Semiconductor device

Abstract

A device layer comprising a semiconductor is disposed on the insulating surface. The field effect transistor includes a source region of a first conductivity type formed in the device layer, a drain region of the first conductivity type, a body region of a second conductivity type opposite to the first conductivity type, and a gate electrode disposed on the device layer. The body region is disposed directly below the gate electrode. The gate electrode and the body region have a long shape in the first direction in a plan view of the insulating surface, the source region is disposed on one side of the gate electrode, and the drain region is disposed on the other side of the gate electrode. The field effect transistor further includes a body contact region of the second conductivity type extending from a plurality of body contact connection portions at an edge of the body region on the source region side toward the source region side. The source region is connected to the body region at a plurality of source body connection sites other than the plurality of body contact connection sites. The maximum value of the length of each of the plurality of source body connection portions in the first direction is equal to or less than eight times the size of the gate electrode in a second direction orthogonal to the first direction.

Description

Technical Field

[0001] The present invention relates to semiconductor devices. Background Art

[0002] When the MOSFET is operated at a high voltage, electron-hole pairs are generated in the body region directly below the gate electrode due to the impact ionization phenomenon. In order to extract the generated holes from the body region, a body contact region connected to the body region is provided (see Patent Document 1). The holes generated in the body region move in the body region and reach the body contact region, and the holes are extracted from the body contact region.

[0003] Patent Document 1: U.S. Patent Application Publication No. 2019 / 0348514

[0004] In the MOSFET described in Patent Document 1, the time required to extract holes generated in the body region from the body region becomes longer, and as a result, there is a possibility that the breakdown voltage may be reduced. Summary of the invention

[0005] An object of the present invention is to provide a semiconductor device capable of efficiently extracting holes from a body region of a MOSFET and suppressing a decrease in withstand voltage.

[0006] According to one aspect of the present invention, a semiconductor device is provided, comprising: a device layer composed of a semiconductor, arranged on an insulating surface; and a field effect transistor, comprising a source region of a first conductivity type formed in the device layer, a drain region of the first conductivity type, a body region of a second conductivity type opposite to the first conductivity type, and a gate electrode arranged on the device layer, the body region being arranged directly below the gate electrode, the gate electrode and the body region having a shape that is long in a first direction when the insulating surface is viewed from above, the source region being arranged on one side of the gate electrode, and the drain region being arranged on the other side of the gate electrode, the field effect transistor further comprising a body contact region of the second conductivity type extending from a plurality of body contact connection portions at an edge of the body region on the source region side toward the source region side, the source region being connected to the body region at a plurality of source body connection portions other than the plurality of body contact connection portions, and the maximum value of the length of each of the plurality of source body connection portions in the first direction is less than or equal to 8 times the dimension of the gate electrode in a second direction orthogonal to the first direction.

[0007] If the maximum value of the length of each of the plurality of source-body connection portions in the first direction is not more than 8 times the dimension of the gate electrode in the second direction, the breakdown voltage can be maintained high. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a top view of the semiconductor device according to the first embodiment.

[0009] Figure 2A as well as Figure 2B They are Figure 1 Cross-sectional views at the dashed line 2A-2A and the dashed line 2B-2B.

[0010] Figure 3 This is a plan view for explaining a process of extracting holes generated in the body region due to impact ionization from the body region.

[0011] Figure 4 : is a graph showing the calculation result of the relationship between the length Wsb of the source-body connection part and the resistance Rbody of the hole movement path.

[0012] Figure 5 : is a graph showing the relationship between the area efficiency and the length Wsb of the source-body connection portion.

[0013] Figure 6 : is a graph showing the relationship between the breakdown voltage and the length Wsb of the source-body connection portion.

[0014] Figure 7 is a top view of the semiconductor device according to the second embodiment.

[0015] Figure 8 is a top view of a semiconductor device according to a third embodiment.

[0016] Description of Reference Numerals

[0017] 10…SOI substrate; 11…support substrate; 12…buried oxide film; 13…device layer; 13A…active region; 20…field effect transistor; (FET) 20B…body region; 20BC…body contact region; 20BC1…first body contact region; 20BC2…second body contact region; 20D…drain region; 20DR…drift region; 20G…gate electrode; 20GI…gate insulating film; 20GP…gate electrode protrusion; 20S…source region; 20SE…source extension region; 20SW…sidewall spacer; 21…body contact connection portion; 22…source-body connection portion; 25, 26…silicide film; 27…interlayer insulating film; 28D…drain contact through hole; 28S…source contact through hole. DETAILED DESCRIPTION

[0018] [First embodiment]

[0019] Reference Figures 1 to 6 The semiconductor device of the first embodiment is described with reference to the accompanying drawings.

[0020] Figure 11 is a top view of a semiconductor device according to the first embodiment. The semiconductor device according to the first embodiment includes a field effect transistor, such as a MOSFET, provided on an SOI substrate.

[0021] On the SOI substrate (see below Figure 2A as well as Figure 2B The device layer (described below) is divided into an active region 13A. An n-type conductive source region 20S, a drift region 20DR, a drain region 20D, and a p-type conductive body region 20B are formed in the active region 13A. A gate electrode 20G is arranged to substantially overlap the body region 20B.

[0022] The gate electrode 20G has a shape that is long in one direction when viewed from above, and is configured to intersect the active region 13A. For example, the gate electrode 20G passes through the source region 13A from one side of the rectangular active region 13A to the opposite side. The length direction (gate width direction) of the gate electrode 20G is defined as the y direction, and the gate electrode 20G is defined as the surface ( Figure 1 An xyz orthogonal coordinate system is used in which the direction parallel to the paper surface and perpendicular to the y direction (gate length direction) is set as the x direction, and the normal direction of the surface of the device layer is set as the z direction.

[0023] In a plan view, the source region 20S is arranged on one side of the gate electrode 20G, and the drift region 20DR is arranged on the other side of the gate electrode 20G. The drain region 20D is arranged at a position farther than the drift region 20DR and in contact with the drift region 20DR when viewed from the gate electrode 20G.

[0024] The body contact region 20BC of p-type conductivity extends from multiple locations of the edge of the body region 20B on the source region 20S side toward the source region 20S side. The connection portion between the body contact region 20BC and the body region 20B is called a body contact connection portion 21. The body contact connection portion 21 refers to a portion where the width in the y direction changes in the region of p-type conductivity including the body region 20B and the body contact region 20BC. The source region 20S is composed of multiple parts separated by multiple body contact regions 20BC in the y direction. The source region 20S is connected to the body region using multiple locations other than the multiple body contact connection portions 21. The connection portion between the source region 20S and the body region 20B is called a source body connection portion 22. The source body connection portion 22 refers to a portion where the conductivity changes from n-type to p-type toward the x direction. The dimension (gate width) of the body region 20B in the y direction is marked as Wu. The length of each body contact connection portion 21 in the y direction is represented by Wbc, and the length of each source body connection portion 22 in the y direction is represented by Wsb.

[0025] In a plan view, a plurality of source contact vias 28S are disposed in a portion included in the source region 20S, and a plurality of drain contact vias 28D are disposed in a portion included in the drain region 20D. The source contact vias 28S are electrically connected to the source region 20S and the body contact region 20BC, and the drain contact vias 28D are electrically connected to the drain region 20D.

[0026] Figure 2A as well as Figure 2B They are Figure 1 The SOI substrate 10 includes a support substrate 11 made of silicon, an insulating layer (referred to as a buried oxide film 12), and a device layer 13. The device layer 13 is arranged on the insulating surface of the buried oxide film 12. An element isolation region (not shown) is formed on the device layer 13, and an active region 13A ( Figure 1 ). A gate electrode 20G is disposed on the active region 13A of the device layer 13 via a gate insulating film 20GI. A side wall spacer 20SW covers the side surfaces of the gate electrode 20G.

[0027] like Figure 2A As shown, a body region 20B of p-type conductivity, a source region 20S of n-type conductivity, a source extension region 20SE, a drift region 20DR, and a drain region 20D are arranged in the device layer 13. The body region 20B, the source region 20S, the source extension region 20SE, the drift region 20DR, and the drain region 20D reach the interface between the device layer 13 and the buried oxide film 12 from the upper surface of the device layer 13.

[0028] The body region 20B is arranged directly below the gate electrode 20G. For example, the body region 20B is included in the gate electrode 20G when viewed from above, and the size of the body region 20B in the x direction on the surface of the device layer 13 is smaller than the size of the gate electrode 20G in the x direction. The source extension region 20SE is arranged directly below the sidewall spacer 20SW on one side of the gate electrode 20G. The front end portion of the drift region 20DR is arranged directly below the sidewall spacer 20SW on the other side.

[0029] The source extension region 20SE and the drift region 20DR are in contact with the body region 20B via the pn junction interface. The source region 20S is connected to the body region 20B via the source extension region 20SE. In this specification, the source region 20S and the source extension region 20SE are sometimes collectively referred to as the source region 20S. The drain region 20D is connected to the body region 20B via the drift region 20DR.

[0030] A silicide film 25 is disposed on the upper surface of the source region 20S, and a silicide film 26 is disposed on the upper surface of the drain region 20D. An interlayer insulating film 27 is disposed on the device layer 13 to cover the gate electrode 20G and the sidewall spacer 20SW. A source contact through hole 28S and a drain contact through hole 28D are disposed in the interlayer insulating film 27. The source contact through hole 28S is electrically connected to the source region 20S via the silicide film 25. The drain contact through hole 28D is electrically connected to the drain region 20D via the silicide film 26.

[0031] exist Figure 2B In the cross section shown, a body contact region 20BC is arranged in contact with the body region 20B in the device layer 13. The body region 20B and the body contact region 20BC both have p-type conductivity and are electrically connected to each other. Figure 2A ) continuously covers the upper surface of the body contact region 20BC. The source contact via 28S is also electrically connected to the body contact region 20BC via the silicide film 25. Therefore, the same potential as the source region 20S, generally the ground potential, is applied to the body contact region 20BC.

[0032] Next, the outline of the method for manufacturing the semiconductor device of the first embodiment is described. An SOI substrate 10 composed of a support substrate 11, a buried oxide film 12, and a device layer 13 is prepared. An element isolation region (not shown) is formed in the device layer 13 to divide the active region 13A ( Figure 1 ) Thereafter, p-type dopants such as boron are implanted into the active region 13A to form the body region 20B and the body contact region 20BC.

[0033] Then, an oxidation treatment is performed to form a silicon oxide film that becomes a gate insulating film 20GI on the entire surface of the device layer 13. In addition, a polysilicon film that becomes a gate electrode 20G is deposited, and an n-type dopant is injected into the polysilicon film. The gate insulating film 20GI and the gate electrode 20G are obtained by patterning the silicon oxide film and the polysilicon film. In addition, an insulating film may be formed on the polysilicon film as needed. The insulating film has the function of preventing the dopant from being injected into the gate electrode 20G when the gate electrode 20G is used as a mask in the subsequent ion implantation process. In addition, a through oxide film may be formed as needed before the ion implantation into the device layer 13.

[0034] Using the gate electrode 20G as a mask, a p-type dopant for forming a halo region (not shown) and an n-type dopant for forming a source extension region 20SE are injected. Next, a p-type dopant for forming a body contact region 20BC is injected using a resist pattern (not shown) and the gate electrode 20G as a mask. And, using other resist patterns (not shown) and the gate electrode 20G as a mask, an n-type dopant for forming a drift region 20DR is injected. When injecting the dopant for forming the source extension region 20SE, the dopant injected into the device layer 13 on the drain region 20D side is absorbed by the drift region 20DR. Then, a sidewall spacer 20SW is formed.

[0035] Next, the other resist patterns (not shown), the gate electrode 20G, and the sidewall spacer 20SW are used as masks to implant n-type dopants for forming the source region 20S and the drain region 20D. Directly below the sidewall spacer 20SW on the source region 20S side, a source extension region 20SE ( Figure 2A ).

[0036] The activation annealing of the dopant injected into the device layer 13 may be performed each time the dopant is injected, or may be performed collectively after all the dopant injection steps.

[0037] Next, a silicide film 25 is formed on the upper surface of the source region 20S and the body contact region 20BC, and a silicide film 26 is formed on the upper surface of the drain region 20D. The silicide films 25 and 26 can be formed by, for example, depositing a metal film such as cobalt or titanium and then reacting it with silicon. Then, an interlayer insulating film 27, a source contact through hole 28S, a drain contact through hole 28D, etc. are formed.

[0038] Next, refer to Figure 3 , a process of extracting holes generated in the body region 20B by impact ionization from the body region 20B will be described.

[0039] Figure 3 2 is a top view for explaining the process of extracting holes generated in the body region 20B by impact ionization from the body region 20B. Figure 3 The source region 20S arranged on the left side (in the figure) contacts the body region 20B at the source-body connection portion 22. The body contact region 20BC extends from the body contact connection portion 21 of the body region 20B toward the side where the source region 20S is arranged. Figure 3 The drift region 20DR is configured in the middle (right side).

[0040] During high voltage operation, electron-hole pairs are generated mainly near the interface between the body region 20B and the drift region 20DR by impact ionization. The generated electrons reach the drain region 20D ( Figure 1 The holes h move toward the source region 20S in the body region 20B, but do not reach the source region 20S due to a potential barrier generated at the pn junction interface between the source region 20S and the body region 20B.

[0041] The hole h reaches the body contact region 20BC connected to the body region 20B. The hole h passes through the body contact region 20BC and the silicide film 25 ( Figure 2B ) and source contact through hole 28S ( Figure 2A ) reaches the ground potential region. In order for the holes h to reach the body contact region 20BC, they must move not only in the x direction but also in the y direction within the body region 20B. In order to efficiently extract the holes h from the body region 20B, it is desirable to reduce the resistance of the path along which the holes h generated by impact ionization move.

[0042] The movement path of the hole h generated in the center of the source-body connection part 22 in the y direction to the body contact region 20BC is the longest. The resistance of this movement path is marked as Rbody. The size of the body region 20B in the x direction is approximately equal to the size of the gate electrode 20G in the x direction (gate length L). The size of the gate length L is determined by the frequency of the target high-frequency signal, etc., and is 0.4μm or less as an example.

[0043] Next, refer to Figure 4 , the relationship between the length Wsb of the source-body connection portion 22 and the resistance Rbody of the moving path of the holes h will be described. Figure 4 This is a graph showing the calculation result of the relationship between the length Wsb of the source body connection part 22 and the resistance Rbody of the moving path of the hole h. The horizontal axis represents the length Wsb of the source body connection part 22 in units of [μm], and the vertical axis represents the resistance Rbody in units of [Ω]. In addition, the gate length L is set to 0.25μm, the gate width Wu is set to 5μm, and the length Wbc of the body contact connection part 21 in the y direction is set to 0.2μm.

[0044] In addition, the length Wbc of the body contact connection parts 21 at the two ends in the y direction is 1 / 2 of the length Wbc of the body contact connection parts 21 other than the two ends in the y direction, that is, 0.1 μm. Therefore, the two body contact regions 20BC at the two ends are counted as one. In addition, the sheet resistance of the body region 20B is set to 1×10 17 Ω / sq.

[0045] Figure 4The numerical value with a circle in the figure indicates the number n of the body contact regions 20BC. In a structure where the number n is 1, the body contact regions 20BC are arranged at both ends of the body region 20B in the y direction. In a structure where the number n of the body contact regions 20BC is 2 or more, the body contact regions 20BC are arranged so that the lengths Wsb of the plurality of source-body connection portions 22 are equal. For example, in a structure where the number n is 2, the body contact regions 20BC are arranged at both ends of the body region 20B in the y direction, and the body contact region 20BC is also arranged at the center of the body region 20B in the y direction. In this case, the length Wsb of each source-body connection portion 22 is 2.3 μm.

[0046] If the length Wsb of the source-body connection part 22 becomes longer, the moving distance of the holes h to the body contact region 20BC becomes longer, so the resistance Rbody becomes larger. In the range where the length Wsb of the source-body connection part 22 is shorter than 4L, the gate length L dominates the length of the moving path of the holes h over the length Wsb. In the range where the length Wsb of the source-body connection part 22 is greater than 4L, the length Wsb dominates the length of the moving path of the holes h.

[0047] Therefore, if the length Wsb is longer than 4L, the slope of the increase in resistance Rbody relative to the increase in length Wsb becomes larger than when it is shorter than 4L. From the viewpoint of suppressing the increase in resistance Rbody, it is preferable to make the length Wsb less than 4L. When the length Wsb of the plurality of source body connection portions 22 is not constant, it is preferable to make the maximum value of the length Wsb less than 4L.

[0048] Next, refer to Figure 5 The relationship between the area efficiency and the length Wsb of the source-body connection portion 22 will be described. Figure 5 This is a graph showing the relationship between the area efficiency and the length Wsb of the source-body connection part 22. The horizontal axis represents the length Wsb in units of [μm], and the vertical axis represents the area efficiency in units of [%]. Here, the area efficiency means the ratio of the total length Wsb of the source-body connection part 22 to the gate width Wu. The area efficiency can be considered to be the ratio of the area in the body region 20B that can actually be used as a channel.

[0049] exist Figure 5 Zhong Ye and Figure 4 Similarly, the gate length L is set to 0.25 μm, and the gate width Wu is set to 5 μm. The length Wbc of the body contact connection portion 21 in the y direction and the number n of the body contact regions 20BC are counted in the same manner as Figure 4 The same situation. Figure 5 The numerical value with a circle symbol shown indicates the number n of the body contact regions 20BC.

[0050] As the length Wsb becomes shorter, the area efficiency decreases. In particular, in the range where the length Wsb is shorter than 3L, the area efficiency decreases significantly. In order to avoid a significant decrease in area efficiency, it is preferred that the length Wsb be greater than 3L. In the case where the lengths Wsb of the plurality of source body connection portions 22 are different, it is preferred that the minimum length Wsb be greater than 3L.

[0051] Next, refer to Figure 6 , the relationship between the withstand voltage and the length Wsb is explained. The withstand voltage is a measured value. Figure 6 Graph showing the relationship between the breakdown voltage and the length Wsb of the source body connection portion 22. The horizontal axis represents the length Wsb in units of [μm], and the vertical axis represents the breakdown voltage in units of [V]. Figure 6 Zhong Ye and Figure 4 Similarly, the gate length L is set to 0.25 μm, and the gate width Wu is set to 5 μm. The length Wbc of the body contact connection portion 21 in the y direction and the number n of the body contact regions 20BC are counted in the same manner as Figure 4 The same situation. Figure 6 The numerical value with a circle symbol shown indicates the number n of the body contact regions 20BC.

[0052] As the length Wsb increases, the withstand voltage decreases. If the length Wsb exceeds 10L, the decrease in the withstand voltage increases with the increase in the length Wsb. In order to maintain the withstand voltage high, as an example, it is preferred that the length Wsb be 10L or less.

[0053] Next, a preferred thickness of the device layer 13 will be described.

[0054] In the source region 20S ( Figure 2A ) does not reach the interface between the device layer 13 and the buried oxide film 12, a region of p-type conductivity identical to that of the body region 20B is secured between the source region 20S and the buried oxide film 12. In this structure, even if the body contact region 20BC is spaced apart from the body region 20B, holes can be extracted from the body region 20B by passing through the region of p-type conductivity between the source region 20S and the buried oxide film 12.

[0055] like Figure 2AAs shown, in the case where the source region 20S reaches the interface between the device layer 13 and the buried oxide film 12 from the upper surface of the device layer 13, if the body contact region 20BC is arranged at a distance from the body region 20B, the holes in the body region 20B cannot reach the body contact region 20BC. In the case where the source region 20S reaches the interface between the device layer 13 and the buried oxide film 12 from the upper surface of the device layer 13, a significant effect can be obtained by adopting a structure in which the body contact region 20BC is arranged to be in contact with the body region 20B. In the case where the thickness of the device layer 13 is less than 50nm, it is difficult to ensure a region of p-type conductivity between the source region 20S and the buried oxide film 12. Therefore, in the case where the thickness of the device layer 13 is less than 50nm, a significant effect can be obtained by adopting the structure of the first embodiment.

[0056] Next, a semiconductor device according to a modified example of the first embodiment will be described.

[0057] The semiconductor device of the first embodiment includes an n-channel MOSFET. Alternatively, a p-channel MOSFET may be included. In the p-channel MOSFET as well, the preferred relationship between the length Wsb and the gate length L is the same as that of the n-channel MOSFET.

[0058] In the first embodiment ( Figure 1 ), one gate electrode 20G is arranged to intersect one active region 13A. In addition, in a multi-finger MOSFET in which a plurality of gate electrodes 20G are arranged to intersect one active region 13A, the structure of the first embodiment can also be adopted. In the case of a multi-finger MOSFET, the gate width Wu can be considered as the size of each of the plurality of fingers of the gate electrode 20G in the gate width direction.

[0059] [Second embodiment]

[0060] Next, refer to Figure 7 The semiconductor device of the second embodiment is described below. Figures 1 to 6 The common structure of the semiconductor device of the first embodiment described with reference to the accompanying drawings is omitted.

[0061] Figure 7 is a top view of the semiconductor device according to the second embodiment.

[0062] In the first embodiment ( Figure 1), the body contact regions 20BC extend from the body contact connection portion 21 of the body region 20B toward the source region 20S and reach the edge on the opposite side of the source region 20S. In contrast, in the second embodiment, the body contact regions 20BC extending from the body contact connection portion 21 do not reach the edge on the opposite side of the source region 20S. Therefore, the source region 20S is not separated by the body contact regions 20BC, but is composed of a continuous region.

[0063] In the second embodiment, as in the first embodiment, the holes generated in the body region 20B move in the body region 20B, pass through the body contact connection portion 21, and reach the body contact region 20BC. Thus, in the second embodiment, the process of extracting the holes in the body contact region 20BC is the same as in the first embodiment.

[0064] Next, the excellent effects of the second embodiment will be described.

[0065] In the second embodiment as well, by making the relationship between the length Wsb of the source-body connection portion 22 and the gate length L satisfy the same relationship as in the first embodiment, the same excellent effects as in the first embodiment can be obtained.

[0066] [Third embodiment]

[0067] Next, refer to Figure 8 The semiconductor device of the third embodiment is described below. Figures 1 to 6 The common structure of the semiconductor device of the first embodiment described with reference to the accompanying drawings is omitted.

[0068] Figure 8 2 is a top view of the semiconductor device of the third embodiment. In the third embodiment, the body contact region 20BC is composed of a first body contact region 20BC1 and a second body contact region 20BC2. The first body contact region 20BC1 is connected to the first embodiment ( Figure 1 ) and extends from the body contact connection portion 21 of the body region 20B toward the source region 20S. The first body contact region 20BC1 is similar to the second embodiment ( Figure 7 ) is the same as the body contact region 20BC and does not reach the edge on the opposite side of the source region 20S.

[0069] The gate electrode protrusion 20GP protruding from the gate electrode 20G toward the source region 20S overlaps with the first body contact region 20BC1 in a plan view. When an n-type dopant is injected into the source region 20S, the gate electrode protrusion 20GP acts as a mask, so the first body contact region 20BC1 directly below the gate electrode protrusion 20GP has p-type conductivity like the body region 20B, and the concentration of the dopant in the first body contact region 20BC1 is the same as the concentration of the dopant in the body region 20B.

[0070] In order to surround the front end of the first body contact region 20BC1 from three sides, a second body contact region 20BC2 having p-type conductivity is formed. The concentration of the p-type dopant in the second body contact region 20BC2 is higher than the concentration of the p-type dopant in the first body contact region 20BC1. Figure 2A ) are similarly provided with a silicide film. The holes that move in the body region 20B and reach the body contact connection portion 21 reach the region of the ground potential via the first body contact region 20BC1 and the second body contact region 20BC2.

[0071] Next, the excellent effects of the third embodiment will be described.

[0072] In the third embodiment, the length Wbc of the body contact connection part 21 is substantially equal to the dimension of the gate electrode protrusion 20GP in the y direction. Generally, the processing accuracy of the gate electrode 20G is higher than that of other structural elements. Therefore, the length Wbc of the body contact connection part 21 can be shortened without depending on the size of the second body contact region 20BC2. In other words, the length Wsb of the source body connection part 22 can be lengthened. Therefore, the area efficiency can be improved.

[0073] In the third embodiment as well, by making the relationship between the length Wsb of the source-body connection portion 22 and the gate length L satisfy the same relationship as in the first embodiment, the same excellent effects as in the first embodiment can be obtained.

[0074] The above-mentioned embodiments are illustrative, and it is of course possible to partially replace or combine the structures shown in different embodiments. The same effects of the same structure based on multiple embodiments are not mentioned in sequence in each embodiment. In addition, the present invention is not limited to the above-mentioned embodiments. For example, it is obvious to those skilled in the art that various changes, improvements, combinations, etc. can be made.

[0075] Based on the above-described embodiments described in this specification, the following inventions are disclosed.

[0076] <1>

[0077] A semiconductor device comprising:

[0078] A device layer composed of a semiconductor is disposed on an insulating surface; and

[0079] A field effect transistor comprising a source region of a first conductivity type formed in the device layer, a drain region of the first conductivity type, a body region of a second conductivity type opposite to the first conductivity type, and a gate electrode disposed on the device layer.

[0080] The body region is arranged directly below the gate electrode.

[0081] When the insulating surface is viewed from above, the gate electrode and the body region have a shape that is long in a first direction, the source region is arranged on one side of the gate electrode, and the drain region is arranged on the other side of the gate electrode.

[0082] The field effect transistor further includes a body contact region of the second conductivity type, the body contact region of the second conductivity type extending from a plurality of body contact connection portions at an edge of the body region on the source region side toward the source region side,

[0083] The source region is connected to the body region at a plurality of source-body connection sites other than the plurality of body contact connection sites,

[0084] A maximum value of the length of each of the plurality of source-body connection locations in the first direction is not more than 10 times a dimension of the gate electrode in a second direction perpendicular to the first direction.

[0085] <2>

[0086] The semiconductor device according to <1>, wherein:

[0087] A maximum value of the length of each of the plurality of source-body connection locations in the first direction is not more than four times a dimension of the gate electrode in a second direction perpendicular to the first direction.

[0088] <3>

[0089] The semiconductor device according to <1> or <2>, wherein:

[0090] A minimum value of the length of each of the plurality of source-body connection locations in the first direction is at least three times a dimension of the gate electrode in a second direction perpendicular to the first direction.

[0091] <4>

[0092] The semiconductor device according to any one of <1> to <3>, wherein:

[0093] The source region extends from the upper surface of the device layer to the insulating surface.

[0094] <5>

[0095] The semiconductor device according to any one of <1> to <4>, wherein:

[0096] The thickness of the device layer is 50 nm or less.

[0097] <6>

[0098] The semiconductor device according to any one of <1> to <5>, wherein:

[0099] The device further includes a drift region that is disposed between the body region and the drain region and is of the first conductivity type and has a lower concentration than that of the drain region.

Claims

1. A semiconductor device, wherein: have: A device layer composed of a semiconductor is disposed on an insulating surface; and A field effect transistor comprises a source region of a first conductivity type formed in the device layer, a drain region of the first conductivity type, a body region of a second conductivity type opposite to the first conductivity type, and a gate electrode arranged on the device layer, The body region is arranged directly below the gate electrode, When the insulating surface is viewed from above, the gate electrode and the body region have a shape that is long in a first direction, the source region is arranged on one side of the gate electrode, and the drain region is arranged on the other side of the gate electrode. The field effect transistor further includes a body contact region of the second conductivity type extending from a plurality of body contact connection portions at an edge of the body region on the source region side toward the source region side, The source region is connected to the body region at a plurality of source-body connection sites other than the plurality of body contact connection sites, The maximum value of the length of each of the plurality of source-body connection locations in the first direction is not more than 10 times the dimension of the gate electrode in a second direction perpendicular to the first direction.

2. The semiconductor device according to claim 1, wherein The maximum length of each of the plurality of source-body connection locations in the first direction is not more than four times the dimension of the gate electrode in a second direction perpendicular to the first direction.

3. The semiconductor device according to claim 1 or 2, wherein: The minimum length of each of the plurality of source-body connection locations in the first direction is at least three times the dimension of the gate electrode in a second direction perpendicular to the first direction.

4. The semiconductor device according to any one of claims 1 to 3, wherein: The source region extends from the upper surface of the device layer to the insulating surface.

5. The semiconductor device according to any one of claims 1 to 4, wherein: The thickness of the device layer is less than 50 nm.

6. The semiconductor device according to any one of claims 1 to 5, wherein: The device further includes a drift region that is disposed between the body region and the drain region and is of the first conductivity type and has a lower concentration than that of the drain region.

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