Vertical semiconductor wireless radio frequency identification structure, wireless radio frequency identification tag device and manufacturing method thereof

Abstract

The invention discloses a vertical semiconductor radio frequency identification (RFID) structure, which is characterized in that the vertical semiconductor radio frequency identification (RFID) structure is provided; the vertical semiconductor radio frequency identification structure comprises a semiconductor radio frequency identification structure, a tag integrated circuit (IC) layer, a first conductive layer and a second conductive layer. The tag tag integrated circuit layer is formed on a front side of the semiconductor substrate. The first conductive layer is formed over a back side of the semiconductor substrate opposite the front side, and the second conductive layer is formed over a side of the tag tag integrated circuit layer remote from the semiconductor substrate such that the tag tag integrated circuit layer and the semiconductor substrate are sandwiched between the first conductive layer and the second conductive layer. The second conductive layer is electrically coupled to the tag tag integrated circuit layer.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor structure, and more particularly to a vertical semiconductor radio-frequency identification (RFID) structure having conductive layers at both ends. Background Art

[0002] Radio Frequency Identification (RFID) is a wireless communication technology that allows a reader to automatically identify and track tags that can be attached to objects using electromagnetic fields. Generally, an RFID system includes an RFID reader and an RFID tag. RFID tags can be passive and can be triggered by electromagnetic interrogation pulses generated by a nearby RFID reader. When the RFID tag is triggered, the RFID tag can transmit data back to the RFID reader so that the RFID reader can use the read data to complete identification or tracking.

[0003] RFID tags usually consist of two parts: an antenna and a tag integrated circuit (IC). The antenna is usually formed by a coil, which can be used to transmit and receive electromagnetic signals. The tag IC may contain logic circuits (such as a controller) for performing operations, a memory for storing data, and analog circuits for detecting and decoding signals received from the antenna. Passive RFID tags can use the RF signal sent by the RFID reader and received by its antenna as a power supply. Because passive RFID tags can be attached to a variety of products, operate without power, and allow remote identification and tracking, they have been widely used in many applications, especially in inventory management. Summary of the invention

[0004] One aspect of the present disclosure provides a vertical semiconductor radio frequency identification (RFID) structure. The vertical semiconductor RFID structure includes a semiconductor substrate, a tag IC layer, a first conductive layer, and a second conductive layer. The tag IC layer is formed on a front side of the semiconductor substrate. The first conductive layer is formed above a rear side of the semiconductor substrate opposite to the front side. The second conductive layer is formed above a side of the tag IC layer away from the semiconductor substrate, so that the tag IC layer and the semiconductor substrate are sandwiched between the first conductive layer and the second conductive layer. The second conductive layer is electrically coupled to the tag IC layer.

[0005] Another aspect of the present disclosure provides an RFID tag device. The RDIF tag device includes an antenna substrate, an antenna, and the aforementioned vertical semiconductor RFID structure coupled to the antenna. The antenna is disposed on the antenna substrate and includes a first terminal and a second terminal. The second conductive layer, the tag IC layer, the semiconductor substrate, and the first conductive layer of the vertical semiconductor RFID structure are stacked in sequence along a first direction, and the first direction is parallel to a top surface of the antenna. From a top view, the first conductive layer overlaps with the first terminal and does not overlap with the second terminal, and the second conductive layer overlaps with the second terminal and does not overlap with the first terminal. The first conductive layer is electrically coupled to the first terminal, and the second conductive layer is electrically coupled to the second terminal.

[0006] Another aspect of the present disclosure provides a method for manufacturing an RFID tag device. The method includes receiving a semiconductor substrate having a tag IC layer, the tag IC layer being formed on a front side of the semiconductor substrate; forming a first conductive layer entirely on a rear side of the semiconductor substrate opposite to the front side; and forming a second conductive layer entirely above a side of the tag IC layer away from the semiconductor substrate, so that the tag IC layer and the semiconductor substrate are sandwiched between the first conductive layer and the second conductive layer. The second conductive layer, the tag IC layer, the semiconductor substrate, and the first conductive layer are stacked in sequence along a first direction, and the second conductive layer is electrically coupled to the tag IC layer. The method further includes cutting along the first direction to form a vertical semiconductor RFID structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more complete understanding of the present invention may be obtained by referring to the detailed description and claims when considered in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements throughout the drawings.

[0008] Figure 1 An RFID system according to an embodiment of the present disclosure is shown;

[0009] Figure 2 A structure of an RFID tag according to a comparative embodiment of the present disclosure is shown;

[0010] Figure 3 A cost analysis of the assembly process of an RFID tag device is shown;

[0011] Figure 4 A semiconductor RFID structure according to an embodiment of the present disclosure is shown;

[0012] Figure 5 An RFID tag device according to an embodiment of the present disclosure is shown;

[0013] Figure 6 Shows Figure 5A side view of an RFID tag device according to an embodiment of the present disclosure;

[0014] Figure 7 An RFID tag device according to another embodiment of the present disclosure is shown;

[0015] Figure 8 An RFID tag device according to another embodiment of the present disclosure is shown;

[0016] Fig. 9 An RFID tag device according to another embodiment of the present disclosure is shown;

[0017] Fig.10 An RFID tag device according to another embodiment of the present disclosure is shown;

[0018] Fig.11 An RFID tag device according to another embodiment of the present disclosure is shown;

[0019] Fig.12 A flow chart of a method for manufacturing an RFID tag device according to an embodiment of the present disclosure is shown;

[0020] FIG. 13A to FIG. 13E Shown for manufacturing Figure 5 A cross-sectional or side view of one or more stages of an RFID tag device;

[0021] FIG. 14A to FIG. 14B A cross-sectional or side view illustrating stages for attaching a semiconductor RFID structure to an antenna according to one embodiment of the present disclosure. Implementation

[0022] The following description is accompanied by the accompanying drawings, which are incorporated in this specification and constitute a part of this specification, and these drawings illustrate embodiments of the present invention, but the present invention is not limited to these embodiments. In addition, the following embodiments can be appropriately integrated to complete another embodiment.

[0023] References to "one embodiment," "an embodiment," "exemplary embodiments," "other embodiments," "another embodiment," etc. indicate that the embodiments of the invention described herein may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Furthermore, repeated use of the phrase "in an embodiment" does not necessarily refer to the same embodiment, although it may.

[0024] In order to make the present invention fully understood, detailed steps and structures are given in the following description. Obviously, the implementation of the present invention is not limited to the specific details known to those with common knowledge in the field. In addition, the known structures and steps are no longer described in detail to avoid unnecessary limitations on the present invention. The preferred embodiments of the present invention will be described in detail below. However, in addition to the embodiments, the present invention can also be widely implemented in other embodiments. The scope of the present invention is not limited to the embodiments, but is defined by the scope of the patent application.

[0025] Radio Frequency Identification (RFID) systems typically include an RFID reader (also called an RFID reader / writer or RFID interrogator) and an RFID tag. RFID systems can be used in a variety of ways to locate and identify objects to which the tags are attached. RFID systems are often used in product-related and service-related industries to track objects that are being processed, counted, or manipulated. In this case, RFID tags are usually attached to a single item or its packaging.

[0026] Figure 1 An RFID system according to one embodiment of the present disclosure is shown. The RFID system includes an RFID reader 9 and one or more RFID tags 8. In principle, RFID technology requires the use of an RFID reader 9 to interrogate one or more RFID tags 8. The reader 9 can perform the interrogation by sending RF waves 92. The RF waves 92 are usually electromagnetic waves, at least in far-field applications. The RF waves 92 can also be mainly radio waves or magnetic waves in near-field applications. The RF waves 92 can encode one or more instructions for instructing the tag 8 to perform one or more actions.

[0027] A tag 8 sensing the interrogating RF wave 92 may respond by transmitting another RF wave 82. The tag 8 may generate the return RF wave 82 itself, or by reflecting a portion of the interrogating RF wave 92 in a process known as backscattering. Backscattering may be generated in a variety of ways.

[0028] The reflected RF waves 82 may encode data stored in the tag, such as a number. The response is demodulated and decoded by the reader 9 to identify, count, or otherwise interact with the associated item. The decoded data can represent a serial number, price, date, destination, other attributes, any combination of attributes, and the like. Thus, when the reader 9 receives the tag data, it can learn about the item bearing the tag 8 and / or information about the tag 8 itself.

[0029] RFID tags 8 typically include an antenna portion, a wireless portion, a power management portion, and often a logic portion, a memory, or both. In some RFID tags, the power management portion includes an energy storage device, such as a battery. RFID tags with energy storage devices are called battery-assisted, semi-active, or active tags. Other RFID tags are capable of being powered only by the RF signals they receive. Such RFID tags do not include energy storage devices and are called passive tags. Of course, even passive tags typically include temporary energy and data / flag storage elements, such as capacitors or inductors.

[0030] Figure 2 FIG. 2 shows a structure of an RFID tag 8 according to a comparative embodiment of the present disclosure. The RFID tag 8 includes an RFID tag integrated circuit (IC) 800 and an antenna 80. Figure 2 As shown, the RFID tag IC 800 is turned over and attached to the antenna 80 .

[0031] The RFID tag IC 800 includes a semiconductor layer 810, a tag IC layer 820, and conductive bumps 830 and 840. The semiconductor layer 810 may include a semiconductor substrate, such as a silicon substrate. The tag IC layer 820 may include circuits formed therein for implementing the RFID tag function, such as logic circuits (e.g., controllers), memories, and analog circuits. The conductive bumps 830 and 840 are formed on the tag IC layer 820 and coupled to the circuits formed in the tag IC layer 820 as external ports of the RFID tag IC 800. In some cases, the conductive bumps 830 and 840 can be formed by electroplating, and the conductive bumps 830 and 840 may include copper, nickel, silver, gold, or a combination thereof.

[0032] The antenna 80 may be formed of a coil having a specific pattern (not shown) to transmit and receive RF signals. The RFID tag IC 800 is coupled to the antenna 80 through the conductive bumps 830 and 840 for receiving and transmitting RF signals through the antenna 80. For example, the antenna 80 may be a dipole antenna and may include an RF terminal 80A (or as a positive signal terminal) and a ground terminal 80B (or as a negative signal terminal), and the conductive bump 830 may be coupled to the RF terminal 80A, while the conductive bump 840 may be coupled to the ground terminal 80B to receive RF signals through the RF terminal 80A and the ground terminal 80B. In addition, an anisotropic conductive adhesive AD8 may be applied between the RFID tag IC 800 and the antenna 80 to adhere the RFID tag IC 800 to the antenna 80 and provide electrical connections between the conductive bump 830 and the RF terminal 80A and between the conductive bump 840 and the ground terminal 80B.

[0033] like Figure 2 As shown, since the RFID tag IC 800 is usually provided with conductive bumps 830 and 840 facing upward, during the assembly process of the RFID tag 8, the RFID tag IC 800 needs to be turned upside down so that the RFID tag IC 800 can be attached to the antenna 80 through the conductive bumps 830 and 840. In order to facilitate the execution of such bare die pick-up and flip chip processes, the wafer area of ​​the RFID tag IC 800 is usually not too small. Otherwise, the robot arm may not be able to correctly pick up and flip the RFID tag IC 800. In addition, another obstacle that makes it difficult to reduce the wafer area of ​​the RFID tag IC 800 is that the area of ​​the tag IC layer 820 must be large enough to accommodate the conductive bumps 830 and 840 thereon. With current technology, the wafer area of ​​the RFID tag IC 800 may not be less than 300μm×300μm. Therefore, the number of tag ICs that can be produced per wafer is quite limited.

[0034] Additionally, the flip chip process can be costly. Figure 3 The cost analysis of the assembly process of an RFID tag device is shown. Figure 3 It can be seen that the cost of flip chip assembly accounts for more than 90% of the total cost. The remaining cost mainly comes from the thinning process of thinning the thickness of the RFID tag IC 800, the cutting process and the testing process.

[0035] Figure 4 A semiconductor RFID structure 100 according to an embodiment of the present disclosure is shown. The semiconductor RFID structure 100 can be, for example, an RFID tag IC, which can be coupled to an antenna to form an RFID tag. The semiconductor RFID structure 100 allows the assembly process of the RFID tag to not use a flip chip process, thereby reducing manufacturing costs and breaking through the minimum area limit required for the flip chip process. In this way, more advanced processes (e.g., less than or equal to 45nm technology) can be used to produce more tag ICs on each wafer, thereby further reducing the manufacturing cost of the tag IC.

[0036] like Figure 4As shown, the semiconductor RFID structure 100 includes a semiconductor substrate 110, a tag IC layer 120, a conductive layer 130, and a conductive layer 140. The tag IC layer 120 is formed on the front side 110A of the semiconductor substrate 110, and the conductive layer 130 is formed on the back side 110B of the semiconductor substrate 110, and the back side 110B of the semiconductor substrate 110 is opposite to the front side 110A of the semiconductor substrate 110. In addition, the conductive layer 140 may be formed on the side 120A of the tag IC layer 120 away from the semiconductor substrate 110. Therefore, the tag IC layer 120 and the semiconductor substrate 110 are sandwiched between the conductive layer 130 and the conductive layer 140.

[0037] In this embodiment, the semiconductor RFID structure 100 may have a rod shape. For example, the length L1 (i.e., the thickness of the semiconductor RFID structure 100 measured along the direction D1) may be longer than the edge of the cross section of the semiconductor RFID structure 100 cut along the direction D2 (perpendicular to the direction D1). Therefore, the semiconductor RFID structure 100 is also referred to as a vertical semiconductor RFID structure 100.

[0038] In some embodiments, adjacent side surfaces A1 , A2 , A3 , and A4 of the second conductive layer 140 , the tag IC layer 120 , the semiconductor substrate 110 , and the first conductive layer 130 are parallel to the direction D1 and are aligned.

[0039] In some embodiments, the semiconductor substrate 110 can include a suitable semiconductor material, such as silicon, germanium, gallium, glass, or a combination thereof. In some embodiments, the tag IC layer 120 can include devices (not shown) formed in an active region at the front side 110A of the semiconductor substrate 110, such as transistors and capacitors, and an interconnect structure (not shown) for providing routing connections between the devices, so that the required circuits of the semiconductor RFID structure 100 can be formed in the tag IC layer 120. In this embodiment, the semiconductor RFID structure 100 can be an RFID tag IC, and the tag IC layer 120 can include at least one of a logic circuit (e.g., a controller), a memory, and an analog circuit. When an RFID reader sends a request to the RFID tag, the analog circuit can detect and decode the signal received by the antenna coupled to the tag IC, and the controller can perform corresponding operations to retrieve data stored in the memory, such as an identification code, and send the data back to the RFID reader through the analog circuit and the antenna.

[0040] In some embodiments, the conductive layer 130 and the conductive layer 140 may be coupled to the tag IC layer 120 as input / output ports of the analog circuit of the semiconductor RFID structure 100. In some embodiments, the conductive layer 140 may be coupled to the tag IC layer 120 through a through silicon via (TSV) (not shown) formed in the semiconductor substrate 110.

[0041] In some embodiments, in order to form the desired connection between the devices in the tag IC layer 120, the interconnect structure may include metal lines extending laterally at different levels and metal vias extending vertically to connect the metal lines at different levels. In addition, the tag IC layer 120 may also include several dielectric layers stacked on each other to separate the metal lines at different levels. The dielectric layer may include a dielectric material such as SiO, SiN or doped SiO. In some embodiments, the interconnect structure and the dielectric layer may be formed in the back-end of line (BEOL), the device may be formed in the front-end of line (FEOL), and the tag IC layer 120 may include structures formed in the front-end process and the back-end process.

[0042] In some embodiments, conductive layers 130 and 140 may include one or more materials that provide good electrical coupling with antenna 10. For example, conductive layers 130 and 140 may include copper, gold, nickel, or a combination thereof. In some embodiments, conductive layers 130 and 140 may have a thickness of 1 μm to 20 μm.

[0043] In some embodiments, the conductive layers 130 and 140 may include a metal layer or multiple layers of different metals. For example, the conductive layers 130 and 140 may include a copper layer, a nickel layer, and a gold layer, wherein the gold layer is disposed on the outer surface, and the nickel layer may be sandwiched between the copper layer and the gold layer. However, the present disclosure is not limited thereto. In some embodiments, more or fewer metal layers may be used to form the conductive layers 130 and 140.

[0044] Figure 5 FIG. 1 shows an RFID tag device 1 according to an embodiment of the present disclosure. In some embodiments, the RFID tag device 1 can be used as an RFID tag, such as Figure 1 The RFID tag device 1 includes an antenna substrate SB1, an antenna 10, and a semiconductor RFID structure 100. Figure 5 As shown, the antenna 10 may be disposed on an antenna substrate SB1.

[0045] In some embodiments, the antenna substrate SB1 may be, for example but not limited to, a flexible substrate, such as a plastic sheet or paper, wherein the plastic sheet may be, for example, a polyethylene terephthalate (PET) sheet, or a polyvinyl toluene (PVT) sheet. The antenna 10 may be a dipole antenna, which includes a first terminal 10A and a second terminal 10B, and the semiconductor RFID structure 100 may be attached to the antenna 10 to couple to the antenna 10. Specifically, from a top view, the conductive layer 130 may overlap with the first terminal 10A but not with the second terminal 10B, and the conductive layer 140 may overlap with the second terminal 10B but not with the first terminal 10A. In this case, the conductive layer 130 may be electrically coupled to the first terminal 10A, and the conductive layer 140 may be electrically coupled to the second terminal 10B. In some embodiments, the first terminal 10A and the second terminal 10B can be the RF terminal (or positive signal terminal) and the ground terminal (or negative signal terminal) of the antenna 10. In some embodiments, antenna 10 may include copper, silver, aluminum, or alloys of any of the above materials.

[0046] In addition, if Figure 5 As shown, the conductive layer 140, the tag IC layer 120, the semiconductor substrate 110 and the conductive layer 130 of the semiconductor RFID structure 100 are stacked in sequence along a first direction D1, and the first direction D1 is parallel to the antenna substrate SB1 and the top surface of the antenna 10. In addition, the semiconductor RFID structure 100, the antenna 10 and the antenna substrate SB1 are stacked in sequence along a second direction D2, wherein the second direction D2 is perpendicular to the first direction D1.

[0047] That is, unlike the RFID tag 8 in which the RFID tag IC 800 is attached to the antenna 80 through conductive bumps 830 and 840 formed on the same surface of the tag IC layer 820, the semiconductor RFID structure 100 is capable of being attached to the antenna 10 through conductive layers 130 and 140 located on two relatively different sides of the semiconductor RFID structure 100.

[0048] In this case, in the assembly process of the RFID tag device 1, the semiconductor RFID structure 100 can be attached to the antenna 10 by rotating approximately 90 degrees without performing a flip chip operation. As a result, the manufacturing cost of the RFID tag device 1 can be greatly reduced. In addition, since the assembly process of the RFID tag device 1 does not require the use of a flip chip operation, the minimum area standard required for the flip chip operation is no longer a necessary consideration. In addition, since the semiconductor RFID structure 100 can be attached to the antenna 10 through the conductive layers 130 and 140 on both sides thereof, the minimum chip area condition required to form conductive bumps (such as conductive bumps 830 and 840 formed on the RFID tag IC 800) is no longer necessary, which allows the semiconductor RFID structure 100 to have greater flexibility in design. Therefore, the semiconductor RFID structure 100 can be manufactured in a smaller size, thereby further reducing the manufacturing cost of the semiconductor RFID structure 100 and the RFID tag device 1.

[0049] like Figure 5 As shown, the semiconductor RFID structure 100 can be stacked on the antenna 10 and the antenna substrate SB1, wherein the rod-shaped extension direction (e.g., direction D1) of the semiconductor RFID structure 100 is parallel to the top surface of the antenna 10 and the antenna substrate SB1. In this case, in the RFID tag device 1, the thickness portion contributed by the semiconductor RFID structure 100 can be determined by the side length of the cross section of the rod.

[0050] For example, the cross-sectional area of ​​the semiconductor RFID structure 100 is as follows: Figure 5 The boundary area CA1 between the tag IC layer 120 and the semiconductor substrate 110 shown is a rectangular shape having a long side LE1 and a short side SE1. In some embodiments, the long side LE1 may be perpendicular to the second direction D2, and the short side SE1 may be parallel to the second direction D2. That is, the long side LE1 may be parallel to the top surface of the antenna 10 and the antenna substrate SB1, and the short side SE1 may be perpendicular to the top surface of the antenna 10 and the antenna substrate SB1. In this case, at least a portion of the thickness of the RFID tag device 1 may be determined by the length of the short side SE1. However, the present embodiment is not limited to this. In some other embodiments, the long side LE1 may be perpendicular to the top surface of the antenna 10 and the antenna substrate SB1, and the short side SE1 is parallel to the top surface of the antenna 10 and the antenna substrate SB1. In this case, at least a portion of the thickness of the RFID tag device 1 may be determined by the length of the long side LE1. In addition, in some embodiments, the length L1 is greater than the short side SE1 and the long side LE1, however, the present disclosure is not limited to this.

[0051] exist Figure 5In the illustrated embodiment, by appropriately designing the layout of the tag IC layer 120, the length of the short side SE1 and the thickness of a portion of the RFID tag device 1 can be determined without thinning the semiconductor substrate 110 of the semiconductor RFID structure 100. However, in some embodiments, in order to facilitate the step of picking up the semiconductor RFID structure 100 to attach the semiconductor RFID structure 100 to the antenna 10, the length of the short side SE1 cannot be too small. In some embodiments, the length of the short side SE1 is about 30 μm to about 300 μm. In addition, in some embodiments, in order to reduce the area of ​​the RFID tag device 1 and facilitate the formation of TSV, the semiconductor substrate 110 of the semiconductor RFID structure 100 may also be thinned to reduce the length L1 of the semiconductor RFID structure 100 along the first direction D1 (i.e., the stacking thickness of the semiconductor RFID structure 100). In some embodiments, the length L1 of the semiconductor RFID structure 100 is about 300 μm to about 800 μm, which may depend on whether the thinning process is performed and to what extent the thinning process is performed.

[0052] Figure 6 FIG. 1 shows a side view of an RFID tag device 1 according to an embodiment of the present disclosure. Figure 5 as well as Figure 6 As shown, the conductive layer 130 can directly contact the first terminal 10A of the antenna 10, and the conductive layer 140 can directly contact the second terminal 10B of the antenna 10. However, the present disclosure is not limited thereto. In some embodiments, the conductive layers 130 and 140 can also be bonded to the terminals 10A and 10B of the antenna 10 using a conductive adhesive material.

[0053] Figure 7 An RFID tag device 2 according to another embodiment of the present disclosure is shown. The difference between the RFID tag device 2 and the RFID tag device 1 is that the RFID tag device 2 further includes an anisotropic conductive adhesive (also known as anisotropic conductive film, ACF) AD1. The anisotropic conductive adhesive AD1 includes, for example but not limited to, conductive particles dispersed in a viscous resin. In this embodiment, the anisotropic conductive adhesive AD1 can be disposed between the semiconductor RFID structure 100 and the antenna 10. When heat and pressure are applied, the conductive layer 130 and the first terminal 10A of the antenna 10 facing each other and the conductive layer 140 and the second terminal 10B of the antenna 10 facing each other will clamp the conductive particles, thereby destroying the insulating coating of the conductive particles to establish an electrical connection therebetween. Therefore, the anisotropic conductive adhesive AD1 can not only help enhance the bonding between the semiconductor RFID structure 100 and the antenna 10, but also improve the conductivity between the conductive layer 130 and the first terminal 10A and the conductivity between the conductive layer 140 and the second terminal 10B.

[0054] In addition, particles not sandwiched between the conductive layers 130, 140 and the terminals 10A and 10B can move within the base resin of the anisotropic conductive adhesive AD1, thereby keeping its insulating coating intact and preventing short circuits. In other words, the anisotropic conductive adhesive AD1 can also improve the insulation quality in the direction D1 (lateral direction) perpendicular to the pressure direction, thereby protecting the first terminal 10A and the second terminal 10B of the antenna 10 from short circuits.

[0055] Figure 8 An RFID tag device 3 according to another embodiment of the present disclosure is shown. The RFID tag device 3 is different from the RFID tag device 1 in that the RFID tag device 3 includes a semiconductor RFID structure 200, and the semiconductor RFID structure 200 has conductive layers 230 and 240 formed by reflowing the conductive layers 130 and 140 to facilitate assembly of the RFID tag device 3. The reflow process may be, for example, a thermal reflow process.

[0056] Fig. 9 An RFID tag device 4 according to another embodiment of the present disclosure is shown. The RFID tag device 4 is different from the RFID tag device 3 in that the RFID tag device 4 further includes an anisotropic conductive adhesive AD1, which is adhered between the semiconductor RFID structure 200 and the antenna 10 to provide better bonding and conductivity between the semiconductor RFID structure 200 and the antenna 10, and better insulation between the terminals 10A and 10B of the antenna 10.

[0057] Fig.10 An RFID tag device 5 according to another embodiment of the present disclosure is shown. The RFID tag device 5 differs from the RFID tag device 1 in that the RFID tag device 5 further includes conductive contact layers 12 and 14. The conductive contact layer 12 surrounds the conductive layer 130 and is coupled between the conductive layer 130 and the first terminal 10A of the antenna 10. The conductive contact layer 14 surrounds the conductive layer 140 and is coupled between the conductive layer 140 and the second terminal 10B of the antenna 10. In some embodiments, the conductive contact layers 12 and 14 can be formed by immersing the conductive layers 130 and 140 in a conductive material, such as, but not limited to, a paste of copper, gold, nickel, silver, tin, or a combination thereof. However, the present disclosure is not limited thereto. In some embodiments, the conductive contact layers 12 and 14 can be formed by an electroplating process. By adding the conductive contact layers 12 and 14 on the conductive layers 130 and 140 , the contact area between the conductive layer 130 and the first terminal 10A and the contact area between the conductive layer 140 and the second terminal 10B can be increased, thereby facilitating the assembly of the RFID tag device 5 .

[0058] Fig.11 An RFID tag device 6 according to another embodiment of the present disclosure is shown. Compared with the RFID tag device 5, the RFID tag device 6 further includes an anisotropic conductive adhesive AD1 for adhering the metal materials 12 and 14 surrounding the conductive layers 130 and 140 to the antenna 10 and the antenna substrate SB1, thereby enhancing the bonding and conductivity between the semiconductor RFID structure 100 and the antenna 10, and enhancing the insulation between the terminals 10A and 10B of the antenna 10.

[0059] Fig.12 The flowchart of a method M1 for manufacturing an RFID tag device according to an embodiment of the present disclosure is shown. The method M1 includes steps S110 to S160, but is not limited to Fig.12 In some embodiments, the method M1 may be used to manufacture the RFID tag device 1 .

[0060] FIG. 13A to FIG. 13E The method M1 is shown in FIG. Figure 6 A cross-sectional view or side view of one or more stages of the RFID tag device 1.

[0061] In step S110, Fig.13A As shown, a semiconductor substrate 110 having a tag IC layer 120 may be received, wherein the tag IC layer 120 may be formed on a front side 110A of the semiconductor substrate 110. In some embodiments, the semiconductor substrate 110 may be thinned to facilitate forming TSVs in the semiconductor substrate 110. For example, the initial thickness of the semiconductor substrate 110 may be greater than 700 μm and may be thinned to approximately 300 μm. However, the present disclosure is not limited thereto. In some embodiments, the semiconductor substrate 110 may be thinned to approximately 100 μm to further facilitate the TSV process.

[0062] In steps S120 and S130, Fig. 13B As shown, the conductive layer 130 is formed on the back side 110B of the semiconductor substrate 110, and the conductive layer 140 is formed on the exposed side 120A of the tag IC layer 120. In some embodiments, the conductive layer 130 can be deposited on the entire back side 110B of the semiconductor substrate 110, and the conductive layer 140 can be deposited on the entire exposed side 120A of the tag IC layer 120.

[0063] In some embodiments, the conductive layers 130 and 140 may include the same conductive material. For example, the conductive layers 130 and 140 may include appropriate metals, such as copper, gold, nickel, alloys of at least two of the aforementioned materials, or a multilayer structure formed by at least two of the aforementioned materials. In addition, in some embodiments, steps S120 and S130 may be performed in the same metal deposition process, such as a chemical vapor deposition (CVD) process. However, the present disclosure is not limited thereto.

[0064] In some embodiments, steps S120 and S130 may be performed in a wafer-level process, and in step S140, such as Fig. 13C As shown, a cutting process (i.e., a sawing process) is performed to form a vertical semiconductor RFID structure 100. In some embodiments, passivation may be further performed after the edge cutting of the semiconductor RFID structure 100 is completed. In some embodiments, the cutting blade may cut through the second conductive layer 140, the tag IC layer 120, the semiconductor substrate 110, and the first conductive layer 130, so that the adjacent side surfaces of the second conductive layer 140, the tag IC layer 120, the semiconductor substrate 110, and the first conductive layer 130 exposed by the cutting process will be coplanar. In other words, the adjacent side surfaces of the second conductive layer 140, the tag IC layer 120, the semiconductor substrate 110, and the first conductive layer 130 will be cut flush.

[0065] In some embodiments, step S140 may be cut along direction D1 (i.e., the stacking direction of the conductive layer 140, the tag IC layer 120, the substrate 110, and the conductive layer 130) so that the semiconductor RFID structure 100 has a rectangular cross-section. Figure 5 As shown, the boundary area CA1 between the tag IC layer 120 and the semiconductor substrate 110 is in the shape of a rectangle having a long side LE1 and a short side SE1 .

[0066] In step S150, Fig.13D As shown, the antenna 10 can be rotated about 90 degrees, and in step S160, as shown in FIG. Fig.13E As shown, the semiconductor RFID structure 100 can be attached to the antenna 10 so that the conductive layer 130 is electrically coupled to the first terminal 10A, and the conductive layer 140 is electrically coupled to the second terminal 10B. In this way, the stacking direction D1 of the conductive layer 140, the tag IC layer 120, the semiconductor substrate 110, and the conductive layer 130 will be perpendicular to the stacking direction of the semiconductor RFID structure 100, the antenna 10, and the antenna substrate SB1.

[0067] In addition, in some embodiments, the semiconductor RFID structure 100 can be formed by using a longer side (eg, Figure 5 The antenna 10 is attached to the antenna 10 in such a manner that the long side LE1 of the region CA1 shown is parallel to the surface of the antenna substrate SB1. In this case, the short side of the cross section (for example, Figure 5 The short side SE1 of the area CA1 shown in FIG. 1 will contribute a portion of the height of the RFID tag device 1. In other words, Figure 5 As shown, the long side LE1 ( Fig.13E The second side SE1 (not shown) may be perpendicular to the direction D2, and the short side SE1 may be parallel to the second direction D2. However, the present disclosure is not limited thereto.

[0068] In some embodiments, Figure 6 As shown, step S160 can directly attach the semiconductor RFID structure 100 to the antenna 10. However, in some embodiments, anisotropic conductive adhesive AD1 can also be used to improve the bonding and conductivity between the semiconductor RFID structure 100 and the antenna 10, and to improve the insulation quality between the first terminal 10A and the second terminal 10B of the antenna 10, such as Figure 7 shown.

[0069] FIG. 14A to FIG. 14B An embodiment according to the present disclosure is shown for manufacturing Figure 7 The RFID tag device 2 shown is a cross-sectional view or a side view of the stage where the semiconductor RFID structure 100 is attached to the antenna 10 .

[0070] like Fig.14A As shown, the anisotropic conductive adhesive AD1 can be applied in the form of a viscous fluid on the antenna substrate SB1 between the first terminal 10A and the second terminal 10B of the antenna 10 , wherein the anisotropic conductive adhesive AD1 at least partially overlaps the first terminal 10A and the second terminal 10B of the antenna 10 .

[0071] Next, the semiconductor RFID structure 100 may be placed on the anisotropic conductive adhesive AD1, and a curing process may be performed under continuous application of pressure and heat. Fig. 14B As shown, by pressing the semiconductor RFID structure 100 toward the antenna 10, the conductive layer 130 and the first terminal 10A facing each other will clamp the conductive particles in the anisotropic conductive adhesive AD1 and destroy the insulating coating of the conductive particles, thereby establishing an electrical connection between the conductive layer 130 and the first terminal 10A. Similarly, during the operation of heating and pressurizing the anisotropic conductive adhesive AD1, an electrical connection can be established between the conductive layer 140 and the second terminal 10B facing each other. Therefore, by performing Fig.14A as well as Fig. 14B The process shown in FIG. 1 can be used to attach the semiconductor RFID structure 100 to the antenna 10 by means of anisotropic conductive adhesive AD1. Figure 7shown.

[0072] In this embodiment, the anisotropic conductive adhesive AD1 can not only adhere the semiconductor RFID structure 100 to the antenna 10, but also provide electrical connections between the conductive layer 130 and the first terminal 10A and between the conductive layer 140 and the second terminal 10B. In addition, the anisotropic conductive adhesive AD1 can further improve the insulation quality perpendicular to the pressure direction to protect the terminals 10A and 10B of the antenna 10 from being short-circuited.

[0073] In some embodiments, in order to further facilitate the assembly process of the RFID tag device 1, the conductive layers 130 and 140 may be reflowed before attaching the semiconductor RFID structure 100 to the antenna 10. In this case, the conductive layers 130 and 140 will have the following characteristics: Figure 8 The conductive layers 230 and 240 shown may be convex, spherical, drop-shaped, or other similar shapes. In some embodiments, anisotropic conductive adhesive AD1 may also be applied to the conductive layers 230 and 240 to obtain better adhesion and conductivity, such as Fig. 9 shown.

[0074] Or, if Fig.10 As shown, before attaching the semiconductor RFID structure 100 to the antenna 10, the method M1 may further include forming a conductive contact layer 12 surrounding the conductive layer 130 and a conductive contact layer 14 surrounding the conductive layer 140. In some embodiments, the conductive contact layers 12 and 14 may include copper, gold, nickel, silver, tin, or a combination thereof. In some embodiments, the conductive contact layers 12 and 14 may be formed on the conductive layers 130 and 140 by electroplating or immersing the conductive layers 130 and 140 in a conductive material. In addition, in some embodiments, anisotropic conductive adhesive AD1 may also be applied to the conductive contact layers 12 and 14 to obtain better adhesion and conductivity, such as Fig.11 shown.

[0075] In summary, the vertical semiconductor RFID structure provided by the embodiment of the present disclosure may be in the shape of a rod, and a conductive layer may be formed at both ends of the rod, so that the semiconductor RFID structure may be attached to the antenna without performing a flip chip operation. In this way, the manufacturing cost and chip area of ​​the RFID tag device may be significantly reduced.

[0076] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications may be made herein without departing from the spirit and scope of the present invention as defined by the appended claims. For example, many of the processes discussed above may be implemented in different ways and replaced by other processes or combinations thereof.

[0077] Furthermore, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, production, compositions of matter, means, methods, and steps described in the specification. As will be readily understood by those of ordinary skill in the art from this disclosure, processes, machines, production, compositions of matter, means, methods, or steps (currently existing or to be developed in the future) may be used in accordance with the present invention to perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein. Therefore, the appended claims are intended to include within their scope such processes, machines, production, compositions of matter, means, methods, and steps.

[0078] Explanation of symbols

[0079] 1: RFID tag device

[0080] 2: RFID tag device

[0081] 3: RFID tag device

[0082] 4: RFID tag device

[0083] 5: RFID tag device

[0084] 6: RFID tag device

[0085] 8: RFID tags

[0086] 9: RFID reader

[0087] 10: Antenna

[0088] 10A: First terminal

[0089] 10B: Second terminal

[0090] 12: Conductive contact layer

[0091] 14: Conductive contact layer

[0092] 80: Antenna

[0093] 80A: RF terminal

[0094] 80B: Ground terminal

[0095] 82: RF waves

[0096] 92: RF waves

[0097] 100: Semiconductor RFID structure

[0098] 110: Semiconductor substrate

[0099] 110A: Front

[0100] 110B: Rear

[0101] 120: Label IC layer

[0102] 120A: Side

[0103] 130: Conductive layer

[0104] 140: Conductive layer

[0105] 200: Semiconductor RFID structure

[0106] 230: Conductive layer

[0107] 240: Conductive layer

[0108] 800: RFID tag IC

[0109] 810: Semiconductor layer

[0110] 820: Tag IC layer

[0111] 830: Conductive bump

[0112] 840: Conductive bump

[0113] A1~A4: Side surface

[0114] CA1: Area

[0115] AD1: Anisotropic conductive adhesive

[0116] AD8: Anisotropic Conductive Adhesive

[0117] CA1: junctional area

[0118] D1: Direction

[0119] D2: Direction

[0120] L1: Length

[0121] LE1: Long edge

[0122] M1: Methods

[0123] S110~S160: Steps

[0124] SB1: Antenna substrate

[0125] SE1: Short edge

Claims

1. A vertical semiconductor radio frequency identification structure, characterized in that: include: a semiconductor substrate; A tag integrated circuit layer is formed on a front side of the semiconductor substrate; a first conductive layer formed on a back side of the semiconductor substrate opposite to the front side; as well as a second conductive layer formed on a side of the tag integrated circuit layer away from the semiconductor substrate, so that the tag integrated circuit layer and the semiconductor substrate are sandwiched between the first conductive layer and the second conductive layer, The second conductive layer is electrically coupled to the tag integrated circuit layer.

2. The vertical semiconductor radio frequency identification structure of claim 1, wherein The second conductive layer, the tag integrated circuit layer, the semiconductor substrate and the first conductive layer are stacked in sequence along a first direction, and The second conductive layer, the tag integrated circuit layer, the semiconductor substrate and adjacent side surfaces of the first conductive layer are parallel to the first direction and aligned. 3 . The vertical semiconductor RFID structure as claimed in claim 1 , wherein the second conductive layer is electrically coupled to the tag integrated circuit layer through a through silicon via formed in the semiconductor substrate.

4. The vertical semiconductor radio frequency identification structure as claimed in claim 1, wherein the second conductive layer, the tag integrated circuit layer, the semiconductor substrate and the first conductive layer are stacked in sequence along a first direction, and a length of the vertical semiconductor radio frequency identification structure along the first direction is about 300 μm to about 800 μm. 5 . The vertical semiconductor RFID structure as claimed in claim 1 , wherein a boundary region between the tag integrated circuit layer and the semiconductor substrate is in a rectangular shape having a long side and a short side, and a length of the short side is about 30 μm to about 300 μm. 6 . The vertical semiconductor radio frequency identification structure as claimed in claim 1 , wherein the tag integrated circuit layer comprises at least one of a logic integrated circuit, a memory integrated circuit, a power integrated circuit or an analog integrated circuit.

7. A radio frequency identification tag device, characterized in that: include: an antenna substrate; An antenna is disposed on the antenna substrate, wherein the antenna comprises: a first terminal; and a second terminal; and The vertical semiconductor radio frequency identification structure of claim 1, coupled to the antenna, in: The second conductive layer, the tag integrated circuit layer, the semiconductor substrate and the first conductive layer of the vertical semiconductor wireless radio frequency identification structure are stacked in sequence along a first direction, and the first direction is parallel to a top surface of the antenna substrate; From a top view, the first conductive layer overlaps with the first terminal but does not overlap with the second terminal, and the second conductive layer overlaps with the second terminal but does not overlap with the first terminal; and The first conductive layer is electrically coupled to the first terminal, and the second conductive layer is electrically coupled to the second terminal. 8 . The RFID tag device as claimed in claim 7 , wherein the vertical semiconductor RFID structure, the antenna and the antenna substrate are stacked in sequence along a second direction, and the first direction is perpendicular to the second direction.

9. The wireless radio frequency identification tag device as claimed in claim 8, wherein a boundary area between the tag integrated circuit layer and the semiconductor substrate is in a rectangular shape having a long side and a short side, wherein the long side is perpendicular to the second direction, and the short side is parallel to the second direction. 10 . The RFID tag device of claim 9 , wherein a length of the short side is about 30 μm to about 300 μm. 11 . The RFID tag device as claimed in claim 7 , wherein the first conductive layer and the second conductive layer have a spherical shape, a convex shape or a drop shape.

12. The radio frequency identification tag device according to claim 7, further comprising: a first conductive contact layer surrounding the first conductive layer and coupled between the first conductive layer and the first terminal of the antenna; as well as A second conductive contact layer surrounds the second conductive layer and is coupled between the second conductive layer and the second terminal of the antenna. 13 . The wireless radio frequency identification tag device as claimed in claim 7 , further comprising an anisotropic conductive adhesive filled between the first conductive layer and the first terminal and between the second conductive layer and the second terminal.

14. A method for manufacturing a radio frequency identification tag device, characterized in that: include: Receiving a semiconductor substrate having a tag integrated circuit layer formed on a front side of the semiconductor substrate; Forming a first conductive layer over the entire surface of a rear side of the semiconductor substrate opposite to the front side; A second conductive layer is formed on a whole surface above a side of the tag integrated circuit layer away from the semiconductor substrate, so that the tag integrated circuit layer and the semiconductor substrate are sandwiched between the first conductive layer and the second conductive layer, wherein the second conductive layer, the tag integrated circuit layer, the semiconductor substrate and the first conductive layer are stacked in sequence along a first direction, and the second conductive layer is electrically coupled to the tag integrated circuit layer; as well as Cutting along the first direction to form a vertical semiconductor radio frequency identification structure.

15. The method of claim 14, further comprising: Rotating the vertical semiconductor radio frequency identification structure 90 degrees; as well as Attaching the vertical semiconductor radio frequency identification structure to an antenna disposed on an antenna substrate, wherein the antenna comprises a first terminal and a second terminal, the first conductive layer is electrically coupled to the first terminal and the second conductive layer is electrically coupled to the second terminal, and the first direction is parallel to a top surface of the antenna substrate; The vertical semiconductor radio frequency identification structure, the antenna and the antenna substrate are stacked in sequence along a second direction, and the second direction is perpendicular to the first direction.

16. The method of claim 15, further comprising: before attaching the vertical semiconductor RFID structure to the antenna, reflowing the first conductive layer and the second conductive layer; or Before attaching the vertical semiconductor RFID structure to the antenna, a first conductive contact layer surrounding the first conductive layer and a second conductive contact layer surrounding the second conductive layer are formed.

17. The method of claim 15, further comprising: An anisotropic conductive adhesive is applied on the antenna substrate between the first terminal and the second terminal of the antenna.

18. The method of claim 14, wherein the second conductive layer is coupled to the tag integrated circuit layer through a through silicon via formed in the semiconductor substrate.

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