Its high resolution can clearly reveal defects such as electromigration, voids, and fractures in the chip metallization layer, as well as dislocations and leakage in PN junctions. Through functions such as voltage contrast imaging, SEM can also be used to locate fault areas such as latch-up in CMOS circuits. If combined with an energy dispersive spectrometer (EDS), it can also analyze the elemental composition of observed defects or contaminants, helping to trace the root cause of failure. In addition, combined with focused ion beam (FIB) technology, SEM can achieve point section cutting and internal structure observation of chips, and is a powerful tool for precise failure analysis.

[0004] At present, a Chinese patent with publication number CN101246132B discloses a focused ion beam device, which includes a housing, a scanning electron microscope device and a sample stage are arranged vertically in the housing, and a focused ion beam device is also arranged obliquely in the housing. The sample stage is connected to a focusing deflection device, and the inclination angle of the sample stage is adjusted by the focusing deflection device, so that the sample stage is adjusted to a position perpendicular to the focused ion beam device. However, due to the limitation of sample chamber space and compact structure design, the existing sample stage on the market has a small adjustable inclination angle, which limits the use of chip detection. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a chip detection scanning electron microscope.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] The chip detection scanning electron microscope comprises a shell, a scanning electron microscope device and a sample stage are vertically arranged in the shell, a focused ion beam device is also obliquely arranged in the shell, the sample stage comprises a base and a first platform swingably arranged on the base, a deflection device for driving the first platform to deflect is arranged on the base, a connecting seat is detachably arranged on the base, a second platform is swingably arranged on the connecting seat and located above the first platform, a driving mechanism is also arranged on the connecting seat, the driving mechanism comprises a transmission unit coupled to the first platform and an actuating unit coupled to the second platform, the transmission unit is adapted to receive the thrust generated when the first platform deflects and drive the actuating unit to actuate the second platform to deflect.

[0008] Preferably, the sample stage further comprises a carrier swingably arranged on the base, the first platform and the deflection device are arranged on the carrier, and the connecting seat is detachably connected to the carrier.

[0009] Preferably, the sample stage further comprises a linear carrier moving mechanism arranged on the base, and the carrier is arranged on a carrier moving end of the linear carrier moving mechanism.

[0010] Preferably, the actuating unit comprises a swing arm pivoted to the connecting seat, the swing arm comprises oppositely arranged first and second arms, the transmission unit comprises a transmission rod arranged on the swing arm, the transmission rod extends towards the first platform and deviates from the center of the first platform, a torsion spring is connected to the rotation shaft of the second platform, a ratchet wheel is also arranged on the rotation shaft of the second platform, the first and second arms are respectively located on the two sides of the ratchet wheel, a reset spring is connected to the swing arm and used to drive the end of the first arm to be buckled to the ratchet wheel, when the first platform deflects, the first platform pushes the transmission rod to drive the end of the first arm to be disengaged from the ratchet wheel, and the end of the second arm enters the buckling position.

[0011] Preferably, the transmission unit comprises a driving rod obliquely arranged on the connecting base and slidingly fitted on the connecting base, the driving rod comprises a sliding base and a driving bar elastically connected to the sliding base in the lateral direction, and a ratchet structure is arranged on the lateral wall of the driving bar; the actuating unit comprises a ratchet wheel arranged on the rotating shaft of the second platform; when the first platform is deflected, the first platform pushes the driving rod to slide, so that the ratchet structure is engaged with the ratchet wheel and pushes the second platform to be deflected; the driving rod is connected with a reset spring, and the reset spring is used for pushing the driving rod to return to the initial position, during which the ratchet wheel pushes the ratchet structure and makes the driving bar elastically move.

[0012] Preferably, the driving rod and the ratchet wheel are arranged in two groups, and the tooth shapes of the two ratchet wheels are opposite to each other, and the two driving rods are arranged symmetrically.

[0013] Preferably, the bottom end of the transmission rod is provided with a ball.

[0014] Preferably, the bottom end of the driving rod is provided with a ball.

[0015] Preferably, the transmission unit comprises a piston rod, and the piston rod is offset from the axis of the first platform; the actuating unit comprises a chamber arranged in the connecting base, and a sliding column is arranged on the rotating shaft of the second platform and slidingly fitted in the chamber; the chamber and the inner cavity of the piston rod are connected through a pipeline, a one-way valve is arranged in the pipeline, and the one-way valve is adapted to allow fluid to flow to only one side of the chamber; a liquid storage bag is further arranged on the connecting base and connected with the pipeline of the inner cavity of the piston rod; when the first platform is deflected, the first platform pushes the plunger of the piston rod, so that the fluid is filled into the chamber.

[0016] Preferably, the chamber is divided into a left chamber and a right chamber by the sliding column, two piston rods are symmetrically arranged, the inner cavities of the two piston rods are respectively connected with the right chamber and the left chamber through pipelines, and the inner cavities of the two piston rods are both connected with the liquid storage bag through pipelines; a pressure relief pipeline is arranged between the end of each of the left chamber and the right chamber and the liquid storage bag, a gate valve is arranged on each of the pressure relief pipelines, a spring rod is arranged on the plunger of each of the piston rods, and the two spring rods and the two gate valves are alternately corresponding; when the piston rod is pushed and compressed, the spring rod pushes the corresponding gate valve and drives the corresponding pressure relief pipeline to be opened.

[0017] The beneficial effects of the present application are: the chip to be detected is placed on the second platform, the first platform will push the transmission unit when deflected, and then the transmission unit will transmit the thrust to the actuating unit, and then the actuating unit will drive the second platform to be deflected. Compared with the prior art, the chip detection scanning electron microscope of the present application utilizes the deflection of the original sample stage (i.e. the first platform) of the equipment to realize the deflection driving of the second platform. Through multiple deflections of the first platform, a larger deflection of the second platform can be realized, so that the chip detection use scenario is expanded, for example, the detection and observation of a larger angle of the chip can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Structure schematic view of an embodiment;

[0019] Figure 2 Structure schematic view of a swing arm;

[0020] Figure 3 Structure schematic view of a driving rod;

[0021] Figure 4 Structure schematic view of a piston rod.

[0022] The drawings show: 1, housing; 2, scanning electron microscope device; 3, sample stage; 4, focused ion beam device; 5, base; 6, first platform; 7, connecting seat; 8, second platform; 9, driving mechanism; 10, transmission unit; 11, actuating unit; 12, stage; 13, linear transfer mechanism; 14, swing arm; 15, first arm; 16, second arm; 17, transmission rod; 18, torsional spring; 19, ratchet; 20, return spring; 21, driving rod; 22, sliding seat; 23, driving bar; 24, ratchet structure; 25, ball; 26, piston rod; 27, chamber; 28, sliding column; 29, liquid storage bag; 30, plunger; 31, left cavity; 32, right cavity; 33, pressure relief pipeline; 34, gate valve; 35, spring rod. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be described below in conjunction with embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] As Figures 1 to 4As shown, a scanning electron microscope (SEM) for chip inspection includes a housing 1, a scanning electron microscope device 2 and a sample stage 3 vertically arranged inside the housing 1, and a focused ion beam device 4 inclinedly arranged inside the housing 1. In conventional chip inspection, the chip to be inspected needs to be fixed on the sample stage 3, and then the sample stage 3 is deflected so that the surface of the chip to be inspected is perpendicular to the ion beam emitted by the focused ion beam device 4, and then the chip is inspected. The above process is disclosed in detail in patent CN101246132B, which is incorporated herein by reference.

[0025] In brief, the sample stage 3 may include a base 5 and a first platform 6 oscillatingly mounted on the base 5, for example, driven to deflect by a deflection device (not shown) on the base 5. In a preferred example, a linear transfer mechanism 13 is provided on the base 5. For example, the linear transfer mechanism 13 may also be multi-axis, and the transfer mechanism 13 drives the stage 12 at its transfer end to perform transfer in, for example, the X, Y, and Z axes. The stage 12 itself is adapted to rotate circumferentially, and the aforementioned first platform 6 and deflection device are mounted on the stage 12.

[0026] Therefore, the first platform 6 can undergo multi-degree-of-freedom motion, such as translation in the X, Y, and Z axes, rotation along the axial direction, and deflection actuated by a deflection device. However, to address the limitation of the deflection angle of the sample stage 3 in existing scanning electron microscopes, this disclosure preferably includes a connecting seat 7 on the stage 12, from... Figure 1 As can be seen, the connecting base 7 is mounted on top of the first platform 6 in an erected manner. The second platform 8 is swayably mounted on the connecting base 7, which puts the first platform 6 and the second platform 8 in a vertically opposite position.

[0027] The connecting base 7 is also provided with a drive mechanism 9 consisting of a transmission unit 10 and an actuation unit 11. The transmission unit 10 is specifically capable of coupling with the first platform 6, while the actuation unit 11 is coupled to the second platform 8. The transmission unit 10 is specifically adapted to receive the thrust generated when the first platform 6 deflects, which is transmitted to the actuation unit 11, which then actuates to drive the second platform 8 to deflect.

[0028] It is understandable that although the deflection angle of the first platform 6 is limited, the first platform 6 can be deflected multiple times at a limited angle through the aforementioned driving mechanism 9, which can drive the second platform 8 to deflect at a larger angle. The chip can then be fixed on the second platform 8 for scanning and detection. For example, different detection surfaces at multiple angles on the chip can be detected without having to repeatedly disassemble and reassemble the chip to change the angle.

[0029] See Figure 1 ,Figure 2 In some embodiments, the actuation unit 11 may include a swing arm 14 pivotally connected to the connecting seat 7, and the swing arm 14 includes a first arm 15 and a second arm 16 disposed opposite to each other; while the transmission unit 10 includes a transmission rod 17 disposed on the swing arm 14, and the transmission rod 17 extends downward close to the first platform 6, and the position of the transmission rod 17 is offset from the axis of the first platform 6.

[0030] In addition, a torsion spring 18 is connected to the pivot of the second platform 8, and a ratchet 19 is also provided on the pivot of the second platform 8. The first support arm 15 and the second support arm 16 are located on both sides of the ratchet 19. At the same time, a return spring 20 is connected to the swing arm 14. Under the push of the return spring 20, the end of the first support arm 15 will engage with the ratchet 19, so that the torsion spring 18 and the second platform 8 can maintain a relatively stationary state.

[0031] In this embodiment, the second platform 8 can be manually rotated to its limit position, so that the torsion spring 18 is in and maintains its energy storage state. When the chip on the second platform 8 needs to adjust its angle, the first platform 6 can be deflected, for example, the side of the first platform 6 opposite to the transmission rod 17 can be raised, thereby driving the swing arm 14 to swing. During this process, the first arm 15 will disengage from the ratchet 19, and the second arm 16 will enter the latching position to abut against the rotated ratchet 19, thereby causing the second platform 8 to drive the chip to deflect. When the first platform 6 returns to the horizontal position, the swing arm 14 will swing in the opposite direction under the action of the return spring 20. At this time, the second arm 16 will disengage from the ratchet 19, and the first arm 15 will enter the latching position to abut against the rotated ratchet 19. This process is repeated to achieve a larger angle of deflection for the second platform 8 and the chip.

[0032] Furthermore, the contact between the swing arm 14 and the ratchet 19 facilitates the angular positioning of the chip. For example, when performing failure analysis on the same batch of chips, the first platform 6 can be controlled to deflect the same number of times, so that the chips can be positioned at the same location to observe whether the chips have the same defects.

[0033] See Figure 3 Alternatively, the transmission unit 10 may include a drive rod 21 inclinedly arranged on the connecting seat 7, and the drive rod 21 includes a sliding seat 22 and a drive bar 23 laterally elastically connected to the sliding seat 22 by an elastic element such as a spring, wherein the sliding seat 22 is slidably adapted to the connecting seat 7, and the side wall of the drive bar 23 is provided with a ratchet structure 24. For example, the drive bar 23 can be understood as a rack-like structure, except that the teeth on the side wall of the drive bar 23 are ratchet-shaped; while the actuation unit 11 may include a ratchet 19 provided on the rotating shaft of the second platform 8.

[0034] In this embodiment, if the chip on the second platform 8 needs to be adjusted in angle, the first platform 6 can be deflected. For example, the side of the first platform 6 opposite to the drive rod 21 can be raised. Subsequently, the ratchet structure 24 of the drive bar 23 will engage with the ratchet 19, thereby pushing the ratchet 19 and the second platform 8 to deflect. When the first platform 6 returns to the horizontal position, the drive rod 21 can fall under the action of gravity or the return spring 20 connected to it. However, since the ratchet structure 24 and the ratchet 19 are in opposite contact states and do not engage, the ratchet 19 will push the ratchet structure 24 and cause the drive bar 23 to bounce. Finally, the drive rod 21 will return to its initial position. This process is repeated to achieve a larger angle of deflection for the second platform 8 and the chip.

[0035] For example, the drive levers 21 and ratchet 19 are arranged in two groups. Two ratchet 19s are axially arranged on the rotating shaft of the second platform 8, with their teeth facing opposite directions. The two drive levers 21 are arranged symmetrically. It can be understood that, for example, controlling the first platform 6 to lift to the left can drive the second platform 8 to rotate clockwise, while controlling the first platform 6 to lift to the right can drive the second platform 8 to rotate counterclockwise, allowing the chip to deflect in both directions for detection.

[0036] See Figure 4 In another configuration, the transmission unit 10 may include a piston rod 26, which is also offset from the axis of the first platform 6. The actuation unit 11 may include a chamber 27 formed in the connecting seat 7, and a sliding column 28 is constructed on the rotating shaft of the second platform 8, which is slidably fitted into the chamber 27. The chamber 27 is connected to the inner cavity of the piston rod 26 by a pipeline, and the pipeline is also provided with a one-way valve (not shown) that only allows fluid to flow to one side of the chamber 27. In addition, a liquid reservoir 29 is provided on the connecting seat 7, which is also connected to the inner cavity pipeline of the piston rod 26, thereby replenishing the inner cavity of the piston rod 26 with fluid using the liquid reservoir 29.

[0037] In this embodiment, if the chip on the second platform 8 needs to be adjusted in angle, the first platform 6 can be deflected. For example, the side of the first platform 6 opposite to the piston rod 26 can be raised, pushing the plunger 30 of the piston rod and causing fluid in the inner cavity of the piston rod 26 to fill the chamber 27. As the fluid in the chamber 27 increases, its internal pressure rises, thereby driving the sliding column 28 to slide. When the first platform 6 returns to the horizontal position, the plunger 30 can fall under the action of gravity or a reset spring (not shown), and then the fluid in the reservoir 29 can be replenished into the inner cavity of the piston rod 26. This process is repeated to achieve a larger angle of deflection for the second platform 8 and the chip.

[0038] In a preferred example, both the piston rod and the cross-section of the chamber 27 are constructed to be arc-shaped, so that the sliding of the piston rod can drive the shaft of the second platform 8 to deflect more smoothly and reliably.

[0039] For example, the chamber 27 is preferably adapted to the piston rod to divide the chamber 27 into a left chamber 31 and a right chamber 32. The piston rod 26 is preferably arranged symmetrically in two parts, and the inner cavities of the two piston rods 26 are respectively connected to the left chamber 31 and the right chamber 32, and the inner cavities of the two piston rods 26 are both connected to the reservoir 29.

[0040] In addition, the ends of the left cavity 31 and the right cavity 32 are connected to the reservoir 29 by pressure relief lines 33, and each pressure relief line 33 is equipped with a gate valve 34. Each piston rod 30 is also equipped with a spring rod 35 (the internal spring is not shown), and the two spring rods 35 correspond to the two gate valves 34 in an alternating manner, that is, the left spring rod 35 is opposite to the right gate valve 34, and the right spring rod 35 is opposite to the left gate valve 34.

[0041] In this example, lifting the first platform 6 to either the left or right actuates the corresponding piston rod 26 to inject fluid into the left cavity 31 or the right cavity 32, respectively. This allows the second platform 8 to deflect in both directions, thus widening the chip's deflection angle range. Notably, when the left side of the first platform 6 is lifted, the left plunger 30 rises to inject fluid into the left cavity 31, causing the shaft to reverse. Before this, the left spring rod 35 abuts against and pushes the right gate valve 34, opening the corresponding pressure relief line 33. At this time, the fluid in the right cavity 32 flows into the reservoir 29 through the pressure relief line 33; the reverse is also true.

[0042] The gate valve 34 described above is existing technology, which opens and closes the flow path by pressing the gate plate, and will not be elaborated further. It can be understood that through the cooperation of the spring rod 35, the gate valve 34, and the pressure relief line 33, the fluid in the left chamber 31, the right chamber 32, and the reservoir 29 forms a loop, which reduces the load on the first platform 6 used to drive the piston rod 26. Of course, this preferred example does not preclude the possibility of injecting fluid into the left chamber 31 and the right chamber 32 respectively, and using the pressure difference between the left and right chambers 31 and 32 to control the deflection direction of the second platform 8.

[0043] In a preferred embodiment, the bottom ends of the transmission rod 17, the drive rod 21, and the plunger 30 can all be provided with balls 25 to provide rolling contact with the first platform 6, thereby preventing damage to the first platform 6.

[0044] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A chip detection scanning electron microscope, comprising a housing (1), wherein a scanning electron microscope device (2) and a sample stage (3) are vertically arranged inside the housing (1), and a focusing ion beam device (4) is also inclinedly arranged inside the housing (1), wherein the sample stage (3) comprises a base (5) and a first platform (6) oscillatingly arranged on the base (5), and a deflection device for driving the first platform (6) to deflect is provided on the base (5), characterized in that: A connecting seat (7) is provided on the base (5), and a second platform (8) is swayably provided on the connecting seat (7), the second platform (8) being located above the first platform (6); The connecting seat (7) is also provided with a drive mechanism (9), which includes a transmission unit (10) coupled to the first platform (6) and an actuation unit (11) coupled to the second platform (8). The transmission unit (10) is adapted to receive the thrust generated when the first platform (6) deflects and transmit it to the actuation unit (11) to drive the actuation unit (11) to actuate the second platform (8) to deflect. The actuation unit (11) includes a swing arm (14) pivotally connected to the connecting seat (7). The swing arm (14) includes a first arm (15) and a second arm (16) arranged opposite to each other. The transmission unit (10) includes a transmission rod (17) arranged on the swing arm (14). The transmission rod (17) extends toward the first platform (6) and is offset from the axis of the first platform (6). A torsion spring (18) is connected to the pivot of the second platform (8), and a ratchet (19) is also provided on the pivot of the second platform (8). The first support arm (15) and the second support arm (16) are located on both sides of the ratchet (19). The swing arm (14) is connected to a return spring (20), which is used to drive the end of the first support arm (15) to engage with the ratchet (19). When the first platform (6) deflects, the first platform (6) pushes the transmission rod (17) to drive the end of the first support arm (15) out of the ratchet (19), while the end of the second support arm (16) enters the engaging position; or, The transmission unit (10) includes a drive rod (21) inclinedly arranged on the connecting seat (7), and the drive rod (21) is slidably adapted to the connecting seat (7). The drive rod (21) includes a sliding seat (22) and a drive bar (23) laterally elastically connected to the sliding seat (22). The side wall of the drive bar (23) is provided with a ratchet structure (24). The actuation unit (11) includes a ratchet (19) mounted on the pivot of the second platform (8); When the first platform (6) deflects, the first platform (6) pushes the drive rod (21) to slide, so as to drive the ratchet structure (24) to engage with the ratchet (19) and push the second platform (8) to deflect; A return spring (20) is connected to the drive rod (21). The return spring (20) is used to push the drive rod (21) back to its initial position. During this period, the ratchet (19) pushes the ratchet structure (24) and causes the drive bar (23) to spring; or, The transmission unit (10) includes a piston rod (26), and the piston rod (26) is offset from the axis of the first platform (6); The actuation unit (11) includes a chamber (27) opened in the connecting seat (7), and a sliding column (28) is constructed on the rotating shaft of the second platform (8), the sliding column (28) being slidably adapted to the chamber (27); The chamber (27) and the inner cavity of the piston rod (26) are connected by a pipeline. A one-way valve is provided in the pipeline. The one-way valve is adapted to allow fluid to flow only to the side of the chamber (27). The connecting seat (7) is also provided with a liquid storage bladder (29), which is connected to the inner cavity of the piston rod (26); When the first platform (6) deflects, the first platform (6) pushes the plunger (30) of the piston rod (26) to drive fluid into the chamber (27).

2. The scanning electron microscope for chip detection according to claim 1, characterized in that: The sample stage (3) also includes a platform (12) rotatably mounted on the base (5), the first platform (6) and the deflection device are mounted on the platform (12), and the connecting seat (7) is mounted on the platform (12).

3. The scanning electron microscope for chip detection according to claim 2, characterized in that: The sample stage (3) also includes a linear transfer mechanism (13) disposed on the base (5), and the stage (12) is disposed on the transfer end of the linear transfer mechanism (13).

4. The scanning electron microscope for chip detection according to claim 1, characterized in that: The drive rod (21) and the ratchet (19) are arranged in two groups, with the teeth of the two ratchets (19) facing opposite directions and the two drive rods (21) arranged symmetrically.

5. The scanning electron microscope for chip detection according to claim 1, characterized in that: The bottom end of the transmission rod (17) is provided with a ball bearing (25).

6. The scanning electron microscope for chip detection according to claim 1, characterized in that: The bottom end of the drive rod (21) is provided with a ball bearing (25).

7. The scanning electron microscope for chip detection according to claim 1, characterized in that: The chamber (27) is divided into a left chamber (31) and a right chamber (32) by the sliding column (28). There are two piston rods (26) symmetrically arranged. The inner cavities of the two piston rods (26) are respectively connected to the pipelines of the right chamber (32) and the left chamber (31), and the inner cavities of the two piston rods (26) are connected to the pipeline of the reservoir (29). The ends of the left cavity (31) and the right cavity (32) are connected to the liquid storage bladder (29) by a pressure relief pipeline (33). Each pressure relief pipeline (33) is equipped with a gate valve (34). Each piston rod (26) has a spring rod (35) on its plunger (30). The two spring rods (35) and the two gate valves (34) are staggered and correspond to each other. When the piston rod (26) is pushed and compressed, the spring rod (35) pushes the corresponding gate valve (34) and drives the corresponding pressure relief line (33) to open.

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