Electrostatic discharge protection structure
By employing an alternating serpentine gate structure and a combined drain-source design in the electrostatic discharge protection structure, the problem of insufficient performance of electrostatic discharge protection structures in semiconductor integrated circuits is solved, achieving higher protection capability and smaller chip footprint.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SEMICON MFG INT (SHANGHAI) CORP
- Filing Date
- 2023-06-28
- Publication Date
- 2026-06-05
AI Technical Summary
Existing electrostatic discharge protection structures are insufficient in performance in semiconductor integrated circuits, making it difficult to meet the requirements of smaller process nodes, and they occupy a large chip area.
By employing alternating gate structures extending along the first and second directions, and adding a second gate structure extending along the second direction to the drain and source, a serpentine structure is formed, which increases the breakdown current and effective channel length, and optimizes the current discharge path.
It improves the protection capability of the electrostatic discharge protection structure, reduces the chip area occupied, reduces the probability of ESD circuit non-uniformity activation, and enhances the current discharge capability.
Smart Images
Figure CN119230542B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor manufacturing, and more particularly to an electrostatic discharge protection structure. Background Technology
[0002] Integrated circuits are susceptible to damage from static electricity. In existing chip designs, electrostatic discharge (ESD) protection circuits are often used to reduce chip damage.
[0003] However, with the rapid growth of the integrated circuit (IC) industry, semiconductor technology, driven by Moore's Law, continues to advance towards smaller process nodes, making integrated circuits smaller, more precise, and more complex.
[0004] Therefore, the performance of existing electrostatic protection structures needs to be improved. Summary of the Invention
[0005] The problem solved by the embodiments of the present invention is to provide an electrostatic discharge protection structure to improve the performance of electrostatic discharge protection structures.
[0006] To address the aforementioned problems, this invention provides an electrostatic discharge protection structure, comprising: a substrate; a gate structure located on the substrate, the gate structure including a first gate structure extending along a first direction and a second gate structure extending along a second direction, the first and second directions intersecting, and the first and second gate structures alternately connected, the gate structure including a first sidewall and a second sidewall opposite to the first sidewall; a drain electrode distributed along the gate structure on one side of the first sidewall and located in the substrate, wherein the drain electrode distributed along the first gate structure is integrally connected with the drain electrode distributed along the second gate structure; and a source electrode distributed along the gate structure on one side of the second sidewall and located in the substrate, wherein the source electrode distributed along the first gate structure is integrally connected with the source electrode distributed along the second gate structure.
[0007] Optionally, the first direction is perpendicular to the second direction, the gate structure is a serpentine structure, and the first and second directions are the extension directions of the serpentine structure.
[0008] Optionally, both the source and the drain are comb-shaped structures, each including a comb handle extending in a first direction and comb teeth connected to the comb handle and extending in a second direction, wherein the comb teeth of the source and the comb teeth of the drain are arranged to cross each other.
[0009] Optionally, the electrostatic discharge protection structure further includes: a source-drain plug, the source-drain plug including a first source-drain plug connected to the drain and a second source-drain plug connected to the source.
[0010] Optionally, there are multiple first source-drain plugs and multiple second source-drain plugs, with the first source-drain plugs arranged along the extension direction of the drain electrode and the second source-drain plugs arranged along the extension direction of the source electrode.
[0011] Optionally, the electrostatic discharge protection structure further includes: an isolation structure located in a substrate between the gate structure and the source, and in a substrate between the gate structure and the drain.
[0012] Optionally, the substrate includes an active region, and the gate structure, drain, and source are all located in the active region; the electrostatic discharge protection structure further includes a pickup region, which includes a first pickup region located on the periphery of the active region.
[0013] Optionally, the pickup region further includes a second pickup region located between the adjacent first gate structure and the source. The second pickup region is connected to the first pickup region, and the first pickup region and the second pickup region constitute the pickup region.
[0014] Optionally, the second pickup region is located between the adjacent first gate structure and source at the center of the active region.
[0015] Optionally, the electrostatic discharge protection structure further includes: an isolation structure located in a substrate between the gate structure and the source, and in a substrate between the gate structure and the drain; the second pickup region is located in the isolation structure distributed along the source side of the first gate structure.
[0016] Optionally, the electrostatic discharge protection structure further includes a pickup area plug; the pickup area plug is connected to the pickup area.
[0017] Optionally, there may be multiple pickup area plugs, which are arranged along the extension direction of the pickup area.
[0018] Optionally, the electrostatic discharge protection structure further includes a barrier layer located on the surface of the drain electrode on the side close to the gate structure.
[0019] Optionally, the barrier layer also extends to cover the top and sidewalls of the gate structure near the drain side.
[0020] Optionally, the material of the barrier layer includes silicon oxide or silicon nitride.
[0021] Optionally, the barrier layer is a silicide barrier layer.
[0022] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:
[0023] The electrostatic discharge protection structure provided in this embodiment of the invention includes a gate structure, wherein the gate structure includes a first gate structure extending along a first direction and a second gate structure extending along a second direction, and the first gate structure and the second gate structure are alternately connected; a drain electrode is distributed along one side of the first sidewall of the gate structure and located in the substrate, and a source electrode is distributed along one side of the second sidewall of the gate structure and located in the substrate. Compared with a scheme that only includes a first gate structure extending along the first direction, a drain electrode, and a source electrode, this embodiment of the invention adds a second gate structure extending along the second direction, and the first gate structure and the second gate structure are alternately connected, that is, the first gate structure and the second gate structure are connected as a single structure. Therefore, when part of the gate structure is triggered by ESD stress, other gate structures can be triggered quickly because they are located at the same potential. Thus, the first gate structure and the second gate structure connected as a single structure reduce the probability of ESD circuit non-uniformity activation and correspondingly increase the breakdown current value. Furthermore, by adding a second gate structure, drain, and source extending along the second direction, and by integrating the drain and source extending along the second direction with the drain and source extending along the first direction into a single structure, the effective channel length and current discharge path of the electrostatic discharge protection structure are increased, which correspondingly increases the breakdown current value. Therefore, more current can be generated to replace the avalanche current, thereby improving the protection capability and performance of the electrostatic discharge protection structure. At the same time, adding a second gate structure, drain, and source extending along the second direction can also make more effective use of the chip area, so that the electrostatic discharge protection structure occupies a smaller chip area while improving its protection capability, thus saving chip area.
[0024] In an optional configuration, the first direction is perpendicular to the second direction, and the gate structure is a serpentine structure. The first and second directions are the extension directions of the serpentine structure, meaning the gate structure is a multi-finger serpentine structure. The entire multi-finger gate structure can serve as a single gate structure with a relatively large width. Since the multi-finger serpentine structure is more regular, it helps to reduce the difficulty of forming the gate structure and makes it easier to achieve better uniformity of resistance between each finger gate structure and the source. This results in a better uniform conduction effect of the gate structure, further increasing the breakdown current value, thereby further improving the protection capability of the electrostatic discharge protection structure and further improving the performance of the electrostatic discharge protection structure. Attached Figure Description
[0025] Figure 1This is a schematic diagram of the first embodiment of the electrostatic discharge protection structure of the present invention;
[0026] Figure 2 This is a schematic diagram of the second embodiment of the electrostatic discharge protection structure of the present invention;
[0027] Figure 3 This is a schematic diagram of the third embodiment of the electrostatic discharge protection structure of the present invention. Detailed Implementation
[0028] In existing technologies, improving the protection capability of electrostatic discharge (ESD) protection structures is often achieved by increasing their area. However, as semiconductor integrated circuit process nodes become smaller, the area of ESD protection structures faces numerous limitations. Therefore, the performance of ESD protection structures still needs improvement.
[0029] To address the aforementioned technical problems, embodiments of the present invention provide an electrostatic discharge protection structure, comprising: a substrate; a gate structure located on the substrate, the gate structure including a first gate structure extending along a first direction and a second gate structure extending along a second direction, the first and second directions intersecting, and the first and second gate structures alternately connected, the gate structure including a first sidewall and a second sidewall opposite to the first sidewall; a drain electrode distributed along the gate structure on one side of the first sidewall and located in the substrate, wherein the drain electrode distributed along the first gate structure is integrally connected with the drain electrode distributed along the second gate structure; and a source electrode distributed along the gate structure on one side of the second sidewall and located in the substrate, wherein the source electrode distributed along the first gate structure is integrally connected with the source electrode distributed along the second gate structure.
[0030] The electrostatic discharge protection structure provided in this embodiment of the invention includes a gate structure, wherein the gate structure includes a first gate structure extending along a first direction and a second gate structure extending along a second direction, and the first gate structure and the second gate structure are alternately connected; a drain electrode is distributed along one side of the first sidewall of the gate structure and located in the substrate, and a source electrode is distributed along one side of the second sidewall of the gate structure and located in the substrate. Compared with a scheme that only includes a first gate structure extending along the first direction, a drain electrode, and a source electrode, this embodiment of the invention adds a second gate structure extending along the second direction, and the first gate structure and the second gate structure are alternately connected, that is, the first gate structure and the second gate structure are connected as a single structure. Therefore, when part of the gate structure is triggered by ESD stress, other gate structures can be triggered quickly because they are located at the same potential. Thus, the first gate structure and the second gate structure connected as a single structure reduce the probability of ESD circuit non-uniformity activation and correspondingly increase the breakdown current value. Furthermore, by adding a second gate structure, drain, and source extending along the second direction, and by integrating the drain and source extending along the second direction with the drain and source extending along the first direction into a single structure, the effective channel length and current discharge path of the electrostatic discharge protection structure are increased, which correspondingly increases the breakdown current value. Therefore, more current can be generated to replace the avalanche current, thereby improving the protection capability and performance of the electrostatic discharge protection structure. At the same time, adding a second gate structure, drain, and source extending along the second direction can also make more effective use of the chip area, so that the electrostatic discharge protection structure occupies a smaller chip area while improving its protection capability, thus saving chip area.
[0031] To make the above-mentioned objects, features and advantages of the embodiments of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0032] Figure 1 This is a schematic diagram of an embodiment of the electrostatic discharge protection structure of the present invention.
[0033] In this embodiment, the electrostatic discharge protection structure includes: a substrate 100; a gate structure 110 located on the substrate 100, the gate structure 110 including a first gate structure 1101 extending along a first direction Y and a second gate structure 1102 extending along a second direction X, the first direction Y and the second direction X intersecting, and the first gate structure 1101 and the second gate structure 1102 alternately connected, the gate structure 110 including a first sidewall 111 and a second sidewall 112 opposite to the first sidewall 111; and a drain 120, along... The gate structure 110 is distributed on one side of the first sidewall 111 and located in the substrate 100, wherein the drain 120 distributed along the first gate structure 1101 is connected to the drain 120 distributed along the second gate structure 1102 as a single structure; the source 130 is distributed along the gate structure 110 on one side of the second sidewall 112 and located in the substrate 100, wherein the source 130 distributed along the first gate structure 1101 is connected to the source 130 distributed along the second gate structure 1102 as a single structure.
[0034] The substrate 100 is used to provide a process platform for the formation of electrostatic discharge protection structures.
[0035] In this embodiment, the substrate 100 is used to form a metal-oxide-semiconductor (MOS) field-effect transistor.
[0036] In this embodiment, the substrate 100 includes a substrate (not shown), which is a silicon substrate. In other embodiments, the substrate material can be germanium, silicon germanide, silicon carbide, gallium arsenide, or indium gallium ionide, or other materials. The substrate can also be a silicon-on-insulator substrate or a germanium-on-insulator substrate, or other types of substrates.
[0037] In this embodiment, the substrate 100 includes an active region I, and the gate structure 110, drain 120 and source 130 are located in the active region I.
[0038] The active region I is used to define the locations of the channel region and the source / drain doped regions.
[0039] The gate structure 110 is used to control the opening and closing of the conductive channel.
[0040] In this embodiment, the gate structure 110 is a device gate structure, which includes a gate dielectric layer (not shown) and a gate electrode layer (not shown) covering the gate dielectric layer.
[0041] The gate dielectric layer is used to isolate the gate electrode layer from the substrate 100 of the active region I.
[0042] The material of the gate dielectric layer includes one or more of HfO2, ZrO2, HfSiO, HfSiON, HfTaO, HfTiO, HfZrO, Al2O3, SiO2, and La2O3.
[0043] In this embodiment, the gate structure 110 is a metal gate structure. Therefore, the material of the gate electrode layer includes one or more of TiN, TaN, Ta, Ti, TiAl, W, Al, TiSiN, and TiAlC. The gate electrode layer includes a work function layer and an electrode layer covering the work function layer, or it may only include a work function layer.
[0044] Accordingly, the gate dielectric layer includes a high-k gate dielectric layer. The material of the high-k gate dielectric layer is a high-k dielectric material, which refers to a dielectric material with a relative permittivity greater than that of silicon oxide. Specifically, the material of the high-k gate dielectric layer can be selected from HfO2, ZrO2, HfSiO, HfSiON, HfTaO, HfTiO, HfZrO, or Al2O3, etc. As an example, the material of the high-k gate dielectric layer is HfO2.
[0045] In other embodiments, the gate structure may also be a polysilicon gate structure.
[0046] The gate structure 110 includes a first gate structure 1101 extending along a first direction Y and a second gate structure 1102 extending along a second direction X. The first direction Y and the second direction X intersect. Compared with a scheme that only includes a first gate structure extending along the first direction, the addition of a second gate structure 1102 extending along the second direction X, and the alternating connection of the first gate structure 1101 and the second gate structure 1102, i.e., the first gate structure 1101 and the second gate structure 1102 being integrated into a single structure, means that when some gate structures 110 are triggered by ESD stress, other gate structures 110, being at the same potential, can be triggered quickly. Therefore, the integrated first gate structure 1101 and the second gate structure 1102 reduce the probability of ESD circuit non-uniformity activation and correspondingly increase the breakdown current value. At the same time, adding the second gate structure 1102 extending along the second direction X also allows for more efficient use of chip area, resulting in a smaller chip area occupied by the ESD protection structure while improving its protection capability, thus saving chip area.
[0047] Furthermore, the second gate structure 1102 extending along the second direction X and the second gate structure 1102 extending along the first direction Y are integrated into one structure, which is beneficial to increasing the process window for forming the gate structure 110.
[0048] Specifically, the first direction Y is perpendicular to the second direction X, the gate structure 110 has a serpentine structure, and the first direction Y and the second direction X are the extension directions of the serpentine structure.
[0049] The first direction Y is perpendicular to the second direction, and the gate structure 110 has a serpentine structure. The first direction Y and the second direction X are the extension directions of the serpentine structure, that is, the gate structure 110 is a multi-finger serpentine structure. The entire multi-finger gate structure 110 can serve as a single gate structure with a large width. Since the multi-finger serpentine structure is more regular, it is beneficial to reduce the difficulty of forming the gate structure 110, and it is easier to make the resistance value between each finger gate structure 110 and the source 130 more uniform, thereby making the gate structure 110 more uniformly conductive, further increasing the breakdown current value, and further improving the protection capability of the electrostatic discharge protection structure, and also further improving the performance of the electrostatic discharge protection structure.
[0050] It should be noted that the gate structure 110 includes a first sidewall 111 and a second sidewall 112 opposite to the first sidewall 111. The first sidewall 111 of the first gate structure 1101 and the first sidewall 111 of the second gate structure 1102 are connected, and the second sidewall 112 of the first gate structure 1101 and the second sidewall 112 of the second gate structure 1102 are connected, thereby making the drain 120 distributed along the first gate structure 1101 and the drain 120 distributed along the second gate structure 1102 a single structure, and the source 130 distributed along the first gate structure 1101 and the source 130 distributed along the second gate structure 1102 a single structure.
[0051] The drain 120 and source 130 are used to provide a source of charge carriers for the conductive channel when the device is in operation.
[0052] The drain 120 is distributed along the gate structure 110 on one side of the first sidewall 111 of the gate structure 110 and located in the substrate 100, and the source 130 is distributed along the gate structure 110 on one side of the second sidewall 112 of the gate structure 110 and located in the substrate 100. Compared with a scheme that only includes a first gate structure, drain, and source extending along the first direction, this scheme adds a second gate structure 1102, a drain 120, and a source 130 extending along the second direction X. The drain 120 and source 130 extending along the second direction X are respectively connected to the drain 120 extending along the first direction X. The source 130 and drain 120 are integrated into a single structure, which increases the effective channel length and the current discharge path of the electrostatic discharge protection structure, and correspondingly increases the breakdown current value. Therefore, more current can be generated to replace the avalanche current, thereby improving the protection capability and performance of the electrostatic discharge protection structure. At the same time, the addition of drain 120 and source 130 extending along the second direction X can also make more effective use of chip area. This allows the electrostatic discharge protection structure to occupy a smaller chip area while improving its protection capability, thus saving chip area.
[0053] In this embodiment, both the drain 120 and the source 130 are doped with N-type ions, or both are doped with P-type ions. The N-type ions include P ions, As ions, or Sb ions, etc., and the P-type ions include B ions, Ga ions, or In ions, etc.
[0054] In this embodiment, the first direction Y is perpendicular to the second direction X, and the gate structure 110 has a serpentine structure, with the first direction Y and the second direction X being the extension directions of the serpentine structure. Correspondingly, both the source 130 and the drain 120 have comb-like structures. Both the source 130 and the drain 120 include a comb shank (not shown) extending along the first direction Y, and comb teeth (not shown) connected to the comb shank and extending along the second direction X. The comb teeth of the source 130 and the comb teeth of the drain 120 are arranged intersecting each other.
[0055] Since the first direction Y is perpendicular to the second direction X, the gate structure 110 has a serpentine structure. The source 130 and the drain 120 both include a comb shank extending along the first direction Y and a comb tooth extending along the second direction X and connected to the comb shank. The comb tooth of the source 130 and the comb tooth of the drain 120 are arranged to cross each other, which is beneficial to increase the process window for forming the source 130 and the drain 120, while further improving the area utilization of the electrostatic discharge protection structure.
[0056] In this embodiment, the electrostatic discharge protection structure further includes a source-drain plug 140, which includes a first source-drain plug 141 connected to the drain electrode 120 and a second source-drain plug 142 connected to the source electrode 130.
[0057] The source-drain plug 140 is used to realize the electrical connection between the drain 120 and the source 130 and the external circuit.
[0058] Specifically, there are multiple first source drain plugs 141 and second source drain plugs 142. The first source drain plugs 141 are arranged along the extension direction of the drain electrode 120, and the second source drain plugs 142 are arranged along the extension direction of the source electrode 130.
[0059] It should be noted that the gate structure 110 includes a first gate structure 1101 extending along the first direction Y and a second gate structure 1102 extending along the second direction X. The first direction Y and the second direction X intersect. The drain 120 is distributed along the gate structure 110 on one side of the first sidewall 111. The drain 120 distributed along the first gate structure 1101 and the drain 120 distributed along the second gate structure 1102 are connected to each other as an integral structure. Accordingly, the drain 120 includes a drain 120 extending along the first direction Y and a drain 120 extending along the second direction X.
[0060] Similarly, since the source electrode 130 is distributed along the gate structure 110 on one side of the second sidewall 112, and the source electrode 130 distributed along the first gate structure 1101 is connected to the source electrode 130 distributed along the second gate structure 1102 as a single structure, the source electrode 130 also includes a source electrode 130 extending along the first direction Y and a source electrode 130 extending along the second direction X.
[0061] Therefore, as Figure 1 As shown, the first source drain plug 141 includes a first source drain plug 141 arranged along the first direction Y (i.e., the first source drain plug 141 arranged longitudinally) and a first source drain plug 141 arranged along the second direction X (i.e., the first source drain plug 141 arranged laterally). In other words, the first source drain plug 141 located on the drain electrode 120 extending along the first direction Y is arranged along the first direction Y, and the first source drain plug 141 located on the drain electrode 120 extending along the second direction X is arranged along the second direction X.
[0062] Similarly, the second source drain plug 142 includes a second source drain plug 142 arranged along the first direction Y (i.e., a second source drain plug 142 arranged longitudinally) and a second source drain plug 142 arranged along the second direction X (i.e., a second source drain plug 142 arranged laterally). In other words, the second source drain plug 142 located on the source electrode 130 extending along the first direction Y is arranged along the first direction Y, and the second source drain plug 142 located on the source electrode 130 extending along the second direction X is arranged along the second direction X.
[0063] The number of the first source drain plug 141 and the second source drain plug 142 are both multiple, which makes it easier to reduce the current value flowing through a single source drain plug 140, thereby increasing the current discharge capability of the electrostatic discharge protection structure.
[0064] In this embodiment, the electrostatic discharge protection structure further includes a pickup area 150, which includes a first pickup area 151 located on the periphery of the active area I.
[0065] The pickup area 150 is used as a bulk end and is used to connect to the grounding end.
[0066] The first pickup area 151 is located on the periphery of the active area I, so that when the electrostatic discharge protection structure discharges current, the discharge current flows from the source 130 to the ground terminal through the first pickup area 151.
[0067] In this embodiment, the electrostatic discharge protection structure further includes a pickup area plug 153; the pickup area plug 153 is connected to the pickup area 150.
[0068] The pickup area plug 153, which is connected to the pickup area 150, is used to realize the electrical connection between the first pickup area 151 and the grounding terminal, thereby facilitating the discharge of current by the electrostatic discharge protection structure.
[0069] Specifically, there are multiple pickup area plugs 153, which are arranged along the extension direction of the pickup area 150.
[0070] The first pickup area 151 is located on the periphery of the active area I, that is, the first pickup area 151 surrounds the active area I. Therefore, the first pickup area 151 includes a first pickup area 151 arranged along the first direction Y and a first pickup area 151 arranged along the second direction X.
[0071] Correspondingly, such as Figure 1As shown, the pickup area plug 153 includes pickup area plugs 153 arranged along the first direction Y (i.e., longitudinally arranged pickup area plugs 153) and pickup area plugs 153 arranged along the second direction X (i.e., laterally arranged pickup area plugs 153). In other words, the pickup area plugs 153 located on the first pickup area 151 extending along the first direction Y are arranged along the first direction Y, and the pickup area plugs 153 located on the first pickup area 151 extending along the second direction X are arranged along the second direction X.
[0072] The number of pickup area plugs 153 is multiple and they are arranged along the extension direction of the pickup area 150, so that when the electrostatic discharge protection structure discharges current, it is easier to reduce the current value flowing through a single pickup area plug 153, thereby making the current discharge effect of the electrostatic discharge protection structure better.
[0073] refer to Figure 2 , Figure 2 This is a schematic diagram of the second embodiment of the electrostatic discharge protection structure of the present invention.
[0074] The similarities between the second embodiment and the previous embodiment will not be repeated here. The difference between the second embodiment and the previous embodiment is that the electrostatic discharge protection structure further includes: an isolation structure 270 located in the substrate 200 between the gate structure 210 and the source 230, and in the substrate 200 between the gate structure 210 and the drain 220.
[0075] An isolation structure 270 is provided in the substrate 200 between the gate structure 210 and the source 230, and between the gate structure 210 and the drain 220. This helps to increase the resistance between the source 230 and the drain 220, as well as the resistance between the gate structure 210 and the source 230. Consequently, the breakdown current is further increased, thereby further improving the protection capability of the electrostatic discharge protection structure.
[0076] Specifically, the material of the isolation structure 270 can be a dielectric material such as silicon oxide, silicon nitride, or silicon oxynitride. As an example, the material of the isolation structure 270 is silicon oxide.
[0077] refer to Figure 3 , Figure 3 This is a schematic diagram of the third embodiment of the electrostatic discharge protection structure of the present invention.
[0078] The similarities between the third embodiment and the previous embodiments will not be repeated here. The difference between the third embodiment and the previous embodiments is that the pickup area 350 further includes a second pickup area 352, located between the adjacent first gate structure 3101 and source 330. The second pickup area 352 is connected to the first pickup area 351, and the first pickup area 351 and the second pickup area 352 constitute the pickup area 350.
[0079] It should be noted that the second pickup area 352 is located between adjacent first gate structures 3101 and source 330, meaning that the second pickup area 352 is located between each first gate structure 3101 and its adjacent source 330, or between a portion of the first gate structure 3101 and its adjacent source 330.
[0080] The second pickup region 352 is located between the adjacent first gate structure 3101 and source 330, shortening the distance between the drain 320 and the pickup region 350. When a voltage is applied to the drain 320 to turn on the parasitic NPN transistor, the generated current can flow out from the closer pickup region 350, thereby reducing the probability of excessive current in some regions of the MOS transistors when the resistance in some regions is too high, causing some regions of the MOS transistors to turn on preferentially while other regions of the MOS transistors cannot turn on. This reduces the probability of damage to some regions of the MOS transistors.
[0081] Specifically, the second pickup area 352 is located between the adjacent first gate structure 3101 and source 330 at the center of the active area I”.
[0082] The center of the active region I” is farther away from the first pickup region 351. Therefore, the second pickup region 352 is located between the adjacent first gate structure 3101 and source 330 at the center of the active region I”. This helps to prevent the resistance at the center of the active region I” from being too high, which would lead to the MOS transistor at the center being turned on first and the MOS transistor at the edge being unable to turn on. This reduces the probability of the MOS transistor at the center having excessive current, and thus reduces the probability of the MOS transistor at the center being damaged.
[0083] In this embodiment, the electrostatic discharge protection structure includes: an isolation structure 370 located in a substrate 300 between the gate structure 310 and the source 330, and in a substrate 300 between the gate structure 310 and the drain 320; correspondingly, the second pickup region 352 is located in the isolation structure 370 distributed along the source 330 side of the first gate structure 310.
[0084] In this embodiment, the pickup area plug 353 is also connected to the second pickup area 352. The pickup area plug 353 is connected to the first pickup area 351 and the second pickup area 352, and is also used to realize the electrical connection between the first pickup area 351 and the second pickup area 352, thereby facilitating the discharge of current by the electrostatic discharge protection structure.
[0085] Specifically, there are also multiple pickup area plugs 353 connected to the second pickup area 352, and they are arranged along the extension direction of the second pickup area 352.
[0086] In this embodiment, the electrostatic discharge protection structure further includes a barrier layer 360 located on the surface of the drain 320 near the gate structure 310.
[0087] The barrier layer 360 is located on the side surface of the drain 320 near the gate structure 310, which helps to reduce the probability of the discharge current of the electrostatic discharge protection structure flowing laterally through the surface of the drain 320. This makes the discharge current of the electrostatic discharge protection structure flow to the ground terminal through the drain 320 and the pickup area 350 more effectively, thus improving the discharge current effect of the electrostatic discharge protection structure.
[0088] Therefore, the barrier layer 360 has an insulating function. In this embodiment, the material of the barrier layer 360 includes silicon oxide and silicon nitride. The use of silicon oxide or silicon nitride in the barrier layer 360 facilitates the formation of a high-resistivity barrier layer 360, which in turn helps maintain a high-resistivity state in the area covered by the barrier layer 360. This results in a better reduction of the probability of the discharge current flowing laterally out through the surface of the drain electrode 320.
[0089] Specifically, the electrostatic discharge protection structure includes a first source-drain plug 341 connected to the drain 320. Therefore, the barrier layer 360 is located between the first source-drain plug 341 and the gate structure 310.
[0090] In this embodiment, the barrier layer 360 also extends to cover the sidewall and part of the top of the gate structure 310 near the drain 320.
[0091] The barrier layer 360 also extends to cover the top and sidewall of the gate structure 310 near the drain 320, which helps to further reduce the probability of the discharge current flowing laterally out through the surface of the drain 320.
[0092] In this embodiment, the barrier layer 360 is a salicide block (SAB).
[0093] The semiconductor structure manufacturing process typically includes the formation of a silicide barrier layer. Using the process of forming a silicide barrier layer to form a barrier layer is beneficial for integration with existing process technologies, further improving process integration and process compatibility. Moreover, the silicide barrier layer process is relatively mature and easy to implement.
[0094] 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. An electrostatic discharge protection structure, characterized in that, include: Base; The substrate includes an active region, and the gate structure, drain, and source are all located in the active region; The pickup region includes a first pickup region located around the active region; the pickup region also includes a second pickup region located between an adjacent first gate structure and a source, the second pickup region being connected to the first pickup region, and the first pickup region and the second pickup region constituting the pickup region. A gate structure is located on the substrate. The gate structure includes a first gate structure extending along a first direction and a second gate structure extending along a second direction. The first direction and the second direction intersect, and the first gate structure and the second gate structure are alternately connected. The gate structure includes a first sidewall and a second sidewall opposite to the first sidewall. The drain electrode is distributed along the gate structure on one side of the first sidewall and located in the substrate, wherein the drain electrode distributed along the first gate structure is connected to the drain electrode distributed along the second gate structure as a single structure. The source electrode is distributed along the gate structure on one side of the second sidewall and located in the substrate, wherein the source electrode distributed along the first gate structure is integrated with the source electrode distributed along the second gate structure.
2. The electrostatic discharge protection structure as described in claim 1, characterized in that, The first direction is perpendicular to the second direction, and the gate structure is a serpentine structure, with the first and second directions being the extension directions of the serpentine structure.
3. The electrostatic discharge protection structure as described in claim 2, characterized in that, Both the source and drain electrodes are comb-shaped structures. Each source and drain electrode includes a comb handle portion extending along a first direction and a comb tooth portion connected to the comb handle portion and extending along a second direction. The comb tooth portions of the source electrode and the comb tooth portions of the drain electrode are arranged to cross each other.
4. The electrostatic discharge protection structure as described in any one of claims 1 to 3, characterized in that, The electrostatic discharge protection structure further includes: a source-drain plug, the source-drain plug including a first source-drain plug connected to the drain electrode and a second source-drain plug connected to the source electrode.
5. The electrostatic discharge protection structure as described in claim 4, characterized in that, There are multiple first source-drain plugs and multiple second source-drain plugs. The first source-drain plugs are arranged along the extension direction of the drain electrode, and the second source-drain plugs are arranged along the extension direction of the source electrode.
6. The electrostatic discharge protection structure as described in claim 1, characterized in that, The electrostatic discharge protection structure further includes: an isolation structure located in the substrate between the gate structure and the source, and in the substrate between the gate structure and the drain.
7. The electrostatic discharge protection structure as described in claim 1, characterized in that, The second pickup region is located between the adjacent first gate structure and the source at the center of the active region.
8. The electrostatic discharge protection structure as described in claim 1, characterized in that, The electrostatic discharge protection structure further includes: an isolation structure located in the substrate between the gate structure and the source, and in the substrate between the gate structure and the drain; The second pickup area is located in the isolation structure on the source side distributed along the first gate structure.
9. The electrostatic discharge protection structure as described in any one of claims 7 to 8, characterized in that, The electrostatic discharge protection structure also includes a pickup area plug; the pickup area plug is connected to the pickup area.
10. The electrostatic discharge protection structure as described in claim 9, characterized in that, The number of pickup area plugs is multiple, and the pickup area plugs are arranged along the extension direction of the pickup area.
11. The electrostatic discharge protection structure as described in claim 1, characterized in that, The electrostatic discharge protection structure further includes a barrier layer located on the surface of the drain electrode on the side closest to the gate structure.
12. The electrostatic discharge protection structure as described in claim 11, characterized in that, The barrier layer also extends to cover the top and sidewalls of the portion of the gate structure near the drain.
13. The electrostatic discharge protection structure as described in claim 11, characterized in that, The barrier layer is made of silicon oxide or silicon nitride.
14. The electrostatic discharge protection structure as described in claim 11, characterized in that, The barrier layer is a silicide barrier layer.