Patent Publication Number: US-2023154869-A1

Title: Semiconductor structure and method for manufacturing preparing same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of International Application No. PCT/CN2022/075705 filed on Feb. 9, 2022, which claims priority to Chinese Patent Application No. 202111186670.3 filed on Oct. 12, 2021. The disclosures of the above-referenced applications are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     In a semiconductor manufacturing process, it is required to saw a wafer into chips, and then make these chips into different semiconductor packaging structures. In some implementations, wafer sawing is not only a key process of a semiconductor packaging process, but also a bottleneck process in the capacity of the whole semiconductor packaging process. 
     With the development of semiconductor technology, an integration of chips becomes higher and higher, while a dimension of the corresponding chips becomes smaller and smaller, a sawing width becomes smaller and smaller, and a sawing lane becomes narrower and narrower. Therefore, compared with a wide sawing lane, it becomes more difficult to separate the chips. 
     It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the disclosure, and therefore may include information that does not constitute a related art known to a person of ordinary skill in the art. 
     SUMMARY 
     The disclosure relates to the technical field of semiconductors, in particular to a semiconductor structure and a method for manufacturing the same. 
     A purpose of the disclosure is to overcome deficiencies of the above-mentioned implementations and to provide a semiconductor structure and a method for manufacturing the semiconductor structure. 
     According to one aspect of the present disclosure, a semiconductor structure is provided. The semiconductor structure includes: a base layer; a device layer that is located on the base layer and includes a first dielectric layer and device structures, in which the first dielectric layer fills the device layer and isolates the device structures; a stress propagating layer that is located on the device layer and includes a second dielectric layer and a plurality of stress propagating patterns arranged at intervals, in which the second dielectric layer fills the stress propagating layer and isolates the stress propagating patterns. 
     According to another aspect of the present disclosure, a method for manufacturing a semiconductor structure is provided, which includes the following operations. 
     A base layer is provided. 
     A device layer is formed on the base layer. The device layer includes a first dielectric layer and device structures. The first dielectric layer fills the device layer and isolates the device structures. 
     A stress propagating layer is formed on the device layer. The stress propagating layer includes a second dielectric layer and a plurality of stress propagating patterns arranged at intervals. The second dielectric layer fills the stress propagating layer and isolates the stress propagating patterns. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Drawings herein are incorporated into and constitute a part of the specification, show embodiments consistent with the disclosure and serve to explain the principles of the disclosure together with the specification. It is apparent that the drawings described below are only some embodiments of the disclosure, from which other drawings can be obtained without creative effort for a person of ordinary skill in the art. 
         FIG.  1    schematically shows a structure of a semiconductor structure. 
         FIG.  2    schematically shows a partial enlarged diagram of a defect generated by sawing a part indicated by I in  FIG.  1   . 
         FIG.  3    schematically shows a structure of a semiconductor structure of an exemplary embodiment of the disclosure. 
         FIG.  4    schematically shows a top view of the semiconductor structure shown in  FIG.  3   . 
         FIG.  5    schematically shows a structure of a semiconductor structure shown in 
         FIG.  4    during sawing. 
         FIG.  6    schematically shows a top view of a semiconductor structure of another exemplary embodiment of the disclosure. 
         FIG.  7    schematically shows a structure of a semiconductor structure of yet exemplary embodiment of the disclosure. 
         FIG.  8    schematically shows a flowchart of an exemplary embodiment of a method for manufacturing a semiconductor structure of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments will be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to perfect and complete this disclosure, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. In addition, it is apparent that the accompanying drawings are merely exemplary illustrations of the disclosure, and may be not drawn to scale. 
     Although relative terms such as “above” and “below” are used in the specification to describe a relative relationship of one component to another component as illustrated in the drawings, these terms are used in the specification only for convenience of descriptive purposes, for example according to the direction of the example described in the accompanying drawings. It is to be understanding that, if the apparatus in the drawings is turned over, the component described as “above” other components would then be oriented “below” the other components. When a structure is described as “on” other structures, it may mean that this structure is integrally formed with the other structures, or that this structure is “directly” arranged on the other structures, or that this structure is “indirectly” arranged on the other structures through another structure. 
     The terms “a/an”, “one”, “the/said”, and “at least one” are used to indicate that there are one or more elements/components/etc. The terms “include/comprise” and “has/have/having” are used to indicate an open-ended inclusion, means that additional elements/components/etc. may be present in addition to the listed elements/components/etc. The terms “first”, “second” and “third” etc. are used only for indicating, and are not intend to limit the number of objects to which they refer. 
     Referring to  FIG.  1   , a semiconductor structure  8 , such as a wafer, has a plurality of chip areas  4 . A sawing lane  5  is provided between two adjacent chip areas  4 . The wafer is sawed along the sawing lane  5  to separate the adjacent chips. With the improvement of integration of semiconductor devices, a width of the sawing lane  5  becomes narrower and narrower, resulting in an increasing stress on part of a dielectric layer close to the sawing lane  5 . A crack  7  generated during sawing the wafer may extend into adjacent chip areas  4  to produce an error shown in  FIG.  2   , which destroys a interconnect structure of the chip areas  4 , cracks a plug layer in the interconnect structure, and disconnects a signal transmission channel, and leads to the failure of the chip, finally resulting in that some functions of the chip cannot work normally or performances of the chip cannot meet design requirements, and thus the sawing yield decreases. 
     As shown in  FIG.  3   , a semiconductor structure is provided in an embodiment of the disclosure. The semiconductor structure includes a base layer  1 , a device layer  2 , and a stress propagating layer  3 . The base layer  1  includes a substrate  11  and a memory device  12 . In some embodiments, the substrate  11  may be germanium, silicon germanium, gallium arsenide or silicon on insulator. Those skilled in the art can select the material of the substrate  11  as required, which is not limited herein. The memory device  12  includes a transistor, a resistor, a capacitor, an inductor, etc. The memory device  12  mentioned may be used to constitute a volatile memory (DRAM, SDRAM, etc.), a nonvolatile memory (Nand, NOR, Flash, etc.). A person skilled in the art can determine the corresponding type of the memory device  12  to be formed as required, which is not limited herein. 
     The device layer  2  is located on the base layer  1 . The device layer  2  includes a first dielectric layer  22  and device structures  21 . The first dielectric layer  22  fills the device layer  2  and isolates the device structures  21 . In some embodiments, the device structures  21  include testing structures, which may be, in particular, alignment marks for alignment, test pads for testing the performance of the chip, and the like. 
     The stress propagating layer  3  is located on the device layer  2 . The stress propagating layer  3  includes a second dielectric layer  31  and a plurality of stress propagating patterns  32  arranged at intervals. The second dielectric layer  31  fills the stress propagating layer  3  and isolates the stress propagating patterns  32 . 
     Specifically, the plurality of stress propagating patterns  32  are disposed on a side, facing away from the base layer  1 , of the first dielectric layer  22 . The adjacent stress propagating patterns  32  are disposed at intervals. The second dielectric layer  31  fills the stress propagating layer  3 , isolates the stress propagating patterns  32 , and covers the first dielectric layer  22 . 
     Since the plurality of stress propagating patterns  32  are arranged in the second dielectric layer  31  at intervals, stress dispersion can be effectively avoided, thereby ensuring that sawing stress is intensively transferred from the first dielectric layer  22  to the second dielectric layer  31 , and further ensuring complete separation of the chips after sawing. Meanwhile, since the stress propagating patterns  32  are arranged at intervals, a lateral diffusion of the stress is avoided during sawing the chips, and a sawing area  6  can be prevented from extending to the chip areas  4 , thereby improving the sawing yield of the chips and ensuring the structural integrity of the chips. 
     In some embodiments, a hardness of the second dielectric layer  31  is higher than that of the first dielectric layer  22 . That is, the second dielectric layer  31  has higher brittleness. When the sawing stress is propagated to the second dielectric layer  31 , the second dielectric layer  31  can be completely sawed even if the stress decreases at this time, thereby improving the sawing yield. 
     In some embodiments, the material of the first dielectric layer  22  may be a low-K dielectric material, which is beneficial to reduce a coupling capacitance between device structures  21 . The low-K dielectric material may include doped silicon oxide, organic polymer or porous material, etc., Specifically, The low-K dielectric material may be fluorinated silicate glass (FSG), carbon doped glass, organo silicate glass (OSG), hydrogen doped glass, porous carbon doped glass, porous silicon dioxide. The second dielectric layer  31  is a general dielectric material or a high-K dielectric material, such as silicon oxide, silicon nitride and silicon oxynitride, that having a hardness higher than that of the low-K dielectric material, which can ensure that the second dielectric layer  31  is completely sawed when the stress is spread to the second dielectric layer  31 , and finally the chips are completely separated. 
     In some embodiments, referring to  FIG.  4   , a sawing direction is indicated by arrows shown therein. The semiconductor structure has the plurality of chip areas  4 . A sawing lane  5  is provided between two adjacent chip areas  4 . The device layer  2  and the stress propagating layer  3  are arranged at least in the sawing lane  5 , and the semiconductor structure is sawed along the sawing lines  5 . 
     In some embodiments, referring to  FIG.  4   , at least two columns of the stress propagation patterns  32  are provided in the sawing lane  5  along the sawing direction. The plurality of stress propagating patterns  32  in the two columns are arranged at intervals. That is, in one sawing lane  5 , two stress propagating patterns  32  are arranged horizontally at intervals along a direction perpendicular to the sawing direction, and thus the stress propagating patterns  32  is arranged in the sawing lane  5  in an array of 2×N (N is the number of the stress propagating patterns  32  along the sawing direction, and is a positive integer greater than or equal to 2). 
     In some embodiments, the semiconductor structure  8  may be sawed along the sawing lane  5  by a laser or a rotating blade to separate adjacent chip areas  4 . Referring to  FIG.  5   , during sawing the semiconductor structure  8 , a sawing is performed by laser or the rotating blade saws along a area between the two columns of stress propagation patterns  32 . Since the stress propagating patterns  32  are arranged at intervals, a lateral diffusion of the stress is avoided during sawing the semiconductor structure  8 , which then can prevent a sawing area  6  from extending to the chip area  4 , thereby improving the sawing yield of the chips and ensuring the structural integrity of the chips. 
     In some embodiments, the stress propagating patterns  32  may also be staggered. 
     For example, the stress propagation patterns  32  in one column are arranged in corresponding to gaps between every two adjacent one of the stress propagation patterns  32  in another column, so as to further improve a blocking degree to the stress. 
     In some embodiments, referring to  FIG.  6   , the stress propagation patterns  32  in one sawing lane  5  may also be provided in three, four, or more columns along the sawing direction. Specifically, within one sawing lane  5 , the plurality of stress propagating patterns  32  may be arranged in an array of 3×N, 4×N, or M×N, where N is the number of stress propagating patterns  32  along the sawing direction, and is a positive integer greater than or equal to 2. In the above array arrangement, three, four, or more columns of the stress propagating patterns  32  may be staggered from each other or partially staggered in one sawing lane  5 . All of the above arrangements fall within the scope of the disclosure protection. 
     In some embodiments, for different sawing lanes  5  of the same semiconductor structure  8 , the numbers of columns of the stress propagating patterns  32  may be different. Specifically, the stress propagating patterns may have different sizes, and thus when the size of the stress propagating patterns  32  is smaller, the number of the corresponding columns can be increased. In addition, the width of the sawing lane  5  is varied depending on the setting of the chip areas  4 . Therefore, the number of columns of the stress propagating patterns  32  that can be arranged may also be different. 
     In some embodiments, the stress propagating patterns  32  may be provided not only in the sawing lane  5 , but also in the chip areas  4 . Specifically, corresponding areas may be pre-set in the chip area  4 . For example, when the sawing lane  5  is set very narrow, blank areas may be arranged in the edge areas of the chip areas  4 . By forming the stress propagating patterns  32  in the blank areas, the stress generated during sawing can also be avoided from extending to the chip areas  4 , so as to protect the chip areas  4 . 
     In some embodiments, referring to  FIG.  3   , the device structures  21  may also include first device structures  211  and second device structures  212 . The first dielectric layer  22  includes a first sub-dielectric layer  221  and a second sub-dielectric layer  222 . 
     Specifically, the plurality of first device structures  211  are formed at intervals on the base layer  1 . The first sub-dielectric layer  221  fills the first device structures  211  and covers the base layer  1 . The plurality of second device structures  212  are formed at intervals on the first sub-dielectric layer  221 . The second sub-dielectric layer  222  fills the second device structures  212  and covers the first sub-dielectric layer  221 . 
     In some embodiments, third device structures and corresponding filling dielectric layer may also be arranged as required, which is not limited here. 
     In some embodiments, referring to  FIG.  7   , the device layer  2  may include only the first sub-dielectric layer  221  and the first device structures  211 , which is not limited here in total number thereof. 
     In some embodiments, with reference to  FIG.  4    to  FIG.  6   , the cross-section of the stress propagating patterns  32  in a direction parallel to the base layer  1  may be in one or more shapes of rectangle, circle, an ellipse, or a trapezoid. In addition, the stress propagating layer  3  of the semiconductor structure  8  may include a plurality of first stress propagating patterns and a plurality of second stress propagating patterns. In the direction parallel to the base layer  1 , the cross-section of the first stress propagating patterns is in the shape of circle, and the cross-section of the second stress propagating patterns is in the shape of ellipse. That is to say, the first stress propagating patterns may be different from the second stress propagating patterns. Of course, the stress propagating layer may further include third stress propagating patterns, and the cross-section of the third stress propagating patterns may be in the shape of trapezoid in the direction parallel to the base layer  1 . The cross-section of the stress propagating patterns  32  may be in other shapes and will not be repeated here. 
     In some embodiments, the stress propagating patterns  32  may be made of metallic aluminum. In addition, copper, tungsten and the like may also be used. The above materials may be compatible with the prior art. That is, the stress propagating patterns  32  can be formed simultaneously with the formation of a metal distribution layer. 
     Based on the same inventive concept, the exemplary embodiments of the disclosure also provide a method for manufacturing a semiconductor structure. Referring to  FIG.  8    schematically showing the flowchart of an exemplary embodiment of a method for manufacturing a semiconductor structure of the disclosure, the method for manufacturing a semiconductor structure includes the following steps. 
     In step S 10 , a base layer  1  is provided. 
     In step S 20 , a device layer  2  is formed on the base layer  1 . The device layer  2  includes a first dielectric layer  22  and device structures  21 . The first dielectric layer  22  fills the device layer  2  and isolates the device structures  21 . 
     In step S 30 , a stress propagating layer  3  is formed on the device layer  2 . The stress propagating layer  3  includes a second dielectric layer  31  and a plurality of stress propagating patterns  32  arranged at intervals. The second dielectric layer  31  fills the stress propagating layer  3  and isolates the stress propagating patterns  32 . 
     Each step of the method for manufacturing the semiconductor structure will be described in detail below. 
     In step S 10 , a base layer  1  is provided. 
     In some embodiments, the base layer  1  includes a substrate  11  and memory devices  12 . Those skilled in the art may select the memory devices  12  and the material of the substrate  11  as required, which have been mentioned in detail in the foregoing description for semiconductor structure, and are not limited herein. 
     In step S 20 , the device layer  2  is formed on the base layer  1 . The device layer  2  includes the first dielectric layer  22  and the device structure  21 . The first dielectric layer  22  fills the device layer  2  and isolates the device structures  21 . 
     In some embodiments, a first conductive material layer is formed on the base layer  1  by a process such as deposition or electroplating. A patterning process is performed on the first conductive material layer to form the first device structures  211  arranged at intervals. The first device structures  211  arranged at intervals expose the base layer  1 . 
     A first sub-dielectric layer  221  is deposited on the first device structures  211  and the base layer  1 . The first sub-dielectric layer  221  covers the first device structures  211  and the base layer  1 . The first sub-dielectric layer  221  is polished to flatten an upper surface of the first sub-dielectric layer  221 . 
     A second conductive material layer is formed on the first sub-dielectric layer  221  by a process such as deposition or electroplating. A patterning process is performed on the second conductive material layer to form second device structures  212  arranged at intervals. The second device structures  212  arranged at intervals expose the first sub-dielectric layer  221 . 
     A second sub-dielectric layer  222  is formed on the second device structures  212  and the first sub-dielectric layer  221  by deposition. The second sub-dielectric layer  222  covers the first sub-dielectric layer  221  and the second device structures  212 . The second sub-dielectric layer  222  is polished to flatten an upper surface of the second sub-dielectric layer  222 . 
     The first sub-dielectric layer  221  and the second sub-dielectric layer  222  together form the first dielectric layer  22 . The first device structures  211  and the second device structures  212  together constitute the device structures  21 . 
     Referring to  FIG.  7   , the device layer  2  may include only the first sub-dielectric layer  221  and the first device structures  211 , which is not limited here in total number thereof. 
     In step S 30 , the stress propagating layer  3  is formed on the device layer  2 . The stress propagating layer  3  includes a second dielectric layer  31  and the plurality of stress propagating patterns  32  arranged at intervals. The second dielectric layer  31  fills the stress propagating layer  3  and isolates the stress propagating patterns  32 . 
     In some embodiments, a stress propagating material layer is formed on the first dielectric layer  22  by deposition or electroplating. A patterning process is performed the stress propagating material layer to form the plurality of stress propagating patterns  32  arranged at intervals. The stress propagating patterns  32  arranged at intervals expose the first dielectric layer  22 . 
     A second dielectric layer  31  is formed on the plurality of stress propagating patterns  32  arranged at intervals and the first dielectric layer  22  by deposition. The second dielectric layer  31  covers the plurality of stress propagating patterns  32  arranged at intervals and the first dielectric layer  22 . 
     It is to be noted that, the deposition process involved in the above process may specifically include plasma vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating (Plating). The polishing process may include a chemical mechanical polishing process. The patterning process may be realized by photolithography, wet etching, dry etching, etc. A mask layer used in the patterning process may include spin coating hard mask, photoresist, etc. The above processes can be obtained in the existing technology, which will not be repeated here. 
     In some embodiments, the hardness of the first dielectric layer  22  is less than that of the second dielectric layer  31 . Specific materials of the first dielectric layer  22  and the second dielectric layer  31  have been described in detail above and are therefore not repeated here. 
     In some embodiments, the semiconductor structure  8  has the plurality of chip areas  4 . A sawing lane  5  is provided between two adjacent ones of the chip areas  4 . The device layer  2  and the stress propagating layer  3  are formed at least within the sawing lane  5 . The specific arrangement of the stress propagating patterns  32  has been described in detail above and will not be repeated here. 
     In some embodiments, the semiconductor structure  8  may be sawed along the sawing lane  5  to form a plurality of chips. Specially, the semiconductor structure  8  may be sawed along the sawing lane  5  by laser or a rotating blade to separate the chip areas  4 . Sawing by the rotating blade may include mechanical sawing, scribing and breaking. The chips after sawing are picked from a sawing tape by a chip picking device (such as a chip bonder or a chip sorter) to form individual chips. 
     In some embodiments, two columns of the stress propagation patterns  32  are arranged along the sawing direction in one sawing lane  5 . The sawing may be performed by laser or the rotating blade saws along an area between the two columns of stress propagating patterns  32 . 
     In addition, in a case that three columns of stress propagation patterns  32  are arranged in one sawing line  5  along the sawing direction, the sawing may be performed by laser or the rotary blade along the middle column of the stress propagating patterns  32 , or may be performed along any one of two gaps among the three columns of the stress propagating patterns  32 . 
     After the sawing process, the individual chips are packaged into packages for manufacturing electronic devices such as computers. The chip is integrated into a lead-frame package, which is directly disposed on the substrate of the base plate of personal computer, or packaged by solder bumping technology. 
     It is to be noted that, although each step of the method for manufacturing a semiconductor structure of the disclosure is described in a specific order in the drawings, it does not require or imply that these steps should be performed in the specific order, or that all of the shown steps must be performed in order to achieve the desired results. Additionally or alternatively, some steps may be omitted, a plurality of steps may be merged and performed in form of one step, and/or one step may be split and performed in form of the plurality of steps. 
     Those skilled in the art may readily think of other embodiments of the disclosure after considering the specification and practicing the disclosure disclosed herein. The application is intended to cover any variant, uses or adaptations of the disclosure that follow general principles of the disclosure and include common knowledge or common techniques in the art not disclosed in the disclosure. The specification and embodiments are only regarded as illustratively, and a true scope and spirit of the disclosure are indicated by the appended claims.