TVS device and preparation method thereof

Abstract

The invention discloses a TVS (Transient Voltage Suppressor) device and a preparation method thereof, and the TVS device comprises a substrate; a plurality of tube cores and a plurality of scribing channels, wherein the tube cores and the scribing channels are arranged on one side of the substrate at intervals; the scribing channel is provided with a first groove, the first groove extends into the substrate, and the side wall of the first groove is provided with an insulating isolation layer; the scribing channels insulate and isolate the adjacent tube cores; and the first electrode is positioned on one side, far away from the tube core and the scribing channel, of the substrate. According to the technical scheme, deep groove isolation columns do not need to be formed at the edges of the tube cores, isolation of the independent tube cores can be achieved through the scribing channel area, and the area of the active area of the TVS device can be effectively increased. And meanwhile, the manufacturing processes of isolating the independent tube core and forming the scribing groove to separate the independent tube core are integrated, so that the preparation process of the TVS device is simplified, and the cost can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a TVS device and its fabrication method. Background Technology

[0002] Figure 1 This is a schematic diagram of a TVS device provided by existing technology. For conventional transient voltage suppressor (TVS) devices, such as... Figure 1 As shown, deep trench isolation pillars 13 need to be formed within the first conductivity type active region 12, the second conductivity type epitaxial layer 11, and part of the first conductivity type substrate 10 to isolate independent die structures 16. The deep trench isolation pillars 13 and the dicing channel 15 are located in different regions; the dicing channel 15 is used to separate the independent die structures 16. Both the deep trench isolation pillars 13 and the dicing channel 15 occupy the area of ​​the first conductivity type active region 12 of the TVS device, resulting in a smaller area of ​​the first conductivity type active region 12. Furthermore, for conventional TVS devices, forming the deep trench isolation pillars 13 and forming the dicing trenches in the dicing channel 15 to separate the independent die structures 16 are independent process steps, which increases the complexity of TVS device fabrication and leads to higher fabrication costs. Summary of the Invention

[0003] This invention provides a TVS device and its fabrication method to solve the problems of small active area, complex fabrication process and high fabrication cost of conventional TVS devices.

[0004] In a first aspect, the present invention provides a TVS device, wherein the TVS device comprises:

[0005] Substrate;

[0006] Multiple dies and multiple dicing channels are spaced apart on one side of the substrate; each dicing channel has a first groove that extends into the substrate and has an insulating layer on its sidewall; the dicing channels insulate adjacent dies.

[0007] The first electrode is located on the side of the substrate away from the die and the scribe line.

[0008] Optional, the die includes:

[0009] Epitaxial layer, located on one side of the substrate;

[0010] The active region is located on the side of the epitaxial layer away from the substrate;

[0011] The second electrode and the first insulating layer are located on the side of the active region away from the substrate, and the first insulating layer is located on both sides of the second electrode in the thickness direction perpendicular to the substrate.

[0012] Optionally, the conductivity type of the substrate and the active region includes a first conductivity type, and the conductivity type of the epitaxial layer includes a second conductivity type;

[0013] Alternatively, the conductivity type of the substrate and the active region may include a second conductivity type, and the conductivity type of the epitaxial layer may include a first conductivity type.

[0014] Optionally, the insulating isolation layer includes a first insulating isolation layer and a second insulating isolation layer;

[0015] The first insulating layer is located on the sidewall of the first groove, and the second insulating layer is located on the side of the first insulating layer away from the substrate.

[0016] Optionally, the first insulating layer includes a silicon oxide insulating layer, and the second insulating layer includes a silicon nitride insulating layer.

[0017] Secondly, the present invention provides a method for fabricating a TVS device, wherein the method for fabricating a TVS device includes:

[0018] Provide substrate;

[0019] Multiple dies and multiple scribe lines are formed at intervals on one side of the substrate; each scribe line is provided with a first groove that extends into the substrate and has an insulating layer on its sidewall; the scribe lines insulate adjacent dies.

[0020] The first electrode is formed on the side of the substrate away from the die and scribe line.

[0021] Optionally, multiple dies and multiple dicing tracks are spaced apart on one side of the substrate, including:

[0022] An epitaxial layer is formed on one side of the substrate;

[0023] An active region is formed on the side of the epitaxial layer away from the substrate;

[0024] A first insulating layer is formed on the side of the active region away from the substrate;

[0025] The epitaxial layer, active region, first insulating layer and part of the substrate are etched to form the first groove;

[0026] An insulating layer is formed on the sidewall of the first groove;

[0027] The first insulating layer is etched to form the second groove;

[0028] A second electrode is formed within the second groove.

[0029] Optionally, an insulating layer is formed on the sidewall of the first groove, comprising:

[0030] An insulating layer is formed at the bottom and sidewalls of the first groove;

[0031] Remove the insulating layer at the bottom of the first groove.

[0032] Optionally, forming an insulating layer at the bottom and sidewalls of the first groove and removing the insulating layer at the bottom of the first groove includes:

[0033] A first insulating layer is formed at the bottom and sidewalls of the first groove;

[0034] A second insulating layer is formed on the side of the first insulating layer away from the substrate;

[0035] Remove the first and second insulating layers from the bottom of the first groove.

[0036] Optionally, etching the epitaxial layer, the active region, the first insulating layer, and a portion of the substrate to form the first groove includes:

[0037] A mask layer is formed on the side of the first insulating layer away from the substrate; the mask layer is provided with mask trenches;

[0038] The first insulating layer is etched to form the third groove, and the vertical projection of the third groove on the substrate coincides with the vertical projection of the mask trench on the substrate;

[0039] The active region, epitaxial layer and part of the substrate corresponding to the third groove are etched to form the first groove.

[0040] The technical solution of this invention forms a first groove in the dicing channel region and an insulating isolation layer on the sidewall of the first groove. The insulating isolation layer on the sidewall of the first groove can isolate individual dies. Since the first groove is provided in the dicing channel region, and no insulating isolation layer is provided at the bottom of the first groove, it is equivalent to forming a dicing groove in the dicing channel region to separate individual dies. Therefore, the technical solution of this invention eliminates the need to form deep groove isolation pillars at the die edge; the isolation of individual dies can be achieved using the dicing channel region, effectively increasing the active area of ​​the TVS device. Simultaneously, the fabrication processes for isolating individual dies and forming the dicing groove to separate individual dies are combined into one, simplifying the TVS device fabrication process and effectively reducing costs. The TVS device provided by this invention has a simpler structure and more reliable performance.

[0041] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of a TVS device provided by existing technology;

[0044] Figure 2 This is a schematic diagram of the structure of a TVS device provided in an embodiment of the present invention;

[0045] Figure 3 This is a flowchart of a method for fabricating a TVS device according to an embodiment of the present invention;

[0046] Figures 4-5 This is a structural diagram corresponding to each step in the fabrication method of a TVS device provided in an embodiment of the present invention;

[0047] Figure 6 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention;

[0048] Figures 7-12 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention;

[0049] Figure 13 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention;

[0050] Figure 14 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention;

[0051] Figure 15 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention;

[0052] Figure 16 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention;

[0053] Figure 17 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention;

[0054] Figures 18-19 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention;

[0055] Figures 20-24These are structural diagrams corresponding to each step in the conventional TVS device fabrication process. Detailed Implementation

[0056] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0058] Figure 2 This is a schematic diagram of the structure of a TVS device provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the TVS device includes: a substrate 1; a plurality of dies 2 and a plurality of scribe lines 3, the dies 2 and scribe lines 3 being spaced apart on one side of the substrate 1; each scribe line 3 having a first groove 31 extending into the substrate 1, the sidewall of the first groove 31 being provided with an insulating layer 32; the scribe lines 3 insulatingly isolating adjacent dies 2; and a first electrode 4 located on the side of the substrate 1 away from the dies 2 and scribe lines 3.

[0059] Specifically, the TVS device includes multiple dies 2 and multiple scribe lines 3, which are spaced apart in a direction perpendicular to the thickness of the substrate 1. A first groove 31 is provided in the region of the scribe line 3, and the first groove 31 extends into the interior of the substrate 1. An insulating layer 32 may be provided on the sidewall of the first groove 31, and no insulating layer 32 is provided on the bottom of the first groove 31. Figure 2 The insulating isolation layer 32 on the side wall of the first groove 31 is equivalent to Figure 1 The deep-groove isolation post 13 is used to isolate the individual die 2. There is no need to form one at the edge of the die 2. Figure 1The deep-groove isolation pillar 13 in the TVS device utilizes the area of ​​the dicing channel 3 to achieve isolation of the independent die 2, effectively increasing the active area of ​​the TVS device. For example, the active area of ​​the TVS device can be increased by 10%-15%. Furthermore, a first groove 31 is formed in the area of ​​the dicing channel 3, and no insulating isolation layer 32 is provided at the bottom of the first groove 31, which is equivalent to forming a dicing groove in the area of ​​the dicing channel 3 to separate the independent die 2. The processes for isolating the independent die 2 and forming the dicing groove to separate the independent die 2 are combined into one, simplifying the TVS device fabrication process and effectively reducing costs. For example, the cost can be effectively reduced by approximately 15%.

[0060] The technical solution of this invention involves forming a first groove in the dicing channel region and an insulating layer on the sidewall of the first groove. The insulating layer on the sidewall of the first groove can isolate individual dies. Since the first groove is provided in the dicing channel region, and no insulating layer is provided at the bottom of the first groove, it is equivalent to forming a dicing groove in the dicing channel region to separate individual dies. Therefore, the technical solution of this invention eliminates the need to form deep groove isolation pillars at the die edge; the isolation of individual dies can be achieved using the dicing channel region, effectively increasing the active area of ​​the TVS device. Simultaneously, the fabrication processes for isolating individual dies and forming the dicing groove to separate individual dies are combined into one, simplifying the TVS device fabrication process and effectively reducing costs. The TVS device provided by this invention has a simpler structure and more reliable performance.

[0061] Optionally, based on the above embodiments, continue to refer to... Figure 2 The die 2 includes: an epitaxial layer 21 located on one side of the substrate 1; an active region 22 located on the side of the epitaxial layer 21 away from the substrate 1; a second electrode 24 located on the side of the active region 22 away from the substrate 1; and a first insulating layer 23 located on both sides of the second electrode 24 in a direction perpendicular to the thickness of the substrate 1.

[0062] Specifically, substrate 1 may include a silicon substrate, a silicon carbide substrate, or a gallium nitride substrate, etc.; epitaxial layer 21 may include a silicon epitaxial layer, a silicon carbide epitaxial layer, or a gallium nitride epitaxial layer, etc.; and active region 22 may include a silicon active region, a silicon carbide active region, or a gallium nitride active region, etc. Substrate 1 and active region 22 have the same conductivity type, while the conductivity type of epitaxial layer 21 is different from that of substrate 1 and active region 22. For example, substrate 1 may be an N+ substrate, epitaxial layer 21 may be a P- epitaxial layer, and active region 22 may be an N-type active region. Alternatively, substrate 1 may be a P+ substrate, epitaxial layer 21 may be an N- epitaxial layer, and active region 22 may be a P-type active region. First insulating layer 23 may be a silicon dioxide insulating layer, and second electrode 24 may be a metal electrode, with second electrode 24 in contact with active region 22. Insulating layer 32 may extend from the sidewall of first groove 31 to the sidewall and surface of first insulating layer 23. Figure 2 The insulating layer 32 on the sidewall of the first groove 31 is used to isolate the individual die 2. It is not necessary to form an insulating layer 32 at the edge of the die 2. Figure 1 The deep trench isolation pillar 13 in the TVS device can achieve isolation of the independent die 2 by utilizing the area of ​​the dicing channel 3, thereby effectively increasing the area of ​​the active region 22 of the TVS device. For example, the active region area 22 of the TVS device can be increased by 10%-15%.

[0063] Optionally, based on the above embodiments, continue to refer to... Figure 2 The substrate 1 and the active region 22 have a first conductivity type, and the epitaxial layer 21 has a second conductivity type. Alternatively, the substrate 1 and the active region 22 have a second conductivity type, and the epitaxial layer 21 has a first conductivity type.

[0064] Specifically, substrate 1 can be an N+ substrate, epitaxial layer 21 can be a P- epitaxial layer, and active region 22 can be an N-type active region. Alternatively, substrate 1 can be a P+ substrate, epitaxial layer 21 can be an N- epitaxial layer, and active region 22 can be a P-type active region.

[0065] Optionally, based on the above embodiments, continue to refer to... Figure 2 The insulating isolation layer 32 includes a first insulating isolation layer 321 and a second insulating isolation layer 322. The first insulating isolation layer 321 is located on the sidewall of the first groove 31, and the second insulating isolation layer 322 is located on the side of the first insulating isolation layer 321 away from the substrate 1.

[0066] Specifically, the insulating isolation layer 32 provided on the sidewall of the first groove 31 can be two insulating isolation layers 32 made of different materials. The first insulating isolation layer 321 can be provided on the sidewall of the first insulating isolation layer 321, and then the second insulating isolation layer 322 is provided on the side of the first insulating isolation layer 321 away from the substrate 1. The materials and thicknesses of the first insulating isolation layer 321 and the second insulating isolation layer 322 can be set according to the actual situation. This arrangement can better isolate the independent die 2, resulting in a better isolation effect for the independent die 2.

[0067] Optionally, based on the above embodiments, continue to refer to... Figure 2 The first insulating layer 321 includes a silicon oxide insulating layer, and the second insulating layer 322 includes a silicon nitride insulating layer.

[0068] Specifically, the first insulating layer 321 can be a silicon oxide insulating layer, and the second insulating layer 322 can be a silicon nitride insulating layer. This configuration can better isolate the individual die 2, resulting in a better isolation effect for the individual die 2.

[0069] Figure 3 This is a flowchart of a method for fabricating a TVS device according to an embodiment of the present invention. Figures 4-5 This is a structural diagram corresponding to each step in the fabrication method of a TVS device provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the fabrication method of TVS devices includes:

[0070] S100: Provides a substrate.

[0071] Specifically, such as Figure 4 As shown, a substrate 1 is first provided. The semiconductor material of the substrate 1 may include silicon, silicon carbide, or gallium nitride, etc. The substrate 1 can be an N+ substrate, or it can also be a P+ substrate.

[0072] S110: Multiple dies and multiple dicing channels are formed at intervals on one side of the substrate; the dicing channels are provided with a first groove, the first groove extends into the substrate, and the sidewall of the first groove is provided with an insulating isolation layer; the dicing channels are used to insulate and isolate adjacent dies.

[0073] Specifically, such as Figure 5 As shown, multiple dies 2 and multiple dicing channels 3 are disposed on one side of the substrate 1, with the dies 2 and dicing channels 3 spaced apart. The dicing channel 3 is provided with a first groove 31, and the sidewall of the first groove 31 is provided with an insulating layer 32.

[0074] S120: The first electrode is formed on the side of the substrate away from the die and dicing track.

[0075] Specifically, such as Figure 1As shown, a first electrode 4 is formed on the side of the substrate 1 away from the die 2 and the dicing channel 3 by processes such as deposition. The first electrode 4 can be a metal electrode.

[0076] The technical solution of this invention involves forming a first groove in the dicing channel region and an insulating layer on the sidewall of the first groove. The insulating layer on the sidewall of the first groove can isolate individual dies. Since the first groove is provided in the dicing channel region, and no insulating layer is provided at the bottom of the first groove, it is equivalent to forming a dicing groove in the dicing channel region to separate individual dies. Therefore, the technical solution of this invention eliminates the need to form deep groove isolation pillars at the die edge; the isolation of individual dies can be achieved using the dicing channel region, effectively increasing the active area of ​​the TVS device. Simultaneously, the fabrication processes for isolating individual dies and forming the dicing groove to separate individual dies are combined into one, simplifying the TVS device fabrication process and effectively reducing costs. The TVS device provided by this invention has a simpler structure and more reliable performance.

[0077] Optionally, based on the above embodiments, Figure 6 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention. Figures 7-12 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention, such as... Figure 6 As shown, the fabrication method of TVS devices includes:

[0078] S200: Provides a substrate.

[0079] S210: An epitaxial layer is formed on one side of the substrate.

[0080] Specifically, such as Figure 7 As shown, an epitaxial layer 21 is formed on one side of substrate 1 using epitaxial processes such as chemical vapor deposition (CVE), molecular beam epitaxy (MBD), or atomic layer epitaxy (ALE). The semiconductor material of the epitaxial layer 21 may include silicon, silicon carbide, or gallium nitride. The conductivity type of the epitaxial layer 21 is reversed; for example, substrate 1 can be an N+ substrate, and epitaxial layer 21 can be a P- epitaxial layer. Alternatively, substrate 1 can be a P+ substrate, and epitaxial layer 21 can be an N- epitaxial layer.

[0081] S220: An active region is formed on the side of the epitaxial layer away from the substrate.

[0082] Specifically, such as Figure 8As shown, an active region 22 is formed on the side of the epitaxial layer 21 away from the substrate 1. The active region 22 can be formed by doping processes such as ion implantation on the side of the epitaxial layer 21 away from the substrate 1. The semiconductor material of the active region 22 can be the same as the semiconductor material of the epitaxial layer 21. The conductivity type of the active region 22 can be the same as the conductivity type of the substrate 1. For example, the substrate 1 can be an N+ substrate, the epitaxial layer 21 can be a P- epitaxial layer, and the active region 22 can be an N-type active region. Alternatively, the substrate 1 can be a P+ substrate, the epitaxial layer 21 can be an N- epitaxial layer, and the active region 22 can be a P-type active region.

[0083] S230: A first insulating layer is formed on the side of the active region away from the substrate.

[0084] Specifically, such as Figure 9 As shown, a first insulating layer 23 is formed on the side of the active region 22 away from the substrate 1. For example, the first insulating layer 23 can be a silicon dioxide insulating layer, and silicon dioxide is deposited on the side of the active region 22 away from the substrate 1 to form the first insulating layer 23.

[0085] S240: Etching the epitaxial layer, active region, first insulating layer and part of the substrate to form the first groove.

[0086] Specifically, such as Figure 10 As shown, a third groove 25 can be formed on the first insulating layer 23 first by photolithography and laser etching, and then the active region 22, epitaxial layer 21 and part of substrate 1 can be etched by wet etching to form the first groove 31. The first groove 31 is located in the region of the scribe line 3.

[0087] S250: An insulating layer is formed on the sidewall of the first groove.

[0088] Specifically, such as Figure 11 As shown, an insulating layer 32 is formed on the sidewall of the first groove 31. The insulating layer 32 can also extend to the sidewall of the third groove 25 and the side of the first insulating layer 23 away from the substrate 1. Exemplarily, the insulating layer 32 can be formed on the sidewall of the first groove 31 by a process such as deposition.

[0089] S260: Etch the first insulating layer to form the second groove.

[0090] Specifically, such as Figure 12 As shown, the etched insulating layer 32 and the first insulating layer 23 form the second groove 26.

[0091] S270: A second electrode is formed in the second groove.

[0092] Specifically, such as Figure 5 As shown, a second electrode 24 is formed in the second groove by processes such as deposition. The second electrode can be a metal electrode.

[0093] S280: The first electrode is formed on the side of the substrate away from the die and dicing track.

[0094] Optionally, based on the above embodiments, Figure 13 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention. Figure 14 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention, such as... Figure 13 As shown, the fabrication method of TVS devices includes:

[0095] S300: Provides a substrate.

[0096] S310: An epitaxial layer is formed on one side of the substrate.

[0097] S320: An active region is formed on the side of the epitaxial layer away from the substrate.

[0098] S330: A first insulating layer is formed on the side of the active region away from the substrate.

[0099] S340: Etching the epitaxial layer, active region, first insulating layer and part of the substrate to form the first groove.

[0100] S350: An insulating layer is formed at the bottom and sidewalls of the first groove.

[0101] Specifically, such as Figure 14 As shown, an insulating layer 32 can now be formed on the bottom and sidewalls of the first groove 31 through processes such as deposition.

[0102] S360: Remove the insulating layer at the bottom of the first groove.

[0103] Specifically, such as Figure 11 As shown, the insulating isolation layer 32 at the bottom of the first groove 31 is removed by processes such as photolithography and etching. This is equivalent to forming a dicing groove in the area of ​​the dicing channel 3 to separate the independent die 2.

[0104] S370: Etch the first insulating layer to form the second groove.

[0105] S380: A second electrode is formed in the second groove.

[0106] S390: The first electrode is formed on the side of the substrate away from the die and dicing track.

[0107] Optionally, based on the above embodiments, Figure 15 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention. Figure 16 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention, such as... Figure 15 As shown, the fabrication method of TVS devices includes:

[0108] S400: Provides a substrate.

[0109] S410: An epitaxial layer is formed on one side of the substrate.

[0110] S420: An active region is formed on the side of the epitaxial layer away from the substrate.

[0111] S430: A first insulating layer is formed on the side of the active region away from the substrate.

[0112] S440: Etching the epitaxial layer, active region, first insulating layer and part of the substrate to form the first groove.

[0113] S450: A first insulating layer is formed at the bottom and sidewalls of the first groove.

[0114] Specifically, such as Figure 16 As shown, a first insulating layer 321 is formed at the bottom and sidewalls of the first groove 31. The first insulating layer 321 can extend to the sidewalls of the third groove 25 and the side of the first insulating layer 23 away from the substrate 1. For example, the first insulating layer 321 may include a silicon oxide insulating layer, which can be formed at the bottom and sidewalls of the first groove 31 by processes such as deposition.

[0115] S460: A second insulating layer is formed on the side of the first insulating layer away from the substrate.

[0116] Specifically, such as Figure 14 As shown, a second insulating layer 322 is formed on the side of the first insulating layer 321 away from the substrate 1. The second insulating layer 322 can extend to the sidewall of the third groove 25 and the side of the first insulating layer 23 away from the substrate 1. Exemplarily, the second insulating layer 322 may include a silicon nitride insulating layer, and the second insulating layer 322 can be formed on the side of the first insulating layer 321 away from the substrate 1 by processes such as deposition.

[0117] S470: Remove the first and second insulating layers from the bottom of the first groove.

[0118] Specifically, such as Figure 11 As shown, the first insulating isolation layer 321 and the second insulating isolation layer 322 at the bottom of the first groove 31 are removed by processes such as photolithography and etching. This is equivalent to forming a dicing groove in the area of ​​the dicing track 3 to separate the independent die 2.

[0119] S480: Etch the first insulating layer to form the second groove.

[0120] S490: A second electrode is formed in the second groove.

[0121] S491: A first electrode is formed on the side of the substrate away from the die and dicing track.

[0122] Optionally, based on the above embodiments, Figure 17 This is a flowchart of another method for fabricating a TVS device provided in an embodiment of the present invention. Figures 18-19 This is a structural diagram corresponding to some steps in another method for fabricating a TVS device provided in this embodiment of the invention, such as... Figure 17 As shown, the fabrication method of TVS devices includes:

[0123] S500: Provides a substrate.

[0124] S510: An epitaxial layer is formed on one side of the substrate.

[0125] S520: An active region is formed on the side of the epitaxial layer away from the substrate.

[0126] S530: A first insulating layer is formed on the side of the active region away from the substrate.

[0127] S540: A mask layer is formed on the side of the first insulating layer away from the substrate; the mask layer is provided with mask trenches.

[0128] Specifically, such as Figure 18 As shown, a mask layer 27 is formed on the side of the first insulating layer 23 away from the substrate 1. The mask layer 27 can be a photoresist. Mask trenches 28 are formed on the mask layer 27 by means of masking, exposure, and development.

[0129] S550: The first insulating layer is etched to form the third groove, and the vertical projection of the third groove on the substrate coincides with the vertical projection of the mask trench on the substrate.

[0130] Specifically, such as Figure 19 As shown, a third groove 25 is formed on the first insulating layer 23 by photolithography and laser etching processes. The vertical projection of the third groove 25 on the substrate 1 coincides with the vertical projection of the mask trench 28 on the substrate 1.

[0131] S560: The active region, epitaxial layer and part of the substrate corresponding to the third groove are etched to form the first groove.

[0132] Specifically, such as Figure 10 As shown, the active region 22, epitaxial layer 21, and part of the substrate 1 are further etched using processes such as wet etching to form a first groove 31. The first groove 31 is located in the region of the scribe line 3.

[0133] S570: An insulating layer is formed on the sidewall of the first groove.

[0134] S580: Etch the first insulating layer to form the second groove.

[0135] S590: A second electrode is formed in the second groove.

[0136] S591: A first electrode is formed on the side of the substrate away from the die and dicing track.

[0137] For conventional TVS devices, Figures 20-24 These are structural diagrams corresponding to each step in the conventional TVS device fabrication process, such as... Figure 20 As shown, a second conductivity type epitaxial layer 11, a first conductivity type active region 12, an insulating layer 19, and a photoresist 18 are sequentially formed on one side of a first conductivity type substrate 10. Trenches are formed on the insulating layer 19 and the photoresist 18 through photolithography and etching processes. Figure 21 As shown, after removing the photoresist 18, the first conductivity type active region 12, the second conductivity type epitaxial layer 11, and part of the first conductivity type substrate 10 corresponding to the trench on the insulating layer 19 are etched to form a deep trench. The deep trench and the scribe line 15 are in different regions. Figure 22 As shown, remove insulation layer 19. Figure 23 As shown, a deep trench isolation pillar 13 is formed on the side of the deep trench and the first conductivity type active region 12 away from the first conductivity type substrate 10. The deep trench isolation pillar 13 and the scribe line 15 are in different regions. Figure 24 As shown, deep trench isolation pillars 13 are etched on the side of the first conductivity type active region 12 away from the first conductivity type substrate 10 to form trenches. Figure 1 As shown, a front electrode 14 is formed in the trench of the deep trench isolation pillar 13, and a back electrode 17 is formed on the side of the first conductivity type substrate 10 away from the second conductivity type epitaxial layer 11. Finally, photolithography and etching processes are used to form a scribe-groove separated die structure 16 in the region of the scribe line 15. As can be seen from the above steps, for existing conventional TVS devices, forming the deep trench isolation pillar 13 and forming the scribe-groove separated die structure 16 in the scribe line 15 are independent process steps, which increases the complexity of TVS device fabrication and leads to higher fabrication costs. In the technical solution of this embodiment, a first groove 31 is provided in the scribe line 3 region, and the first groove 31 extends into the substrate 1. An insulating isolation layer 32 is provided on the sidewall of the first groove 31, and no insulating isolation layer 32 is provided at the bottom of the first groove 31. Figure 2 The insulating isolation layer 32 on the side wall of the first groove 31 is equivalent to Figure 1 The deep-groove isolation post 13 is used to isolate the individual die 2. There is no need to form one at the edge of the die 2. Figure 1The deep-groove isolation pillar 13 in the TVS device utilizes the area of ​​the dicing channel 3 to achieve isolation of the independent die 2, effectively increasing the active area of ​​the TVS device. For example, the active area of ​​the TVS device can be increased by 10%-15%. Furthermore, a first groove 31 is formed in the area of ​​the dicing channel 3, and no insulating isolation layer 32 is provided at the bottom of the first groove 31, which is equivalent to forming a dicing groove in the area of ​​the dicing channel 3 to separate the independent die 2. The processes for isolating the independent die 2 and forming the dicing groove to separate the independent die 2 are combined into one, simplifying the TVS device fabrication process and effectively reducing costs. For example, the cost can be effectively reduced by approximately 15%.

[0138] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0139] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A TVS device, characterized in that, include: Substrate; Multiple dies and multiple dicing channels are spaced apart on one side of the substrate; The dicing channel is provided with a first groove that extends into the substrate, and the sidewall of the first groove is provided with an insulating layer; the dicing channel insulates and isolates adjacent dies. The first electrode is located on the side of the substrate away from the die and the dicing channel.

2. The TVS device according to claim 1, characterized in that, The die includes: An epitaxial layer, the epitaxial layer being located on one side of the substrate; An active region, wherein the active region is located on the side of the epitaxial layer away from the substrate; A second electrode and a first insulating layer, wherein the second electrode is located on the side of the active region away from the substrate, and the first insulating layer is located on both sides of the second electrode in a thickness direction perpendicular to the substrate.

3. The TVS device according to claim 2, characterized in that, The substrate and the active region have a first conductivity type, and the epitaxial layer has a second conductivity type. Alternatively, the substrate and the active region may have a second conductivity type, and the epitaxial layer may have a first conductivity type.

4. The TVS device according to claim 1, characterized in that, The insulating isolation layer includes a first insulating isolation layer and a second insulating isolation layer; The first insulating layer is located on the sidewall of the first groove, and the second insulating layer is located on the side of the first insulating layer away from the substrate.

5. The TVS device according to claim 4, characterized in that, The first insulating layer includes a silicon oxide insulating layer, and the second insulating layer includes a silicon nitride insulating layer.

6. A method for fabricating a TVS device, characterized in that, include: Provide substrate; Multiple dies and multiple dicing channels are formed at intervals on one side of the substrate; The dicing channel is provided with a first groove that extends into the substrate, and the sidewall of the first groove is provided with an insulating layer; the dicing channel insulates and isolates adjacent dies. A first electrode is formed on the side of the substrate away from the die and the dicing channel.

7. The method for fabricating a TVS device according to claim 6, characterized in that, Multiple dies and multiple dicing channels are spaced apart on one side of the substrate, including: An epitaxial layer is formed on one side of the substrate; An active region is formed on the side of the epitaxial layer away from the substrate; A first insulating layer is formed on the side of the active region away from the substrate; The first groove is formed by etching the epitaxial layer, the active region, the first insulating layer, and a portion of the substrate. An insulating layer is formed on the sidewall of the first groove; The first insulating layer is etched to form the second groove; A second electrode is formed within the second groove.

8. The method for fabricating a TVS device according to claim 7, characterized in that, An insulating layer is formed on the sidewall of the first groove, comprising: An insulating layer is formed at the bottom and sidewalls of the first groove; Remove the insulating layer from the bottom of the first groove.

9. The method for fabricating a TVS device according to claim 8, characterized in that, Forming an insulating layer at the bottom and sidewalls of the first groove and removing the insulating layer at the bottom of the first groove includes: A first insulating layer is formed at the bottom and sidewalls of the first groove; A second insulating layer is formed on the side of the first insulating layer away from the substrate; Remove the first insulating layer and the second insulating layer from the bottom of the first groove.

10. The method for fabricating a TVS device according to claim 7, characterized in that, Etching the epitaxial layer, the active region, the first insulating layer, and a portion of the substrate to form the first groove includes: A mask layer is formed on the side of the first insulating layer away from the substrate; the mask layer is provided with mask trenches; The first insulating layer is etched to form a third groove, and the vertical projection of the third groove on the substrate coincides with the vertical projection of the mask trench on the substrate; The first groove is formed by etching the active region, the epitaxial layer, and a portion of the substrate corresponding to the third groove.

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