Electrostatic discharge protection device and method for manufacturing an electrostatic discharge protection device

Abstract

The present invention relates to electrostatic discharge protection devices and methods for manufacturing electrostatic discharge protection devices. An ESD protection device can be provided, comprising a substrate comprising a first conductive region and a second conductive region arranged therein. The first conductive region can comprise a first terminal region and a second terminal region electrically coupled to each other. The second conductive region can comprise a third terminal region and a fourth terminal region electrically coupled to each other. The second conductive region can further comprise a fifth terminal region electrically coupled to the first terminal region and the second terminal region. The fifth terminal region can be arranged between the third terminal region and the fourth terminal region in a lateral direction. The first conductive region, the first terminal region, the third terminal region, and the fifth terminal region can have a first conductivity type. The second conductive region, the second terminal region, and the fourth terminal region can have a second conductivity type different from the first conductivity type.

Description

Technical Field

[0001] This disclosure generally relates to electrostatic discharge (ESD) protection devices and methods for manufacturing ESD protection devices. Background Technology

[0002] ESD protection devices are commonly used to protect electrical equipment from ESD events. One type of ESD protection device is the silicon controlled rectifier (SCR) device, which conducts current away from the device during an ESD event. However, the trigger voltage of a typical SCR device is often very high. Therefore, there is a risk that overcurrent may not be conducted away from the device during an ESD event, leading to ESD failure in the equipment. Although the trigger voltage of an SCR device can be reduced by adding a highly doped diffusion node across the PN junction between the P-well and N-well of the SCR device, this often increases the holding voltage and on-resistance of the SCR device. Summary of the Invention

[0003] According to various non-limiting embodiments, an electrostatic discharge (ESD) protection device can be provided, comprising: a substrate including a first conductive region and a second conductive region disposed therein; wherein the first conductive region may include a first terminal region and a second terminal region electrically coupled to each other; wherein the second conductive region may include a third terminal region and a fourth terminal region electrically coupled to each other; wherein the second conductive region may further include a fifth terminal region disposed in a lateral direction between the third terminal region and the fourth terminal region and electrically coupled to the first terminal region and the second terminal region; wherein the first conductive region, the first terminal region, the third terminal region and the fifth terminal region may have a first conductivity type, and wherein the second conductive region, the second terminal region and the fourth terminal region may have a second conductivity type different from the first conductivity type.

[0004] According to various non-limiting embodiments, a method for manufacturing an ESD protection device can be provided, comprising: providing a substrate; forming a first conductive region and a second conductive region within the substrate; forming a first terminal region and a second terminal region within the first conductive region; forming a third terminal region, a fourth terminal region, and a fifth terminal region within the second conductive region; wherein the fifth terminal region may be arranged laterally between the third terminal region and the fourth terminal region; electrically coupling the first terminal region, the second terminal region, and the fifth terminal region; and electrically coupling the third terminal region and the fourth terminal region. The first conductive region, the first terminal region, the third terminal region, and the fifth terminal region may have a first conductivity type; and the second conductive region, the second terminal region, and the fourth terminal region may have a second conductivity type different from the first conductivity type. Attached Figure Description

[0005] In the accompanying drawings, similar reference numerals generally indicate the same parts throughout the different views. Furthermore, the drawings are not necessarily drawn to scale, but generally focus on illustrating the principles of the invention. Now, for illustrative purposes only, non-limiting embodiments of the invention are described with reference to the following drawings, in which:

[0006] Figure 1 A simplified cross-sectional view of an ESD protection device according to various non-limiting embodiments is shown;

[0007] Figure 2 A simplified cross-sectional view of an ESD protection device according to an alternative, non-limiting embodiment is shown;

[0008] Figure 3 A simplified cross-sectional view of an ESD protection device according to an alternative, non-limiting embodiment is shown;

[0009] Figure 4 A simplified cross-sectional view of an ESD protection device according to an alternative, non-limiting embodiment is shown;

[0010] Figure 5 A simplified cross-sectional view of an ESD protection device according to an alternative, non-limiting embodiment is shown;

[0011] Figure 6 A simplified cross-sectional view of an ESD protection device according to an alternative, non-limiting embodiment is shown; and

[0012] Figure 7 A flowchart of a method for manufacturing an ESD protection device according to various non-limiting embodiments is shown. Detailed Implementation

[0013] The embodiments generally relate to semiconductor devices. More specifically, some embodiments relate to ESD protection devices. ESD protection devices may, for example, be incorporated into integrated circuits (ICs). These devices or ICs can be used in devices such as, but not limited to, consumer electronics.

[0014] The invention, including its various aspects, features, advantages, and details, will be explained more fully below with reference to the non-limiting examples shown in the accompanying drawings. Descriptions of well-known materials, manufacturing tools, processing techniques, etc., are omitted to avoid unnecessarily obscuring the invention. However, it should be understood that while the detailed descriptions and specific examples indicate aspects of the invention, they are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions, and / or arrangements within the spirit and / or scope of the basic inventive concept will be apparent to those skilled in the art from this disclosure.

[0015] As used throughout the specification and claims, approximate language may be used to modify any quantitative expression that is permissible to vary without causing a change in the essential function associated with it. Therefore, values ​​modified by one or more terms such as “approximate,” “about,” or “basically” are not limited to the specified exact values. In some cases, approximate language may correspond to the precision of the instrument used to measure the value. Furthermore, the modification of direction by one or more terms such as “basically” means that the direction applies within the normal tolerance range of the semiconductor industry. For example, “basically parallel” means extending in approximately the same direction within the normal tolerance range of the semiconductor industry, while “basically perpendicular” means an angle of ninety degrees plus or minus the normal tolerance range of the semiconductor industry.

[0016] The terminology used herein is for the purpose of describing specific examples only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that the terms “comprise” (and any form of inclusion, such as “comprises” and “comprising”), “have” (and any form of having, such as “has” and “having”), “inclue” (and any form of inclusion, such as “includes” and “including”), and “contain” (and any form of containing, such as “contains” and “containing”) are open-ended linking verbs. Thus, a method or apparatus that “comprises,” “has,” “includes,” or “contains” one or more steps or elements has, but is not limited to, having only those steps or elements. Similarly, a method step or device element that “comprises,” “has,” “includes,” or “contains” one or more features has, but is not limited to, having only those features. Furthermore, devices or structures configured in a certain way are configured at least in this manner, but may also be configured in ways not listed.

[0017] As used herein, when referring to two physical elements, the term "connection" indicates a direct connection between the two physical elements. However, the term "coupled" can indicate a direct connection or a connection through one or more intermediate elements.

[0018] As used herein, the terms “may” and “may” indicate: the possibility of occurring in a set of circumstances; possessing a specified property, characteristic, or function; and / or qualifying one verb by expressing one or more of the capabilities, functions, or possibilities associated with the qualifying verb. Thus, the use of “may” and “may” indicates that the modified term is obviously suitable, permissible, or appropriate for the specified capability, function, or purpose, while taking into account that in some cases the modified term may not be suitable, permissible, or appropriate for the specified capability, function, or purpose. For example, in some cases an event or capability may be expected, while in others it may not occur—this distinction is captured by the terms “may” and “may”.

[0019] Figure 1 A simplified cross-sectional view of an ESD protection device 100 according to various non-limiting embodiments is shown. The ESD protection device 100 may be a silicon controlled rectifier (SCR) device.

[0020] like Figure 1 As shown, the ESD protection device 100 may include a substrate 102. The substrate 102 may include semiconductor materials, such as, but not limited to, silicon (Si), germanium (Ge), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), or combinations thereof. For example, the substrate 102 may include single-crystal silicon. In some non-limiting embodiments, the substrate 102 may include a semiconductor-on-insulator substrate, such as, but not limited to, silicon-on-insulator (SOI) substrate, germanium-on-insulator (GeOI) substrate, silicon-on-insulator (SiCOI) substrate, gallium arsenide-on-insulator (GaAsOI) substrate, gallium nitride-on-insulator (GaNOI) substrate, or combinations thereof.

[0021] The substrate 102 may include a first conductive region 104 and a second conductive region 106 disposed therein. For example... Figure 1 As shown, the first conductive region 104 and the second conductive region 106 can be arranged adjacent to each other in the lateral direction and can be joined together. The depth D of the first conductive region 104 104 With depth D of the second conductive region 106 106 They can be approximately equal, and their ranges can be from about 0.2 μm to about 1 μm.

[0022] The first conductive region 104 may include a first terminal region 108 and a second terminal region 110; while the second conductive region 106 may include a third terminal region 112 and a fourth terminal region 114. The second conductive region 106 may also include a fifth terminal region 116 disposed laterally between the third terminal region 112 and the fourth terminal region 114. Figure 1As shown, terminal regions 108, 110, 112, 114, and 116 can be arranged along the top surface 102t of substrate 102. For example, the top surfaces of these terminal regions 108, 110, 112, 114, and 116 can be coplanar and aligned with the top surface 102t of substrate 102. The depth D of terminal regions 108, 110, 112, 114, and 116 is... T They can be substantially equal and can both range from about 0.05 μm to about 0.2 μm.

[0023] In various non-limiting embodiments, substrate 102, first and second conductive regions 104, 106, and first to fifth terminal regions 108-116 may include dopants. Substrate 102 may have the same conductivity type as the first conductive region 104 (in other words, it may include dopants of the same conductivity type). For example, substrate 102, first conductive region 104, first terminal region 108, third terminal region 112, and fifth terminal region 116 may have a first conductivity type (in other words, they may include dopants of the first conductivity type). On the other hand, second conductive region 106, second terminal region 110, and fourth terminal region 114 may have a second conductivity type different from the first conductivity type (in other words, they may include dopants of the second conductivity type). In various non-limiting embodiments, the first conductivity type may be P-type and the second conductivity type may be N-type. However, the first conductivity type may alternatively be N-type, and the second conductivity type may alternatively be P-type. P-type dopants may include boron (B), indium (In), or combinations thereof; while N-type dopants may include phosphorus (P), arsenic (As), antimony (Sb), or combinations thereof. Therefore, the junction 150 between the fifth terminal region 116 and the second conductive region 106, and the junction 160 between the first conductive region 104 and the second conductive region 106 can be PN junctions.

[0024] The doping concentrations (dopant concentrations per unit volume) of the first and second conductive regions 104 and 106 can be approximately equal and can each be higher than the doping concentration of the substrate 102. Furthermore, the doping concentrations of the terminal regions 108, 110, 112, 114, and 116 can be approximately equal. The doping concentrations of the first and second terminal regions 108 and 110 can each be higher than the doping concentration of the first conductive region 104, and the doping concentrations of the third, fourth, and fifth terminal regions 112, 114, and 116 can each be higher than the doping concentration of the second conductive region 106. For example, the doping concentration of the substrate 102 can range from approximately 1e15 cm⁻¹. -3 Approximately 5e15cm -3 The doping concentration of each of the first conductive region 104 and the second conductive region 106 can range from approximately 5e17cm. -3 Approximately 5e18cm -3The doping concentration of each of the first to fifth terminal regions 108, 110, 112, 114, and 116 can range from approximately 5e19cm. -3 Approximately 1e21cm -3 .

[0025] In various non-limiting embodiments, each of the first and second conductive regions 104, 106 can be a well. The first terminal region 108 and the fourth terminal region 114 can be well nodes; the second terminal region 110, the third terminal region 112, and the fifth terminal region 116 can be diffusion nodes. For example, the substrate 102 can be a P-type substrate, the first conductive region 104 can be a P-well, the second conductive region 106 can be an N-well, the first terminal region 108 can be a P-well (PW) node, the second terminal region 110 can be an N-diffusion (ND) node, the third terminal region 112 and the fifth terminal region 116 can be P-diffusion (PD) nodes, and the fourth terminal region 114 can be an N-well (NW) node.

[0026] refer to Figure 1 The ESD protection device 100 may further include first, second, third, fourth, and fifth insulating elements 118, 120, 122, 124, and 126. The first insulating element 118 may be disposed between the first terminal region 108 and the side surface of the substrate 102, and the fifth insulating element 126 may be disposed between the fourth terminal region 114 and the opposite side surface of the substrate 102. The second insulating element 120 may be disposed laterally between the first terminal region 108 and the second terminal region 110, the third insulating element 122 may be disposed laterally between the second terminal region 110 and the third terminal region 112, and the fourth insulating element 124 may be disposed laterally between the third terminal region 112 and the fifth terminal region 116. Figure 1 As shown, insulating elements 118, 120, 122, 124, and 126 can be arranged along the top surface 102t of the substrate 102. For example, the top surfaces of these insulating elements 118, 120, 122, 124, and 126 can be coplanar and aligned with the top surface 102t of the substrate 102. The depth D of the insulating elements 118, 120, 122, 124, and 126 is... I They can be approximately equal to, and can be greater than, the depth D of terminal areas 108, 110, 112, 114, and 116. T For example, the depth D of each insulating element 118, 120, 122, 124, 126 IThe range can be from about 0.1 μm to about 0.2 μm. Therefore, each of the first and fifth insulating elements 118, 126 can isolate terminal regions 108, 110, 112, 114, 116 from external interference; while the second, third, and fourth insulating elements 120, 122, 124 can isolate each pair of adjacent terminal regions 108, 110 / 110, 112 / 112, 116. Each insulating element 118, 120, 122, 124, 126 may include an electrically insulating material, such as a dielectric material, such as, but not limited to, silicon oxide. For example, each insulating element 118, 120, 122, 124, 126 may be a shallow trench isolation (STI) region.

[0027] The ESD protection device 100 may also include an isolation element 128 disposed in the lateral direction between the fourth terminal area 114 and the fifth terminal area 116. For example... Figure 1 As shown, a lateral spacing S can be arranged between the fourth terminal area 114 and the fifth terminal area 116. 46 Furthermore, the isolation element 128 can span the lateral spacing S between terminal areas 114 and 116. 46 The entire length of the space extends. Therefore, the isolation element 128 can engage the fourth terminal region 114 and can also engage the fifth terminal region 116 (e.g., along the side surfaces of terminal regions 114, 116, such as...). Figure 1 (As shown). The isolation element 128, the fourth terminal region 114, and the fifth terminal region 116 may be arranged along the top surface 102t of the substrate 102. For example, the top surfaces of the isolation element 128, the fourth terminal region 114, and the fifth terminal region 116 may be coplanar and aligned with the top surface 102t of the substrate 102. A portion of the second conductive region 106 may be arranged below the isolation element 128 and laterally between the fourth terminal region 114 and the fifth terminal region 116.

[0028] like Figure 1 As shown, the depth D of the isolation element 128 128 It can be less than the depth D of each of the insulating elements 118, 120, 122, 124, and 126. I For example, the depth D of isolation element 128 128The range can be from about 0.01 μm to about 0.5 μm. The isolation element 128 may also include an electrically insulating material, such as a dielectric material, such as, but not limited to, silicon oxide. Therefore, the isolation element 128 can electrically isolate the fifth terminal region 116 from the fourth terminal region 114 along the top surface 102t of the substrate 102. In some non-limiting embodiments, the isolation element 128 may include a material different from that of the insulating elements 118, 120, 122, 124, 126. For example, the isolation element 128 may include a block of silicide; while each insulating element 118, 120, 122, 124, 126 may be an STI region including silicon oxide. In alternative non-limiting embodiments, the isolation element 128 and each insulating element 118, 120, 122, 124, 126 may include the same electrically insulating material. For example, the isolation element 128 and the insulating elements 118, 120, 122, 124, and 126 can be STI regions, where the isolation element 128 is a very shallow STI region.

[0029] ESD protection device 100 may include conductive units (including, for example, conductive lines 130, 132, 134) connecting a first terminal region 108, a second terminal region 110, and a fifth terminal region 116 to a first conductive pad 136. In other words, the first terminal region 108, the second terminal region 110, and the fifth terminal region 116 may be electrically coupled to each other. ESD protection device 100 may also include another conductive unit (including, for example, conductive lines 138, 140) connecting a third terminal region 112 and a fourth terminal region 114 to a second conductive pad 142. In other words, the third terminal region 112 and the fourth terminal region 114 may be electrically coupled to each other. An additional conductive pad 144 may be disposed above the respective terminal regions 108, 110, 112, 114, 116 to facilitate the connection of conductive lines 130, 134, 138 to regions 108, 110, 112, 114, 116. Each of the conductive wires 130, 132, 134, 138, 140 and the conductive pads 136, 142, 144 may include a conductive material, such as, but not limited to, metal.

[0030] In an exemplary non-limiting embodiment, the first conductivity type can be P-type and the second conductivity type can be N-type. In this non-limiting embodiment, when the ESD protection device 100 is operating, the first conductive pad 136 can be grounded and the second conductive pad 142 can be connected to the input / output terminal of the device to be protected. The voltage at the input / output terminal can be a positive voltage, so the PN junctions 150 and 160 in the ESD protection device 100 can be reverse biased. When an ESD event occurs in the device, the voltage at the device's input / output terminal can exceed the trigger voltage. This can cause the PN junction 150 to break down and a first discharge current flows from the second conductive pad 142 through the ESD protection device 100 to ground. For example, the first discharge current can flow from the second conductive pad 142 sequentially through the fourth terminal region 114, the second conductive region 106, the fifth terminal region 116, and the first conductive pad 136 to ground. Subsequently, a second discharge current can flow from the second conductive pad 142 through the ESD protection device 100 to ground. For example, a second discharge current can flow from the second conductive pad 142 sequentially through the third terminal region 112, the second conductive region 106, the fifth terminal region 116, and the first conductive pad 136 to ground. The duration of the second discharge current can be shorter than the duration of the first discharge current. Subsequently, the PN junction 160 can break down, and a third discharge current can flow from the second conductive pad 142 through the ESD protection device 100 to ground. For example, the third discharge current can flow from the second conductive pad 142 sequentially through the third terminal region 112, the second conductive region 106, the first conductive region 104, the second terminal region 110, and the first conductive pad 136 to ground. In other words, the first conductive region 104, together with the second and fifth terminal regions 110 and 116, can be used as the cathode of the ESD protection device 100; while the second conductive region 106, together with the third and fourth terminal regions 112 and 114, can be used as the anode of the ESD protection device 100. Therefore, during an ESD event, the overcurrent can be redirected from the device, protecting the device from ESD failure. Those skilled in the art will understand that when the first conductivity type and the second conductivity type are replaced by N-type and P-type, respectively, the directions of the first and second discharge currents will change accordingly.

[0031] Because the fourth and fifth terminal regions 114, 116 have higher doping concentrations, the PN junction 150 can break down at a lower voltage compared to the breakdown voltage of the PN junction 160. Therefore, the trigger voltage of the ESD protection device 100 can be lower than that of prior art devices. For example, the trigger voltage range of prior art devices can be approximately 10V to 14V; while the trigger voltage range of the ESD protection device 100 can be approximately 6V to 10V (and approximately 8V in a non-limiting embodiment). Furthermore, including the fifth terminal region 116 in the lateral direction between the third and fourth terminal regions 112, 114 (rather than to the left / right of both regions 112, 114) allows the ESD protection device 100 to maintain similar current-voltage (IV) characteristics to prior art devices. For example, the holding voltage / clamping voltage of the ESD protection device 100 can be maintained at a level similar to that of prior art devices. Additionally, the base width of the ESD protection device 100 can also be similar to that of prior art devices.

[0032] Including an isolation element 128 in the lateral direction between the fourth and fifth terminal regions 114, 116 can further reduce the breakdown voltage of the PN junction 150 (or in other words, can further reduce the trigger voltage of the ESD protection device 100). However, the isolation element 128 may be optional.

[0033] Figure 2 A cross-sectional view of an ESD protection device 200 according to an alternative, non-limiting embodiment is shown. The ESD protection device 200 is similar to the ESD protection device 100; therefore, common features are indicated by the same reference numerals and need not be discussed further.

[0034] like Figure 2 As shown, the ESD protection device 200 may not include the isolation element 128. Therefore, a portion of the second conductive region 106 can be arranged laterally between the fourth terminal region 114 and the fifth terminal region 116, wherein this portion of the second conductive region 106, the fourth terminal region 114, and the fifth terminal region 116 can be arranged along the top surface 102t of the substrate 102. For example, the top surfaces of this portion of the second conductive region 106, the fourth terminal region 114, and the fifth terminal region 116 can be coplanar and aligned with the top surface 102t of the substrate 102.

[0035] By adjusting the lateral spacing S between the fourth and fifth terminal areas 114 and 116 46 The length of the device can be adjusted to regulate the trigger voltage of the ESD protection device 100 / 200. For example, the trigger voltage of the ESD protection device 100 can be adjusted by reducing the lateral spacing S between the fourth and fifth terminal areas 114, 116. 46 To reduce.

[0036] Figure 3 A cross-sectional view of an ESD protection device 300 according to an alternative, non-limiting embodiment is shown. The ESD protection device 300 is similar to the ESD protection device 200; therefore, common features are indicated by the same reference numerals and need not be discussed further.

[0037] like Figure 3 As shown, the fourth terminal region 114 and the fifth terminal region 116 of the ESD protection device 300 can be arranged horizontally against each other and can be joined together. The junction 302 between the fourth and fifth terminal regions 114 and 116 can be a PN junction, and due to the higher doping concentration of the fourth and fifth terminal regions 114 and 116, the breakdown voltage of this PN junction 302 can be less than the breakdown voltage of the PN junction 160 between the first and second conductive regions 104 and 106. Due to the junction between the fourth and fifth terminal regions 114 and 116, the breakdown voltage of this PN junction 302 can also be less than the breakdown voltage of the PN junction 150 in the ESD protection devices 100 and 200. Therefore, the trigger voltage of the ESD protection device 300 can be less than the trigger voltage of the ESD protection devices 100 and 200. However, reducing the lateral spacing S between the fourth and fifth terminal regions 114 and 116... 46 This will increase the leakage current of the ESD protection device 300. The lateral spacing S between the fourth and fifth terminal areas 114 and 116... 46 The range can be from about 0 μm to about 0.5 μm, and in some non-limiting embodiments, in order to achieve the best balance between achieving a smaller trigger voltage and reducing leakage current, the spacing S between the fourth and fifth terminal regions 114, 116 is... 46 The range can be from about 0.2 μm to about 0.5 μm.

[0038] Figure 4 A simplified cross-sectional view of an ESD protection device 400 according to an alternative, non-limiting embodiment is shown. The ESD protection device 400 is similar to the ESD protection device 100; therefore, common features are indicated by the same reference numerals and need not be discussed further.

[0039] like Figure 4As shown, the ESD protection device 400 may also include a substrate 102, which includes a first conductive region 104 and a second conductive region 106 disposed therein. Similar to the ESD protection device 100, the first conductive region 104 may include first and second terminal regions 108, 110; while the second conductive region 106 may include third, fourth, and fifth terminal regions 112, 114, 116, wherein the fifth terminal region 116 is disposed laterally between the third and fourth terminal regions 112, 114. The first, second, and fifth terminal regions 108, 110, 116 may be electrically connected to each other and electrically connected to a first conductive pad 136 via conductive units (including, for example, conductive lines 130, 132, 134). Similarly, the third and fourth terminal regions 112, 114 may be electrically coupled to each other and electrically coupled to a second conductive pad 142 via another conductive unit (including, for example, conductive lines 138, 140). An isolation element 128 may also be disposed laterally between the fourth and fifth terminal regions 114, 116.

[0040] However, compared to ESD protection device 100, in ESD protection device 400, substrate 102 may have a different conductivity type than the first conductive region 104. For example, in ESD protection device 400, the first conductive region 104, first terminal region 108, third terminal region 112, and fifth terminal region 116 may have a first conductivity type; while substrate 102, second conductive region 106, second terminal region 110, and fourth terminal region 114 may have a second conductivity type different from the first conductivity type. In various non-limiting embodiments, the first conductivity type may be N-type and the second conductivity type may be P-type. For example, substrate 102 may be a P-type substrate, first conductive region 104 may be an N-well, second conductive region 106 may be a P-well, first terminal region 108 may be an N-well (NW) node, second terminal region 110 may be a P-diffusion (PD) node, third and fifth terminal regions 112 and 116 may be N-diffusion (ND) nodes, and fourth terminal region 114 may be a P-well (PW) node. However, the first conductivity type can be P-type instead and the second conductivity type can be N-type instead.

[0041] In an exemplary non-limiting embodiment, the first conductivity type can be N-type and the second conductivity type can be P-type. In this non-limiting embodiment, when the ESD protection device 400 is operating, the first conductive pad 136 can be connected to the input / output terminal of the device to be protected (where the voltage at the terminal can be a positive voltage), and the second conductive pad 142 can be grounded. The operation of the ESD protection device 400 can be similar to that of the ESD protection device 100. For example, when the voltage at the input / output terminal of the device exceeds the trigger voltage, the PN junction 150 may break down, and a first discharge current can flow from the first conductive pad 136 through the ESD protection device 400 (e.g., sequentially through the fifth terminal region 116, the second conductive region 106, the fourth terminal region 114, and the second conductive pad 142) to ground. Subsequently, a second discharge current can flow from the first conductive pad 136 through the ESD protection device 400 (e.g., sequentially through the fifth terminal region 116, the second conductive region 106, the third terminal region 112, and the second conductive pad 142) to ground. The duration of the second discharge current can be shorter than the duration of the first discharge current. Subsequently, the PN junction 160 can break down and the third discharge current can flow from the first conductive pad 136 through the ESD protection device 400 (e.g., sequentially through the second terminal area 110, the first conductive area 104, the second conductive area 106, the third terminal area 112, and the second conductive pad 142) to ground. Thus, the overcurrent can be redirected from the device, protecting it from damage caused by an ESD event. Those skilled in the art will understand that when the first and second conductivity types are alternatively P-type and N-type, respectively, the directions of the first and second discharge currents will change accordingly.

[0042] Similar to ESD protection device 100, in ESD protection device 400, the breakdown voltage of PN junction 150 can be less than the breakdown voltage of PN junction 160. Therefore, compared to prior art devices, the trigger voltage of ESD protection device 400 can also be smaller. For example, the trigger voltage range of prior art devices can be about 10V to 14V; while the trigger voltage range of ESD protection device 400 can be about 6V to 10V (and in a non-limiting embodiment, about 8V).

[0043] The isolation element 128 in the ESD protection device 400 can also be optional. Figure 5 A cross-sectional view of an ESD protection device 500 according to an alternative, non-limiting embodiment is shown. The ESD protection device 500 is similar to the ESD protection device 400; therefore, common features are designated with the same reference numerals and need not be discussed further. Figure 5As shown, the ESD protection device 500 may not include the isolation element 128. Therefore, a portion of the second conductive region 106 can be arranged laterally between the fourth and fifth terminal regions 114, 116, wherein this portion of the second conductive region 106, the fourth terminal region 114, and the fifth terminal region 116 can be arranged along the top surface 102t of the substrate 102. For example, the top surfaces of this portion of the second conductive region 106, the fourth terminal region 114, and the fifth terminal region 116 can be coplanar and aligned with the top surface 102t of the substrate 102.

[0044] The spacing S between the fourth terminal area 114 and the fifth terminal area 116 can also be adjusted. 46 To adjust the trigger voltage of the ESD protection device 400 / 500. Figure 6 A cross-sectional view of an ESD protection device 600 according to an alternative, non-limiting embodiment is shown. The ESD protection device 600 is similar to the ESD protection device 500; therefore, common features are designated with the same reference numerals and need not be discussed further. Figure 6 As shown, in ESD protection device 600, the fourth terminal area 114 and the fifth terminal area 116 can be arranged horizontally against each other and can be connected to each other. Similar to ESD protection device 300 as described above, since the lateral spacing between the fourth and fifth terminal areas 114, 116 is essentially zero, the trigger voltage of ESD protection device 600 can be lower than the trigger voltage of ESD protection devices 400 and 500.

[0045] Figure 7 A flowchart of a method for manufacturing an ESD protection device according to various non-limiting embodiments is shown.

[0046] At 702, the method may include providing a substrate. The substrate may be, for example, the substrate 102 described above.

[0047] At 704, the method may include forming a first conductive region and a second conductive region within the substrate. The first and second conductive regions may, for example, be the first conductive region 104 and the second conductive region 106 as described above. 702 may include any process known to those skilled in the art. For example, 702 may include doping specific portions of the substrate 102 with suitable dopant to form conductive regions 104, 106.

[0048] At 706, the method may include forming a first terminal region and a second terminal region within a first conductive region. The first terminal region and the second terminal region may, for example, be the first terminal region 108 and the second terminal region 110 as described above. 706 may include any process known to those skilled in the art. For example, 706 may include doping specific portions of the substrate 102 with a suitable dopant to form terminal regions 108, 110.

[0049] At 708, the method may include forming a third terminal region, a fourth terminal region, and a fifth terminal region within the second conductive region, wherein the fifth terminal region may be arranged laterally between the third and fourth terminal regions. The third, fourth, and fifth terminal regions may, for example, be third terminal region 112, fourth terminal region 114, and fifth terminal region 116 as described above. 708 may include any process known to those skilled in the art. For example, 708 may include doping specific portions of the substrate 102 with a suitable dopant to form terminal regions 112, 114, and 116.

[0050] At 710, the method may include electrically coupling the first terminal region, the second terminal region, and the fifth terminal region. 710 may include any process known to those skilled in the art. For example, 710 may include forming conductive lines (e.g., conductive lines 130, 132, 134 as described above) to connect the first terminal region, the second terminal region, and the fifth terminal region. These conductive lines may be formed using a back-end process (BEOL) technology.

[0051] At 712, the method may include electrically coupling the third terminal region and the fourth terminal region. 712 may include any process known to those skilled in the art. For example, 712 may include forming conductive lines (e.g., conductive lines 138, 140 as described above) to connect the third terminal region and the fourth terminal region. Similarly, these conductive lines 138, 140 may be formed using a BEOL process.

[0052] The order described above for this method is intended to be exemplary only, and the method is not limited to the order specifically described above unless otherwise specified.

[0053] Furthermore, the method may also include forming insulating elements (e.g., insulating elements 118, 120, 122, 124, 126 as described above). This may include removing a portion of substrate 102 (e.g., by etching substrate 102) to form openings / trenches and filling these openings / trenches with an electrically insulating material. The method may also include forming an isolation element 128 by similarly removing a portion of substrate 102 to form openings / trenches and filling the openings / trenches with an electrically insulating material. The method may also additionally include forming conductive pads (e.g., conductive pads 136, 142, 144 as described above) using any methods known to those skilled in the art. In some non-limiting embodiments, the method may also include smoothing the top surface of the substrate (e.g., substrate 102 as described above) using any process known to those skilled in the art, such as, but not limited to, chemical mechanical polishing (CMP) processes. In these non-limiting embodiments, the top surfaces of the terminal regions, insulating elements, and isolation elements (e.g., terminal regions 108-116, insulating elements 118-126, and isolation elements 128 as described above) may be coplanar and aligned with the top surface 102t of the substrate 102.

[0054] The above method can be used to manufacture any of the ESD protection devices 100, 200, 300, 400, 500, and 600. Compared with methods used to manufacture prior art devices, the ESD protection devices 100, 200, 300, 400, 500, and 600 can be manufactured without the use of any additional masks.

[0055] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the foregoing embodiments are to be considered exemplary in all respects and not to limit the invention described herein. Accordingly, the scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes falling within the meaning and scope of equivalents of the claims are intended to be included therein.

Claims

1. An electrostatic discharge (ESD) protection device, comprising: A substrate, comprising a first conductive region and a second conductive region disposed therein; The first conductive region includes a first terminal region and a second terminal region that are electrically coupled to each other and electrically coupled to a first conductive pad. The second conductive region includes a third terminal region and a fourth terminal region that are electrically coupled to each other and to the second conductive pad; The second conductive region further includes a fifth terminal region that is arranged in the lateral direction between the third terminal region and the fourth terminal region and is electrically coupled to the first terminal region, the second terminal region and the first conductive pad; The first conductive region, the first terminal region, the third terminal region, and the fifth terminal region have a first conductivity type; and the second conductive region, the second terminal region, and the fourth terminal region have a second conductivity type different from the first conductivity type. in: (i) A portion of the second conductive region is arranged in the lateral direction between the fourth terminal region and the fifth terminal region to form a PN junction between the fifth terminal region and the second conductive region; or (ii) The fifth terminal region and the fourth terminal region are arranged horizontally to each other and joined together to form a PN junction between the fifth terminal region and the fourth terminal region.

2. The ESD protection device according to claim 1, wherein the substrate has the first conductivity type.

3. The ESD protection device according to claim 1, wherein the substrate has the second conductivity type.

4. The ESD protection device of claim 1, further comprising an isolation element disposed in the lateral direction between the fourth terminal region and the fifth terminal region when a portion of the second conductive region is disposed in the lateral direction between the fourth terminal region and the fifth terminal region to form the PN junction between the fifth terminal region and the second conductive region.

5. The ESD protection device of claim 4, wherein the isolation element engages the fourth terminal region and also engages the fifth terminal region.

6. The ESD protection device according to claim 4, wherein the isolation element, the fourth terminal region, and the fifth terminal region are arranged along the top surface of the substrate.

7. The ESD protection device according to claim 4, wherein the isolation element comprises an electrically insulating material.

8. The ESD protection device of claim 4, wherein a portion of the second conductive region is disposed below the isolation element and is disposed in the lateral direction between the fourth terminal region and the fifth terminal region.

9. The ESD protection device of claim 4, wherein the isolation element comprises a block of silicide.

10. The ESD protection device of claim 4 further includes an insulating element disposed in the lateral direction between the third terminal area and the fifth terminal area.

11. The ESD protection device of claim 10, wherein the depth of the isolation element is less than the depth of the insulating element.

12. The ESD protection device of claim 10, wherein the isolation element and the insulating element comprise the same electrically insulating material.

13. The ESD protection device of claim 12, wherein the insulating element and the isolating element comprise a shallow trench isolation region.

14. The ESD protection device of claim 1, wherein when the portion of the second conductive region is arranged in the lateral direction between the fourth terminal region and the fifth terminal region, the portion of the second conductive region, the fourth terminal region and the fifth terminal region are arranged along the top surface of the substrate.

15. The ESD protection device according to claim 1, wherein the depth of the fifth terminal region is substantially equal to the depth of the fourth terminal region.

16. The ESD protection device according to claim 1, wherein the first conductivity type is P-type and the second conductivity type is N-type.

17. The ESD protection device according to claim 1, wherein the first conductivity type is N-type and the second conductivity type is P-type.

18. The ESD protection device according to claim 1, wherein the ESD protection device comprises a silicon controlled rectifier device.

19. A method for manufacturing an ESD protection device, the method comprising: Provide substrate; A first conductive region and a second conductive region are formed within the substrate; A first terminal region and a second terminal region are formed within the first conductive region; A third terminal region, a fourth terminal region, and a fifth terminal region are formed within the second conductive region; wherein the fifth terminal region is arranged in the lateral direction between the third terminal region and the fourth terminal region; Electrically coupling the first terminal area, the second terminal area, and the fifth terminal area to the first conductive pad; and The third terminal area and the fourth terminal area are electrically coupled to the second conductive pad; The first conductive region, the first terminal region, the third terminal region, and the fifth terminal region have a first conductivity type; and the second conductive region, the second terminal region, and the fourth terminal region have a second conductivity type different from the first conductivity type. in: (i) A portion of the second conductive region is arranged in the lateral direction between the fourth terminal region and the fifth terminal region to form a PN junction between the fifth terminal region and the second conductive region; or (ii) The fifth terminal region and the fourth terminal region are arranged horizontally to each other and joined together to form a PN junction between the fifth terminal region and the fourth terminal region.

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