Method of manufacturing semiconductor device and semiconductor device

Abstract

To provide a method of manufacturing a semiconductor device and the semiconductor device, less likely causing voids in corners of an annular guard ring.SOLUTION: A method of manufacturing a semiconductor device includes steps of: irradiating a photoresist with light transmitted through an opening of a photomask that has the opening including linear parts and a corner part connecting ends of the two linear parts to provide an exposed portion to the photoresist; forming a circuit patten having a shape corresponding to the exposed portion of the photoresist; forming an annular trench groove having a shape along the shape of the circuit pattern in a film to be etched while using the photoresist; and forming a guard ring in the trench groove. A first width that is a distance between an inner periphery edge and an outer periphery edge of the corner of the opening of the photomask is shorter than a virtual width that is a distance between a first intersection point between first straight lines along the outer periphery edges of the adjacent two linear parts and a second intersection point between second straight lines along the inner periphery edges of the adjacent two linear parts.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a semiconductor device and a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a semiconductor device in which a guard ring is provided in a groove formed in a semiconductor substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-55183 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, we assume that the guard ring has a substantially rectangular shape when viewed in the thickness direction of the semiconductor substrate. That is, we assume that the guard ring has four linear portions and four corners connecting the ends of two adjacent linear portions. In other words, we assume that the grooves formed in the semiconductor substrate have a substantially rectangular shape.

[0005] When the inner peripheral edges of two straight portions are connected at right angles and the outer peripheral edges of two straight portions are connected at right angles, the first width, which is the distance between the connection (corner) of the inner peripheral edges of the two straight portions and the connection (corner) of the outer peripheral edges of the two straight portions, is greater than the second width, which is the distance between the inner peripheral edge and the outer peripheral edge of the straight portions.

[0006] That is, in this case, the first width of the groove is larger than the second width of the groove. For example, when a guard ring is provided in such a groove using CVD (Chemical Vapor Deposition), voids are likely to occur at the corners of the formed guard ring.

[0007] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a method for manufacturing a semiconductor device in which voids are less likely to occur at the corners of an annular guard ring, and to provide a semiconductor device. [Means for solving the problem]

[0008] A method for manufacturing a semiconductor device according to the present disclosure includes the steps of: providing a photoresist on a film to be etched formed on a semiconductor substrate; irradiating the photoresist with light that has passed through an opening of a photomask, the opening having a ring shape when viewed in the thickness direction of the semiconductor substrate and including at least two straight portions and at least one corner connecting ends of two adjacent straight portions, to provide an exposed portion in the photoresist; forming a circuit pattern in the photoresist, the hole having a shape corresponding to the exposed portion; forming an annular trench groove in the film to be etched, the shape of which conforms to the shape of the circuit pattern, while using the photoresist as a mask; and forming a guard ring in the trench groove, wherein a first width, which is the distance between an inner edge and an outer edge of the corner of the opening of the photomask, is shorter than a virtual width, which is the distance between a first intersection of first straight lines along the outer edge of two adjacent straight portions and a second intersection of second straight lines along the inner edge of two adjacent straight portions. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view of a portion of a semiconductor substrate that is the base of a semiconductor device manufactured by a method for manufacturing a semiconductor device according to an embodiment; [Figure 2] FIG. 2 is a schematic side view showing a cross-sectional view of an individual piece and a semiconductor manufacturing apparatus. [Figure 3] FIG. 2 is a schematic bottom view of a photomask. [Figure 4] 4 is an enlarged view showing a part of an opening formed in the photomask of FIG. 3. [Figure 5] FIG. 10 is a plan view showing a photoresist provided on an individual piece. [Figure 6]FIG. 6 is an enlarged view showing a part of the circuit pattern and trench groove shown in FIG. 5. [Figure 7] FIG. 1 is a schematic plan view of a semiconductor device. [Figure 8] FIG. 10 is a schematic bottom view of a photomask according to a modified example. [Figure 9] 9 is an enlarged view showing a part of an opening formed in the photomask of FIG. 8. FIG. [Figure 10] FIG. 10 is a plan view showing a photoresist provided on an individual piece. [Figure 11] FIG. 1 is a schematic plan view of a semiconductor device. [Figure 12] FIG. 12 is an enlarged view showing a part of the circuit pattern and trench groove shown in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0010] A semiconductor device and a method for manufacturing the semiconductor device according to the embodiment will be described below.

[0011] The semiconductor device 35 of this embodiment is manufactured in the following manner.

[0012] As shown in Fig. 1, a semiconductor substrate 10 having a circular planar shape is supported in semiconductor manufacturing equipment 55 (see Fig. 2) (only a portion of the semiconductor substrate 10 is shown in Fig. 1). The semiconductor substrate 10 and various components provided on the semiconductor substrate 10, which will be described later, are diced along cut lines 11A and 11B shown in Fig. 1, ultimately resulting in a semiconductor device 35 having a substantially rectangular planar shape. In the following description, the portion having a substantially rectangular planar shape surrounded by two cut lines 11A and two cut lines 11B before becoming the semiconductor device 35 will be referred to as an individual piece 10A.

[0013] 2, the semiconductor manufacturing equipment 55 forms a film to be etched 12 on the entire upper surface of the semiconductor substrate 10. The film to be etched 12 includes, for example, a silicon oxide film and a metal film.

[0014] Furthermore, the semiconductor manufacturing equipment 55 applies a photoresist 15 to the entire upper surface of the film 12 to be etched, as shown in FIG.

[0015] As shown in FIG. 2, the semiconductor manufacturing apparatus 55 includes an exposure light source 60, a projection lens 62 positioned below the exposure light source 60, and a photomask 70 positioned between the exposure light source 60 and the projection lens 62. A light-shielding film 71 is provided on the underside of a light-transmitting base material 70A of the photomask 70. As shown in FIG. 3, the light-shielding film 71 has a number of openings 71A formed therein, each of which has an annular shape when viewed in the thickness direction of the semiconductor substrate 10. As shown in FIG. 3, the planar shape of each opening 71A is approximately rectangular. That is, each opening 71A includes four linear portions 72 and four corner portions 73 connecting the ends of two adjacent linear portions 72. Two adjacent linear portions 72 are perpendicular to each other in a planar view.

[0016] As shown in FIG. 4, the inner peripheral edge 73A of each corner 73 of each opening 71A is the intersection of the inner peripheral edges 72A of two adjacent linear portions 72. In other words, the inner peripheral edge 73A is the intersection (second intersection) of straight lines (second straight lines) that run along the inner peripheral edges 72A of two adjacent linear portions 72. The planar shape of the outer peripheral edge 73B of each corner 73 is an arc shape centered on the inner peripheral edge 73A. The distance between the inner peripheral edge 73A and the outer peripheral edge 73B is defined as a first width W1. The distance between the inner peripheral edge 73A and the intersection 72B2 of extensions 72B1 of the ends of the outer peripheral edges 72B of two adjacent linear portions 72 and the inner peripheral edge 73A is defined as an imaginary width W1A. In other words, the imaginary width W1A is the distance between the inner peripheral edge 73A and the intersection (first intersection) of straight lines (first straight lines) that run along the outer peripheral edge portions 72B of two adjacent linear portions 72. In this case, the first width W1 is shorter than the imaginary width W1A.

[0017] 4, a second width W2 is defined as the distance between the inner peripheral edge 72A and the outer peripheral edge 72B of each linear portion 72. The first width W1 and the second width W2 are substantially the same.

[0018] 2 irradiates light downward, the light transmitted through the openings 71A of the photomask 70 and the projection lens 62 forms an image on the upper surface of the photoresist 15. As a result, a large number of exposed portions, which are portions irradiated with light, are formed in the photoresist 15.

[0019] Next, the semiconductor manufacturing equipment 55 applies a developer to the photoresist 15 and removes each exposed portion from the photoresist 15. This patterning the photoresist 15. As a result of this patterning, as shown in FIG. 5, a large number of circuit patterns 17 having planar shapes corresponding to the openings 71A are formed in the photoresist 15 (only one circuit pattern 17 is shown in FIG. 5). That is, a circuit pattern 17 is formed in each individual piece 10A. The planar shape of the circuit pattern 17 is approximately rectangular. That is, the circuit pattern 17 has four linear portions 19 corresponding to each linear portion 72, and four corners 21 connecting the ends of two adjacent linear portions 19 and corresponding to the corners 73. Two adjacent linear portions 19 are perpendicular to each other in a planar view.

[0020] As shown in FIG. 6 , the inner peripheral edge 21A of each corner 21 of each circuit pattern 17 is the intersection of the inner peripheral edges 19A of two adjacent linear portions 19. The planar shape of the outer peripheral edge 21B of each corner 21 is an arc centered on the inner peripheral edge 21A. The distance between the inner peripheral edge 21A and the outer peripheral edge 21B is defined as a first width W1-X. The distance between the inner peripheral edge 21A and the intersection 19B2 of the extensions 19B1 of the ends of the outer peripheral edges 19B of two adjacent linear portions 19 and the inner peripheral edge 21A is defined as a virtual width W1A-X. In this case, the first width W1-X is shorter than the virtual width W1A-X.

[0021] 6, the distance between the inner peripheral edge 19A and the outer peripheral edge 19B of each linear portion 19 is defined as a second width W2-X. The first width W1-X and the second width W2-X are substantially the same. Note that, when the opening 71A and the circuit pattern 17 have the same dimensions, the first width W1 and the first width W1-X are substantially the same, the imaginary width W1A and the imaginary width W1A-X are substantially the same, and the second width W2 and the second width W2-X are substantially the same.

[0022] Next, the semiconductor manufacturing equipment 55 etches the film 12 to be etched using the photoresist 15 as a mask. As a result, as shown in FIG. 5, a trench 25 having a planar shape substantially identical to the circuit pattern 17 is formed in the film 12 to be etched. The trench 25 includes four linear portions 27 corresponding to the linear portions 19 and four corners 29 connecting the ends of two adjacent linear portions 27 and corresponding to the corners 21. Furthermore, as shown in FIG. 6, the inner peripheral edge 29A of each corner 29 is the intersection of the inner peripheral edges 27A of two adjacent linear portions 27. The planar shape of the outer peripheral edge 29B of each corner 29 is an arc shape centered on the inner peripheral edge 29A. Furthermore, the distance between the inner peripheral edge 29A and the outer peripheral edge 29B is a first width W1-X. The distance between the inner peripheral edge 29A and an intersection 27B2 of extensions 27B1 of the ends of the outer peripheral edges 27B of two adjacent straight portions 27 is a virtual width W1A-X. The distance between the inner peripheral edge 27A and the outer peripheral edge 27B of each straight portion 27 is a second width W2-X.

[0023] An inner peripheral edge 29A of a corner 29 of the trench 25 is an intersection (second intersection) of straight lines (second straight lines) that run along the inner peripheral edges 27A of two adjacent linear portions 27. The distance between the inner peripheral edge 29A and the intersection (first intersection) of straight lines (first straight lines) that run along the outer peripheral edges 27B of two adjacent linear portions 27 of the trench 25 is the imaginary width W1A-X.

[0024] Next, the semiconductor manufacturing equipment 55 removes the photoresist 15 .

[0025] 7, semiconductor manufacturing equipment 55 uses tungsten by CVD (Chemical Vapor Deposition) to form guard ring 32 in trench groove 25, the guard ring having a shape that follows trench groove 25. Therefore, guard ring 32 has four linear portions 33 that follow linear portions 27 of trench groove 25 and four corner portions 34 that follow corner portions 29.

[0026] Although not shown in the figure, before the trench groove 25 is formed, each individual piece 10A of the semiconductor substrate 10 has a circuit pattern made of a conductive material formed on the inner periphery of the trench groove 25 in a planar view.

[0027] Furthermore, the semiconductor manufacturing equipment 55 dices the semiconductor substrate 10 thus formed and the etched film 12 integrated with the semiconductor substrate 10 along cut lines 11A and 11B, thereby manufacturing a number of semiconductor devices 35 (see FIG. 7) each having a substantially rectangular planar shape and including a circuit pattern and guard rings 32 made of a conductive material.

[0028] (Action and effect) Next, the operation and effects of this embodiment will be described.

[0029] According to the method for manufacturing a semiconductor device of this embodiment described above, a photoresist 15 is formed on the to-be-etched film 12 formed on the individual piece 10A (semiconductor substrate 10). Furthermore, a photomask 70 has a large number of openings 71A, each of which has four linear portions 72 and four corner portions 73 connecting the ends of two adjacent linear portions 72. The photoresist 15 is irradiated with light that has passed through each of the openings 71A, thereby forming a large number of exposed portions in the photoresist 15. Furthermore, a circuit pattern 17, which is an opening having a shape corresponding to each exposed portion, is formed in the photoresist 15. Furthermore, using the photoresist 15 as a mask, an annular trench groove 25 having a shape that follows the shape of the circuit pattern 17 is formed in the to-be-etched film 12. Furthermore, a guard ring 32 is formed in the trench groove 25. Therefore, the planar shape of the guard ring 32 is substantially the same as the planar shape of the trench groove 25.

[0030] The distance between the inner peripheral edge 73A and the outer peripheral edge 73B of each corner 73 of each opening 71A of the photomask 70 is a first width W1, and the distance between the inner peripheral edge 73A and an intersection 72B2 of extension lines 72B1 of the ends of the outer peripheral edges 72B of two adjacent straight portions 72 is an imaginary width W1A. The first width W1 is shorter than the imaginary width W1A. Furthermore, the distance between the inner peripheral edge 72A and the outer peripheral edge 72B of each straight portion 72 is a second width W2 that is substantially the same as the first width W1.

[0031] The distance between the inner peripheral edge 29A and the outer peripheral edge 29B of each corner 29 of each trench groove 25 formed in the etched film 12 using the photomask 70 having the opening 71A of this shape is a first width W1-X, and the distance between the inner peripheral edge 29A and an intersection 27B2 of extensions 27B1 of the ends of the outer peripheral edges 27B of two adjacent straight portions 27 is a virtual width W1A-X. Furthermore, the distance between the inner peripheral edge 27A and the outer peripheral edge 27B of each straight portion 27 is a second width W2-X that is substantially the same as the first width W1-X.

[0032] Furthermore, the width W3 (see FIG. 7) of the corners 34 of the guard ring 32 is substantially equal to the first width W1-X, and the width W4 (see FIG. 7) of the linear portions 33 of the guard ring 32 is substantially equal to the second width W2-X. That is, the width W3 is substantially equal to the width W4. When the width W3 of the corners 34 is not larger than the width W4 of the linear portions 33, voids are less likely to occur at the corners 34 of the guard ring 32 than when the width W3 is significantly larger than the width W4. In particular, when the width W3 of the corners 34 is substantially equal to the width W4 of the linear portions 33, as in this embodiment, voids are less likely to occur at the corners 34 of the guard ring 32. Therefore, when the semiconductor substrate 10 and the etching target film 12 integrated with the semiconductor substrate 10 are diced along the cut lines 11A and 11B, the circuit pattern located on the inner periphery of the trench groove 25 is less likely to be damaged.

[0033] Furthermore, it is not difficult to provide the opening 71A having the outer peripheral edge 73B having an arc-shaped planar shape in the photomask 70. Therefore, according to the method for manufacturing a semiconductor device of this embodiment, it is easy to form the trench groove 25 in the to-be-etched film 12 so that the first width W1-X is shorter than the imaginary width W1A-X.

[0034] Although the semiconductor device and the manufacturing method of the semiconductor device according to the embodiment have been described above, the design of these can be appropriately modified within the scope of the gist of the present invention.

[0035] For example, the present invention may be implemented in the modified embodiments shown in FIGS.

[0036] Semiconductor manufacturing apparatus 55 of this modified example forms circuit patterns 22 (see FIG. 10) in photoresist 15 using a photomask 80 shown in FIG. 8. As shown in FIG. 8, a number of openings 81A are formed in a light-shielding film 81 of photomask 80, each of which has an annular shape when viewed in the thickness direction of semiconductor substrate 10. The planar shape of each opening 81A is approximately rectangular. Each opening 81A has four linear portions 82 and four corner portions 83 connecting the ends of two adjacent linear portions 82.

[0037] 9, the inner peripheral edge 83A of each corner 83 of the opening 81A is a straight line connecting the ends of the inner peripheral edge 82A of two adjacent linear portions 82. In plan view, the angle α formed between the inner peripheral edge 83A and the inner peripheral edge 82A of the two adjacent linear portions 82 is 45°.

[0038] The outer peripheral edge 83B of each corner 83 is a straight line connecting the ends of the outer peripheral edge 82B of two adjacent linear portions 82. In plan view, the angle β formed between the outer peripheral edge 83B and the outer peripheral edge 82B of the two adjacent linear portions 82 is 45°.

[0039] Here, the distance between the inner peripheral edge 83A and the outer peripheral edge 83B is defined as a first width W5. The first width W5 is substantially the same as a second width W6, which is the distance between the inner peripheral edge 82A and the outer peripheral edge 82B. Furthermore, the distance between the intersection 82B2 of the extension lines 82B1 of the ends of the outer peripheral edges 82B of two adjacent linear portions 82 and the intersection 82A2 of the extension lines 82A1 of the ends of the inner peripheral edges 82A of two adjacent linear portions 82 is defined as an imaginary width W5A. In this case, the first width W5 is shorter than the imaginary width W5A.

[0040] The intersection 82B2 is the intersection (first intersection) of straight lines (first straight lines) that run along the outer peripheral edge portions 82B of two adjacent straight portions 82, and the intersection 82A2 is the intersection (second intersection) of straight lines (second straight lines) that run along the inner peripheral edge portions 82A of two adjacent straight portions 82.

[0041] When the exposure light source 60 irradiates light downward, the light that has passed through each opening 81A of the photomask 80 and the projection lens 62 forms an image on the upper surface of the photoresist 15. As a result, a large number of exposed portions, which are portions irradiated with light, are formed in the photoresist 15.

[0042] Next, the semiconductor manufacturing equipment 55 applies a developer to the photoresist 15 and removes each exposed portion from the photoresist 15. This patterning the photoresist 15. As a result of this patterning, a large number of circuit patterns 22 having planar shapes corresponding to the openings 81A are formed in the photoresist 15, as shown in FIG. 10. That is, the circuit patterns 22 are formed on each of the individual pieces 10A.

[0043] Next, the semiconductor manufacturing equipment 55 etches the film 12 to be etched while using the photoresist 15 as a mask. As a result, as shown in FIG. 11 , a trench 44 having a planar shape substantially identical to that of the circuit pattern 22 is formed in the film 12 to be etched. The trench 44 includes four linear portions 45 corresponding to the linear portions 82, and four corners 46 connecting the ends of two adjacent linear portions 45 and corresponding to the corners 83. Each corner 46 includes an inner peripheral edge 46A corresponding to the inner peripheral edge 83A, and an outer peripheral edge 46B corresponding to the outer peripheral edge 83B.

[0044] The inner peripheral edge 46A of each corner 46 is a straight line connecting the ends of the inner peripheral edge 45A of two adjacent linear portions 45. As shown in Fig. 12, the angle α formed between the inner peripheral edge 46A and the inner peripheral edge 45A of the two adjacent linear portions 45 in a plan view is 45°.

[0045] The outer peripheral edge 46B of each corner 46 is a straight line connecting the ends of the outer peripheral edge 45B of two adjacent linear portions 45. In plan view, the angle β formed between the outer peripheral edge 46B and the outer peripheral edge 45B of the two adjacent linear portions 45 is 45°.

[0046] Here, the distance between the inner peripheral edge 46A and the outer peripheral edge 46B is a first width W5-X, and the distance between the inner peripheral edge 45A and the outer peripheral edge 45B is a second width W6-X. When the opening 81A and the circuit pattern 22 have the same dimensions, the first width W5 and the first width W5-X are substantially the same, and the second width W6 and the second width W6-X are substantially the same.

[0047] 12, the imaginary width W5A-X is the distance between an intersection (first intersection) 45B2 of straight lines (first straight lines) along the outer peripheral edge portions 45B of two adjacent linear portions 45 of the trench 44 and an intersection (second intersection) 45A2 of straight lines (second straight lines) along the inner peripheral edge portions 45A of two adjacent linear portions 45. The first width W5A-X is shorter than the imaginary width W5A-X.

[0048] Next, the semiconductor manufacturing equipment 55 removes the photoresist 15 .

[0049] Furthermore, semiconductor manufacturing equipment 55 uses CVD to form guard ring 50 of tungsten in trench 44, the guard ring having a shape that follows trench 44 (see FIG. 11). Therefore, guard ring 50 has four linear portions 51 that follow linear portion 27 and four corner portions 52 that follow corner portion 46.

[0050] Therefore, the width W8 (see FIG. 11) of the corner portions 52 of the guard ring 50 of the semiconductor device 53 of the modified example is substantially the same as the first width W5-X, and the width W9 (see FIG. 11) of the linear portions 51 of the guard ring 50 is substantially the same as the second width W6-X. That is, the width W8 is substantially the same as the width W9. Therefore, voids are unlikely to occur at the corner portions 52 of the guard ring 50 in the semiconductor device 53 of the modified example. Therefore, when the semiconductor substrate 10 and the film 12 to be etched, which is integrated with the semiconductor substrate 10, are diced along the cut lines 11A and 11B, the circuit pattern located on the inner periphery of the trench 44 is unlikely to be damaged.

[0051] The openings formed in the photomasks of the embodiments and variants may have a shape different from openings 71A and 81A, as long as they have a shape that includes at least two linear portions and at least one corner portion connecting the ends of two adjacent linear portions.

[0052] This disclosure also includes the following:

[0053] (Appendix 1) providing a photoresist on a film to be etched formed on a semiconductor substrate; a step of irradiating the photoresist with light that has passed through an opening of a photomask, the opening having a ring shape when viewed in a thickness direction of the semiconductor substrate and including at least two linear portions and at least one corner portion connecting ends of two adjacent linear portions, to form an exposed portion in the photoresist; forming a circuit pattern in the photoresist, the circuit pattern being a hole having a shape corresponding to the exposed portion; forming an annular trench groove in the film to be etched, the trench groove having a shape that conforms to the shape of the circuit pattern, while using the photoresist as a mask; and forming a guard ring in the trench; and A method for manufacturing a semiconductor device in which a first width, which is the distance between the inner peripheral edge and the outer peripheral edge of the corner of the opening of the photomask, is shorter than a virtual width, which is the distance between a first intersection of first straight lines along the outer peripheral edges of two adjacent straight lines and a second intersection of second straight lines along the inner peripheral edges of two adjacent straight lines. (Appendix 2) The outer peripheral edge of the corner is arc-shaped, The inner peripheral edge portions of two adjacent linear portions are directly connected to each other. A method for manufacturing the semiconductor device described in Appendix 1. (Appendix 3) The inner peripheral edge portion of the corner portion and the outer peripheral edge portion of the corner portion have a linear shape inclined at 45° with respect to the linear portion, Both ends of the inner peripheral edge of the corner portion are connected to the ends of the inner peripheral edge of two adjacent linear portions, respectively. A method for manufacturing the semiconductor device described in Appendix 1. (Appendix 4) A semiconductor device manufactured by the method for manufacturing a semiconductor device according to any one of Supplementary Notes 1 to 3. (Appendix 5) a semiconductor substrate; a film to be etched formed on the semiconductor substrate; a trench groove formed in the film to be etched, which has an annular shape when viewed in a thickness direction of the semiconductor substrate, and which includes at least two linear portions and at least one corner portion connecting ends of two adjacent linear portions; a guard ring formed in the trench groove and shaped to follow the trench groove; Equipped with A semiconductor device in which a first width, which is the distance between the inner peripheral edge and the outer peripheral edge of the corner of the opening of the photomask, is shorter than a virtual width, which is the distance between a first intersection of first straight lines along the outer peripheral edges of two adjacent straight lines and a second intersection of second straight lines along the inner peripheral edges of two adjacent straight lines. [Explanation of symbols]

[0054] 10. Semiconductor substrate 12 Film to be etched 15 Photoresist 17 Circuit Pattern 22 Circuit Pattern 25 Trench 32 Guard Ring 44 Trench 50 Guard Ring 70 Photomask 71A opening 72 Straight section 72B Outer edge 72B2 Intersection 73 Corner 73A Inner edge 73B Outer edge 80 Photomask 81A Opening 82 Straight section 82B Outer edge 82B2 Intersection 83 Corner 83A Inner edge 83B Outer edge W1 W5 1st width W1A W1A-X Virtual width

Claims

1. providing a photoresist on a film to be etched formed on a semiconductor substrate; a step of irradiating the photoresist with light that has passed through an opening of a photomask, the opening having a ring shape when viewed in a thickness direction of the semiconductor substrate and including at least two linear portions and at least one corner portion connecting ends of two adjacent linear portions, to form an exposed portion in the photoresist; forming a circuit pattern in the photoresist, the circuit pattern being a hole having a shape corresponding to the exposed portion; forming an annular trench groove in the film to be etched, the trench groove having a shape that conforms to the shape of the circuit pattern, while using the photoresist as a mask; and forming a guard ring in the trench; and A method for manufacturing a semiconductor device in which a first width, which is the distance between the inner edge and outer edge of the corner of the opening of the photomask, is shorter than a virtual width, which is the distance between a first intersection of first straight lines along the outer edge of two adjacent straight lines and a second intersection of second straight lines along the inner edge of two adjacent straight lines.

2. The outer peripheral edge of the corner is arc-shaped, 2. The method for manufacturing a semiconductor device according to claim 1, wherein the inner peripheral edge portions of two adjacent linear portions are directly connected to each other.

3. the inner peripheral edge portion of the corner portion and the outer peripheral edge portion of the corner portion have a linear shape inclined at 45° with respect to the linear portion, 2. The method for manufacturing a semiconductor device according to claim 1, wherein both ends of the inner peripheral edge of the corner portion are connected to the ends of the inner peripheral edge of two adjacent linear portions, respectively.

4. A semiconductor device manufactured by the method for manufacturing a semiconductor device according to any one of claims 1 to 3.

5. a semiconductor substrate; a film to be etched formed on the semiconductor substrate; a trench groove formed in the etched film, which has an annular shape when viewed in a thickness direction of the semiconductor substrate, and which includes at least two linear portions and at least one corner portion connecting ends of two adjacent linear portions; a guard ring formed in the trench groove and shaped to follow the trench groove; Equipped with A semiconductor device in which a first width, which is the distance between the inner peripheral edge and the outer peripheral edge of the corner of the trench groove, is shorter than a virtual width, which is the distance between a first intersection of first straight lines along the outer peripheral edges of two adjacent straight lines and a second intersection of second straight lines along the inner peripheral edges of two adjacent straight lines.

Images