Wafer, electronic component, and method using a laser penetration-influencing structure

Abstract

A wafer (100) comprising: • an array of a plurality of electronic components (102); and • a separation frame (104) which separates adjacent electronic components (102); • wherein the separation frame (104) has a laser penetration-influencing structure (106) configured to locally influence laser penetration in a different manner at the laser penetration-influencing structure (106) than at another region of the separation frame (104) away from the laser penetration-influencing structure when the separation frame (104) is subjected to laser processing during stealth dicing; • wherein the laser penetration-influencing structure (106) comprises a pattern of substructures (110) arranged along one or more straight separation lines (112) of the separation frame (104); • wherein the substructures (110) comprise a plurality of pairs of stripes, each pair of stripes having a spacing between its stripes; • wherein the dividing line (112) extends straight along the distances between the strips of the respective pairs of strips.

Description

Background of the inventionField of the invention

[0001] The present invention relates to a wafer, an electronic component, and a method for separating electronic components from a wafer. Description of the state of the art

[0002] Packages can be described as encapsulated electronic chips with electrical connections that are mounted to an electronic peripheral, such as a printed circuit board. Before packaging, a semiconductor wafer is singulated into a plurality of electronic chips. After the wafer is singulated into the singulated electronic chips, the electronic chips on the wafer can subsequently be used for further processing.

[0003] Dicing can be accomplished by mechanically cutting or laser cutting the wafer. However, the separated electronic components can be damaged during the dicing process.

[0004] US 2017 / 0 053 832 A1 discloses a wafer structure comprising a semiconductor substrate and semiconductor dies arranged thereon. Furthermore, the wafer structure comprises a functional layer, for example made of metal, which connects the semiconductor dies to one another. When dicing the semiconductor dies using a laser, the functional layer represents an undesirable obstacle. To achieve complete dicing, additional trenches are formed beneath the functional layer.

[0005] US 2004 / 0 137 702 A1 discloses a method for singulating a semiconductor wafer using a laser. The semiconductor wafer includes electronic chips to be separated along laser cutting regions. Furthermore, the semiconductor wafer includes a region between the electronic chips. Metal test pads are formed on the region. A dummy wiring layer is formed at the laser cutting regions, which is configured to facilitate laser absorption.

[0006] US 2009 / 0 149 002 A1 discloses a semiconductor substrate in which electronic devices are formed, which are to be singulated along dividing tracks. Stacked objects, for example, metal elements, are arranged in the dividing tracks and, due to their reflective properties, interfere with the singulation of the electronic devices by laser. To achieve complete singulation, the areas in which the stacked objects will later be arranged are first treated with a laser. The stacked objects are then arranged on the semiconductor substrate, and only then are the remaining areas of the dividing tracks laser-treated.

[0007] DE 10 2014 101 283 A1 discloses a semiconductor chip on which a dielectric material and an electrically conductive material are arranged. To produce the semiconductor chip, a semiconductor wafer is treated with a laser beam, creating a crack. The semiconductor wafer is then singulated along the cracks to form individual semiconductor chips. Summary of the invention

[0008] There may be a need to separate electronic components from a wafer with a low risk of damage.

[0009] According to an exemplary embodiment, a wafer is provided comprising an array of a plurality of electronic components and a separation frame separating adjacent electronic components, wherein the separation frame comprises a laser penetration-influencing structure configured to locally influence laser penetration in a different manner at the laser penetration-influencing structure than at another region of the separation frame away from the laser penetration-influencing structure when the separation frame is subjected to laser processing during stealth dicing, wherein the laser penetration-influencing structure comprises a pattern of substructures arranged along one or more straight separation lines of the separation frame, wherein the substructures comprise a plurality of stripe pairs, each stripe pair having a distance between its stripes,where the dividing line extends straight along the distances between the stripes of the respective pairs of stripes.,

[0010] According to another exemplary embodiment, an electronic component is provided, comprising a semiconductor body, an active region in and / or at a central portion of the semiconductor body, and a separation frame structure in an edge region of the semiconductor body, wherein the separation frame structure comprises a laser penetration-influencing structure configured to locally influence laser penetration while the separation frame structure is subjected to laser processing during stealth dicing, wherein a defect density created by stealth dicing in a sidewall of the electronic component is locally reduced in the regions of the separation frame structure where the laser penetration-influencing structure is arranged, compared to regions of the separation frame structure where the laser penetration-influencing structure is absent.

[0011] According to yet another exemplary embodiment, a method for separating electronic components from a wafer is provided, the method comprising providing the wafer with a separation frame that separates adjacent electronic components, providing the separation frame with a laser penetration-influencing structure configured to locally influence laser penetration in a different manner at the laser penetration-influencing structure than at another region of the separation frame away from the laser penetration-influencing structure, and subjecting the laser penetration-influencing structure to laser processing during stealth dicing along the separation frame to locally influence laser penetration, such that a defect density generated by stealth dicing along a separation line is locally reduced in regions,where the laser penetration-influencing structure is arranged, compared to regions of the parting line where the laser penetration-influencing structure is absent.

[0012] According to an exemplary embodiment, the separation of a wafer into individual electronic components, which are previously integrally bonded in the wafer assembly and spaced apart by a separation frame, can be performed with a reduced risk of damage due to the implementation of a dedicated laser penetration-influencing structure formed in the separation frame. During stealth dicing, a wafer can be separated into electronic components by first mechanically weakening the separation frame using laser processing and subsequently breaking the laser-weakened separation frame to obtain the individual electronic components.By integrating the laser penetration-influencing structure as a hardware feature in the dicing frame, laser processing can be more precisely controlled with respect to stealth dicing by influencing the laser beam in a controlled manner in the region of the laser penetration-influencing structure and influencing it in a different manner compared to a region of the dicing frame away from the laser penetration-influencing structure. Preferably, but not necessarily, the laser penetration-influencing structure can locally mitigate the influence of the laser beam on the material of the dicing frame. Thus, by structurally adjusting the dicing frame to control the laser influence in accordance with a design of the laser penetration-influencing structure, undesirable phenomena and thus damage to the wafer and / or its separated electronic components can be reliably avoided.This can improve yield at high throughput. Furthermore, due to the structural implementation of the laser penetration-influencing structure and the separation frame, it can be ensured that the laser beam impinging on the separation frame is influenced in a spatially defined manner, without the need for a human operator to individually inspect the separated electronic components in a laborious manner. Thus, adjustment of the stealth dicing process based on the laser penetration-influencing structure can be more reliable and involve less effort compared to spatially dependent control of the laser beam and its properties. In contrast to exemplary embodiments, the latter approach may require manual and individual control of an actual influence of the controlled laser beam on the quality of the separated electronic components.Illustratively, an exemplary embodiment may (partially or completely) interrupt laser penetration (preferably without interrupting the laser beam itself) by means of a hardware design in the separation frame in the form of the laser penetration-influencing structure for selectively shadowing or shielding the laser beam from one or more defined portions of the wafer or electronic component. With respect to their influence on laser penetration, a number of defects may be smaller in a region of the separation frame where the laser penetration-influencing structure is present compared to another region of the separation frame where the laser penetration-influencing structure is absent.In particular, this may allow to reduce a number of laser intersection points (e.g., candlesticks) and an associated (or resulting) defect density in one or more dedicated areas of the separation frame. Description of further exemplary embodiments

[0013] Further exemplary embodiments of the wafer, the electronic component, and the method are explained below.

[0014] Preferably, a laser spot density can be selected just high enough to achieve complete separation with straight separation lines. A higher spot density may only cost processing time, may cost defect density, and may cost fracture strength. However, the minimum desired or required density of spots across the separation lines and even within a separation line may not be the same. In particular, a distinction can be made between cutting areas and outside them. This can lead to favorable separation results.

[0015] In the context of the present application, the term "wafer" may, in particular, refer to a semiconductor substrate that has been processed to form a plurality of integrated circuit elements in an active region of the wafer, which can be singulated into a plurality of separate electronic components or chips. For example, a wafer may have a disc shape and may include a matrix-like arrangement of electronic components in rows and columns. It is possible for a wafer to have a round geometry or a polygonal geometry (e.g., a rectangular geometry or a triangular geometry).

[0016] In the context of the present application, the term "electronic component" may in particular include a semiconductor chip (in particular a power semiconductor chip), an active electronic device (for example, a transistor), a passive electronic device (for example, a capacitance, an inductance, or an ohmic resistor), a sensor (for example, a pressure sensor, a light sensor, or a gas sensor), an actuator (for example, a loudspeaker), and a microelectromechanical system (MEMS, for example, a loudspeaker, an element comprising a mechanical spring, etc.). However, in other embodiments, the electronic component may also be of a different type, for example, a mechatronic element, in particular a mechanical switch, etc.

[0017] In the context of the present application, the term "separation frame" may specifically refer to a physical structure of a wafer between adjacent, integrally connected electronic components. For example, such a separation frame may comprise straight sections running along rows and columns, which are connected to each other at intersection or crossing regions.

[0018] In the context of the present application, the term “separation frame structure” may in particular refer to a portion of a separation frame, for example an annular portion of a separation frame, which forms an outer ring of an individual electronic component of the wafer from which the electronic component is separated.

[0019] In the context of the present application, the term "dicing" may specifically refer to the process of separating a plurality of separate electronic components from an integral wafer as sections of the previous wafer. Such separation or dicing may be accomplished, in particular, by stealth dicing.

[0020] In the context of the present application, the term "laser penetration-influencing structure" may specifically refer to a dedicated structural feature in the separation frame that is selectively configured to influence a laser beam propagating through the separation frame at the laser penetration-influencing structure in a different manner compared to another region of the separation frame away from the laser penetration-influencing structure. More specifically, the laser penetration-influencing structure may selectively attenuate the penetration of the laser beam into the laser penetration-influencing structure more strongly in a depth direction compared to the penetration of the laser beam into the separation frame away from the laser penetration-influencing structure.For example, the material, the material composition, the surface roughness, and / or any other properties of the laser penetration-influencing structure can be configured to influence and, in particular, suppress laser penetration. In particular, the laser penetration-influencing structure can defocus a laser beam that would otherwise be focused to a specific depth level in the frame structure in the region of the laser penetration-influencing structure. By this measure, the laser penetration-influencing structure can specifically control the laser influence on the separation frame in a spatially dependent manner.Preferably, partial structures of the laser penetration-influencing structure, which relate to a separation line according to which the electronic components of a wafer are to be separated by stealth dicing, are arranged symmetrically with respect to such a separation line or with respect to a corresponding straight section of the separation frame.

[0021] In the context of the present application, the term "stealth dicing" can, in particular, refer to a technology for separating a wafer into electronic components by first laser processing the wafer along desired separation lines and then breaking the laser-processed wafer along the laser-defined separation lines using a mechanical influence, in particular a tensile force. Stealth dicing can, in particular, refer to a two-step process in which, first, defect regions are introduced into a wafer by irradiating a laser beam along desired cutting lines, and second, the wafer can be expanded (in particular, an underlying support membrane on which the wafer may be mounted can be expanded) to induce breakage of the wafer for separation into the individual electronic components thereof.In particular, stealth dicing may comprise laser processing a wafer along a separation frame, and then continuing stealth dicing after laser processing by expanding the wafer to induce fracture in the separation frame to thereby separate the electronic components.

[0022] In the context of the present application, the term "separation line" may, in particular, refer to a preferably straight trajectory along which the wafer is separated in order to separate the individual electronic components from the wafer assembly. For example, a separation line may be a linear path along which a laser beam moves, resulting in a subsequent breakage of the wafer during chip separation.

[0023] In the context of the present application, the term "active region" may, in particular, refer to a surface region of a semiconductor body, a wafer, or an electronic component, in and / or on which surface region at least one monolithically integrated circuit element is formed. In particular, such an active region may form a surface region of a wafer or an electronic component on a front side thereof.

[0024] A core idea of ​​an exemplary embodiment can be seen in the reduction of defect density during stealth dicing by providing a laser penetration-influencing structure, which can be configured to cause laser spot interruptions. More specifically, such a laser penetration-influencing structure can be configured to achieve one or more laser spot interruptions by means of a dicing line (or scribe line) configuration that reuses design elements of a chip circuit design and layer stack to influence laser penetration into the bulk silicon of the wafer and its electronic components.

[0025] In one embodiment, the laser penetration-influencing structure is a defect density suppression structure for locally suppressing the formation of defects during the separation of the electronic components from the wafer. Accordingly, the laser penetration-influencing structure of an electronic component may be a defect density suppression structure for suppressing the formation of defects during the separation of the electronic component from the wafer. With respect to, for example, MEMS (microelectromechanical structure)-type electronic components, stealth dicing may create defects in the separation frame such that particles with dimensions on the order of a few micrometers are discharged or released during separation and inadvertently become trapped between moving parts of the MEMS. This may degrade the function of the MEMS-type electronic components or even damage them.To prevent this, the laser penetration-influencing structure may be configured to suppress the formation of such damaging particles by appropriately influencing the penetration of the laser beam into the material of the separation frame in a region of the laser penetration-influencing structure.

[0026] The above-described embodiment can be particularly advantageously implemented when a thickness of the semiconductor body is at least 300 µm, in particular in a range from 300 µm to 1 mm, or even greater. With such relatively thick wafers and electronic components (typical for MEMS applications), the risk of forming an excessively large amount of defects in the form of micrometer-sized particles, which are separated from the semiconductor body by laser processing in the context of stealth dicing, can be particularly pronounced. Illustratively, the greater the thickness of an electronic component, the larger the sidewall area, and the greater the number of candlesticks, which, upon breaking up a wafer into individual electronic components, lead to the formation of damaging particles.In such a scenario, providing a laser penetration-influencing structure configured as a defect density suppression structure may be particularly advantageous.

[0027] In one embodiment, the laser penetration-affecting structure is a fracture strength enhancing structure for increasing fracture strength during separation of the electronic components from the wafer. Accordingly, the laser penetration-affecting structure of an electronic component may be a fracture strength enhancing structure for increasing fracture strength during separation of the electronic component from a wafer. Particularly in an embodiment relating to very thin wafers and electronic components, dicing by stealth dicing may involve a considerable risk of fracture. By configuring the laser penetration-affecting structure to increase fracture strength, the risk of damage due to separation of the electronic components from a very thin wafer and separation along undesired trajectories may be significantly reduced.

[0028] The above-described embodiment can be implemented particularly advantageously when a thickness of the semiconductor body is not greater than 300 µm, in particular in a range from 100 µm to 300 µm. With such relatively thin wafers, the risk of fracture during stealth dicing can be particularly pronounced. Thus, providing a laser penetration-influencing structure configured to increase fracture resistance can be particularly advantageous.

[0029] In one embodiment, the laser penetration-influencing structure comprises a pattern configured to trim a laser beam during stealth dicing. Such a pattern can be a physical structure that influences the interaction with the laser beam, thereby shaping the laser beam that penetrates the separation frame. The focusing properties of the laser beam within an interior of the separation frame can also be trimmed using the laser penetration-influencing structure. For example, a focal point of a laser beam at a specific depth level in the separation frame can be specifically perturbed in a spatially dependent manner using the laser penetration-influencing structure. Thus, excessive energy influence can be prevented in a portion of the separation frame associated with the laser penetration-influencing structure, thereby, for example, reducing a defect density.

[0030] In one embodiment, the laser penetration-influencing structure is configured to locally block a laser beam when irradiated onto this portion of the separation frame. Thus, the laser beam can be prevented from penetrating the separation frame in the region of the laser penetration-influencing structure, or the intensity of the laser beam can be greatly reduced in the region of the laser penetration-influencing structure compared to a region of the separation frame away from the laser penetration-influencing structure.

[0031] In one embodiment, the laser penetration-influencing structure comprises or consists of a metallic structure for reflecting a laser beam. Thus, the laser penetration-influencing structure may be a metallic pattern. Such a metallic pattern may selectively reflect or block at least the majority of the laser beam in the regions of the separation frame where the metallic pattern is present. Since semiconductor processing stages (e.g., in the back end of the line, BEOL) typically comprise metal formation stages, the laser penetration-influencing structure may be formed simultaneously with and as part of an active area formation process that forms an active area of ​​the electronic components of the wafer. Thus, the laser penetration-influencing structure may be produced efficiently and substantially without additional effort in the manner described.

[0032] In one embodiment, the laser penetration-influencing structure comprises or consists of a locally heavily doped region for absorbing a laser beam. For example, a dopant can be selectively introduced into a region of the laser penetration-influencing structure, but not into other portions of the separation frame away from the laser penetration-influencing structure. Such a dopant can be a trace of an impurity element that is selectively introduced into the laser penetration-influencing structure of the separation frame and that locally modifies the properties of the semiconductor body, and in particular its properties with respect to interaction with a laser beam. The dopant atoms are incorporated into the crystal lattice when implanted into crystalline substances (in particular, a semiconductor, e.g., silicon or germanium).However, the dopant can also be introduced into a non-crystalline or polycrystalline substance. If the semiconductor body is a Group IV material (e.g., silicon), the dopant atoms can in particular be made of a Group III material (e.g., boron) or a Group V material (e.g., antimony). It is also possible for the dopant atoms to comprise both a Group III material and a Group V material. In yet another embodiment, the dopant atoms can form a counter-doping to the semiconductor substrate (i.e., can be of an inverse dopant type). Selectively doping the laser penetration-influencing structure compared to the rest of the separation frame can lead to selective absorption of the laser radiation by the laser penetration-influencing structure.This can selectively suppress the propagation of the laser beam into lower depth levels of the separation frame under the laser penetration-influencing structure.

[0033] In one embodiment, the laser penetration-influencing structure comprises or consists of a dielectric material having a different dielectric constant compared to a surrounding material, thereby manipulating a focus position, in particular a focus depth, of the laser beam. For example, a focus point can be changed by adjusting dielectric properties. For example, a thick layer with a high dielectric constant can shift the focus point of the laser beam further away from the surface. For example, the lowest spot may then no longer be in the bulk material.

[0034] In a specific embodiment, when different dielectric materials with different dielectric constant values ​​are present in the separation frame, and in particular in its laser penetration-influencing structure, interference phenomena may occur upon interaction with the laser beam. For example, different structures of dielectric materials with different dielectric constant values ​​may form a Bragg grating. Consequently, the electromagnetic laser radiation may experience constructive and destructive interference, which can be adjusted by appropriately selecting a shape, a dimension, and a dielectric constant of the dielectric materials. By this measure, the laser focusing properties can be manipulated in specific areas, and laser penetration can thus be significantly attenuated locally.

[0035] In one embodiment, the laser penetration-influencing structure has a locally increased surface roughness compared to the surrounding material, thereby defocusing a laser beam. By selectively roughening a surface of the separation frame only in the region of the laser penetration-influencing structure, the laser beam can be specifically perturbed in the local extension of the laser penetration-influencing structure, and local scattering can be triggered. As a result, defocusing of the laser beam can be achieved selectively in the region of the laser penetration-influencing structure.

[0036] In one embodiment, the laser penetration-influencing structure is configured to influence the laser penetration in different ways at different depth levels in the separation frame. Such an embodiment is particularly Fig. 7. During laser processing in stealth dicing, the laser beam can be sequentially focused on different depth levels of the separation frame. Consequently, laser-cut sections (also referred to as candlesticks) can be formed at different specific depth levels of the separation frame, and particles can be discharged or detached from the separation frame during mechanical separation following the laser processing. Illustratively, the semiconductor material can be temporarily melted locally at the laser-cut sections. By appropriately configuring the laser penetration-influencing structure, the laser influence can be individually adjusted to different depth levels of the separation frame, thereby further refining the controllability of the laser influence.

[0037] When candlesticks are formed at different depth levels of a wafer or electronic component during stealth dicing laser processing, it may be preferable to first focus the laser beam on the deepest depth level, then on the second-deepest depth level, and so on, until the laser beam is focused on the shallowest depth level at the end of laser processing. This sequence or order can prevent a shallowest depth from being inadvertently affected in a disruptive manner by laser processing at a deeper level. For example, candlesticks can be formed at depth levels of 200 µm, 100 µm, and 30 µm below the top surface of the wafer or electronic component.

[0038] In one embodiment, the laser penetration-influencing structure comprises a pattern of substructures arranged along one or more straight separation lines of the separation frame. In other words, a plurality of substructures of the laser penetration-influencing structure can be arranged along a straight line (cf. Fig. 6). This allows to adjust the laser influence during a straight movement of a laser beam along a straight separation line of the separation frame.

[0039] In one embodiment, the pattern is a regular pattern of substructures. For example, the regular pattern of substructures may be a periodic pattern of repeating substructures (again, see Fig. 6, which shows an example).

[0040] In one embodiment, the pattern is absent in intersection areas of the separation frame. In intersection areas of the separation frame, which correspond to corners of the electronic components to be separated, the risk of damage during separation by breakage of the laser-processed wafer is particularly pronounced (see reference numeral 130). Fig. 4 for illustration). Clearly, the actual separation trajectories in the corners of the individual electronic components may deviate from the target separation lines. In addition, during wafer expansion, damaging particles may be discharged or released to cause breakage, and such particles may create artifacts (in particular, they may get between moving parts of a MEMS-type electronic component and may destroy its mechanical function). Therefore, it may be advantageous to arrange the laser penetration-influencing structure along edges (preferably along edges along two perpendicular directions) of the electronic components.In these regions, dicing by stealth dicing is less critical, and thus, reducing laser penetration—and consequently reducing defect density—can improve the reliability of the separated electronic components without compromising high-quality separation. In contrast, it may be advantageous to refrain from reducing laser penetration by means of the laser penetration-influencing structure in the intersection regions of the dicing frame, which correspond to the corner regions of the electronic components, since cutting artifacts, as indicated by reference numeral 130 in FIG. Fig. 4 can be a significant problem.

[0041] In one embodiment, the substructures comprise a plurality of stripe pairs, wherein each stripe pair has a spacing between its two stripes. A laser beam-associated separation line can correspond to the spacing between the stripes of the stripe pairs. More specifically, the laser beam-associated separation line can extend along the spacings of the stripe pairs, which are arranged along a straight line. Preferably, various ones of the stripe pairs can be spaced along a respective one of the one or more straight separation lines. Clearly, such a geometry can lead to efficient laser interference between adjacent stripe pairs and deliberately less efficient laser interference at a corresponding spacing between the stripes of a respective stripe pair.

[0042] In one embodiment, the electronic component is configured as a microelectromechanical system (MEMS). MEMS components can be small integrated devices that combine mechanical and electrical components. MEMS components can be manufactured using integrated circuit batch processing techniques and can range in size from a few micrometers to millimeters. Examples of MEMS-type electronic components include microphones, elements that include at least one mechanical spring, microelectromechanical pressure sensors, etc.

[0043] In one embodiment, the laser penetration-influencing structure is arranged along at least a portion of each of four outer edges of the semiconductor body. The separation accuracy by stealth cutting may be less critical along straight surrounding edges of the semiconductor body, so that selectively mitigating the laser influence on the separation frame by means of the laser penetration-influencing structure may be advantageous for suppressing the defect density.

[0044] In one embodiment, the laser penetration-influencing structure is absent in each of the four outer corner regions of the semiconductor body. Since the separation accuracy of the wafer into the individual electronic components by stealth dicing may be more critical in the corner regions of the electronic components compared to the edge regions, the separation frame may be free of a laser penetration-influencing structure in the intersection regions between perpendicularly extending straight sections of the separation frame. Consequently, the laser influence may not be attenuated and thus may be selectively strong at the corners of the electronic components to be separated. This increases the reliability of correct separation of the electronic components in their corner regions.

[0045] In one embodiment, the method comprises performing the laser processing by guiding a laser beam along the separation frame in a first direction and in a second direction that is transverse to (in particular, perpendicular to) the first direction. Using this approach, separation of a matrix-like array of electronic components into rows and columns of a wafer can be accomplished.

[0046] In one embodiment, the method comprises performing the laser processing by guiding a laser beam multiple times along the separation frame to act on the wafer at different depth levels. Each time a respective straight section of the separation frame is passed, a straight array of cutting spots (candlesticks) can be formed at a corresponding depth level, onto which the laser beam can be focused. By repeatedly passing a corresponding straight section, the laser beam can be focused at different depth levels, so that a plurality of straight arrays of candlesticks can be formed. This enables the individual electronic components to be correctly separated from the wafer.

[0047] In one embodiment, the method comprises performing the laser processing by guiding a laser beam along the separation frame such that the penetration of the laser beam into the wafer is at least partially blocked by the laser penetration-influencing structure. In other words, the laser penetration-influencing structure may be configured (e.g., by being made of a metal) to block a greater amount of laser energy compared to the other regions of the separation frame away from the laser penetration-influencing structure.

[0048] In one embodiment, the method comprises performing the laser processing by guiding a laser beam along the separation frame such that the penetration of the laser beam into the wafer occurs more efficiently away from the laser penetration-influencing structure compared to the penetration of the laser beam into the wafer at the laser penetration-influencing structure. Thus, the penetration of the laser beam into an interior of the separation frame can be inhibited by the laser penetration-influencing structure.

[0049] In one embodiment, the method comprises performing the laser processing by continuously guiding a laser beam along the separation frame. Thus, the laser beam can be continuously irradiated along the separation frame. Thus, complex control of the laser energy over time acting on a separation frame may be dispensed with. In contrast, according to exemplary embodiments, laser trimming for influencing laser penetration can be accomplished via the hardware design of the separation frame in the form of providing the laser penetration-influencing structure in a spatially dependent manner.

[0050] However, in alternative embodiments, it may also be possible to control laser intensity during laser processing, for example by repeatedly switching the laser beam on and off.

[0051] In one embodiment, the method comprises forming the laser penetration-influencing structure simultaneously with a process for forming a structural feature of an active region of the electronic components. For forming a functionally active region of an electronic component, various process stages may be performed (e.g., in particular comprising front end of the line (FEOL) processing and back end of the line (BEOL) processing). Such semiconductor processing for creating the active region may, in particular, comprise the formation of patterned metal layers. In a highly advantageous manner, such an active region formation process may be used for simultaneously forming the laser penetration-influencing structure on and / or in the separation frame. Thus, the laser penetration-influencing structure may be formed substantially without additional effort.

[0052] In one embodiment, the electronic component is a power semiconductor chip. Such a power semiconductor chip may have one or more integrated circuit elements integrated therein, for example, transistors (for example, field-effect transistors, such as metal-oxide semiconductor field-effect transistors and / or bipolar transistors, such as insulated-gate bipolar transistors) and / or diodes. Example applications that may be provided by such integrated circuit elements are switching purposes. For example, such another integrated circuit element of a power semiconductor device may be integrated in a half-bridge or a full-bridge. Example applications are automotive applications.

[0053] The one or more electronic components (in particular semiconductor chips) may comprise at least one from the group consisting of a diode and a transistor, more specifically an insulated gate bipolar transistor. For example, the one or more electronic chips may be used as semiconductor chips for power applications, for example in the automotive sector. In one embodiment, at least one semiconductor chip may comprise a logic IC or a semiconductor chip for RF power applications. In one embodiment, the semiconductor components may be used as one or more sensors or actuators in microelectromechanical systems (MEMS), for example as pressure sensors or acceleration sensors, as a microphone, as a loudspeaker, etc.

[0054] A semiconductor substrate, i.e., a silicon substrate, can be used as the substrate or wafer for the semiconductor components. Alternatively, a silicon oxide or other insulating substrate can be provided. It is also possible to implement a germanium substrate or a III-V semiconductor material. For example, exemplary embodiments can be implemented using GaN or SiC technology.

[0055] Furthermore, exemplary embodiments may make use of standard semiconductor processing technologies, for example, suitable etching technologies (including isotropic and anisotropic etching technologies, in particular plasma etching, dry etching, wet etching), patterning technologies (which may involve lithographic masks), deposition technologies (for example, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), sputtering, etc.).

[0056] The above and other objects, features, and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are designated by like reference numerals. Short description of the drawings

[0057] The accompanying drawings, which are included to provide a further understanding of exemplary embodiments of the invention, illustrate exemplary embodiments of the invention.

[0058] In the drawings: Fig. 1 shows a top view of a wafer according to an exemplary embodiment. Fig. 2 shows a top view of an electronic component according to an exemplary embodiment. Fig. 3 shows a flowchart of a method for separating electronic components from a wafer according to an exemplary embodiment. Fig. 4 shows a top view of a wafer according to an exemplary embodiment. Fig. 5 shows a cross-sectional view of a wafer having electronic components to be separated, according to an exemplary embodiment. Fig. 6 shows a top view of a wafer according to an exemplary embodiment. Fig. 7 shows a cross-sectional view of a wafer according to an exemplary embodiment. Detailed description of exemplary embodiments

[0059] The representation in the drawing is schematic and not to scale.

[0060] Before exemplary embodiments are described in more detail with reference to the figures, some general considerations are summarized based on which exemplary embodiments were developed.

[0061] Stealth dicing may be a preferred choice for separating MEMS-type electronic components from a wafer. In particular, stealth dicing may sometimes be the only possible separation technique capable of handling such devices without exposure to moisture, without touching the delicate wafer front surface, and without applying mechanical vibration.

[0062] Depending on the sizes of their features, MEMS-type electronic components can be extremely sensitive to defect density, which can affect the motions of microfabricated elements and lead to a large yield loss and high detection effort to detect and capture such particles.

[0063] However, stealth dicing can result in a higher defect density than other dicing techniques due to particles chipping off the separated chip sidewalls. The number of defects depends on the number of focused laser spots forming so-called candlesticks in the sidewall of a corresponding electronic component. Therefore, minimizing this spot count may be desirable to avoid undesirable interference with moving parts of a separated MEMS-type electronic component.

[0064] A reduction in defect density is particularly desirable for thick wafers. The defect density is proportional to the number of focus spots (candlesticks). For thinner wafers, fracture toughness also plays a role. This is particularly relevant for stealth dicing, as stealth dicing may be less suitable than conventional sawing techniques, especially with regard to fracture toughness and defect density. However, stealth dicing is often the only suitable sawing technique for MEMS.

[0065] One way to reduce such defects is to use a stealth laser with very high power, which requires fewer spots in both the horizontal and vertical directions. Nevertheless, for large wafers and small, delicate micromechanical elements, there may still be a need to further reduce the defect density. For example, in large electronic components (e.g., those with an area of ​​several hundred square millimeters), defect particles as small as a few micrometers can lead to severe yield losses.

[0066] A desired reduction in the number of spots can also be achieved by optimizing the positioning of the stealth spots. It may be desirable for the stealth spot density to be higher near the chip edges than far away from the chip edges. This is derived from the fact that uneven fracture lines, which deviate from the spot position at a scribe line center, predominantly occur near the chip corners (see the top view of Fig. 4).

[0067] Controlling a laser beam to turn it on and off during irradiation along a separation frame of the wafer to adjust stealth spots can typically be laborious. Since there is no process feedback regarding the success and spatial accuracy of such an approach of turning the laser beam on and off during irradiation along a separation frame, laborious manual inspection of individual electronic components may be necessary.

[0068] According to an exemplary embodiment, a dicing frame of a wafer may be equipped with a laser penetration-influencing structure for controlling laser penetration in a spatially dependent manner into a corresponding portion of the dicing frame during dicing of the wafer into individual electronic components, without complicated control of the laser beam. Advantageously, such a laser penetration-influencing structure may be provided for reducing a defect density in an electronic component that is separated from a wafer assembly by stealth dicing. In particular, an exemplary embodiment may implement stealth laser spot interruptions via a dicing line (or scribe line) design, which reuses design elements of a chip circuit design and layer stack to influence laser penetration into the bulk silicon.Such an approach can be particularly advantageously applied to MEMS-type electronic components, which can be efficiently separated using stealth dicing. It may be particularly preferred to implement exemplary embodiments for separating electronic components with large chip sizes and high defect density requirements.

[0069] Advantageously, an exemplary embodiment creates laser spot interruptions using a scribe line or dicing line design that reuses design elements of the chip circuit design and a layer stack to influence laser penetration into the bulk silicon. The layers used can have a placement accuracy significantly better than 1 µm. Advantageously, such design elements can be implemented without additional effort.

[0070] In one embodiment, the design of the laser penetration-influencing structure may be supported by a simulation for optimization.

[0071] Fig. 1 shows a top view of a portion of a wafer 100 according to an exemplary embodiment.

[0072] The wafer 100 shown includes an array of a plurality of electronic components 102. Furthermore, the wafer 100 includes a separation frame 104 that separates adjacent electronic components 102. As shown, the separation frame 104 includes a laser penetration-influencing structure 106 (which may have multiple substructures 110) configured to locally influence laser penetration when the separation frame 104 is subjected to laser processing (in particular, for dicing along the separation lines 112) during stealth dicing.

[0073] Fig. 2 shows a top view of an electronic component 102 according to an exemplary embodiment.

[0074] The illustrated electronic component 102 includes a semiconductor body 114. An active region 116 is formed in and / or on a central portion of the semiconductor body 114. Furthermore, the electronic component 102 includes a separation frame structure 118 in an edge region of the semiconductor body 114. As shown, the separation frame structure 118 includes a laser penetration-influencing structure 106 configured to locally influence laser penetration while the separation frame structure 118 is subjected to laser processing during stealth dicing.

[0075] Fig. 3 shows a flowchart 200 of a method for separating electronic components 102 from a wafer 100 according to an exemplary embodiment. For the description of Fig. 3, the reference numerals are replaced by Fig. 1 and Fig. 2 used.

[0076] As shown by a block 202, the method may include providing the wafer 100 with a separation frame 104 that separates adjacent electronic components 102.

[0077] As shown by a block 204, the method may further include providing the separation frame 104 with a laser penetration-affecting structure 106.

[0078] As shown by a block 206, the method may additionally include subjecting the laser penetration-affecting structure 106 to laser processing during stealth dicing along the separation frame 104 to locally affect the laser penetration.

[0079] Fig. 4 shows a top view of a wafer 100 according to an exemplary embodiment. As indicated by reference numeral 130, dicing the wafer 100 into individual electronic components 102 using stealth dicing may involve problems with uneven separation edges that deviate from straight separation lines 112 along which a laser beam can be moved. The artifacts indicated by reference numeral 130 may occur predominantly in corner regions of the electronic components 102 to be separated.

[0080] Thus, Fig. 4 shows a grid scanned by a laser beam during stealth dicing. During separation by breaking the wafer 100, separation cracks are intended to extend along the grid. However, it may happen, particularly in corner regions of the separated electronic components 102, that a crack takes an undesirable shortcut during separation (see reference numeral 130).

[0081] Fig. 5 shows a cross-sectional view of a wafer 100 with electronic components 102 according to an exemplary embodiment.

[0082] Referring to Fig. 5 and additionally on Fig. 2, properties of an electronic component 102 according to an exemplary embodiment are explained.

[0083] Such an electronic component 102 may include a semiconductor body 114, for example, a silicon block. The semiconductor body 114 may initially form part of a semiconductor (in particular, silicon) wafer 100, from which the electronic components 102 may be separated by stealth dicing.

[0084] An active region 116 may be monolithically integrated into and / or on an upper central region of the semiconductor body 114, for example, using semiconductor technology. The formation of the active region 116 may also include the formation of a microelectromechanical system (MEMS) with relatively movable mechanical parts, which also provide an electrical feature or function. For example, the MEMS-like active region 114 may provide a microphone function in which a movement of a membrane, triggered by an acoustic wave, is converted into an electrical signal. However, many other MEMS applications as such are possible and known to those skilled in the art.

[0085] How better in Fig. 2, a separation frame structure 118 - which initially forms part of a separation frame 104 of a wafer 100 from which the electronic component 102 has been separated - extends as a ring-shaped closed structure along an edge region of the semiconductor body 114 and surrounds the active region 116. Advantageously, and as also shown in Fig. 5, the separation frame structure 118 includes a laser penetration-influencing structure 106 configured to locally influence laser penetration into the separation frame structure 118 while the separation frame structure 118 is subjected to laser processing during stealth dicing to separate the electronic component 102 from the wafer 100. Thus, the presence of the laser penetration-influencing structure 106 along the straight edges of the separation frame structure 118 is a fingerprint of a corresponding electronic component 102 for its separation from the wafer 100 by stealth dicing according to example embodiments.

[0086] Back on Fig. Referring to Figure 2, the laser penetration-influencing structure 106 is arranged along portions of each of four outer straight edges of the semiconductor body 114, which has rectangular main surfaces. In contrast, the laser penetration-influencing structure 106 is absent in each of the four outer corner regions of the semiconductor body 114. Each of the corner regions is formed at an intersection of two perpendicular ones of the four outer straight edges. As a result of this omission of the laser penetration-influencing structure 106 in the corner regions, a precise separation in the corner regions can be ensured to prevent artifacts, as indicated by reference numerals 130 in Fig. 4. At the same time, due to the presence of the laser penetration-influencing structure 106 at the edges, defect formation along the edges can be suppressed. This is best seen in Fig. 5, which shows a plurality of candlesticks 134 formed in a sidewall of the electronic component 102 as a result of laser processing during stealth dicing. In the embodiment shown, the candlesticks 134 are formed at different depth levels d1, d2, d3, d4 by repeatedly scanning the laser beam along a separation frame 104 with a focus at the different depth levels d1, d2, d3, d4. Such candlesticks 134 can be formed as spots in the sidewalls of the electronic components 102, at which a laser beam acting on a wafer 100 during stealth dicing results in cutting.Upon breakage of the wafer 100 at the sidewalls, particles with typical dimensions of a few micrometers can be released or discharged from the candlesticks 134 and can inadvertently become wedged between relatively movable parts of the MEMS-type electronic component 102, disrupting or damaging its function. By arranging—preferably metallic—substructures 110 of the laser penetration-influencing structure 106 according to . Fig. 5 for locally blocking a laser beam, a laser influence on corresponding sections of the separation frame structure 118 can be inhibited such that the density of the candlesticks 134 is reduced where the substructures 110 of the laser penetration-influencing structure 106 are present. This is shown in Fig. 5 can be seen.

[0087] More precisely, Fig. 5 shows a locally higher density of candlesticks 134 in corners (i.e., at the separation lines 112) of a corresponding electronic component 102 compared to a locally lower density of candlesticks 134 along the edges between the corners of a corresponding electronic component 102. This is due to the presence of the substructures 110 of the laser penetration-influencing structure 106 along the edges and due to their absence at the corners. Consequently, the laser penetration-influencing structure 106 acts as a defect density suppression structure for suppressing the formation of defects during the separation of the electronic component 102 from a wafer 100. Each of the candlesticks 134 is a potential source of particles, and thus defects, which are discharged during the separation of the wafer 100 by means of expansion.Locally reducing the density of candlesticks 134 along the edges ensures a smaller defect density along the edges. At the same time, high separation accuracy can also be achieved in the corners. This can protect the moving parts of the MEMS-type electronic component 102 from being blocked by discharged particles and can simultaneously suppress artifacts 130 related to uneven fracture lines in the corners (see ). Fig. 4).

[0088] Back on Fig. Referring to FIG. 5, a thickness D of the semiconductor body 114 can be, for example, 700 µm or greater. Such a large thickness is typical for MEMS applications. For such thick electronic components 102 with correspondingly large sidewall areas and thus high numbers of candlesticks 134, the described defect density-reducing influence of the laser penetration-influencing structure 106 can be of great advantage.

[0089] For example, in other embodiments, when the thickness D is less than 200 µm, a bottleneck may be a limited fracture strength of the wafer 100 and its electronic components 102. Thus, the electronic chips 102 with such a small thickness that are separated from the wafer 100 may be prone to fracture at undesirable locations during separation. To address such a challenge, it may be possible to configure the laser penetration-affecting structure 106 as a fracture strength enhancement structure for increasing fracture strength during separation of the electronic component 102 from a wafer 100.

[0090] Fig. 6 shows a top view of a wafer 100 according to an exemplary embodiment.

[0091] The wafer 100 shown may be a semiconductor wafer, in particular a silicon wafer, and may comprise a matrix-like array of a plurality of electronic components 102, for example, MEMS chips. A separation frame 104 forms an integral part of the wafer 100, is thereby integrally connected to the electronic components 102, and separates or spaced adjacent or juxtaposed electronic components 102 from one another. Illustratively, the separation frame 104 is a grid-like structure formed predominantly from the semiconductor material of the wafer 100.

[0092] In addition to its semiconductor base, the separation frame 104 comprises a laser penetration-influencing structure 106 configured to locally influence the laser penetration when the separation frame 104 is subjected to laser processing during stealth dicing. In particular, when the electronic components 102 are MEMS elements that can be functionally disturbed by defect particles, and when the thickness D of the wafer 100 is large (e.g., over 300 µm), the laser penetration-influencing structure 106 may be configured as a defect density suppression structure for suppressing the formation of defects during the separation of the electronic components 102 from the wafer 100, as described above, for example, with reference to Fig. 5 is explained.

[0093] As in Fig. 6, the laser penetration-influencing structure 106 comprises a metallic pattern in the form of strip-shaped substructures 110, which are arranged symmetrically with respect to the separation lines 112, for trimming a laser beam that scans along the separation lines 112 during stealth dicing. In the presently described embodiment, separation lines 112 are shown extending along two orthogonal directions. Advantageously, the laser penetration-influencing structure 106 is configured to locally block a laser beam when it is irradiated onto the separation frame 104. In other words, a laser beam can be blocked to a greater extent, into the separation frame 104 in a depth direction (i.e., perpendicular to the paper plane of Fig. 6) when it impinges on the laser penetration-affecting structure 106, as compared to a scenario in which the laser beam impinges on the separation frame 104 away from the laser penetration-affecting structure 106.

[0094] As already mentioned, the laser penetration influencing structure 106 can be formed according to Fig. 6 may be a metallic structure for reflecting a laser beam. Alternatively, a laser beam may be inhibited from propagating in an undesirable manner into an interior of the separation frame 104 by means of a laser penetration-influencing structure 106, which is embodied as a locally more highly n- or p-doped region to absorb at least a large portion of the laser beam. Furthermore, the laser penetration-influencing structure 106 may alternatively comprise a dielectric material having a significantly different dielectric constant compared to a surrounding material, thereby manipulating a focus position of the laser beam, in particular a focus depth.Yet another option for the laser penetration-influencing structure 106 is to embody it as a surface portion with a locally increased surface roughness compared to a smaller surface roughness of the surrounding material, thereby defocusing the laser beam.

[0095] As already mentioned and in Fig. 6, the laser penetration-influencing structure 106 of the present embodiment comprises a symmetrical and periodic pattern of metallic substructures 110 arranged along the straight separation lines 112 of the separation frame 104, which extend along two orthogonal directions. Advantageously, the pattern according to Fig. 6 shows a regular, periodic pattern of substructures 110 extending along a straight line, wherein the substructures 110 associated with a respective straight line correspond to a respective separation line 112. Furthermore, the substructures 110 corresponding to a common separation line 112 can be in alignment with each other and with the separation line 112. As shown, the substructures 110 comprise a plurality of stripe pairs, each stripe pair having a spacing between its stripes. Furthermore, various of the stripe pairs are spaced along a respective one of the one or more straight separation lines 112. The geometry according to Fig. 6 ensures both reliable separation and a low defect density when cutting along the edges of the electronic components 102. Since the separation trajectory extends in accordance with the separation lines 112 straight along the distances between the strips of the respective strip pairs, a strip of a respective strip pair forms part of an edge region of each of two adjacent separated electronic components 102 after separation.

[0096] The pattern of partial structures 110 according to Fig. 6 are absent in the intersection areas of the separation frame 104. This prevents artifacts 130 related to odd fracture surfaces (compare Fig. 4) in the corners of the electronic components 102 during separation. Away from the intersection areas, substructures 110 with a laser shadowing or shielding effect can be implemented.

[0097] During the separation of the wafer 100 into the individual electronic components 102 according to Fig. 6, a laser beam is guided along the separation frame 104 in a horizontal direction and in a vertical direction, which is perpendicular to the horizontal direction. In order to create the candlesticks 134 at different depth levels in the wafer 100, the laser beam can be guided a plurality of times (in particular 2 to 7 times) along the separation lines 112 on the separation frame 104 in order to impinge on the wafer 100 at the different depth levels (compare d1-d4 in Fig. 5). Advantageously, the laser beam can be guided along the dicing frame 104 such that the penetration of the laser beam into the wafer 100 is partially or completely blocked by the laser penetration-influencing structure 106. The penetration of the laser beam into the wafer 100 can occur more efficiently away from the laser penetration-influencing structure 106, compared to the penetration of the laser beam into the wafer 100 at the laser penetration-influencing structure 106. To ensure simple laser control, the laser processing can continuously guide the laser beam along the dicing frame 104 so that the laser beam can remain switched on throughout the entire laser processing within the scope of stealth dicing.

[0098] Although not shown, the stealth dicing process may be continued after completion of the laser processing by radially expanding the wafer 100 to induce a fracture in the separation frame 104, thereby separating the electronic components 102.

[0099] Advantageously, the formation of the metallic laser penetration-influencing structure 106 may be performed concurrently with a process of forming a metallic feature in the active area 116 of the electronic components 102 during semiconductor processing. For example, co-lithography may be used to form a portion of the active area 116 and at least a portion of the laser penetration-influencing structure 106, for example, during a BEOL process. For example, a metallic laser penetration-influencing structure 106 may be formed from a final metal layer deposited during semiconductor wafer processing.

[0100] Fig. 6 shows a top view of scribe or separation lines 112 of the wafer 100. The laser penetration-influencing structure 106 represents a pattern for laser blocking. Each pair of stripes has a spacing at a central position indicating a separation position along an associated separation line 112. Advantageously, no blocking pattern of substructures 110 is present near intersections of the separation frame 104.

[0101] As already mentioned, there are various options to influence the penetration of the laser beam by means of a laser penetration-influencing structure 106: In one embodiment, it may be possible to reflect, shield, or block the laser beam, for example, by means of the substructures 110, which are embodied as metal strips or strips of another reflective material. Since at least one metal is typically always available in almost all semiconductor chip products, a corresponding laser penetration-influencing structure 106 can be formed with minimal effort.

[0102] A laser penetration-influencing structure 106 may also be embodied to absorb infrared (IR) laser light near the surface by means of a heavily doped implant layer.

[0103] In yet another embodiment, a laser penetration-influencing structure 106 may be formed by means of a thick dielectric having a significantly different ε r-value, for example silicon nitride (Si3N4), which offsets the sidewall spots according to Bragg's law.

[0104] Additionally or alternatively, it may be possible to form a laser penetration-influencing structure 106 by using a local roughening of the surface or at an interface with the layer stack to prevent the laser light from focusing into a spot. For example, this may be achieved via a wet chemical process or by means of a damage implantation process.

[0105] Fig. 7 shows a cross-sectional view of a wafer 100 according to an exemplary embodiment. The embodiment of Fig. 7 shows that the laser penetration influencing structure 106 can be configured to differently influence the laser penetration into different depth levels d1, d2, d3 in the separation frame 104. Each of the three representations of Fig. Fig. 7 shows a scenario in which a respective laser beam 140, 142, 144 is directed onto a surface 146 of an electronic component 102, which is to be separated from a wafer 100. The separation can be triggered by the formation of candlesticks 134 at the different height levels d1, d2, d3, which in Fig. 7. For this purpose, a corresponding laser beam 140, 142, 144 can be focused on a corresponding one of the different height levels d1, d2, d3. By the different shown designs of the substructures 110 of the laser penetration-influencing structures 106 according to the three examples of Fig. 7 different defect characteristics can be achieved at the different height levels d1, d2, d3.

[0106] With the design, which is on the left side of Fig. 7, and which is subjected to the action of the laser beam 140, the laser beam 140 is significantly blocked by means of the substructures 110 when it is focused on each of the different height planes d1, d2, d3.

[0107] With the design, which is in the central part of Fig. 7, and which is subjected to the action of the laser beam 142, the laser beam 142 is significantly blocked by the substructures 110 when it is focused on the height plane d1. Upon focusing on the height planes d2, d3, the blocking effect of the substructures 110 is significantly less pronounced.

[0108] With the design, which is on the right side of Fig. 7, and which is subjected to the action of the laser beam 144, the laser beam 142 is significantly blocked by the substructures 110 when it is focused on the height planes d2, d3. Upon focusing on the height plane d1, the blocking function of the substructures 110 is significantly less pronounced.

[0109] Thus, depending on the design of the stripes of the substructures 110, it may be possible to block more of the highest or lowest scan positions to optimize the separation rate and, if necessary, the fracture strength. Comparing the blocking rate for each laser cone for the upper-level and lower-level scan positions, it can be seen that the blocked area of ​​the laser cone cross-section differs for the different cone positions depending on the stripe design.

[0110] A person skilled in the art will appreciate that the cone angle in air can be much larger than in silicon, so that Fig. 7 is not to scale in this context. This is schematically indicated by the reference numeral 199 in Fig. 7, which shows refraction of a laser beam at surface 146. The aperture angle above surface 146 is larger than below surface 146. In other words, a flatter or wider funnel is achieved at the top than at the bottom. This is a result of the influence of the dielectric constant on the angle.

Claims

[1] A wafer (100) comprising: • an array of a plurality of electronic components (102); and • a separation frame (104) which separates adjacent electronic components (102); • wherein the separation frame (104) has a laser penetration-influencing structure (106) configured to locally influence laser penetration in a different manner at the laser penetration-influencing structure (106) than at another region of the separation frame (104) away from the laser penetration-influencing structure when the separation frame (104) is subjected to laser processing during stealth dicing; • wherein the laser penetration-influencing structure (106) comprises a pattern of substructures (110) arranged along one or more straight separation lines (112) of the separation frame (104); • wherein the substructures (110) comprise a plurality of pairs of stripes, each pair of stripes having a spacing between its stripes; • wherein the dividing line (112) extends straight along the distances between the strips of the respective pairs of strips. [2] The wafer (100) according to claim 1, wherein the laser penetration-affecting structure (106) is a defect density suppression structure for suppressing formation of defects during separating the electronic components (102) from the wafer (100). [3] The wafer (100) according to claim 1 or 2, wherein the laser penetration-affecting structure (106) is a fracture strength increasing structure for increasing a fracture strength during separation of the electronic components (102) from the wafer (100). [4] The wafer (100) according to any one of claims 1 to 3, wherein the laser penetration-influencing structure (106) has a pattern configured to trim a laser beam during stealth dicing. [5] The wafer (100) according to any one of claims 1 to 4, wherein the laser penetration-influencing structure (106) is configured to locally block a laser beam when it is irradiated onto the separation frame (104). [6] The wafer (100) according to any one of claims 1 to 5, comprising at least one of the following features: wherein the laser penetration-influencing structure (106) comprises or consists of a metallic structure for reflecting a laser beam; wherein the laser penetration-influencing structure (106) comprises or consists of a locally heavily doped region for absorbing a laser beam; wherein the laser penetration-influencing structure (106) comprises or consists of a dielectric material having a different dielectric constant compared to a surrounding material and is configured to manipulate a focus position, in particular a focus depth, of the laser beam; wherein the laser penetration-influencing structure (106) has a locally increased surface roughness compared to the surrounding material to thereby defocus a laser beam. [7] The wafer (100) according to any one of claims 1 to 6, wherein the laser penetration influencing structure (106) is configured to influence the laser penetration in different ways at different depth levels (d1-d4) in the separation frame (104). [8] The wafer (100) according to any one of claims 1 to 7, comprising at least one of the following features: wherein the pattern is a regular, in particular periodic, pattern of substructures (110); wherein the pattern is absent in intersecting regions of the separation frame (104); wherein in particular different ones of the pairs of strips are spaced along a respective one of the one or more straight separation lines (112). [9] An electronic component (102) comprising: • a semiconductor body (114); • an active region (116) in and / or at a central region of the semiconductor body (114); and • a separation frame structure (118) in an edge region of the semiconductor body (114); • wherein the separation frame structure (118) comprises a laser penetration influencing structure (106) configured to locally influence laser penetration while the separation frame structure (118) is subjected to laser processing during stealth dicing; • wherein a defect density created by stealth dicing in a sidewall of the electronic component (102) is locally reduced in the regions of the separation frame structure (118) where the laser penetration-influencing structure (106) is arranged, compared to regions of the separation frame structure where the laser penetration-influencing structure (106) is absent. [10] The electronic component (102) of claim 9, wherein the electronic component (102) is configured as a microelectromechanical system. [11] The electronic component (102) according to claim 9 or 10, wherein the laser penetration-influencing structure (106) is arranged along at least a portion of each of the surrounding edges of the semiconductor body (114). [12] The electronic component (102) according to any one of claims 9 to 11, wherein the laser penetration-influencing structure (106) is absent in each of the corner regions of the semiconductor body (114). [13] The electronic component (102) according to any one of claims 9 to 12, wherein the laser penetration-affecting structure (106) is a defect density suppression structure for suppressing formation of defects during separating the electronic component (102) from a wafer (100). [14] The electronic component (102) according to claim 13, wherein a thickness (D) of the semiconductor body (114) is at least 300 µm, in particular in a range of 300 µm to 1 mm. [15] The electronic component (102) according to any one of claims 9 to 14, wherein the laser penetration-affecting structure (106) is a fracture strength increasing structure for increasing a fracture strength during separation of the electronic component (102) from a wafer (100). [16] The electronic component (102) according to claim 15, wherein a thickness (D) of the semiconductor body (114) is not greater than 300 µm, in particular in a range of 100 µm to 300 µm. [17] A method for separating electronic components (102) from a wafer (100), the method comprising: • Providing the wafer (100) with a separation frame (104) which separates adjacent electronic components (102); • Providing the separation frame (104) with a laser penetration-influencing structure (106) configured to locally influence laser penetration in a different manner at the laser penetration-influencing structure (106) than at another region of the separation frame (104) away from the laser penetration-influencing structure; and • Subjecting the laser penetration-influencing structure (106) to laser processing during stealth dicing along the separation frame (104) to locally influence the laser penetration, such that a defect density generated by stealth dicing along a separation line (112) is locally reduced in regions where the laser penetration-influencing structure (106) is arranged, compared to regions of the separation line (112) where the laser penetration-influencing structure (106) is absent. [18] The method according to claim 17, comprising at least one of the following features: wherein the method comprises carrying out the laser processing by guiding a laser beam along the separation frame (104) in a first direction and in a second direction which is transverse, in particular perpendicular, to the first direction; the method comprising performing the laser processing by guiding a laser beam multiple times along the separation frame (104) to act on the wafer (100) at different depth levels (d1-d4); wherein the method comprises performing the laser processing by guiding a laser beam along the separation frame (104) such that penetration of the laser beam into the wafer (100) is at least partially blocked by the laser penetration-influencing structure (106); wherein the method comprises performing the laser processing by guiding a laser beam along the separation line (104) such that the penetration of the laser beam into the wafer (100) adjacent to the laser penetration-influencing structure (106) takes place more efficiently compared to the penetration of the laser beam into the wafer (100) at the laser penetration-influencing structure (106); the method comprising performing the laser processing by guiding a laser beam continuously along the separation frame (104); wherein the method comprises continuing the stealth dicing after the laser processing by expanding the wafer (100) to induce a fracture in the separation frame (104) to thereby separate the electronic components (102); wherein the method comprises forming the laser penetration-influencing structure (106) concurrently with a process for forming a structural feature of an active region (116) of the electronic components (102). [19] The method of claim 17 or 18, wherein the method comprises using a wafer (100) according to any one of claims 1 to 8.

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