Substrate shielding structure and method of forming the same
By designing an 'S'-shaped coil region and a grounding protection ring in the substrate shielding structure, the problem of reduced inductor quality factor Q caused by substrate eddy currents was solved, thus improving inductor performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SEMICON MFG INT (SHANGHAI) CORP
- Filing Date
- 2022-07-26
- Publication Date
- 2026-05-22
AI Technical Summary
Eddy currents still exist in existing substrate shielding structures, which leads to a decrease in the inductor quality factor Q.
Design a substrate shielding structure, wherein the shielding layer includes a plurality of mutually discrete unit regions arranged along a first direction, each unit region includes a plurality of coil regions arranged along a second direction, the coil regions are electrically interconnected, the coil structure is 'S' shaped on the substrate surface, and a grounded protective ring is provided on the outside of the shielding layer for electrical connection, and the induced magnetic field forming substrate eddy currents is reduced by using Ampere's law.
The quality factor Q of the inductor is significantly improved by suppressing the formation of substrate eddy currents and displacement currents.
Smart Images
Figure CN117542637B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor manufacturing, and more particularly to a substrate shielding structure and a method for forming the same. Background Technology
[0002] Inductors, as key components of radio frequency (RF) integrated circuits, are widely used in voltage-controlled oscillators (VCOs), low-noise amplifiers (LNAs), and power amplifiers. An inductor typically consists of three parts: a coil, a substrate shielding structure, and a guard ring. In RF integrated circuits, the inductor's quality factor (Q) is the ratio of the difference between the peak magnetic energy and peak electrical energy stored in the inductor to its losses over one cycle. The inductor's quality factor Q plays a crucial role in the performance of RF circuits.
[0003] An inductor typically consists of three parts: a coil, a substrate shielding structure, and a guard ring. The substrate shielding structure must induce an electric field through the grounded shielding coil to prevent a perpendicular electric field from entering the substrate and causing displacement current. Furthermore, the substrate shielding structure should avoid large-area, unidirectional conductor structures, making it as fragmented as possible to prevent the induced magnetic field from the induced electric field from forming substrate eddy currents within the conductors of the substrate shielding structure. Suppressing the formation of displacement current and substrate eddy currents can improve the inductor's quality factor Q.
[0004] In existing technologies, the active region and polysilicon layer in the unit cell structure of the substrate shielding structure follow the requirement of fragmentation. However, eddy currents can still be generated in the substrate, leading to a decrease in the quality factor Q.
[0005] Therefore, existing substrate shielding structures still require further improvement. Summary of the Invention
[0006] The technical problem solved by the present invention is to provide a substrate shielding structure and a method for forming the same, so as to increase the inductance quality factor Q.
[0007] To solve the above-mentioned technical problems, the present invention provides a substrate shielding structure, comprising: a substrate; a shielding layer located on the substrate, the shielding layer comprising a plurality of mutually discrete unit regions arranged along a first direction, each unit region comprising a plurality of coil regions arranged along a second direction, adjacent coil regions being electrically interconnected, each coil region comprising a first coil, the first coil comprising at least one coil structure, the projection pattern of the coil structure on the surface of the substrate being "S"-shaped; and a protective ring located outside the shielding layer and surrounding the shielding layer, the protective ring being grounded and electrically connected to the shielding layer.
[0008] Optionally, each coil region further includes a second coil, which is parallel to the first coil, and the projection pattern of the second coil on the substrate surface is axially symmetrical to the projection pattern of the first coil on the substrate surface. The second coil is electrically interconnected with the first coil.
[0009] Optionally, the area where the shielding layer is located is octagonal.
[0010] Optionally, the protective ring includes a first region and a second region along the first direction; the shielding layer includes a third region and a fourth region along the first direction, wherein the third region of the shielding layer is electrically connected to the first region of the protective ring, and the fourth region of the shielding layer is electrically connected to the second region of the protective ring.
[0011] Optionally, it may also include an inductor coil located on the shielding layer.
[0012] Accordingly, the technical solution of the present invention provides a method for forming a substrate shielding structure, comprising: providing a substrate; forming a shielding layer on the substrate, the shielding layer comprising a plurality of mutually discrete unit regions arranged along a first direction, each unit region comprising a plurality of coil regions arranged along a second direction, adjacent coil regions being electrically interconnected, each coil region comprising a first coil, the first coil comprising at least one coil structure, the projection pattern of the coil structure on the surface of the substrate being "S" shaped; forming a protective ring on the substrate located outside the shielding layer and surrounding the shielding layer, the protective ring being grounded and electrically connected to the shielding layer.
[0013] Optionally, each coil region further includes a second coil, which is parallel to the first coil, and the projection pattern of the second coil on the substrate surface is axially symmetrical to the projection pattern of the first coil on the substrate surface. The second coil is electrically interconnected with the first coil.
[0014] Optionally, the area where the shielding layer is located is octagonal.
[0015] Optionally, the protective ring includes a first region and a second region along the first direction; the shielding layer includes a third region and a fourth region along the first direction, wherein the third region of the shielding layer is electrically connected to the first region of the protective ring, and the fourth region of the shielding layer is electrically connected to the second region of the protective ring.
[0016] Optionally, the number of the plurality of first coils in each coil region is greater than or equal to two.
[0017] Optionally, it also includes forming an inductor coil on the shielding layer.
[0018] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:
[0019] In a substrate shielding structure provided by the present invention, a shielding layer located on the substrate includes a plurality of mutually independent unit regions arranged along a first direction. Each unit region includes a plurality of coil regions arranged along a second direction. Adjacent coil regions are electrically interconnected. Each coil region includes a first coil. The first coil includes at least one coil structure. The projection pattern of the coil structure on the substrate surface is "S" shaped. According to Ampere's law, the induced electric fields generated by the induced magnetic field in adjacent coils of the coil structure are in opposite directions. The induced electromotive force with opposite trends can reduce the formation of substrate eddy currents in the substrate shielding structure by the induced magnetic field, suppress the formation of displacement current and substrate eddy currents, and thus improve the quality factor Q of the inductor.
[0020] In a method for forming a substrate shielding structure provided by the present invention, a shielding layer is formed on the substrate. The shielding layer includes a plurality of mutually discrete unit regions arranged along a first direction. Each unit region includes a plurality of coil regions arranged along a second direction. Adjacent coil regions are electrically interconnected. Each coil region includes a first coil. The first coil includes at least one coil structure. The projection pattern of the coil structure on the substrate surface is "S" shaped. According to Ampere's law, the induced electric fields generated by the induced magnetic field in adjacent coils of the coil structure are in opposite directions. The induced electromotive force with opposite trends can reduce the formation of substrate eddy currents in the substrate shielding structure by the induced magnetic field, suppress the formation of displacement current and substrate eddy currents, and thus improve the quality factor Q of the inductor. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of a substrate shielding structure;
[0022] Figures 2 to 5 This is a schematic diagram of the substrate shielding structure in an embodiment of the present invention. Detailed Implementation
[0023] It should be noted that the terms "surface" and "on" in this specification are used to describe the relative spatial position and are not limited to whether there is direct contact.
[0024] As described in the background section, the performance of substrate shielding structures formed in the prior art needs improvement. A substrate shielding structure will now be described and analyzed in conjunction with this study.
[0025] Figure 1 This is a schematic diagram of a substrate shielding structure.
[0026] Please refer to Figure 1The substrate shielding structure includes a plurality of units distributed in an array along a first direction X. Each unit includes: an active region 100 parallel to the first direction X; a plurality of gates 101 located on the active region 100, the plurality of gates 101 being parallel to a second direction Y and arranged along the first direction X, the first direction X and the second direction Y being perpendicular to each other; and a metal layer 102 located on the plurality of gates 101.
[0027] It should be noted that, in order to show the location of the active regions 100, the active regions 100 are marked with dashed lines.
[0028] In shielding structures, large-area, unidirectional conductor structures should be avoided. The active region 100 and gate 101 of the aforementioned substrate shielding structure employ a fragmented design to reduce the formation of substrate eddy currents in the conductors of the substrate shielding structure by the induced magnetic field of the induced electric field. However, eddy currents A will still be generated in the metal layer 102, leading to a decrease in the quality factor Q of the inductor.
[0029] To address the aforementioned technical problem, embodiments of the present invention provide a substrate shielding structure and its formation method. In this structure, a shielding layer is located on the substrate. The shielding layer includes a plurality of mutually independent unit regions arranged along a first direction. Each unit region includes a plurality of coil regions arranged along a second direction. Adjacent coil regions are electrically interconnected. Each coil region includes a first coil, and the first coil includes at least one coil structure. The projection pattern of the coil structure on the substrate surface is "S"-shaped. According to Ampere's law, the induced electric fields generated by the induced magnetic field in adjacent coils of the coil structure have opposite directions. The opposite trends of the induced electromotive force can reduce the formation of substrate eddy currents in the substrate shielding structure, suppress the formation of displacement current and substrate eddy currents, and thereby improve the quality factor Q of the inductor.
[0030] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0031] Figures 2 to 5 This is a schematic diagram of the substrate shielding structure in an embodiment of the present invention.
[0032] Please refer to Figures 2 to 4 , Figure 2 This is a top-down structural diagram. Figure 3 for Figure 2 A magnified view of a portion of region B in the middle. Figure 4 for Figure 2A partial enlarged view of region C shows a substrate (not shown). A shielding layer is formed on the substrate, the shielding layer including a plurality of mutually discrete unit regions A arranged along a first direction X, each unit region A including a plurality of coil regions 201 arranged along a second direction Y, adjacent coil regions 201 being electrically interconnected, each coil region 201 including a first coil 201a, the first coil 201a including at least one coil structure, the projection pattern of the coil structure on the surface of the substrate being "S" shaped; a protective ring 202 is formed on the substrate located outside the shielding layer and surrounding the shielding layer, the protective ring 202 being grounded and electrically connected to the shielding layer.
[0033] Each coil region 201 includes a first coil 201a, which includes at least one coil structure. The projection pattern of the coil structure on the substrate surface is "S" shaped. According to Ampere's law, the induced electric fields generated by the induced magnetic field in adjacent coils of the coil structure are opposite in direction and have opposite trends. This can reduce the formation of substrate eddy currents in the substrate shielding structure by the induced magnetic field, suppress the formation of displacement current and substrate eddy currents, and thus improve the quality factor Q of the inductor.
[0034] In this embodiment, the substrate includes an active region (not shown in the figure) and a gate (not shown in the figure) located on the active region. The active region and the gate follow a fragmented design to avoid large-area unidirectional conductor structures, suppress displacement current and substrate eddy current formation, and improve the quality factor Q of the inductor.
[0035] In this embodiment, each coil region 201 further includes a second coil 201b, which is parallel to the first coil 201a, and the projection pattern of the second coil 201b on the substrate surface is axially symmetrical to the projection pattern of the first coil 201a on the substrate surface. The second coil 201b is electrically interconnected with the first coil 201a. In other embodiments, each coil region 201 may not include a second coil.
[0036] In this embodiment, the area where the shielding layer is located is octagonal.
[0037] The protective ring 202 includes a first region I and a second region II along the first direction X; the shielding layer includes a third region III and a fourth region IV along the first direction X, the third region III of the shielding layer is electrically connected to the first region I of the protective ring 202, and the fourth region IV of the shielding layer is electrically connected to the second region II of the protective ring 202.
[0038] Specifically, each unit area A in the third region III of the shielding layer is electrically connected to each other via a first metal wire 203 and connected to the first region I of the protection ring 202; each unit area A in the fourth region IV of the shielding layer is electrically connected to each other via a second metal wire 204 and connected to the second region II of the protection ring 202.
[0039] It should be noted that, Figures 2 to 4 The image only shows the location and distribution of the protective ring 202, without illustrating its specific structure.
[0040] The number of the plurality of first coils 201a in each coil region 201 is greater than or equal to two. In this embodiment, the number of the plurality of first coils 201a is three.
[0041] Please refer to Figure 5 An inductor coil 205 is also formed on the shielding layer.
[0042] The shielding layer is located between the inductor coil 205 and the substrate to prevent the induced magnetic field of the induced electric field from forming substrate eddy currents in the conductor of the substrate shielding structure, suppress the formation of displacement current and substrate eddy currents, and improve the quality factor Q of the inductor.
[0043] Accordingly, embodiments of the present invention also provide a substrate shielding structure formed by the above method. Please refer to [further details]. Figures 2 to 5 The shielding layer comprises: a substrate (not shown in the figure); a shielding layer on the substrate, the shielding layer comprising a plurality of mutually discrete unit regions A arranged along a first direction X, each unit region A comprising a plurality of coil regions 201 arranged along a second direction Y, adjacent coil regions 201 being electrically interconnected, each coil region 201 comprising a first coil 201a, the first coil 201a comprising at least one coil structure, the projection pattern of the coil structure on the surface of the substrate being “S” shaped; and a protective ring 202 located outside the shielding layer and surrounding the shielding layer, the protective ring 202 being grounded and electrically connected to the shielding layer.
[0044] Each coil region 201 includes a first coil 201a, which includes at least one coil structure. The projection pattern of the coil structure on the substrate surface is "S" shaped. According to Ampere's law, the induced electric fields generated by the induced magnetic field in adjacent coils of the coil structure are opposite in direction and have opposite trends. This can reduce the formation of substrate eddy currents in the substrate shielding structure by the induced magnetic field, suppress the formation of displacement current and substrate eddy currents, and thus improve the quality factor Q of the inductor.
[0045] In this embodiment, each coil region 201 further includes a second coil 201b, which is parallel to the first coil 201a. The projection pattern of the second coil 201b on the substrate surface is axially symmetrical to the projection pattern of the first coil 201a on the substrate surface. The second coil 201b is electrically interconnected with the first coil 201a.
[0046] In this embodiment, the area where the shielding layer is located is octagonal. In other embodiments, the shielding layer is adapted to the structure of the inductor, etc., so the area where the shielding layer is located is not limited to an octagonal shape.
[0047] The protective ring 202 includes a first region I and a second region II along the first direction X; the shielding layer includes a third region III and a fourth region IV along the first direction X, the third region III of the shielding layer is electrically connected to the first region I of the protective ring 202, and the fourth region IV of the shielding layer is electrically connected to the second region II of the protective ring 202.
[0048] In this embodiment, an inductor coil 205 located on the shielding layer is also included.
[0049] The shielding layer is located between the inductor coil 205 and the substrate to prevent the induced magnetic field of the induced electric field from forming substrate eddy currents in the conductor of the substrate shielding structure, suppress the formation of displacement current and substrate eddy currents, and improve the quality factor Q of the inductor.
[0050] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A substrate shielding structure, characterized in that, include: Substrate; A shielding layer located on the substrate includes a plurality of mutually independent unit regions arranged along a first direction, each unit region including a plurality of coil regions arranged along a second direction, adjacent coil regions being electrically interconnected, each coil region including a first coil, the first coil including at least one coil structure, the projection pattern of the coil structure on the surface of the substrate being "S" shaped. A protective ring is located outside the shielding layer and surrounds the shielding layer. The protective ring is grounded and electrically connected to the shielding layer.
2. The substrate shielding structure as described in claim 1, characterized in that, Each coil region also includes a second coil, which is parallel to the first coil, and the projection pattern of the second coil on the substrate surface is axially symmetrical to the projection pattern of the first coil on the substrate surface. The second coil is electrically interconnected with the first coil.
3. The substrate shielding structure as described in claim 1, characterized in that, The area where the shielding layer is located is octagonal.
4. The substrate shielding structure as described in claim 1, characterized in that, The protective ring includes a first region and a second region along the first direction; the shielding layer includes a third region and a fourth region along the first direction, the third region of the shielding layer is electrically connected to the first region of the protective ring, and the fourth region of the shielding layer is electrically connected to the second region of the protective ring.
5. The substrate shielding structure as described in claim 1, characterized in that, Also includes: An inductor coil located on the shielding layer.
6. A method for forming a substrate shielding structure, characterized in that, include: Provide substrate; A shielding layer is formed on the substrate. The shielding layer includes a plurality of mutually independent unit regions arranged along a first direction. Each unit region includes a plurality of coil regions arranged along a second direction. Adjacent coil regions are electrically interconnected. Each coil region includes a first coil. The first coil includes at least one coil structure. The projection pattern of the coil structure on the surface of the substrate is "S". A protective ring is formed on the substrate, located outside the shielding layer and surrounding the shielding layer. The protective ring is grounded and electrically connected to the shielding layer.
7. The method for forming a substrate shielding structure as described in claim 6, characterized in that, Each coil region also includes a second coil, which is parallel to the first coil, and the projection pattern of the second coil on the substrate surface is axially symmetrical to the projection pattern of the first coil on the substrate surface. The second coil is electrically interconnected with the first coil.
8. The method for forming a substrate shielding structure as described in claim 6, characterized in that, The area where the shielding layer is located is octagonal.
9. The method for forming a substrate shielding structure as described in claim 6, characterized in that, The protective ring includes a first region and a second region along the first direction; the shielding layer includes a third region and a fourth region along the first direction, the third region of the shielding layer is electrically connected to the first region of the protective ring, and the fourth region of the shielding layer is electrically connected to the second region of the protective ring.
10. The method for forming a substrate shielding structure as described in claim 6, characterized in that, The number of the first coils in each coil region is greater than or equal to 2.
11. The method for forming a substrate shielding structure as described in claim 6, characterized in that, Also includes: An inductor coil is formed on the shielding layer.