High-voltage device

Abstract

This invention relates to high-voltage devices. According to some embodiments of the invention, a high-voltage device includes: a substrate; at least one first isolation member within the substrate; a first well region; a frame-like gate structure above the first well region and covering a portion of the first isolation member; a drain region within the first well region and separated from the frame-like gate structure by the first isolation member; and a source region separated from the drain region by the first isolation member and the frame-like gate structure. The first well region, the drain region, and the source region comprise a first conductivity type, and the substrate comprises a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other.

Description

Technical Field

[0001] The embodiments of the present invention relate to high-voltage devices. Background Technology

[0002] Technological advancements in semiconductor integrated circuit (IC) materials, design, processing, and manufacturing have enabled the continuous reduction in the size of IC devices, with each generation featuring smaller and more complex circuitry than the previous one.

[0003] Because semiconductor circuits composed of devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) are adapted for high-voltage applications such as high-voltage laterally diffused metal-oxide-semiconductor (HV LDMOS) devices, issues related to reduced voltage performance arise as advanced technologies continue to shrink in size. To prevent source-drain breakdown or to reduce source-drain resistance, standard MOS manufacturing processes often involve multiple high-density implantations. As device reliability degrades, substantial substrate leakage and voltage collapse often occur. Summary of the Invention

[0004] Embodiments of the present invention relate to a high-voltage device comprising: a substrate; at least one first isolation member therein; a first well region; a frame-like gate structure above the first well region and covering a portion of the first isolation member; a drain region therein in the first well region and separated from the frame-like gate structure by the first isolation member; and a source region separated from the drain region by the first isolation member and the frame-like gate structure, wherein the first well region, the drain region, and the source region comprise a first conductivity type, the substrate comprises a second conductivity type, and the first conductivity type and the second conductivity type are complementary to each other.

[0005] Embodiments of the present invention relate to a high-voltage device comprising: a substrate including a frame-like isolator disposed therein; a frame-like gate structure above the substrate and covering a portion of the frame-like isolator; a drain region in the substrate and enclosed by the frame-like isolator; a source region in the substrate and adjacent to the frame-like gate structure on a side opposite to the drain region; a first doped region below the drain region and separated from the substrate; and a second doped region below the source region and separated from the source region and the substrate, wherein the drain region, the source region, and the first doped region comprise a first conductivity type, and the substrate and the second doped region comprise a second conductivity type complementary to the first conductivity type.

[0006] Embodiments of the present invention relate to a high-voltage device comprising: a first frame-shaped isolator and a second frame-shaped isolator, which are separated from each other; a first frame-shaped gate structure covering a portion of the first frame-shaped isolator and a second frame-shaped gate structure covering a portion of the second frame-shaped isolator; a first drain region enclosed by the first frame-shaped isolator and a second drain region enclosed by the second frame-shaped isolator; a first frame-shaped source region surrounding the first frame-shaped gate structure and a second frame-shaped source region surrounding the second frame-shaped gate structure; a first doped region surrounding the first frame-shaped gate structure and the second frame-shaped gate structure; and a second doped region located between the first frame-shaped gate structure and the second frame-shaped gate structure and coupled to the first doped region, wherein the first drain region, the second drain region, the first frame-shaped source region and the second frame-shaped source region comprise a first conductivity type, and the substrate, the first doped region and the second doped region comprise a second conductivity type complementary to the first conductivity type. Attached Figure Description

[0007] When read in conjunction with the accompanying drawings, the following detailed description is the best way to understand aspects of this disclosure. It should be noted that, in accordance with standard industry practice, the various components are not drawn to scale. In fact, the dimensions of the various components can be arbitrarily increased or decreased for clarity of explanation.

[0008] Figure 1 This is a top view of a high-voltage device according to one or more embodiments of an aspect of the present disclosure.

[0009] Figure 2 It is along Figure 1 The cross-sectional view obtained by line I-I'.

[0010] Figure 3 This is a top view of a high-voltage device according to one or more embodiments of an aspect of this disclosure.

[0011] Figure 4 It is along Figure 3 The cross-sectional view obtained from line II-II'. Detailed Implementation

[0012] The following disclosure provides numerous different embodiments or examples of various components for implementing the provided subject matter. Specific examples of components and arrangements are described below to simplify this disclosure. These are, of course, merely examples and are not intended to be limiting. For example, embodiments in which a first component is formed above or on a second component may include those in which the first and second components are in direct contact, and embodiments in which additional components may be formed between the first and second components such that the first and second components are not in direct contact. Additionally, element symbols and / or letters may be repeated in various instances of this disclosure. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0013] This description of illustrative embodiments is intended to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. Any references to direction or orientation in the description of the embodiments disclosed herein are intended only for ease of description and are in no way intended to limit the scope of this disclosure. Relative terms such as “down,” “up,” “horizontal,” “vertical,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to an orientation as described subsequently or as shown in the expository figures. These relative terms are for ease of description only and do not require the device to be constructed or operated in a particular orientation. Unless otherwise explicitly stated, terms such as “attach,” “additional,” “connect,” and “interconnect” refer to a relationship in which structures are directly or indirectly fixed or attached to each other by an intermediary structure, and a movable or rigid attachment or relationship. Furthermore, the features and advantages of this disclosure are illustrated by reference to embodiments. Therefore, this disclosure is explicitly not intended to be limited to these embodiments illustrating some possible non-limiting combinations of features that may exist alone or in other combinations of features, the scope of which is defined by the claims appended to this disclosure.

[0014] While the numerical ranges and parameters stated in this disclosure are approximate, the values ​​stated in particular examples are reported as precisely as possible. However, any numerical value inherently contains some error due to the standard deviation necessarily found in the corresponding test measurement. Furthermore, as used herein, the terms “substantially,” “about,” or “approximately” generally mean values ​​or ranges that would be expected by one of ordinary skill in the art. Alternatively, the terms “substantially,” “about,” or “approximately” mean within an acceptable standard error of the mean, as considered by one of ordinary skill in the art. One of ordinary skill in the art will understand that acceptable standard errors can vary depending on the technology. Except in operational / working examples, or unless expressly specified otherwise, all numerical ranges, quantities, values, and percentages (e.g., for material quantities, durations, temperatures, operating conditions, ratios of quantities, and numerical ranges, quantities, values, and percentages of the like disclosed herein) should be understood to be modified by the terms “substantially,” “about,” or “approximately” in all instances. Therefore, unless indicated to the contrary, the numerical parameters stated in this disclosure and the appended claims are approximate values ​​that may vary as necessary. At a minimum, each numerical parameter should be understood based on the number of significant digits reported and by applying common rounding techniques. Ranges may be expressed herein as from one endpoint to another or between two endpoints. Unless otherwise specified, all ranges disclosed herein include endpoints.

[0015] Typically, high-voltage devices are required to have low breakdown capability between the source / body and the substrate. In some comparative approaches, an n-type buried doped layer and a p-type doped region are formed in the high-voltage device to completely isolate it from the substrate. In other comparative approaches, the width of the n-type buried doped layer can be increased in large cell array applications to maintain high voltage during the off-state and a high-voltage gap between the source / body and the substrate. However, this increased width will result in large area losses.

[0016] Furthermore, breakdown voltage (BVD) and on-resistance (Ron) are two important characteristics of high-voltage devices used in power switching circuits. Improving the operation of power switching circuits incorporating MOSFETs recommends using MOSFETs with the highest possible breakdown voltage and the lowest possible on-resistance. However, to improve breakdown resistance, the large area used with a large n-type buried doped layer results in increased on-resistance for the high-voltage device.

[0017] Therefore, this disclosure provides a high-voltage device with a frame-like gate structure. The frame-like gate structure helps reduce the current flowing from the drain region through the drift region. This improves the breakdown voltage and breakdown resistance of the high-voltage device. Furthermore, since the frame-like gate helps improve breakdown resistance, the width of the n-type doped layer can be reduced, thereby reducing the on-resistance. In other words, a high-voltage device incorporating a frame-like gate structure has increased breakdown voltage, improved breakdown resistance, and reduced on-resistance.

[0018] In some embodiments, a high-voltage device 100 is provided. The high-voltage device 100 may be an n-type high-voltage device, but this disclosure is not limited thereto. In some embodiments, the high-voltage device 100 may be referred to as a high-voltage lateral diffused MOS (HV LDMOS) transistor device, a high-voltage extended drain MOS (HV EDMOS) transistor device, or any other HV device.

[0019] refer to Figure 1 and Figure 2 , Figure 1 This describes a top view of the high-voltage device 100, and... Figure 2 It is along Figure 1 A cross-sectional view obtained from line I-I'. In some embodiments, the high-voltage device 100 includes a substrate 102 ( Figure 2 (As shown in the diagram). Substrate 102 may comprise: elemental semiconductors comprising silicon or germanium in single-crystal, polycrystalline, or amorphous form; compound semiconductor materials comprising at least one of silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, and indium antimonide; alloy semiconductor materials comprising at least one of SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, and GaInAsP; any other suitable materials; or combinations thereof. In some embodiments, the alloy semiconductor substrate may be a SiGe alloy having a gradient Ge characteristic, wherein the Si and Ge composition changes from one ratio at one location of the gradient SiGe characteristic to another ratio at another location. In another embodiment, the SiGe alloy is formed over a silicon substrate. In some embodiments, the SiGe alloy may be mechanically strained by another material in contact with the SiGe alloy. Furthermore, substrate 102 may be a semiconductor-on-insulator, such as silicon-on-insulator (SOI). In some embodiments, substrate 102 may comprise a doped epitaxial layer or a buried layer. In some embodiments, substrate 102 may have a multilayer structure, or substrate 102 may comprise a multilayer compound semiconductor structure.

[0020] The high-voltage device 100 includes a well region 110. In some embodiments, the well region 110 includes a first conductivity type, and the substrate 102 includes a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other. In some embodiments, the first conductivity type is n-type, and the second conductivity type is p-type. In some embodiments, the n-type dopant includes arsenic (As), phosphorus (P), other group V elements, or any combination thereof. In some embodiments, the p-type dopant includes boron (B), other group III elements, or any combination thereof. Although the substrate 102 and the well region 110 contain different types of dopant, the doping concentration of the well region 110 is greater than that of the substrate 102. The well region 110 may be referred to as a drift region. In some embodiments, the well region 110 may be referred to as a high-voltage n-type well (HVNW).

[0021] In some embodiments, the high-voltage device 100 includes an isolation member 104, such as a frame-like isolation member 104 disposed in a substrate 102. In some embodiments, such as Figure 2 As shown, the spacer 104 may be a shallow trench spacer (STI). In other embodiments, the spacer 104 includes a localized silicon oxide (LOCOS) structure, or any other suitable isolation structure. Figure 1 and Figure 2 As shown, the bottom of the well region 110 contacts the substrate 102, and the side edges 110e of the well region 110 are below the frame-like spacer 104. In some embodiments, the frame-like spacer 104 may be referred to as surrounding the well region 110. Figure 2 As shown in the diagram, the isolation component 104 is partially placed in the trap area 110.

[0022] In some embodiments, the high-voltage device 100 includes another isolator 106, for example, a frame-like isolator 106. As mentioned above, the isolator 106 may be an STI, LOCOS structure, or any other suitable isolation structure. Depending on the product design, the widths of the isolator 104 and the isolator 106 may be similar or different. The depths of the isolator 104 and the isolator 106 are similar. Figure 2 As shown in the diagram, the spacer 106 is placed in the trap region 110, and the bottom surface and side edges of the spacer 106 are in contact with the trap region 110.

[0023] The high-voltage device 100 further includes a trap region 112 placed within the trap region 110. For example... Figure 2As shown, well region 112 may be a frame-shaped well region 112 disposed between spacer 104 and spacer 106. In some embodiments, at least a portion of the side edges of well region 112 contacts well region 110, and a portion of the bottom of well region 112 contacts well region 110. Well region 112 may contain a second conductivity type. In some embodiments, well region 112 may be referred to as a high-voltage p-type well (HVPW). In some embodiments, well region 112 is separated from substrate 102 by well region 110.

[0024] The high-voltage device 100 further includes a trap region 114. For example... Figure 2 As shown, well region 114 is partially placed within well region 110 and partially within well region 112. In some embodiments, the bottom surface of well region 114 is lower than the bottom surface of well region 112, and therefore well region 114 may be referred to as a deep p-type well (DPW). Figure 2 As shown, the bottom surface of well region 114 is in contact with well region 110. Well region 114 may contain a second conductivity type. In some embodiments, the doping concentration of well region 114 is greater than the doping concentration of well region 112.

[0025] The high-voltage device 100 includes a frame-like gate structure 120 disposed on a substrate 102. For example... Figure 1 and Figure 2 As shown, a frame-like gate structure 120 covers a portion of the separator 106 and a portion of the well region 110. However, the frame-like gate structure 120 is separated from the separator 104. Furthermore, the well region 112 may surround the frame-like gate structure 120. In some embodiments, a channel is formed in the well region 110, directly below the frame-like gate structure 120. The frame-like gate structure 120 includes a first axis Ax1 and a second axis Ax2, wherein the first axis Ax1 is perpendicular to the second axis Ax2. In some embodiments, the lengths of the first axis Ax1 and the second axis Ax2 are similar, such that the frame-like gate structure 120 has a point-symmetric configuration and a line-symmetric configuration, but this disclosure is not limited thereto.

[0026] In some embodiments, the frame-like gate structure 120 includes a gate conductive layer 122 and a gate dielectric layer 124 between the gate conductive layer 122 and the substrate 102. The gate conductive layer 122 may include polysilicon, silicon-germanium, and at least one metallic material comprising elements and compounds (e.g., Mo, Cu, W, Ti, Ta, TiN, TaN, NiSi, CoSi, or other suitable conductive materials known in the art). In some embodiments, the gate conductive layer 122 includes a work function metal layer that provides an n-type or p-type metal work function to the metal gate. The p-type metal work function material includes, for example, ruthenium, palladium, platinum, cobalt, nickel, conductive metal oxides, or other suitable materials. The n-type metal work function material includes, for example, hafnium, zirconium, titanium, tantalum, aluminum, metal carbides (e.g., hafnium carbide, zirconium carbide, titanium carbide, and aluminum carbide), aluminum compounds, or other suitable materials.

[0027] The gate dielectric layer 124 may have a single-layer or multi-layer structure. In some embodiments, the gate dielectric layer 124 is a multi-layer structure including an interface layer and a high-dielectric-coefficient layer. The interface layer may contain a dielectric material, such as silicon oxide, silicon nitride, silicon oxynitride, other dielectric materials, or combinations thereof. The high-dielectric-coefficient layer may contain a high-dielectric-coefficient material, such as HfO2, HfSiO, HfSiON, HfTaO, HfTiO, HfZrO, other suitable high-dielectric-coefficient materials, or combinations thereof. In some embodiments, the high-dielectric-coefficient material may be further selected from metal oxides, metal nitrides, metal silicates, transition metal oxides, transition metal nitrides, transition metal silicates, metal oxynitrides, metal aluminates, and combinations thereof.

[0028] In some embodiments, the frame-like gate structure 120 may include spacers 126i and 126o disposed above the sidewalls. In some embodiments, the frame-like gate structure 120 includes an inner spacer 126i disposed above the inner sidewall of the frame-like gate structure 120, and an outer spacer 126o disposed above the outer sidewall of the frame-like gate structure 120. Figure 2 As shown, the inner spacer 126i can be placed above the spacer 106, while the outer spacer 126o is placed above the substrate 120. It should be noted that, for clarity, [the following is unclear and requires further context]. Figure 1 The inner spacer 126i and the outer spacer 126o are omitted; however, those skilled in the art should readily obtain the relevant information. Figure 2 The positions of the inner spacer 126i and the outer spacer 126o.

[0029] Still referencing Figure 1 and Figure 2The high-voltage device 100 includes a drain region 130D and a doped region 132 disposed in a well region 110. Furthermore, the drain region 130D and the doped region 132 are enclosed by a frame-like isolator 106. In other words, as... Figure 1 As shown, the drain region 130D and the doped region 132 are placed in the central region within the frame-like isolation member 106 and the frame-like gate structure 120. Figure 2 As shown, the drain region 130D and the doped region 132 are separated from the frame-like gate structure 120 by a frame-like isolator 106. The doped region 132 is placed below the drain region 130D. Furthermore, the doped region 132 is separated from the substrate 102 by a well region 110. In some embodiments, the side edges of the drain region 130D contact the isolator 106, and the bottom surface of the drain region 130D contacts the doped region 132. The drain region 130D and the doped region 132 comprise a first conductivity type. The doping concentration of the drain region 130D is greater than the doping concentration of the doped region 132.

[0030] The high-voltage device 100 includes a source region 130S in a substrate 102, adjacent to a frame-like gate structure 120 on the side opposite to the drain region 130D. Therefore, the source region 130S is separated from the drain region 130D by the frame-like gate structure 120 and the frame-like isolator 106. The source region 130S contains a first conductivity type, and the doping concentration of the source region 130S is similar to the doping concentration of the drain region 130D. In some embodiments, such as Figure 1 As shown, the source region 130S placed between the frame-like gate structure 120 and the isolation member 104 has a frame-like configuration surrounding the frame-like gate structure 120.

[0031] In some embodiments, the high-voltage device 100 further includes a doped region 140. The doped region 140 is adjacent to the source region 130S. The doped region 140 includes a second conductivity type. In some embodiments, such as Figure 1 As shown, the doped region 140 has a frame-like configuration surrounding the frame-like source region 130S. In some embodiments, the doped region 140 acts as a body pickup region. Those skilled in the art will recognize that many alternatives, modifications, and variations are possible. For example, depending on different applications and design requirements, the body pickup region 140 and the source region 130S may share a contact plug.

[0032] Furthermore, silicide structures (not shown) can be formed on the drain region 130D, source region 130S, and doped region 140. The silicide structures may include, for example, nickel silicide (NiSi), nickel platinum silicide (NiPtSi), nickel platinum germanium silicide (NiPtGeSi), nickel germanium silicide (NiGeSi), ytterbium silicide (YbSi), platinum silicide (PtSi), iridium silicide (IrSi), erbium silicide (ErSi), cobalt silicide (CoSi), other suitable materials, or combinations thereof.

[0033] The high-voltage device 100 further includes a doped region 142 disposed in the well region 110. In some embodiments, the doped region 142 also has a frame-like configuration surrounding the frame-like gate structure 120. However, because the doped region 142 is partially covered by the frame-like gate structure 120, partially covered by the source region 130S and the doped region 140, and partially covered by the isolator 104, the doped region 142 cannot be observed from a top view. The doped region 142 contains a second conductivity type. Furthermore, the doping concentration of the doped region 142 is less than that of the doped region 140. In some embodiments, the doping concentration of the doped region 142 may be between approximately 2.5E+15 / cm². 3 With approximately 3.5E+18 / cm 3 However, this disclosure is not limited thereto. In some embodiments, the doped region 142 may be referred to as a high-voltage p-type body (HVPB). In some embodiments, the side edges of the doped region 142 may contact the well region 110.

[0034] The high-voltage device 100 further includes another doped region 144 below the doped region 142 and separated from the well region 110 by the well region 112. In some embodiments, the doped region 144 also has a frame-like configuration surrounding the frame-like gate structure 120. The doped region 144 contains a second conductivity type. Furthermore, the doping concentration of the doped region 142 is greater than the doping concentration of the doped region 144. In some embodiments, the top surface of the doped region 144 contacts the doped region 142, and the side edges and bottom surface of the doped region 144 contact the well region 112.

[0035] In some embodiments, the high-voltage device 100 includes another isolation element 108, such as a frame-like isolation element 108 surrounding isolation element 104, well regions 110, 112 and 114, doped regions 140, 142 and 144, source region 130S, frame-like gate structure 120 and drain region 130D.

[0036] In some embodiments, a doped region 150 is formed between spacer 104 and spacer 108. Additionally, a doped region 152 and a well region 154 may be formed below the doped region 150. The doped regions 150, 152, and 154 comprise a second conductivity type. The doping concentration of the doped region 150 is greater than that of the doped region 152, and the doping concentration of the doped region 152 is greater than that of the well region 154. In some embodiments, the doped region 152 is placed below the doped region 150 such that the bottom surface of the doped region 150 contacts the doped region 152. The well region 154 is formed below the doped region 152 such that the bottom surface and side edges of the doped region 152 contact the well region 154. In some embodiments, the well region 154 contacts the well region 110.

[0037] In some embodiments, the doped region 150 may serve as a protective ring for the high-voltage device 100. The doped region 150 allows an electrical bias to be applied to the substrate 102 through the doped region 152 and the well region 154. It should be understood that the formation of the doped region 150 is optional.

[0038] According to some embodiments of the high-voltage device 100, the edge 112e of the trap region 112 contacts the trap region 110. Furthermore, as... Figure 2 As shown, a distance d can be defined between the edge 112e of the well region 112 and the edge 110e of the well region 110. In some embodiments, the distance d may be between about 2 μm and about 3 μm. In some comparative methods, when the distance d between the edge 112e and the edge 110e is less than 2 μm, the current can break down the well region 110, and therefore the device may fail. In alternative comparative methods, when the distance d between the edge 112e and the edge 110e is greater than 3 μm, the device may require more area to accommodate the well region and therefore cannot be scaled down. Compared with the comparative methods, the breakdown capability of the high-voltage device 100 can be improved by more than about 300%.

[0039] It should be noted that the drain-to-source breakdown voltage is the voltage at which the corresponding device (e.g., high-voltage device 100) can operate. When a voltage greater than the breakdown voltage is applied, it causes catastrophic and irreversible damage to the device, rendering it commercially unusable and requiring replacement. Therefore, it is essential to increase the breakdown voltage. In high-voltage device 100, the gate structure 120 has a frame-like configuration. Therefore, when high-voltage device 100 is in the off state, the well region 110 beneath the frame-like gate structure 120 can be completely depleted. In other words, when high-voltage device 100 is in the off state, a frame-like fully depleted region A can be formed. The frame-like fully depleted region A helps to increase the breakdown voltage. In some embodiments, the breakdown voltage of high-voltage device 100 can be improved by more than about 27%. Because the channel width of the frame-like gate structure 120 is increased by point-symmetric and line-symmetric configurations, the on-resistance of high-voltage device 100 can be reduced.

[0040] Furthermore, the high-voltage device 100 has a point-symmetric configuration and a line-symmetric configuration, but this disclosure is not limited thereto.

[0041] refer to Figure 3 and Figure 4 , Figure 3 This describes a top view of the high-voltage device 200, and... Figure 4 It is along Figure 3 The cross-sectional view obtained from line II-II'. Note that, for the sake of brevity, [the following is omitted]. Figure 1 and Figure 3 and Figure 2 and Figure 4 Details (e.g., materials) of the same components shown in the diagram. In some embodiments, the high-voltage device 200 includes a substrate 202 ( Figure 4 (As shown in the diagram). The high-voltage device 200 includes well regions 210-1 and 210-2. In some embodiments, well regions 210-1 and 210-2 comprise a first conductivity type, and the substrate 202 comprises a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other. In some embodiments, the first conductivity type is n-type, and the second conductivity type is p-type. Although the substrate 202 and well regions 210-1 and 210-2 comprise different types of dopants, the doping concentration of well regions 210-1 and 210-2 is greater than the doping concentration of the substrate 202. Furthermore, the doping concentration of well regions 210-1 and 210-2 is the same. Well regions 210-1 and 210-2 may be referred to as drift regions. In some embodiments, well regions 210-1 and 210-2 may be referred to as high-voltage n-type wells (HVNW).

[0042] In some embodiments, the high-voltage device 200 includes frame-shaped isolation members 204-1 and 204-2 disposed in a substrate 202. Figure 3 and Figure 4 As shown, frame-like spacers 204-1 and 204-2 are separated from each other. In some embodiments, such as Figure 4 As shown, frame-like spacers 204-1 and 204-2 can be STI (Surface Mount Technology). In other embodiments, frame-like spacers 204-1 and 204-2 comprise a LOCOS structure or any other structure suitable for isolation. The width and depth of frame-like spacer 204-1 are similar to the width and depth of frame-like spacer 204-2. Figure 3 and Figure 4As shown, the bottoms of well regions 210-1 and 210-2 are in contact with the substrate 202. The side edge 210e-1 of well region 210-1 is below the frame-like isolator 204-1, and the side edge 210e-2 of well region 210-2 is below the frame-like isolator 204-2. In some embodiments, the frame-like isolator 204-1 may be referred to as surrounding well region 210-1, and the frame-like isolator 204-2 may be referred to as surrounding well region 210-2. Figure 4 As shown, the frame-shaped isolator 204-1 is partially placed in the trap area 210-1, and the frame-shaped isolator 204-2 is partially placed in the trap area 210-2.

[0043] In some embodiments, the high-voltage device 200 includes frame-like isolators 206-1 and 206-2, which are separated from each other. As mentioned above, frame-like isolators 206-1 and 206-2 may be STI, LOCOS structures, or any other suitable isolation structure. Depending on the product design, the widths of frame-like isolators 204-1 and 204-2 and the widths of frame-like isolators 206-1 and 206-2 may be similar or different. The depths of frame-like isolators 204-1 and 204-2 and the depths of frame-like isolators 206-1 and 206-2 are similar. Frame-like isolator 206-1 is placed in trap region 210-1, and frame-like isolator 206-2 is placed in trap region 210-2. Figure 4 As shown, the bottom surface and side edges of the frame-shaped spacer 206-1 are in contact with the trap area 210-1, and the bottom surface and side edges of the frame-shaped spacer 206-2 are in contact with the trap area 210-2.

[0044] The high-voltage device 200 further includes a frame-shaped trap zone 212-1 placed in trap zone 210-1, and a frame-shaped trap zone 212-2 placed in trap zone 210-2. Figure 4As shown, a frame-shaped well region 212-1 is placed between frame-shaped isolators 204-1 and 206-1, while a frame-shaped well region 212-2 is placed between frame-shaped isolators 204-2 and 206-2. In some embodiments, at least a portion of the side edges of the frame-shaped well region 212-1 contacts the well region 210-1, and a portion of the bottom of the frame-shaped well region 212-1 contacts the well region 210-1. Similarly, at least a portion of the side edges of the frame-shaped well region 212-2 contacts the well region 210-2, and a portion of the bottom of the frame-shaped well region 212-2 contacts the well region 210-2. Frame-shaped well regions 212-1 and 212-2 may contain a second conductivity type. The doping concentration of frame-shaped well region 212-1 and frame-shaped well region 212-2 is the same. In some embodiments, the frame-shaped trap regions 212-1 and 212-2 may be referred to as high-pressure p-type traps (HVPW). Furthermore, the frame-shaped trap regions 212-1 and 212-2 are separated from each other.

[0045] The high-voltage device 200 further includes mutually separated frame-like trap regions 214-1 and 214-2. For example... Figure 4 As shown, frame-shaped well region 214-1 is partially placed within well region 210-1 and partially within frame-shaped well region 212-1, and frame-shaped well region 214-2 is partially placed within well region 210-2 and partially within frame-shaped well region 212-2. In some embodiments, the bottom surface of frame-shaped well region 214-1 is lower than the bottom surface of frame-shaped well region 212-1; therefore, the bottom surface of frame-shaped well region 214-1 is in contact with well region 210-1. Similarly, the bottom surface of frame-shaped well region 214-2 is in contact with well region 210-2. Therefore, frame-shaped well regions 214-1 and 214-2 may be referred to as deep p-type wells (DPWs). Frame-shaped well regions 214-1 and 214-2 may contain a second conductivity type. In some embodiments, the doping concentration of frame-shaped well regions 214-1 and 214-2 is greater than the doping concentration of frame-shaped well regions 212-1 and 212-2. Furthermore, the doping concentration of the frame-shaped well region 214-1 is the same as that of the frame-shaped well region 214-2.

[0046] The high-voltage device 200 includes mutually separated frame-like gate structures 220-1 and 220-2. For example... Figure 3 and Figure 4As shown, a frame-like gate structure 220-1 covers a portion of a frame-like isolator 206-1 and a portion of a well region 210-1, and a frame-like gate structure 220-2 covers a portion of a frame-like isolator 206-2 and a portion of a well region 210-2. The frame-like gate structure 220-1 is separated from the frame-like isolator 204-1, and the frame-like gate structure 220-2 is separated from the frame-like isolator 204-2. Furthermore, the frame-like gate structure 220-1 may be surrounded by a frame-like well region 212-1, and the frame-like gate structure 220-2 may be surrounded by a frame-like well region 212-2. The frame-like gate structures 220-1 and 220-2 respectively include a first axis Ax1 and a second axis Ax2, with the first axis Ax1 perpendicular to the second axis Ax2. In some embodiments, such as Figure 3 As shown in the figure, the length of the first axis Ax1 is greater than the length of the second axis Ax2.

[0047] In some embodiments, the frame-like gate structures 220-1 and 220-2 each include a gate conductive layer 222 and a gate dielectric layer 224 between the gate conductive layer 222 and the substrate 202. The gate dielectric layer 224 may have a single-layer or multi-layer structure. In some embodiments, the gate dielectric layer 224 is a multi-layer structure including an interface layer and a high dielectric constant layer. In some embodiments, each of the frame-like gate structures 220-1 and 220-2 may include spacers 226i and 226o disposed above the sidewalls. In some embodiments, each of the frame-like gate structures 220-1 and 220-2 includes an inner spacer 226i disposed above the inner sidewall and an outer spacer 226o disposed above the outer sidewall. Figure 4 As shown, the inner spacer 226i can be placed above the frame-like spacers 206-1 or 206-2, while the outer spacer 226o is placed above the substrate 202. Furthermore, it should be noted that, for clarity, [the following text is incomplete and requires further context]. Figure 3 The inner spacer 226i and the outer spacer 226o are omitted; however, those skilled in the art should readily obtain the relevant information. Figure 4 The positions of the inner spacer 226i and the outer spacer 226o.

[0048] Still referencing Figure 3 and Figure 4 The high-voltage device 200 includes a drain region 230D-1 and a doped region 232-1 placed in a well region 210-1, and a drain region 230D-2 and a doped region 232-2 placed in a well region 210-2. Furthermore, the drain region 230D-1 and the doped region 232-1 are enclosed by a frame-like isolator 206-1, and the drain region 230D-2 and the doped region 232-2 are enclosed by a frame-like isolator 206-2. In other words, as... Figure 3As shown, drain region 230D-1 and doped region 232-1 are placed in the central region within frame-shaped isolation member 206-1 and frame-shaped gate structure 220-1, while drain region 230D-2 and doped region 232-2 are placed in the central region within frame-shaped isolation member 206-2 and frame-shaped gate structure 220-2. Figure 4 As shown, drain region 230D-1 and doped region 232-1 are separated from frame-shaped gate structure 220-1 by frame-shaped isolator 206-1, and drain region 230D-2 and doped region 232-2 are separated from frame-shaped gate structure 220-2 by frame-shaped isolator 206-2. Doped regions 232-1 and 232-2 are placed below drain regions 230D-1 and 230D-2. Furthermore, doped region 232-1 is separated from substrate 202 by well region 210-1, and doped region 232-2 is separated from substrate 202 by well region 210-2. In some embodiments, the side edge of drain region 230D-1 contacts frame-shaped isolator 206-1, and the bottom surface of drain region 230D-1 contacts doped region 232-1. Similarly, the side edges of drain region 230D-2 are in contact with the frame-like isolator 206-2, and the bottom surface of drain region 230D-2 is in contact with doped region 232-2. Drain regions 230D-1 and 230D-2 and doped regions 232-1 and 232-2 contain a first conductivity type. The doping concentration of drain regions 230D-1 and 230D-2 is greater than that of doped regions 232-1 and 232-2.

[0049] The high-voltage device 200 includes a frame-shaped source region 230S-1 in the substrate 202, adjacent to the frame-shaped gate structure 220-1 on the side opposite to the drain region 230D-1, and a frame-shaped source region 230S-2 in the substrate 202, adjacent to the frame-shaped gate structure 220-2 on the side opposite to the drain region 230D-2. Therefore, the frame-shaped source region 230S-1 is separated from the drain region 230D-1 by the frame-shaped gate structure 220-1 and the frame-shaped isolator 206-1. Similarly, the frame-shaped source region 230S-2 is separated from the drain region 230D-2 by the frame-shaped gate structure 220-2 and the frame-shaped isolator 206-2. The frame-shaped source regions 230S-1 and 230S-2 comprise a first conductivity type, and the doping concentration of the frame-shaped source regions 230S-1 and 230S-2 is similar to the doping concentration of the drain regions 230D-1 and 230D-2. Furthermore, the frame-shaped source region 230S-1 is positioned between and surrounds the frame-shaped gate structure 220-1 and the frame-shaped isolator 204-1, while the frame-shaped source region 230S-2 is positioned between and surrounds the frame-shaped gate structure 220-2 and the frame-shaped isolator 204-2.

[0050] In some embodiments, the high-voltage device 200 further includes a frame-shaped doped region 240-1 adjacent to the frame-shaped source region 230S-1, and a frame-shaped doped region 240-2 adjacent to the frame-shaped source region 230S-2. The frame-shaped doped regions 240-1 and 240-2 comprise a second conductivity type. In some embodiments, the frame-shaped doped regions 240-1 and 240-2 serve as body pickup regions. Those skilled in the art will recognize that many alternatives, modifications, and variations are possible. For example, depending on different applications and design requirements, the frame-shaped body pickup region 240-1 and the frame-shaped source region 230S-1 may share a contact plug, and the frame-shaped body pickup region 240-2 and the frame-shaped source region 230S-2 may share a contact plug.

[0051] As mentioned above, silicide structures (not shown) can be formed on drain regions 230D-1 and 230D-2, frame-like source regions 230S-1 and 230S-2, and frame-like doped regions 240-1 and 240-2.

[0052] The high-voltage device 200 further includes a frame-shaped doped region 242-1 disposed in well region 210-1 and a frame-shaped doped region 242-2 disposed in well region 210-2. The frame-shaped doped region 242-1 is partially covered by a frame-shaped gate structure 220-1, partially covered by a frame-shaped source region 230S-1 and the frame-shaped doped region 240-1, and partially covered by a frame-shaped isolator 204-1; therefore, the frame-shaped doped region 242-1 cannot be observed from a top view. Similarly, the frame-shaped doped region 242-2 is partially covered by a frame-shaped gate structure 220-2, partially covered by a frame-shaped source region 230S-2 and the frame-shaped doped region 240-2, and partially covered by a frame-shaped isolator 204-2; therefore, the frame-shaped doped region 242-2 cannot be observed from a top view. The frame-shaped doped regions 242-1 and 242-2 contain a second conductivity type. The doping concentration of the frame-shaped doped region 242-1 is the same as that of the frame-shaped doped region 242-2. Furthermore, the doping concentrations of the frame-shaped doped regions 242-1 and 242-2 are lower than those of the frame-shaped doped regions 240-1 and 240-2. In some embodiments, the frame-shaped doped regions 242-1 and 242-2 may be referred to as high-voltage p-type bodies (HVPBs). In some embodiments, the side edges of the frame-shaped doped region 242-1 may contact the well region 210-1, and the side edges of the frame-shaped doped region 242-2 may contact the well region 210-2.

[0053] The high-voltage device 200 further includes another frame-shaped doped region 244-1 below the frame-shaped doped region 242-1 and separated from the well region 210-1 by the frame-shaped well region 212-1, and a frame-shaped doped region 244-2 below the frame-shaped doped region 242-2 and separated from the well region 210-2 by the frame-shaped well region 212-2. The frame-shaped doped region 244-1 surrounds the frame-shaped gate structure 220-1, and the frame-shaped doped region 244-2 surrounds the frame-shaped gate structure 220-2. The frame-shaped doped regions 244-1 and 244-2 contain a second conductivity type. The doping concentration of the frame-shaped doped region 244-1 is the same as that of the frame-shaped doped region 244-2. Furthermore, the doping concentration of the doped regions 242-1 and 242-2 is greater than that of the doped regions 244-1 and 244-2. In some embodiments, the top surface of the frame-shaped doped region 244-1 contacts the frame-shaped doped region 242-1, and the side edges and bottom surface of the frame-shaped doped region 244-1 contact the frame-shaped well region 212-1. Similarly, the top surface of the frame-shaped doped region 244-2 contacts the frame-shaped doped region 242-2, and the side edges and bottom surface of the frame-shaped doped region 244-2 contact the frame-shaped well region 212-2.

[0054] In some embodiments, the high-voltage device 200 includes another frame-shaped isolation member 208 surrounding the isolation members 204-1 and 204-2, the well regions 210-1 and 210-2, the frame-shaped well regions 212-1, 212-2, 214-1 and 214-2, the frame-shaped doped regions 240-1, 240-2, 242-1, 242-2, 244-1 and 244-2, the frame-shaped source regions 230S-1 and 230S-2, the frame-shaped gate structures 220-1 and 220-2, and the drain regions 230D-1 and 230D-2.

[0055] In some embodiments, a frame-shaped doped region 250a is placed between frame-shaped spacers 204-1 and 208. Furthermore, a doped region 250b is placed between frame-shaped spacers 204-1 and 204-2. Frame-shaped doped regions 250a and 250b are coupled. The high-voltage device 200 further includes a frame-shaped doped region 252a and a frame-shaped well region 254a below the frame-shaped doped region 250a, and a doped region 252b and a well region 254b below the doped region 250b. Doped region 252b is coupled to frame-shaped doped region 252a, and well region 254b is coupled to frame-shaped well region 254a.

[0056] The frame-shaped doped regions 250a, 250b, 252a, 252b, 254a, and 254b contain a second conductivity type. The doping concentrations of frame-shaped doped regions 250a and 250b are the same, the doping concentrations of frame-shaped doped regions 252a and 252b are the same, and the doping concentrations of frame-shaped well regions 254a and 254b are the same. Furthermore, the doping concentrations of frame-shaped doped regions 250a and 250b are greater than the doping concentrations of frame-shaped doped regions 252a and 252b, and the doping concentrations of frame-shaped doped regions 252a and 252b are greater than the doping concentrations of frame-shaped well regions 254a and 254b. In some embodiments, the frame-shaped doped region 252a is placed below the frame-shaped doped region 250a such that the bottom surface of the frame-shaped doped region 250a contacts the frame-shaped doped region 252a. A frame-shaped well region 254a is formed below the frame-shaped doped region 252a such that the bottom surface and side edges of the frame-shaped doped region 252a contact the frame-shaped well region 254a. Similarly, a doped region 252b is placed below the doped region 250b such that the bottom surface of the doped region 250b contacts the doped region 252b. A well region 254b is formed below the doped region 252b such that the bottom surface and side edges of the doped region 252b contact the well region 254b. In some embodiments, the frame-shaped well regions 254a and 254b are in contact with both well regions 210-1 and 210-2.

[0057] In some embodiments, the frame-like doped regions 250a and 250b can serve as a guard ring for the high-voltage device 200. The frame-like doped regions 250a and 250b allow an electrical bias to be applied to the substrate 202 through the frame-like doped regions 252a, 252b, 254a, and 254b. It should be understood that the formation of the frame-like doped regions 250a and 250b is optional.

[0058] In addition, such as Figure 3As shown, the high-voltage device 200 has a linearly symmetrical configuration around a central axis CA. In some embodiments, the central axis CA passes through a doped region 250b. Therefore, the arrangement of the components on the left side of the central axis CA (i.e., drain region 230D-1, doped region 232-1, frame-shaped isolation device 204-1, frame-shaped gate structure 220-1, frame-shaped source region 230S-1, frame-shaped doped regions 240-1, 242-1, 244-1, well region 210-1, and frame-shaped well regions 212-1, 214-1) is the same as the arrangement of the components on the right side of the central axis CA (i.e., drain region 230D-2, doped region 232-2, frame-shaped isolation device 204-2, frame-shaped gate structure 220-2, frame-shaped source region 230S-2, frame-shaped doped regions 240-2, 242-2, 244-2, well region 210-2, and frame-shaped well regions 212-2, 214-2). In some embodiments, drain regions 230D-1 and 230D-2 are electrically connected to the same connection structure, frame-shaped gate structures 220-1 and 220-2 are electrically connected to the same connection structure, and frame-shaped source regions 230S-1 and 230S-2 are electrically connected to the same connection structure.

[0059] According to some embodiments of the high-voltage device 200, such as Figure 4 As shown, a distance d can be defined between the edge 212e-1 of well region 212-1 and the edge 210e-1 of well region 210-1, and between the edge 212e-2 of well region 212-2 and the edge 210e-2 of well region 210-2. In some embodiments, the distance d may be between about 2 μm and about 3 μm. In some comparative methods, when the distance d is less than 2 μm, the current can break down well regions 210-1 and 210-2, and therefore the device may fail. In alternative comparative methods, when the distance d is greater than 3 μm, the device may require more area to accommodate the well regions and therefore cannot be scaled down. Compared with the comparative methods, the breakdown capability of the high-voltage device 200 can be improved by more than about 300%.

[0060] Furthermore, in the high-voltage device 200, when the high-voltage device 200 is in the off state, the well region 210-1 under the frame-like gate structure 220-1 and the well region 210-2 under the frame-like gate structure 220-2 can be completely depleted. In other words, when the high-voltage device 200 is in the off state, a frame-like fully depleted region A can be formed. The frame-like fully depleted region A helps to increase the breakdown voltage. In some embodiments, the breakdown voltage of the high-voltage device 200 can be improved by more than about 27%.

[0061] By increasing the channel width through the frame-like gate structures 220-1 and 220-2, the on-resistance of the high-voltage device 200 can be reduced.

[0062] Therefore, this disclosure provides a high-voltage device with a frame-like gate structure. The frame-like gate structure helps reduce the current flowing from the drain region through the drift region. This improves the breakdown voltage and breakdown resistance of the high-voltage device. Furthermore, since the frame-like gate helps improve breakdown resistance, the width of the n-type doped layer can be reduced, thereby reducing the on-resistance. In other words, a high-voltage device incorporating a frame-like gate structure has increased breakdown voltage, improved breakdown resistance, and reduced on-resistance.

[0063] According to one embodiment of this disclosure, a high-voltage device is provided. The high-voltage device includes: a substrate; at least one first isolation member within the substrate; a first well region; a frame-like gate structure above the first well region and covering a portion of the first isolation member; a drain region within the first well region and separated from the frame-like gate structure by the first isolation member; and a source region separated from the drain region by the first isolation member and the frame-like gate structure. In some embodiments, the first well region, the drain region, and the source region comprise a first conductivity type, and the substrate comprises a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other.

[0064] According to one embodiment of this disclosure, a high-voltage device is provided. The high-voltage device includes: a substrate including a frame-like isolator disposed therein; a frame-like gate structure above the substrate and covering a portion of the frame-like isolator; a drain region in the substrate and enclosed by the frame-like isolator; a source region in the substrate and adjacent to the frame-like gate structure on a side opposite to the drain region; a first doped region below the drain region and separated from the substrate; and a second doped region below the source region and separated from both the source region and the substrate. In some embodiments, the drain region, the source region, and the first doped region comprise a first conductivity type, and the substrate and the second doped region comprise a second conductivity type complementary to the first conductivity type.

[0065] According to one embodiment of this disclosure, a high-voltage device is provided. The high-voltage device includes a first frame-like isolator and a second frame-like isolator separated from each other; a first frame-like gate structure covering a portion of the first frame-like isolator and a second frame-like gate structure covering a portion of the second frame-like isolator; a first drain region enclosed by the first frame-like isolator and a second drain region enclosed by the second frame-like isolator; a first frame-like source region surrounding the first frame-like gate structure and a second frame-like source region surrounding the second frame-like gate structure; a first doped region surrounding the first frame-like gate structure and the second frame-like gate structure; and a second doped region between the first frame-like gate structure and the second frame-like gate structure. The second doped region is coupled to the first doped region. In some embodiments, the first drain region, the second drain region, the first frame-like source region, and the second frame-like source region comprise a first conductivity type, and the substrate, the first doped region, and the second doped region comprise a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other.

[0066] The foregoing briefly describes the features of several embodiments to enable those skilled in the art to better understand aspects of this disclosure. Those skilled in the art should understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purpose and / or realize the same advantages of the embodiments described herein. Those skilled in the art should also understand that these equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of this disclosure.

[0067] Symbol Explanation

[0068] 100: High-voltage equipment

[0069] 102: Substrate

[0070] 104: Frame-like spacer

[0071] 106: Frame-like spacer

[0072] 108: Frame-like spacer

[0073] 110: Tunnel

[0074] 110e: Side edge

[0075] 112: Tunnel

[0076] 112e: Edge

[0077] 114: Tunnel

[0078] 120: Frame-like gate structure

[0079] 122: Gate conductive layer

[0080] 124: Gate dielectric layer

[0081] 126i: Inner spacer

[0082] 126o: outer spacer

[0083] 130D: Drain region

[0084] 130S: Source Region

[0085] 132: Doped region

[0086] 140: Doped region

[0087] 142: Doped region

[0088] 144: Doped region

[0089] 150: Doped region

[0090] 152: Doped region

[0091] 154: Trap Zone

[0092] 200: High-voltage equipment

[0093] 202: Substrate

[0094] 204-1: Frame-like spacers

[0095] 204-2: Frame-like spacers

[0096] 206-1: Frame-like spacer

[0097] 206-2: Frame-like spacer

[0098] 208: Frame-like spacer

[0099] 210-1: Tunnel

[0100] 210-2: Trap Zone

[0101] 210e-1: Side edge

[0102] 210e-2: Side edge

[0103] 212-1: Frame-like trap region

[0104] 212-2: Frame-like trap region

[0105] 212e-1: Edge

[0106] 214-1: Frame-like trap region

[0107] 214-2: Frame-like trap region

[0108] 220-1: Frame-like gate structure

[0109] 220-2: Frame-like gate structure

[0110] 222: Gate conductive layer

[0111] 224: Gate dielectric layer

[0112] 226i: Inner spacer

[0113] 226o: outer spacer

[0114] 230D-1: Drain Region

[0115] 230D-2: Drain Region

[0116] 230S-1: Framework-like source pole region

[0117] 230S-2: Framework-like source pole region

[0118] 232-1: Doped Region

[0119] 232-2: Doped Region

[0120] 240-1: Framework-shaped doped region

[0121] 240-2: Framework-shaped doped region / Framework-shaped main body pickup region

[0122] 242-1: Framework-shaped doped region

[0123] 242-2: Framework-shaped doped region

[0124] 244-1: Framework-shaped doped region

[0125] 244-2: Framework-shaped doped region

[0126] 250a: Framework-shaped doped region

[0127] 250b: Doped region

[0128] 252a: Framework-shaped doped region

[0129] 252b: Doped region

[0130] 254a: Frame-like trap region

[0131] 254b: Trap Zone

[0132] Ax1: First axis

[0133] Ax2: Second axis

[0134] d: distance.

Claims

1. A high voltage device comprising: a substrate; a first well region in the substrate; a second well region in the first well region; a third well region in the first well region and the second well region; at least a first spacer in the first well region; a frame-shaped gate structure over the first well region and covering a portion of the first spacer; a drain region in the first well region separated from the frame-shaped gate structure by the first spacer; a source region, wherein in a top view, the source region is separated from the drain region by the first spacer and the frame-shaped gate structure; a first doped region in the first well region separated from the frame-shaped gate structure by the first spacer; a second doped region adjacent to the source region; a third doped region under the second doped region; and a fourth doped region under the third doped region separated from the first well region by the second well region, wherein the first well region, the drain region and the source region comprise a first conductivity type, the substrate, the second well region and the third well region comprise a second conductivity type, and the first conductivity type and the second conductivity type are complementary to each other, wherein the first doped region comprises the first conductivity type, and the second doped region, the third doped region and the fourth doped region comprise the second conductivity type, wherein the second well region is over the third well region and separated from the source region by the third doped region and the fourth doped region, and wherein a doping concentration of the first well region is greater than a doping concentration of the substrate, a doping concentration of the third well region is greater than a doping concentration of the second well region, a doping concentration of the drain region is greater than a doping concentration of the first doped region, and a doping concentration of the third doped region is greater than a doping concentration of the fourth doped region and less than a doping concentration of the second doped region.

2. The high voltage device of claim 1, wherein the fourth doped region has a frame-shaped configuration around the frame-shaped gate structure.

3. The high voltage device of claim 1, wherein a side edge of the second well region is in contact with the first well region.

4. The high voltage device of claim 1, wherein a portion of a bottom of the second well region is in contact with the first well region.

5. The high voltage device of claim 1, wherein the third doped region has a frame-shaped configuration around the frame-shaped gate structure.

6. The high voltage device of claim 1, wherein the first spacer has a frame-shaped configuration.

7. The high voltage device of claim 6, wherein the drain region and the first doped region are enclosed by the first spacer.

8. The high voltage device of claim 1, further comprising a second spacer placed in the substrate and separated from the frame-shaped gate structure and the first spacer, wherein the source region is placed between the frame-shaped gate structure and the second spacer.

9. The high voltage device of claim 8, further comprising: a fourth well region in the substrate in contact with the first well region; a fifth doped region in the fourth well region and separated from the first well region by the fourth well region; and a sixth doped region over the fourth well region and the fifth doped region, wherein the fourth well region, the fifth doped region, and the sixth doped region comprise the second conductivity type.

10. A high voltage device comprising: a substrate; a frame-shaped spacer; a frame-shaped gate structure over the substrate and covering a portion of the frame-shaped spacer; a drain region in the substrate and enclosed by the frame-shaped spacer; a source region in the substrate and adjacent to the frame-shaped gate structure on an opposite side from the drain region; a first doped region under the drain region; and a second doped region under the source region, wherein the drain region, the source region, and the first doped region comprise a first conductivity type, and the substrate and the second doped region comprise a second conductivity type complementary to the first conductivity type; and wherein the high voltage device further comprises: a first well region in the substrate and comprising the first conductivity type; a second well region in the first well region and comprising the second conductivity type; a third doped region over the second well region and comprising the second conductivity type, wherein the third doped region is within the second well region; and a third well region comprising the second conductivity type, wherein a portion of the third well region is in the first well region and a portion of the third well region is in the second well region, and the second doped region is between the third doped region and the source region, and wherein a doping concentration of the first well region is greater than a doping concentration of the substrate, a doping concentration of the third well region is greater than a doping concentration of the second well region, a doping concentration of the drain region is greater than a doping concentration of the first doped region, and a doping concentration of the second doped region is greater than a doping concentration of the third doped region.

11. The high voltage device of claim 10, wherein the third doped region has a frame-shaped configuration around the frame-shaped gate structure.

12. The high voltage device of claim 10, wherein the second well region has a frame-shaped configuration around the frame-shaped gate structure.

13. The high voltage device of claim 10, wherein a bottom surface of the first doped region is separated from the substrate by the first well region.

14. The high voltage device of claim 10, wherein the second well region has a frame-shaped configuration, the source region has a frame-shaped configuration, and the second doped region has a frame-shaped configuration.

15. The high voltage device of claim 10, wherein the third well region has a frame-shaped configuration.

16. A high voltage device comprising: a substrate; a first frame-shaped spacer and a second frame-shaped spacer separated from each other in the substrate; a first frame-shaped gate structure covering a portion of the first frame-shaped spacer and a second frame-shaped gate structure covering a portion of the second frame-shaped spacer; a first drain region enclosed by the first frame-shaped spacer and a second drain region enclosed by the second frame-shaped spacer; a first frame-shaped source region surrounding the first frame-shaped gate structure and a second frame-shaped source region surrounding the second frame-shaped gate structure; a first doped region surrounding the first frame-shaped gate structure and the second frame-shaped gate structure; a second doped region between the first frame-shaped gate structure and the second frame-shaped gate structure and coupled to the first doped region, a third doped region separated from the first frame-shaped gate structure by the first frame-shaped spacer; a fourth doped region adjacent to the first frame-shaped source region; a fifth doped region under the fourth doped region; and a sixth doped region under the fifth doped region and separated from a first well region by a first frame-shaped well region, wherein the first well region is in the substrate, and wherein the fourth, fifth, and sixth doped regions are frame-shaped doped regions, wherein the first drain region, the second drain region, the first frame-shaped source region, and the second frame-shaped source region comprise a first conductivity type, and the substrate, the first doped region, and the second doped region comprise a second conductivity type complementary to the first conductivity type; and wherein the second doped region has a thickness less than the first frame-shaped spacer and the second frame-shaped spacer, wherein the third doped region comprises the first conductivity type and the fourth, fifth, and sixth doped regions comprise the second conductivity type, and wherein a doping concentration of the first drain region is greater than a doping concentration of the third doped region, a doping concentration of the fifth doped region is less than a doping concentration of the fourth doped region, and a doping concentration of the fifth doped region is greater than a doping concentration of the sixth doped region.

17. The high voltage device of claim 16, wherein the first frame-shaped source region and the second frame-shaped source region are separated from each other.

18. The high voltage device of claim 16, further comprising: a second well region, wherein the first well region and the second well region comprise the first conductivity type; and a second frame-shaped well region, wherein the first frame-shaped well region and the second frame-shaped well region comprise the second conductivity type, wherein the first frame-shaped well region is in the first well region and the second frame-shaped well region is in the second well region.

19. The high voltage device of claim 18, wherein the first frame-shaped well region surrounds the first frame-shaped gate structure, the second frame-shaped well region surrounds the second frame-shaped gate structure, and the first frame-shaped well region and the second frame-shaped well region are separated from each other.

20. The high voltage device of claim 16, wherein each of the first frame-shaped gate structure and the second frame-shaped gate structure has a first central axis and a second central axis perpendicular to each other, and a length of the first central axis is greater than a length of the second central axis.

Images