A dicing system with a spring member for dicing semiconductor structures and a method of dicing such structures

Abstract

A dicing system for dicing a semiconductor structure is disclosed. The dicing system can include a dicing arm that can be moved from a starting position to a raised position in which a dicing stress is applied to the semiconductor structure. As the dicing arm is raised, a spring member stores energy, wherein upon the dicing across the structure, the stored spring energy causes the structure to be diced into two pieces.

Description

[0001] Cross-citation of related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 906,860, filed September 27, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to dicing systems for cutting semiconductor structures, and more particularly, to dicing systems that use stored spring energy to separate a semiconductor structure into two pieces. This disclosure also relates to methods for cutting semiconductor structures using such dicing systems. Background Technology

[0004] Conventional cutting systems use vacuum chucks to grip the top and bottom surfaces of the structure to be cut. A set of upper chucks gripping the top surface of the structure is connected to a cutting arm. A motor applies an upward force to the cutting arm to put the semiconductor structure under tension. Once sufficient tension is applied, the blade contacts the outer edge of the semiconductor structure to initiate a cut. After the initial cut, the cutting arm moves upward, and the cut propagates along the semiconductor structure from the edge in contact with the blade toward the opposite edge.

[0005] The dicing process separates a semiconductor structure into two parts. To fabricate a silicon-on-insulator (SII) structure via dicing, the "donor" structure is separated from the layered structure, leaving a silicon device layer disposed on an insulating layer supported by a disposed wafer. The surface quality (e.g., surface roughness) of the resulting structure depends on the quality of the dicing.

[0006] Conventional dicing methods often result in undesirable roughness patterns. Higher post-dicing roughness leads to higher surface roughness in finished structures, such as SOI structures, as measured by atomic force microscopy. High dicing roughness also causes hillock formation during epitaxial growth. Such hillocks are detected as spot defects during final inspection. Conventional dicing methods also result in inconsistent dicing pull, which causes the formation of surface roughness dicing arcs. These dicing arcs generally have an arc center on the side of the dicing initiation point, with the arc's apex perpendicular to the wafer edge. As the dicing propagates across the wafer, the arc apex remains perpendicular to the edge, with the arc becoming straight and potentially reversing its curvature as it approaches a point radially opposite to the dicing initiation point.

[0007] The quality of a cut depends on the cutting control system, the mass properties of the cutting arm, the characteristics of the motor, and control parameters including initial tension and relative blade position. These parameters are difficult to tune to improve the quality of the cut.

[0008] There is a need for novel cutting systems that result in cutting structures with improved surface roughness characteristics, and cutting methods involving the use of such cutting systems.

[0009] This section aims to introduce the reader to various technical aspects that may relate to the various aspects of this disclosure described and / or claimed below. It is believed that this discussion will help provide the reader with background information to facilitate a better understanding of the various aspects of this disclosure. Therefore, it should be understood that these statements should be read in this context and not as an endorsement of prior art. Summary of the Invention

[0010] One aspect of this disclosure relates to a cutting system for cutting a semiconductor structure having a top surface and a bottom surface generally parallel to the top surface. The cutting system includes a cutting arm movable from a starting position to a raised position in which cutting stress is applied to the semiconductor structure. The cutting system includes a suction member for gripping the semiconductor structure on the top surface. A suction rod extends through the cutting arm. The suction rod is connected to the suction member facing a first end of the suction rod. When the cutting arm is in the raised position, a spring member applies a cutting force to the semiconductor structure.

[0011] Another aspect of this disclosure relates to a cutting system for cutting a semiconductor structure having a top surface and a bottom surface generally parallel to the top surface. The cutting system includes one or more suction cups for gripping the semiconductor structure on the top surface. A suction rod is connected to the one or more suction cups facing a first end of the suction rod. During cutting, a spring member applies a cutting force to the semiconductor structure. The suction rod extends through the spring member.

[0012] Another aspect of this disclosure relates to a method for cutting a semiconductor structure having a top surface and a bottom surface generally parallel to the top surface. The top surface of the semiconductor structure is in contact with a suction cup. A vacuum is applied to the suction cup to grip the top surface of the semiconductor structure. A cutting arm moves from a starting position to a raised position, causing a spring member to apply a cutting force to the semiconductor structure. The spring member stores spring energy as the cutting arm is raised. The semiconductor structure contacts a blade to initiate cutting of the semiconductor structure when the cutting arm is in the raised position. The stored spring energy is released after the semiconductor structure contacts the blade to separate the semiconductor structure into two pieces along the cutting plane.

[0013] Various improvements exist to the features mentioned in the foregoing aspects of this disclosure. Other features may also be incorporated into the foregoing aspects of this disclosure. These improvements and additional features may exist individually or in any combination. For example, various features of any of the illustrated embodiments of this disclosure discussed below may be incorporated individually or in any combination into any of the foregoing aspects of this disclosure. Attached Figure Description

[0014] Figure 1 This is a perspective view of a cutting system used for cutting semiconductor structures;

[0015] Figure 2 A detailed perspective view of part of the cutting system;

[0016] Figure 3 This is a cross-sectional side view of the cutting system, with the cutting arm at the starting position;

[0017] Figure 4 This is a cross-sectional side view of the cutting system, with the cutting arm in the raised position and the spring member compressed;

[0018] Figure 5 This is a schematic front view of the cutting system, with the cutting arm in the starting position;

[0019] Figure 6 This is a schematic front view of the cutting system, with the cutting arm in the raised position;

[0020] Figure 7 This is a schematic front view of the cutting system as the spring member releases the stored energy during cutting; and

[0021] Figure 8 It is a diagram of the total spring force that varies with spring compression for an exemplary spring component.

[0022] In various parts of the drawing, the corresponding component symbols indicate the corresponding parts. Detailed Implementation

[0023] For reference Figure 1 It demonstrates the use of cutting semiconductor structures S( Figure 5 The cutting system 5 includes a cutting arm 9 and a suction member 13 extending from the cutting arm 9 for gripping the semiconductor structure S. The suction member 13 extends from a suction rod 23 extending through the cutting arm 9. The cutting system 5 includes a spring member 33 that releases stored spring energy to separate the semiconductor structure, as further described below. In order to apply tensile stress to the semiconductor structure S, the cutting arm 9 starts from a starting position ( Figure 5 Move to the raised position ( Figure 6In the raised position, the spring member 33 and / or the cutting arm 9 apply a cutting force to the semiconductor structure S.

[0024] The semiconductor structure S diced according to embodiments of this disclosure can generally be any structure that is cut after a dicing force is applied to the semiconductor structure and after dicing begins (e.g., using a blade that contacts the peripheral edge). Suitable structures may have weakening regions formed within the structure, such as weakening regions formed by ion implantation. Some structures may include layered silicon-on-insulator structures (e.g., having a donor wafer disposed on a dielectric layer and a disposal wafer), which are diced to form a silicon-on-insulator structure (e.g., to form a silicon device layer on a dielectric layer disposed on a disposal wafer by dicing the donor wafer). The semiconductor structure S includes a top surface 41 ( Figure 5 The semiconductor structure S also includes a bottom surface 43 that is generally parallel to the top surface 41 and a bottom surface 43. The semiconductor structure S also includes a peripheral edge 45 that extends from the top surface 41 to the bottom surface 43.

[0025] The cutting system 5 includes a suction member 13, which is used to propagate the cutting edge 21 towards the structure S. Figure 5 The semiconductor structure S is gripped on its top surface 41. In the illustrated embodiment, the suction member 13 is a suction cup. In other embodiments, an adhesive member may be used to attach the chuck to each of the top and bottom surfaces of the semiconductor structure S to apply a cutting force to the structure S. Although the illustrated embodiment includes first, second, and third suction members 13 for gripping the top surface 41 of the semiconductor structure S toward the cutting propagation leading edge 21 of the structure S, it should be understood that the cutting system 5 may include more or fewer suction members 13 (e.g., one, two, three, four, five, or six or more suction members). Furthermore, although the illustrated embodiment includes first, second, and third suction bars 23 and first, second, and third spring members 33, the cutting system 5 may include more or fewer suction bars 23 and / or spring members 33 (e.g., one, two, three, four, five, or six or more suction bars 23 and / or one, two, three, four, five, or six or more spring members 33).

[0026] Each suction component 13 faces the first end 53 of the corresponding suction rod 23. Figure 2 ) is connected to the suction rod 23. Each suction rod 23 extends through the cutting arm 9. At its starting position ( Figure 5 Move to the raised position ( Figure 6 And when the semiconductor structure is separated ( Figure 7 When the cutting arm 9 and the suction rod 23 are aligned along the suction rod axis A, the cutting arm 9 and the suction rod 23 can move along the suction rod axis A. Figure 3 and 4) moves relative to each other. The cutting arm 9 contains a chamber 11 formed therein. Figure 4 The suction rod 23 moves relative to the cutting arm 9 in the chamber 11.

[0027] The suction rod 23 extends through the corresponding spring member 33. In the illustrated embodiment, the suction rod 23 is not connected to the cutting arm 9, and the cutting arm 9 and the suction rod 23 are movable relative to each other along the suction rod axis A. The cutting system 5 includes an upper bearing 49 and a lower bearing 55. Figure 3 For example, as shown in the linear bushing, it allows the cutting arm 9 and the suction rod 23 to move relative to each other. When the cutting arm is in its initial position ( Figure 5 Move to the raised position ( Figure 6 ) and during the release of stored spring energy during the cutting of the semiconductor structure ( Figure 7 The suction rod 23 moves within bearings 49 and 55. A sealing member 19 (e.g., a Teflon gasket) seals the suction rod 23 within the chamber 11 that moves relative to the cutting arm 9. Figure 4 To reduce particulate contamination in semiconductor structures S.

[0028] Each suction rod 23 includes a channel 25 defined therein. Figure 3 Channel 25 is fluidly connected to chuck 13 to allow chuck 13 to contact the top surface 41 of semiconductor structure S. Figure 5 A vacuum is applied between the two. Channel 25 is connected to vacuum conduit 27. Figure 1 Vacuum conduit 27 is fluidly connected to a vacuum source (e.g., a vacuum pump). Once a vacuum is applied, suction member 13 is sealed to the top surface 41 of semiconductor structure S.

[0029] Each spring member 33 is disposed between the collar 63 and the cutting arm 9. Each collar 63 extends radially outward from the corresponding suction rod 23 toward the second end 31 of the suction rod 23. The spring member 33 is at least partially received in a recess 51 defined in the cutting arm 9. Figure 3 In the recess 51, each recess 51 has a base plate 71 adjacent to the corresponding spring member 33. The spring member 33 is held in place by a retainer 57. Figure 4 The retainer 57 acts as a stop to prevent excessive compression of the spring member 33. When the retainer 57 contacts the base plate 71, it prevents relative movement between the suction rod 23 and the cutting arm 9. Figure 4 As shown in the image.

[0030] In some embodiments, each collar 63 is part of a collar clamp 79. The collar clamp 79 is adjustable such that it can move and re-clamp along the longitudinal axis A of the suction rod 23. In this way, the compression of the spring member 33 can be adjusted (e.g., the pre-compression of the spring member 33 when in the starting position of the cutting arm 9 can be adjusted). Changing the pre-compression of the spring member 33 changes the tension at the end of spring energy release and can change the dynamics of the cutting wave and the surface roughness. Increasing the preload increases the acceleration, which decreases as the spring releases energy. The matching of the position where the spring energy is minimum at the point of energy reduction with the start time of the cutting arm rotation can also affect the final surface roughness.

[0031] In the illustrated embodiment, spring member 33 is a helical compression spring that applies a cutting force to the semiconductor structure S when compressed (i.e., when the cutting arm 9 is raised). In other embodiments, spring member 33 is a tension spring (e.g., a spring member disposed below the cutting arm and connected to the cutting arm and a retaining member disposed below the cutting arm). In other embodiments, spring member 33 is one or more disc springs (i.e., conical disc springs), such as a set of two or more stacked disc springs. In other embodiments, other spring members may be used, such as compressed air springs, compression elastomers, or tension elastomers.

[0032] like Figure 5 As shown, the cutting system 5 includes a first set of front suction members 13 that grip the top surface 41 of the semiconductor structure S towards the cutting propagation leading edge 21 of the structure S (e.g., Figure 1 The three suction members 13 shown in the figure). The cutting system 5 also includes one or more rear suction members 15 (e.g., suction cups) that grip the top surface 41 of the semiconductor structure S toward the trailing edge 35 (i.e., the rear suction members 15 are arranged radially inside the first set of suction members 13).

[0033] Because the cutting arm 9 moves to the lifting position before the semiconductor structure S is cut open ( Figure 6 Therefore, the rear suction member 15 can be configured to accommodate the movement of the cutting arm 9. In some embodiments, the rear suction member 15 is a telescopic bladder suction cup that adapts to changes in the distance between the cutting arm 9 and the semiconductor structure S. The telescopic bladder suction cup 15 includes a telescopic bladder segment 37. Figure 1 The telescopic bladder section 37 is capable of flexing and / or extending during the movement of the cutting arm 9. A rear suction cup 15 is connected to a rear suction rod 39, which is connected to the cutting arm 9. The rear suction rod 39 can be rigid or flexible to allow movement of the cutting arm 9.

[0034] For reference Figure 5In addition to the suction member 13 that grips the top surface 41 of the semiconductor structure S, the cutting system 5 also includes one or more suction members 29 that grip the bottom surface 43 of the semiconductor structure S. The suction members 29 are connected to the suction rod 47, which is fixed in place (i.e., does not move) when the cutting arm 9 is raised.

[0035] According to embodiments of this disclosure, in order to cut the semiconductor structure, the semiconductor structure S is disposed on the lower suction member 29 ( Figure 5 The lower suction member 29 contacts the bottom surface 43 of the semiconductor structure S. The cutting arm 9 descends to bring the top surface 41 of the semiconductor structure S into contact with the upper suction members 13 and 15. A vacuum is applied to the lower suction member 29 to grip the bottom surface 43 of the semiconductor structure S. Vacuum is also applied through the vacuum conduit 27 and the suction rod channel 25. Figure 5 Vacuum is applied to the upper suction members 13 and 15 to grip the top surface 41 of the semiconductor structure S.

[0036] After grasping the semiconductor structure S, the cutting arm 9 is moved from its starting position ( Figure 5 Move to the raised position ( Figure 6 The cutting arm 9 is connected to the pivot structure 59. Figure 1 The cutting system 5 includes a motor 67, which causes the cutting arm 9 to pivot upon activation. The cutting arm 9 pivots about a pivot axis P extending through a pivot structure 59. The motor 67 can be connected to the pivot structure 59 by a chain or belt, or the motor 67 can be a direct-drive motor embedded in the pivot structure 59. The motor 67 can be a DC or AC servo motor and can optionally control the acceleration, deceleration, and / or speed of the cutting arm 9.

[0037] At the starting position of cutting arm 9 ( Figure 5 Move to the raised position ( Figure 6When the cutting arm 9 moves axially upward relative to the suction rod 23, the spring member 33 is compressed, applying a cutting force F to the semiconductor structure S (i.e., an upward force facilitating the cutting of the semiconductor structure) and storing spring energy within the spring. According to some embodiments of this disclosure, the cutting arm 9 is not rotated to the point where the spring is fully compressed and the spring retainer 57 contacts the cutting arm 9. The compression of the spring member 33 allows spring energy to be stored within the spring member 33, which is then released after the initial cutting. The cutting force F applied by the spring member 33 (and any additional force via the motor) is transmitted through the suction rod 23. In the raised position of the cutting arm 9, the lower suction member 29 applies a holding force to the semiconductor structure S, and the upper suction members 13, 15 apply an upward pulling force, causing the semiconductor structure S to tension. In some embodiments, the cutting force F applied by the spring member 33 is the only cutting force applied to the semiconductor structure S (e.g., no upward force is used for cutting other than the force applied by the spring member 33). In some embodiments, after the cut has propagated through the blade 61, the cutting arm does not move upward (i.e., the spring member 33 causes the cut to continue propagating by releasing stored energy).

[0038] Once the cutting arm 9 is in the raised position ( Figure 6 In this process, the blade 61 is actuated to contact the peripheral edge 45 of the semiconductor structure S. The blade 61 can contact the peripheral edge near the damaged area in the semiconductor structure to facilitate cutting along the cutting plane. The blade 61 initiates cutting along the cutting plane 65. Figure 7 The cutting of the semiconductor structure S by the blade 61 causes the semiconductor structure S to separate into two pieces along the cutting plane 65. Once the blade 61 begins cutting, the stored spring energy in the spring member 33 is released, causing the suction rod 23 to move upward through the cutting arm 9, which causes the upper section 69 of the semiconductor structure S to ( Figure 7 Continue to separate from the next section 73.

[0039] In some embodiments, the cutting system is configured to be adjustable to control the quality of the cut. For example, the system may include interchangeable spring members with different spring rates to adjust the energy stored and released during cutting. In some embodiments, the cutting system includes different types of interchangeable springs, such as helical springs and stacked disc springs. Helical springs can provide a linear cutting force that varies with displacement, while disc springs can provide a relatively constant suction force. Alternatively or additionally, the collar clamp 79 described above can be moved along the longitudinal axis of the suction bar to change the stroke of the spring member 33 and the energy stored and released by the spring member 33 during cut propagation.

[0040] Compared to conventional cutting systems, the cutting system disclosed herein offers several advantages. The use of a spring member in the cutting system allows for the storage of spring energy during the lifting of the cutting arm. Once the cut has propagated through the blade, the spring energy is released to cause the semiconductor structure to separate into two pieces. This allows the cut to depend on the stored spring energy rather than the cutting control system, the mass of the cutting arm, and / or the nature of the motor. This allows for a more consistent cut during propagation, which reduces surface roughness of the cut surface and minimizes the cutting arc. In embodiments where the cutting system includes a collar clamp, the collar clamp can be moved along the longitudinal axis of the suction bar to adjust the pre-compression of the spring member. In embodiments where the cutting assembly includes a telescopic bladder suction cup, the cutting arm can move upwards while still gripping the semiconductor structure S toward the trailing edge of the cut propagation. In other embodiments, the pre-compression can be increased or decreased by modifying the design to reposition the attachment point of the spring.

[0041] Example

[0042] The process of this disclosure is further illustrated by the following examples. These examples should not be considered limiting.

[0043] Example 1: Spring force versus compression

[0044] Figure 8 This demonstrates the variation of the total spring force based on spring compression. At the starting position of the cutting arm, the spring energy is 3.61 psi. The spring compresses approximately 12 mm to generate a spring force of 6.5 psi. Cutting propagates and the spring energy is released to the pre-compression of 3.61 psi. The spring is capable of generating a maximum compressive force of 6.971 psi. For wafers cut with a force less than 6.971 psi, the spring alone is sufficient for cutting without the arm contributing a cutting force. In some embodiments, the finishing speed of the suction cup (3.61 psi) at the end of cutting will approximate or match the initial rotational speed of the cutting arm.

[0045] As used herein, the terms “about,” “generally,” “substantially,” and “approximately” when used in conjunction with a range of size, concentration, temperature, or other physical or chemical properties or characteristics mean to cover variations that may exist within the upper and / or lower limits of the range of said properties or characteristics, including variations due to, for example, rounding, measurement methods, or other statistical variations.

[0046] When elements of this disclosure or its embodiments(s) are introduced, the articles “a / an” and “the / said” are intended to mean the presence of one or more of the elements. The terms “comprising,” “including,” “containing,” and “having” are intended to be inclusive and mean that additional elements besides those listed may be present. Terms indicating a particular orientation (e.g., “top,” “bottom,” “side,” etc.) are used for ease of description and do not require any particular orientation of the described items.

[0047] Since various changes can be made to the above-described construction and methods without departing from the scope of this disclosure, everything contained in the above description and shown in the accompanying drawings should be interpreted in an illustrative rather than restrictive sense.

Claims

1. A dicing system for dicing a semiconductor structure having a top surface and a bottom surface parallel to the top surface, the dicing system comprising: A cutting arm that can move from a starting position to a raised position, in which cutting stress is applied to the semiconductor structure; A suction member for gripping the semiconductor structure on the top surface of the semiconductor structure; A suction rod extending through the cutting arm, the suction rod being connected to the suction member facing a first end of the suction rod; A spring member that applies a cutting force to the semiconductor structure when the cutting arm is in the raised position, and the suction rod extends through the spring member; and A collar extending radially outward from the suction rod; a spring member disposed between the collar and the cutting arm; the spring member being compressed when the cutting arm is in the raised position. The collar is part of a collar clamp that is adjustable along the longitudinal axis of the suction rod to change the compression of the spring member. The suction rod is not connected to the cutting arm.

2. The cutting system according to claim 1, wherein the spring member is a compression spring.

3. The cutting system according to claim 1, wherein the spring member is a disc spring.

4. The cutting system of claim 1, wherein the suction member is a suction cup, and the suction rod includes a channel defined therein, the channel being fluidly connected to the suction cup to apply a vacuum to the suction cup.

5. The cutting system according to claim 1, wherein the suction member is a first suction member, the suction rod is a first suction rod, and the spring member is a first spring member, the cutting system comprising... A second suction component is used to grasp the semiconductor structure; A second suction rod extends through the cutting arm and is connected to a second suction member facing a first end of the second suction rod; and A second spring member applies a cutting force to the semiconductor structure when the cutting arm is in the raised position.

6. The cutting system according to claim 5, further comprising: A third suction component is used to grasp the semiconductor structure; A third suction rod extends through the cutting arm and is connected to the third suction member facing the first end of the third suction rod; and A third spring member applies a cutting force to the semiconductor structure when the cutting arm is in the raised position.

7. The cutting system of claim 1, wherein the cutting arm pivots about a pivot axis to move the cutting arm between the starting position and the raised position, the cutting system comprising a motor that causes the cutting arm to pivot after activation of the motor.

8. The cutting system of claim 7, further comprising a telescopic bladder suction cup connected to the cutting arm, the telescopic bladder suction cup being disposed radially inside the suction member.

9. The cutting system of claim 1, wherein the cutting arm defines a recess, the spring member is at least partially received in the recess, the recess having a base plate adjacent to the spring member.

10. The cutting system of claim 1, comprising a bearing disposed within the cutting arm, wherein the suction rod moves within the bearing as the cutting arm moves from the starting position to the raised position.

11. The cutting system of claim 1, comprising one or more suction members for gripping the semiconductor structure on the bottom surface of the semiconductor structure.

12. A dicing system for dicing a semiconductor structure having a top surface and a bottom surface parallel to the top surface, the dicing system comprising: A cutting arm that can move from a starting position to a raised position, in which cutting stress is applied to the semiconductor structure; One or more suction cups for gripping the semiconductor structure on the top surface of the semiconductor structure; A suction rod extending through the cutting arm and connected to one or more suction cups facing a first end of the suction rod; A spring member that applies a cutting force to the semiconductor structure during cutting, and the suction rod extending through the spring member; and A collar extending radially outward from the suction rod; a spring member disposed between the collar and the cutting arm; the spring member being compressed when the cutting arm is in the raised position. The collar is part of a collar clamp that is adjustable along the longitudinal axis of the suction rod to change the compression of the spring member. The suction rod is not connected to the cutting arm.

13. The cutting system of claim 12, further comprising a telescopic bladder suction cup configured to contact the top surface of the semiconductor structure, the telescopic bladder suction cup being disposed radially inside the one or more suction cups.

14. A method for cutting a semiconductor structure having a top surface and a bottom surface parallel to the top surface, the method comprising: The top surface of the semiconductor structure is brought into contact with a suction cup connected to a suction rod extending through a cutting arm. The suction rod extends through a spring member positioned between a collar and the cutting arm. The spring member is compressed when the cutting arm is in a raised position. The collar extends radially outward from the suction rod and is part of a collar clamp that is adjustable along the longitudinal axis of the suction rod to change the compression of the spring member. The suction rod is not connected to the cutting arm. A vacuum is applied to the suction cup to grip the top surface of the semiconductor structure; The cutting arm is moved from the starting position to the raised position to cause the spring member to apply a cutting force to the semiconductor structure. When the cutting arm is raised, the spring member stores spring energy as stored spring energy. The semiconductor structure is brought into contact with the blade to initiate cutting of the semiconductor structure when the cutting arm is in the raised position; and After the semiconductor structure is brought into contact with the blade, the stored spring energy is released to separate the semiconductor structure into two pieces along the cutting plane.

15. The method according to claim 14, wherein: When the cutting arm moves to the raised position, the cutting arm moves axially upward relative to the suction rod; and When the semiconductor structure is separated into two pieces, the suction rod moves axially upward relative to the cutting arm.

16. The method of claim 14, wherein the cutting force applied by the spring member is transmitted through the suction rod, and the cutting force applied by the spring member is the only cutting force applied to the semiconductor structure.

17. The method of claim 14, wherein the cutting arm does not move during the propagation of the cut.

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