Semiconductor equipment
The semiconductor device addresses breakdown voltage limitations by optimizing electrode and insulating member arrangements to reduce electric field concentration and leakage current, enhancing breakdown voltage performance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KK TOSHIBA
- Filing Date
- 2025-01-17
- Publication Date
- 2026-07-30
AI Technical Summary
Existing semiconductor devices face challenges in improving breakdown voltage due to electric field concentration and leakage current issues.
The semiconductor device incorporates a specific electrode and insulating member configuration, including a third electrode with conductive portions and insulating portions arranged to control current flow, reducing electric field concentration and enhancing breakdown voltage through the use of high-permittivity insulating materials.
This configuration suppresses electric field concentration and leakage current, thereby improving the breakdown voltage and maintaining device reliability under high voltage conditions.
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Figure 2026123714000001_ABST
Abstract
Description
Technical Field
[0001] Embodiments relate to semiconductor devices.
Background Art
[0002] In semiconductor devices, improvement of breakdown voltage is desired.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Embodiments of the present invention provide a semiconductor device capable of improving breakdown voltage.
Means for Solving the Problems
[0005] According to embodiments of the present invention, a semiconductor device includes a first electrode, a second electrode, a semiconductor member, a third electrode, and a first insulating member. The semiconductor member is provided between the first electrode and the second electrode in a first direction toward the first electrode and the second electrode. The third electrode is provided between the first electrode and the second electrode. At least a portion of the first insulating member is provided between the third electrode and the semiconductor member. The third electrode includes a first conductive portion and a second conductive portion. The second conductive portion is located between the first electrode and the first conductive portion in the first direction. The semiconductor member includes a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type, and a third semiconductor region of a first conductivity type. The first semiconductor region includes a first partial region and a second partial region. The first partial region is located between the first electrode and the second conductive portion in the first direction. At least a portion of the second semiconductor region is located between the second partial region and the third semiconductor region. The third semiconductor region is electrically connected to the second electrode. The first conductive portion faces the second partial region, the second semiconductor region, and the third semiconductor region in a second direction intersecting the first direction. The first insulating member includes a first insulating portion between the first conductive member and the semiconductor member in the second direction, and a second insulating portion between the second conductive member and the semiconductor member in the second direction. The first length of the first insulating portion along the second direction is shorter than the second length of the second insulating portion along the second direction. [Brief explanation of the drawing]
[0006] [Figure 1] Figure 1 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. [Figure 2] Figure 2 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. [Figure 3] Figure 3 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. [Figure 4] Figure 4 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. [Figure 5]Figure 5 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. [Figure 6] Figure 6 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. [Modes for carrying out the invention]
[0007] The embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual representations, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may differ between drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.
[0008] Figure 1 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. As shown in Figure 1, the semiconductor device 100 according to this embodiment includes a first electrode 51, a second electrode 52, a semiconductor member 10, a third electrode 53, and a first insulating member 41.
[0009] The semiconductor member 10 is provided between the first electrode 51 and the second electrode 52 in a first direction D1 toward the first electrode 51 and the second electrode 52.
[0010] Let the first direction D1 be the Z-axis direction. Let one direction perpendicular to the Z-axis direction be the X-axis direction. Let the direction perpendicular to both the Z-axis and X-axis directions be the Y-axis direction. The second direction D2 is, for example, the X-axis direction.
[0011] The cross-sectional structure shown in Figure 1 extends along the Y-axis.
[0012] The third electrode 53 is provided between the first electrode 51 and the second electrode 52. The third electrode 53 includes a first conductive portion 53a and a second conductive portion 53b.
[0013] At least a part of the first insulating member 41 is provided between the third electrode 53 and the semiconductor member 10. The first insulating member 41 insulates the third electrode 53 and the semiconductor member 10.
[0014] The second conductive portion 53b is between the first electrode 51 and the first conductive portion 53a in the first direction D1. The second conductive portion 53b is separated from the first conductive portion 53a.
[0015] The semiconductor member 10 includes a first semiconductor region 11 of the first conductivity type, a second semiconductor region 12 of the second conductivity type, and a third semiconductor region 13 of the first conductivity type. The first semiconductor region 11 includes a first partial region 11a and a second partial region 11b. The first partial region 11a is between the first electrode 51 and the second conductive portion 53b in the first direction D1. At least a part of the second semiconductor region 12 is between the second partial region 11b and the third semiconductor region 13. The third semiconductor region 13 is electrically connected to the second electrode 52. The first conductive portion 53a faces the second partial region 11b, the second semiconductor region 12, and the third semiconductor region 13 in a second direction D2 intersecting the first direction D1.
[0016] For example, the first conductivity type is one of n-type and p-type. The second conductivity type is the other of n-type and p-type. In an embodiment, the first conductivity type may be p-type and the second conductivity type may be n-type. Hereinafter, the first conductivity type is n-type and the second conductivity type is p-type.
[0017] The first insulating member 41 includes a first insulating portion 41a and a second insulating portion 41b. The first insulating portion 41a is between the first conductive portion 53a and the semiconductor member 10 in the second direction D2. The second insulating portion 41b is between the second conductive portion 53b and the semiconductor member 10 in the second direction D2.
[0018] A first length L1 of the first insulating portion 41a in the second direction D2 is shorter than a second length L2 of the second insulating portion 41b in the second direction D2. The second length L2 is longer than the first length L1.
[0019] In the semiconductor device 100, the current flowing between the first electrode 51 and the second electrode 52 can be controlled by the potential of the third electrode 53. The potential of the third electrode 53 is, for example, a potential referenced to the potential of the first electrode 51. The first electrode 51 functions, for example, as one of the source electrode and the train electrode. The second electrode 52 functions, for example, as the other of the source electrode and the train electrode. The third electrode 53 functions, for example, as the gate electrode. The semiconductor device 100 is, for example, a MOSFET (metal-oxide-semiconductor field-effect transistor). For example, the first electrode 51 is the drain electrode. The second electrode 52 is the source electrode.
[0020] In the lower part of the gate electrode, a reference example is conceivable in which the second length L2 is the same. In this reference example, electric field concentration occurs around the lower part of the gate electrode. This results in damage to the first insulating member 41 and leakage current. In the semiconductor device 100 according to this embodiment, the first length L1 is shorter than the second length L2. The insulating portion at the lower part of the gate electrode is thicker. This reduces the electric field, for example. For example, damage to the first insulating member 41 is suppressed. For example, leakage current is suppressed. For example, when a high voltage is applied to the drain electrode, the electric field applied around the gate electrode can be reduced. According to this embodiment, the breakdown voltage can be improved.
[0021] The third electrode 53 may extend along the third direction D3. The third direction D3 intersects the plane containing the first direction D1 and the second direction D2. The third direction D3 may be, for example, the Y-axis direction.
[0022] As shown in Figure 1, the semiconductor device 100 according to this embodiment further includes a second insulating member 42.
[0023] The first insulating member 41 further includes a fourth insulating portion 41d between the second conductive portion 53b and the first conductive portion 53a in the first direction D1. The second conductive portion 53b separates from the first conductive portion 53a in the first direction D1.
[0024] The distance between the second conductive portion 53b and the first conductive portion 53a along the first direction D1 is defined as the first distance d1. The first distance d1 is, for example, longer than the first length L1. The first distance d1 is, for example, longer than the second length L2.
[0025] The second insulating member 42 is located between the fourth insulating portion 41d and the first conductive portion 53a in the first direction D1. The second insulating member 42 and the fourth insulating portion 41d insulate the first conductive portion 53a from the second conductive portion 53b. The presence of the fourth insulating portion 41d between the second conductive portion 53b and the first conductive portion 53a, and the presence of the third insulating portion 41c between the first partial region 11a and the second conductive portion 53b, for example, mitigates localized concentration of the electric field.
[0026] The semiconductor device 100 may include a substrate layer 60. The substrate layer 60 is located between the first electrode 51 and the first semiconductor region 11 in the first direction D1.
[0027] Figure 2 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. The horizontal axis in Figure 2 represents the drain voltage. The vertical axis represents the drain current. In Figure 2, characteristic Z1 corresponds to a reference example. Characteristics Z2, Z3, Z4, and Z5 correspond to the semiconductor device 100 according to the embodiment. In characteristic Z2, the relative permittivity of the second insulating member 42 is 1.0. In characteristic Z3, the relative permittivity of the second insulating member 42 is 3.9. In characteristic Z4, the relative permittivity of the second insulating member 42 is 7.5. In characteristic Z5, the relative permittivity of the second insulating member 42 is 10.0. Characteristic Z3 corresponds to the case where the second insulating member 42 is SiO2. Characteristic Z4 corresponds to the case where the second insulating member 42 is SiN.
[0028] Characteristics Z2, Z3, and Z4 are shifted to the right (increase in drain voltage) relative to characteristic Z1. In characteristics Z2, Z3, and Z4, the higher the relative permittivity of the second insulating member 42, the more the characteristics shift to the right. The higher the relative permittivity of the second insulating member 42, the lower the leakage current and the higher the breakdown voltage.
[0029] The second concentration of nitrogen (N) in the second insulating member 42 is higher than the first concentration of nitrogen (N) in the fourth insulating portion 41d. Alternatively, the second insulating member 42 contains N, while the fourth insulating portion 41d does not.
[0030] The second concentration of N in the second insulating member 42 may be higher than the first concentration of N in the first insulating portion 41a, the second insulating portion 41b, and the third insulating portion 41c. The second insulating member 42 may contain N, while the first insulating portion 41a, the second insulating portion 41b, and the third insulating portion 41c do not need to contain N.
[0031] In the above, the second insulating member 42 and the fourth insulating portion 41d further contain silicon.
[0032] In this embodiment, the second relative permittivity of the second insulating member 42 may be higher than the first relative permittivity of the fourth insulating portion 41d.
[0033] For example, the second insulating member 42 may be a material having a relative permittivity of a certain level or higher. The relative permittivity of the second insulating member 42 may be, for example, 2.0 or higher. For example, the second insulating member 42 may include at least one of the group consisting of SiO2, AlN, HfO2, and Al2O3.
[0034] The second insulating member 42, which has a high dielectric constant, is provided between the first conductive portion 53a and the second conductive portion 53b. This reduces the electric field applied around the third electrode 53. The breakdown voltage is further improved.
[0035] The third electrode 53, specifically the second conductive portion 53b, is electrically connected to the first conductive portion 53a.
[0036] As shown in Figure 1, the first insulating member 41 further includes a third insulating portion 41c between the first partial region 11a and the second conductive portion 53b in the first direction D1.
[0037] The semiconductor member 10 further includes a fourth semiconductor region 14 of the second conductivity type. The fourth semiconductor region 14 is located between the second semiconductor region 12 and the second electrode 52.
[0038] The semiconductor device 100 may further include a third insulating member 43. At least a portion of the third insulating member 43 is located between the third electrode 53 and the second electrode 52. The third insulating member 43 insulates the third electrode 53 from the second electrode 52.
[0039] Figure 3 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. In Figure 3, the horizontal axis represents the second length L2. The vertical axis represents voltage, indicating the withstand voltage. As shown in Figure 3, the breakdown voltage increases in the range of 20 nm to less than 30 nm in the second length L2. When the second length L2 is 30 nm or more, the breakdown voltage remains constant. In the embodiment, the second length L2 is preferably 30 nm or more. The second length L2 is preferably 30 nm to 40 μm.
[0040] The second length L2 may be 1.2 times or more the first length L1.
[0041] The third length L3 of the third insulating portion 41c along the first direction D1 may be longer than the first length L1.
[0042] As shown in Figure 1, the first conductive portion 53a includes a facing region 53f that faces the second sub-region 11b in the second direction D2. The length of the facing region 53f along the first direction D1 is defined as the fourth length L4. Below, examples of characteristics when the fourth length L4 is changed will be described.
[0043] Figure 4 is a graph illustrating the characteristics of a semiconductor device according to the embodiment. In Figure 4, the horizontal axis represents the fourth length L4, and the vertical axis represents the breakdown voltage BV. As shown in Figure 4, when the fourth length L4 exceeds 150 nm, the breakdown voltage tends to decrease. A fourth length L4 of 150 nm or less is preferable. The fourth length L4 is greater than 0.
[0044] As shown in Figure 1, the sixth length L6 of the first conductive portion 53a in the second direction D2 may be longer than the fifth length L5 of the second conductive portion 53b in the second direction D2.
[0045] As shown in Figure 1, the fifth length L5 of the second conductive portion 53b in the second direction D2 may be shorter than the seventh length L7 of the second insulating member 42 in the second direction D2.
[0046] Figure 5 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. As shown in Figure 5, in the semiconductor device 101 according to this embodiment, the configuration of the second conductive portion 53b differs from the configuration of the second conductive portion 53b in the semiconductor device 100. The configuration of the semiconductor device 101, excluding this, may be the same as that of the semiconductor device 100.
[0047] In the semiconductor device 101, the second length L2 decreases along the direction from the first electrode 51 to the second electrode 52. The second length L2 decreases from length L2b to length L2a along the direction from the first electrode 51 to the second electrode 52. The length (width) of the second conductive portion 53b in the second direction D2 may increase along the direction from the first electrode 51 to the second electrode 52.
[0048] In semiconductor devices 100 and 101, the concentration of the first conductivity type impurity in the first semiconductor region 11 is lower than the concentration of the first conductivity type impurity in the third semiconductor region 13. The concentration of the second conductivity type impurity in the second semiconductor region 12 is lower than the concentration of the second conductivity type impurity in the fourth semiconductor region 14.
[0049] The carrier concentration of the first conductivity type in the first semiconductor region 11 is lower than the carrier concentration of the first conductivity type in the third semiconductor region 13. The carrier concentration of the second conductivity type in the second semiconductor region 12 is lower than the carrier concentration of the second conductivity type in the fourth semiconductor region 14. The first semiconductor region 11 is, for example, n - It is a layer or n layers. The third semiconductor region 13 is, for example, n + It is a layer. The second semiconductor region 12 is, for example, p - It is a layer or a p-layer. The fourth semiconductor region 14 is, for example, a p-layer. + It is a layer.
[0050] Figure 6 is a schematic cross-sectional view illustrating a semiconductor device according to an embodiment. As shown in Figure 6, in the semiconductor device 102 according to this embodiment, the configuration of the second conductive portion 53b differs from the configuration of the second conductive portion 53b in the semiconductor device 100. The configuration of the semiconductor device 102, excluding this, may be the same as that of the semiconductor device 100.
[0051] In the semiconductor device 102, the second length L2 decreases from a certain point along the direction from the first electrode 51 to the second electrode 52. The second length L2 decreases from length L2b to length L2a along the direction from the first electrode 51 to the second electrode 52. The length (width) of the second conductive portion 53b in the second direction D2 may increase along the direction from the first electrode 51 to the second electrode 52.
[0052] According to the embodiment, a semiconductor device capable of improving voltage resistance can be provided.
[0053] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configuration of each element, such as semiconductor members, electrodes, conductive parts, and insulating parts, included in a semiconductor device is included within the scope of the present invention as long as those skilled in the art can appropriately select from the known range to implement the present invention and obtain similar effects.
[0054] Furthermore, combinations of two or more elements from any of the specific examples, to the extent technically feasible, are also included within the scope of the present invention, insofar as they encompass the gist of the invention.
[0055] Furthermore, all semiconductor devices that a person skilled in the art can implement by appropriately modifying the design based on the semiconductor device described above as an embodiment of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention.
[0056] Furthermore, within the scope of the concept of the present invention, a person skilled in the art could conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention.
[0057] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]
[0058] 10 semiconductor member, 11-14 first semiconductor region to fourth semiconductor region, 11a first partial region, 11b second partial region, 41-43 First insulating member to third insulating member, 41a First insulating part, 41b Second insulating part, 41c Third insulating part, 41d Fourth insulating part, 51~53 first electrode to third electrode, 53a first conductive part, 53f opposing region, 53b second conductive part, 60 substrate layers, 100, 101 Semiconductor Systems, L1~L7 1st length~7th length, L2a, L2b 2nd length, d1: First distance
Claims
1. First electrode and The second electrode and A semiconductor member provided between the first electrode and the second electrode in a first direction toward the first electrode and the second electrode, A third electrode is provided between the first electrode and the second electrode, A first insulating member, wherein at least a portion of the first insulating member is provided between the third electrode and the semiconductor member, Equipped with, The third electrode includes a first conductive portion and a second conductive portion, The second conductive portion is located between the first electrode and the first conductive portion in the first direction. The aforementioned semiconductor member is The first semiconductor region of the first conductivity type, The second semiconductor region of the second conductivity type, The third semiconductor region of the first conductivity type, Includes, The first semiconductor region includes a first partial region and a second partial region. The first partial region is located between the first electrode and the second conductive portion in the first direction. At least a portion of the second semiconductor region is located between the second partial region and the third semiconductor region. The third semiconductor region is electrically connected to the second electrode, The first conductive portion faces the second partial region, the second semiconductor region, and the third semiconductor region in a second direction intersecting the first direction. The first insulating member is, In the second direction, the first insulating portion between the first conductive portion and the semiconductor member, In the second direction, the second insulating portion between the second conductive portion and the semiconductor member, Includes, A semiconductor device wherein the first length of the first insulating portion along the second direction is shorter than the second length of the second insulating portion along the second direction.
2. Further comprising a second insulating member, The first insulating member further includes a fourth insulating portion between the second conductive portion and the first conductive portion in the first direction, The second insulating member is located between the fourth insulating portion and the first conductive portion in the first direction. The second concentration of N in the second insulating member is higher than the first concentration of N in the fourth insulating portion, or The semiconductor device according to claim 1, wherein the second insulating member contains N, and the fourth insulating portion does not contain N.
3. The semiconductor device according to claim 2, wherein the second insulating member and the fourth insulating portion further contain silicon.
4. Further comprising a second insulating member, The first insulating member further includes a fourth insulating portion between the second conductive portion and the first conductive portion in the first direction, The second insulating member is located between the fourth insulating portion and the first conductive portion in the first direction. The semiconductor device according to claim 1, wherein the second relative permittivity of the second insulating member is higher than the first relative permittivity of the fourth insulating portion.
5. The second insulating member is SiO ２ AlN, HfO ２ , and Al ２ O ３ The semiconductor device according to claim 2, comprising at least one of the group consisting of the following.
6. The semiconductor device according to any one of claims 1 to 5, wherein the second conductive portion is electrically connected to the first conductive portion.
7. The semiconductor device according to claim 1, wherein the second conductive portion is separated from the first conductive portion.
8. The first insulating member further includes a third insulating portion between the first partial region and the second conductive portion in the first direction, The semiconductor device according to claim 1, wherein the third length of the third insulating portion along the first direction is longer than the first length.
9. The semiconductor member further includes the fourth semiconductor region of the second conductivity type, The semiconductor device according to any one of claims 1 to 5, wherein the fourth semiconductor region is located between the second semiconductor region and the second electrode.
10. Further comprising a third insulating member, The semiconductor device according to claim 1, wherein at least a portion of the third insulating member is located between the third electrode and the second electrode.
11. The first conductive portion includes a facing region that faces the second partial region in the second direction, The semiconductor device according to claim 1, wherein the fourth length of the opposing region along the first direction is longer than 0 nm and less than or equal to 150 nm.
12. The semiconductor device according to claim 1, wherein the second length is 1.2 times or more the first length.
13. The semiconductor device according to claim 1, wherein the second length is 30 nm or more.
14. The semiconductor device according to claim 1, wherein the sixth length of the first conductive portion in the second direction is longer than the fifth length of the second conductive portion in the second direction.
15. The semiconductor device according to any one of claims 2 to 4, wherein the fifth length of the second conductive portion in the second direction is shorter than the seventh length of the second insulating member in the second direction.
16. The semiconductor device according to claim 1, wherein the second length decreases along the direction from the first electrode to the second electrode.
17. The semiconductor device according to claim 1, wherein the first distance along the first direction between the second conductive portion and the first conductive portion is longer than the first length.
18. The semiconductor device according to claim 1, wherein the first distance along the first direction between the second conductive portion and the first conductive portion is longer than the second length.
19. The semiconductor device according to claim 1, wherein the concentration of the first conductivity type impurity in the first semiconductor region is lower than the concentration of the first conductivity type impurity in the third semiconductor region.
20. The semiconductor device according to claim 9, wherein the concentration of the second conductivity type impurity in the second semiconductor region is lower than the concentration of the second conductivity type impurity in the fourth semiconductor region.