Semiconductor device

Abstract

The present invention provides a semiconductor device, comprising: a pad portion disposed above an upper surface of a semiconductor substrate and separated from an emitter electrode; a wiring portion connected to a connection region on the upper surface of the pad portion; a wiring layer disposed between the semiconductor substrate and the pad portion, and including a region overlapping the connection region; an interlayer insulating film disposed between the wiring layer and the pad portion, and having a through-hole below the connection region; a tungsten portion disposed inside the through-hole and electrically connecting the wiring layer and the pad portion, the tungsten portion comprising tungsten; and a barrier metal layer disposed covering the upper surface of the interlayer insulating film below the connection region, the barrier metal layer comprising titanium.

Description

Technical Field

[0001] This invention relates to semiconductor devices. Background Technology

[0002] Conventionally, in semiconductor devices including transistors, it is known to have a structure that includes a barrier metal containing titanium (for example, see Patent Documents 1-3).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2007-227556

[0004] Patent Document 2: Japanese Patent Application Publication No. 2020-31154

[0005] Patent Document 3: Japanese Patent Application Publication No. 2020-35847 Summary of the Invention

[0006] Technical issues

[0007] Sometimes peeling occurs between the barrier metal and the interlayer insulating film.

[0008] Technical solution

[0009] To address the aforementioned issues, in one aspect of the present invention, a semiconductor device is provided, comprising a semiconductor substrate. The semiconductor device may include an emitter electrode disposed above an upper surface of the semiconductor substrate. The semiconductor device may include a pad portion disposed above the upper surface of the semiconductor substrate and separate from the emitter electrode. The semiconductor device may include a wiring portion connected to a connection region on the upper surface of the pad portion. The semiconductor device may include a wiring layer disposed between the semiconductor substrate and the pad portion, including a region overlapping the connection region. The semiconductor device may include an interlayer insulating film disposed between the wiring layer and the pad portion, having a through-hole below the connection region. The semiconductor device may include a tungsten portion disposed inside the through-hole, electrically connecting the wiring layer and the pad portion, the tungsten portion comprising tungsten. The semiconductor device may include a barrier metal layer configured to cover the upper surface of the interlayer insulating film, the barrier metal layer comprising titanium.

[0010] Alternatively, in a top-down view, the area of ​​the region below the connection area that overlaps with the connection area is more than 20% of the area of ​​the region below the connection area.

[0011] Alternatively, the area of ​​the region containing the tungsten portion can be more than 50% of the area of ​​the region connected to the lower portion.

[0012] Alternatively, a tungsten section can be provided in the area below the entire connection.

[0013] Alternatively, it could be a portion of the upper surface of the tungsten-covered interlayer insulating film.

[0014] Alternatively, the tungsten portion may cover the upper surface of the interlayer insulating film in areas other than the region below the connection.

[0015] Alternatively, the tungsten portion can be positioned over the entire area that overlaps with the pad portion when viewed from above.

[0016] Alternatively, the width of the through hole can be greater than 0.5μm and less than 0.8μm.

[0017] Multiple through-holes can be provided in the interlayer insulating film. The distance between two adjacent through-holes can be greater than 0.5 μm and less than 3.2 μm.

[0018] Alternatively, the width of the through hole and the distance between the through holes can satisfy the following relationship:

[0019] X1 / (X1+X2)≥0.2, where X1 is the width of the through hole and X2 is the distance between two adjacent through holes.

[0020] A barrier metal layer can also be disposed on the bottom surface of the through hole. The barrier metal layer covering the upper surface of the interlayer insulating film can be thicker than the barrier metal layer disposed on the bottom surface of the through hole.

[0021] Multiple tungsten portions extending along a first direction can be provided on the upper surface of the interlayer insulating film. The connection area can have a major axis in a second direction when viewed from above. The angle between the first direction and the second direction can be less than 10 degrees.

[0022] The interlayer insulating film, through-holes, and tungsten portion can also be disposed below the emitter electrode. The spacing of the through-holes connecting the lower region can be different from the spacing of the through-holes below the emitter electrode.

[0023] The interlayer insulating film, through-holes, and tungsten portion can also be disposed below the emitter electrode. The width of the through-hole connecting the lower region can be smaller than the width of the through-hole below the emitter electrode.

[0024] The interlayer insulating film can be a BPSG film or a BSG film. The boron concentration in the interlayer insulating film can be above 2.6 wt% and below 5 wt%.

[0025] At least a portion of the through-hole and the tungsten portion may be disposed along a first extending direction parallel to the upper surface of the semiconductor substrate.

[0026] Alternatively, a portion of the through-hole and the tungsten portion may be arranged along a second extending direction that is parallel to the upper surface of the semiconductor substrate and different from the first extending direction.

[0027] Alternatively, the semiconductor device may have a through-hole connection portion that connects a through-hole disposed along a first extending direction to a through-hole disposed along a second extending direction.

[0028] Alternatively, when the interval between the through-hole connecting portions arranged along the second extending direction is set to 'a', the interval between the through-hole connecting portions arranged along the first extending direction is set to 'b', the width of the through-hole arranged along the second extending direction is set to 'c', and the width of the through-hole arranged along the first extending direction is set to 'd', the following formula is satisfied:

[0029] ((a×c)+(bc)×d) / (a×b)≥0.2.

[0030] Alternatively, the upper end of the tungsten portion disposed in the through-hole connection portion may be positioned at a lower position than the upper end of the tungsten portion disposed in the through-hole other than the through-hole connection portion. Attached Figure Description

[0031] Figure 1 This is a top view showing an example of a semiconductor device 100.

[0032] Figure 2A It means Figure 1 A diagram of an example of section AA in the figure.

[0033] Figure 2B It means Figure 1 A diagram of an example of the BB section.

[0034] Figure 3 This is a diagram showing an example of the configuration of the tungsten section 230 when viewed from above.

[0035] Figure 4 This is a diagram showing an example of the results of a tensile test on multiple semiconductor devices 100.

[0036] Figure 5 This is a diagram showing another example of the AA section.

[0037] Figure 6 It means Figure 5 A top view of the configuration example of the tungsten section 230 in the semiconductor device 100 shown.

[0038] Figure 7 This is a diagram showing another example of the AA section.

[0039] Figure 8 It means Figure 7 A top view of the configuration example of the tungsten section 230 in the semiconductor device 100 shown.

[0040] Figure 9 This is a diagram showing another example of the AA section.

[0041] Figure 10 It means Figure 9A top view of the configuration example of the tungsten section 230 in the semiconductor device 100 shown.

[0042] Figure 11 This is a diagram showing another example of the AA section.

[0043] Figure 12 It means Figure 11 A top view of the configuration example of the tungsten section 230 in the semiconductor device 100 shown.

[0044] Figure 13 It is an enlarged cross-sectional view of the vicinity of the through hole 210.

[0045] Figure 14 This is a diagram showing an example of the configuration of the connection region 206 in the upper surface of the gate pad 50.

[0046] Figure 15 This is a diagram showing another configuration example of the connection region 206 in the upper surface of the gate pad 50.

[0047] Figure 16 This is a diagram showing an example of the XZ section in the active part 120.

[0048] Figure 17 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 when viewed from above.

[0049] Figure 18 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 when viewed from above.

[0050] Figure 19 It means Figure 18 A diagram of an example of the CC section.

[0051] Figure 20 It means Figure 18 A diagram of an example of the DD section.

[0052] Figure 21 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 when viewed from above.

[0053] Figure 22 yes Figure 21 Enlarged views of tungsten section 230-1 and tungsten section 230-2 shown.

[0054] Figure 23 This is a diagram showing another example of the shape of the through hole 210 and the tungsten section 230.

[0055] Figure 24 It means Figure 23 A diagram of an example of the EE section.

[0056] Figure 25 It means Figure 23 A diagram of an example of the FF section.

[0057] Figure 26 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 when viewed from above.

[0058] Figure 27 yes Figure 26 Enlarged views of tungsten section 230-1 and tungsten section 230-2 shown.

[0059] Figure 28 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 when viewed from above.

[0060] Figure 29 yes Figure 28 Enlarged views of tungsten section 230-1 and tungsten section 230-2 shown.

[0061] Figure 30 It means Figure 28 Enlarged view of another example of tungsten section 230-1 and tungsten section 230-2 shown.

[0062] Symbol Explanation

[0063] 10: Semiconductor substrate, 11: Well region, 20: Drift region, 21: Top surface, 22: Source region, 23: Contact region, 24: Gate electrode, 25: Trench, 38: Interlayer insulating film, 44: Insulating film, 50: Gate pad, 51: Wiring layer, 52: Emitter electrode, 100: Semiconductor device, 102: Edge, 110: Current sensing region, 120: Active part, 172: Current sensing pad, 174: Anode pad, 176: Cathode pad, 178: Diode element, 201: Opening region, 202: Wiring portion, 204: Connection portion, 206: Connection region, 208: Connection area below, 209: Dashed line, 210: Through-hole, 220: Barrier metal layer, 221: Top surface, 230: Tungsten portion, 231: Through-hole connection portion, 232: Curved portion, 240: Protective component Detailed Implementation

[0064] The present invention will now be described through embodiments, but these embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of the features described in the embodiments are necessary for the technical solution of the invention. In addition, in this specification and the accompanying drawings, elements having substantially the same function or structure are omitted from repeated description by using the same reference numerals; furthermore, elements not directly related to the present invention are omitted from illustration. Additionally, sometimes in one drawing, elements having the same function or structure are representatively labeled with reference numerals, while reference numerals are omitted in other drawings.

[0065] In this specification, one side parallel to the depth direction of the semiconductor substrate is referred to as "upper," and the other side as "lower." One of the two main surfaces of the substrate, layer, or other component is referred to as the upper surface, and the other as the lower surface. The directions "upper" and "lower" are not limited to the direction of gravity or the direction in which the semiconductor module is mounted.

[0066] In this specification, orthogonal coordinate axes of X, Y, and Z are sometimes used to explain technical matters. Orthogonal coordinate axes only determine the relative positions of constituent elements and do not limit specific directions. For example, the Z-axis is not limited to a height direction relative to the ground. It should be noted that the +Z-axis direction and the -Z-axis direction are mutually opposite directions. When the Z-axis direction is described without specifying positive or negative, it refers to a direction parallel to the +Z-axis and -Z-axis. In this specification, orthogonal axes parallel to the upper and lower surfaces of the semiconductor substrate are designated as the X-axis and Y-axis. Additionally, the axis perpendicular to the upper and lower surfaces of the semiconductor substrate is designated as the Z-axis. In this specification, the direction of the Z-axis is sometimes referred to as the depth direction. Furthermore, in this specification, including the X-axis and Y-axis, directions parallel to the upper and lower surfaces of the semiconductor substrate are sometimes referred to as horizontal directions.

[0067] In this specification, when referred to as "the same" or "equal," cases with errors caused by manufacturing deviations, etc., may also be included. Such errors are, for example, within 10%.

[0068] Figure 1 This is a top view showing an example of a semiconductor device 100. The semiconductor device 100 includes a semiconductor substrate 10, an emitter electrode 52, and a gate pad 50. The semiconductor substrate 10 is a substrate formed of a semiconductor material such as silicon or a compound semiconductor. The semiconductor substrate 10 has end edges 102 when viewed from above. In this specification, the view in which the positions of various components are projected onto the upper surface of a defined component such as the semiconductor substrate 10 or the semiconductor device 100 is referred to as a top view. In this example, the semiconductor substrate 10 has two sets of end edges 102 that are opposite each other when viewed from above. Figure 1 The image shows a set of end edges 102-1 and 102-2 that are opposite to each other. Figure 1 In this context, the direction parallel to end edge 102-1 and end edge 102-2 is taken as the Y-axis direction, and the direction perpendicular to end edge 102-1 and end edge 102-2 is taken as the X-axis direction.

[0069] The emitter electrode 52 and the gate pad 50 are electrodes made of metals such as aluminum. The emitter electrode 52 and the gate pad 50 are separated when viewed from above. A protective component such as polyimide can be disposed between the emitter electrode 52 and the gate pad 50. An insulating film is disposed between the emitter electrode 52 and the gate pad 50 and the semiconductor substrate 10. The emitter electrode 52 and the gate pad 50 are connected to the semiconductor substrate 10 or a component disposed on the upper surface of the semiconductor substrate 10 via contact holes provided in the insulating film.

[0070] Figure 2A It means Figure 1 A diagram showing an example of the AA section. The AA section is the XZ plane passing through the gate pad 50 and the connection portion 204. Figure 2B express Figure 1 An example of the BB section. The BB section is through the XZ plane of the emitting electrode 52.

[0071] exist Figure 2B In this configuration, the emitter electrode 52 is electrically connected to the semiconductor substrate 10 via a barrier metal layer 220 and a tungsten portion 230 disposed within a contact hole (through hole) 210 in the interlayer insulating film 38. For example, the emitter electrode 52 can be connected to the source region 22 and contact region 23 of a first conductivity type in an IGBT (Insulated Gate Bipolar Transistor). As an example, the first conductivity type is N-type. A trench 25 can be formed on the surface of the semiconductor substrate 10, and a gate electrode 24 is filled inside the trench 25 through an insulating film 44. In this example, the trench 25 is formed extending along the Y-axis direction on the upper surface 21 of the semiconductor substrate 10. That is, on the upper surface 21 of the semiconductor substrate 10, the trench 25 has a long side in the Y-axis direction.

[0072] exist Figure 2A In this configuration, the gate pad 50 is electrically connected to the wiring layer 51 via a barrier metal layer 220 and a tungsten portion 230 disposed within a contact hole (through hole) 210 in the interlayer insulating film 38. The wiring layer 51 can be disposed on the upper surface of the semiconductor substrate 10 through the insulating film 44. As an example, the wiring layer 51 is made of polysilicon. For example, the gate pad 50 is connected to the gate electrode 24 of the gate trench in an IGBT. The AA section will be described in detail later. The emitter electrode 52 can be connected to the source region 22 of the first conductivity type in a MOS transistor. Figure 1 The insulating film and contact holes are omitted in the text.

[0073] exist Figure 1 In this configuration, the emitter electrode 52 can be the electrode with the largest area when viewed from above, which is disposed on the upper surface of the semiconductor substrate 10. The gate pad 50 can be disposed between the emitter electrode 52 and the end edge 102-1 when viewed from above. The gate pad 50 can also be sandwiched by the emitter electrode 52 in the Y-axis direction.

[0074] A lead frame or wire (not shown) is connected to the upper surface of the emitter electrode 52. Additionally, a wiring portion 202 is connected to the upper surface of the gate pad 50. The wiring portion 202 may have a connection portion 204 that contacts the upper surface of the gate pad 50. The connection portion 204 may be a fixing material such as solder, or it may be part of the wiring. The wiring may be ultrasonically bonded to the upper surface of the emitter electrode 52 in the connection portion 204, or it may be press-fitted to the upper surface of the emitter electrode 52.

[0075] An active portion 120 is provided on the semiconductor substrate 10. The active portion 120 is a region where, when the semiconductor device 100 is controlled to be in a conducting state, the main current flows along the depth direction between the upper and lower surfaces of the semiconductor substrate 10. The active portion 120 is a region inside the semiconductor substrate 10 where transistors such as IGBTs or diodes such as FWDs (freewheeling diodes) are disposed. The region covered by the emitter electrode 52 may also be the active portion 120. In this case, the region sandwiched by the emitter electrode 52 when viewed from above may also be the active portion 120. Furthermore, if a protective ring or field plate is provided in a ring shape along the outer periphery of the semiconductor substrate 10, the region surrounded by the protective ring or field plate may also be the active portion 120. The protective ring is a P-type region extending from the upper surface of the semiconductor substrate 10 to a predetermined depth. The field plate is a conductive component disposed above the upper surface of the semiconductor substrate 10. An insulating film is provided between the field plate and the semiconductor substrate 10. The guard ring and field plate can be configured to be located between the gate pad 50 and the end edge 102-1, as described later.

[0076] As described above, the emitter electrode 52 is electrically connected to the active section 120 via a contact hole (through hole 210). As described above, the gate pad 50 can be connected to the gate channel (wiring layer 51) formed of polysilicon, aluminum, etc., via the contact hole. The gate voltage applied to the gate pad 50 is supplied to the gate electrode 24 of each transistor section in the active section 120 through the gate channel, etc.

[0077] The semiconductor device 100 may include a diode element 178. In this example, the diode element 178 is a PN junction diode disposed above the semiconductor substrate 10. The diode element 178 can function as a temperature sensing unit. The diode element 178 can be disposed approximately in the center of the semiconductor substrate 10 when viewed from above. For example, the diode element 178 can cover the central position of the semiconductor substrate 10. The diode element 178 can be sandwiched by the emitter electrode 52 when viewed from above. In this example, the emitter electrode 52 is divided into at least two regions, and the diode element 178 is sandwiched between the two regions of the emitter electrode 52.

[0078] Semiconductor device 100 may have an anode pad 174 and a cathode pad 176. The anode pad 174 is electrically connected to the anode of diode element 178, and the cathode pad 176 is electrically connected to the cathode of diode element 178. The anode pad 174 and the cathode pad 176 may be connected to diode element 178 by wiring formed of polysilicon or aluminum, etc.

[0079] As an example, the gate pad 50 is disposed on the edge 102-1 side, and the anode pad 174 and cathode pad 176 are disposed on the edge 102-2 side. The edge 102-1 side refers to the side closer to the center of the semiconductor substrate 10 in the X-axis direction, and the edge 102-2 side refers to the side closer to the center of the semiconductor substrate 10. As described above, the gate pad 50 can be disposed between the emitter electrode 52 and the edge 102-1. The anode pad 174 and cathode pad 176 can be disposed between the emitter electrode 52 and the edge 102-2. On the upper surface of the anode pad 174 and cathode pad 176, wiring portions 202 can be connected in the same manner as the gate pad 50.

[0080] The semiconductor device 100 may also include a current sensing pad 172. A current sensing region 110 may be provided on the semiconductor substrate 10 below the current sensing pad 172. The current sensing region 110 may include a transistor portion that is electrically connected in parallel with the transistor portion in the active portion 120 and has the same structure. When viewed from above, the current sensing region 110 is smaller than the active portion 120. The current flowing through the active portion 120 can be estimated based on the current flowing through the current sensing region 110. The current sensing pad 172 may be disposed between the emitter electrode 52 and the end edge 102-2. On the upper surface of the current sensing pad 172, a wiring portion 202 may be connected in the same manner as the gate pad 50.

[0081] Figure 1 The gate pad 50, anode pad 174, cathode pad 176, and current sensing pad 172 shown are examples of pad portions. However, the pad portion is not limited to the aforementioned pads. The pad portion is disposed above the upper surface of the semiconductor substrate 10, is formed of a metal such as aluminum, and is separated from the emitter electrode 52. Figure 2A The structure near the gate pad 50 will be described in detail below, but the area near each pad may also have the same structure as the area near the gate pad 50.

[0082] As mentioned above, Figure 2A It means Figure 1The diagram shows an example of a cross-section AA. Cross-section AA is the XZ plane passing through the gate pad 50 and the connection portion 204. In this example, the semiconductor device 100 includes a semiconductor substrate 10, an insulating film 44, a wiring layer 51, an interlayer insulating film 38, a barrier metal layer 220, a tungsten portion 230, a gate pad 50, a connection portion 204, and a wire wiring portion 202 in this cross-section. Furthermore, a portion of the upper surface of the gate pad 50 can be covered by a protective component 240 such as polyimide. The area on the upper surface of the gate pad 50 exposed from being covered by the protective component 240 is designated as an opening region 201.

[0083] The connecting portion 204 connects to the upper surface of the gate pad 50 at the opening region 201. The portion of the upper surface of the gate pad 50 that contacts the connecting portion 204 is referred to as the connecting region 206. It should be noted that the upper surface of the semiconductor device 100 is sealed with a sealing resin such as silicone gel. This allows the upper surface of the semiconductor device 100 to be electrically insulated from the outside, and also protects the semiconductor device 100 from the influence of foreign matter such as moisture.

[0084] The semiconductor substrate 10 may have a drift region 20 of a first conductivity type and a well region 11 of a second conductivity type. In this specification, the first conductivity type is N-type and the second conductivity type is P-type, but the conductivity types can also be reversed. The drift region 20 may also be disposed on... Figure 1 The entire active portion 120 is shown. The well region 11 is disposed below the gate pad 50 and between the drift region 20 and the upper surface 21 of the semiconductor substrate 10.

[0085] A wiring layer 51 is disposed between the semiconductor substrate 10 and the gate pad 50. The wiring layer 51 is formed of a conductive material such as polysilicon doped with impurities. In this example, the wiring layer 51 also functions as the gate channel described above. The wiring layer 51 includes a region that overlaps with at least a portion of the connection region 206 when viewed from above. The wiring layer 51 may include a region that overlaps with the entire connection region 206, a region that overlaps with the entire opening region 201, or a region that overlaps with the entire gate pad 50.

[0086] An insulating film 44 is disposed between the wiring layer 51 and the upper surface 21 of the semiconductor substrate 10. The insulating film 44 is, for example, a film formed by oxidizing or nitriding the upper surface 21 of the semiconductor substrate 10, but is not limited thereto. In the active portion 120, the insulating film 44 may be formed of the same material as the gate insulating film that insulates the gate electrode from the semiconductor substrate 10.

[0087] Interlayer insulating film 38 is an insulating layer disposed between wiring layer 51 and gate pad 50. As an example, interlayer insulating film 38 is boron-doped silicate glass (BPSG: Boron Phosphorus Silicate Glass or BSG: Boron Silicate Glass). Interlayer insulating film 38 can also be a laminate formed by stacking boron-doped silicate glass on an NSG film. The NSG film is a non-doped silicate glass film composed of NSG (Non-doped Silicate Glass) without boron or phosphorus doping. The thickness of interlayer insulating film 38 is, for example, about 1 μm, but is not limited to this. Through-holes 210 are provided in interlayer insulating film 38. Through-holes 210 extend from the upper surface 221 of interlayer insulating film 38 to the lower surface. By filling the through-holes 210 with conductive material, gate pad 50 is electrically connected to wiring layer 51. The interlayer insulating film 38 has a through-hole 210 at least below the connection region 206. "Below the connection region 206" refers to the area disposed below the connection region 206 and overlapping it when viewed from above. In this example, the interlayer insulating film 38 may also have a through-hole 210 in an area that does not overlap with the connection region 206.

[0088] The tungsten portion 230, formed of a tungsten-containing material, is disposed inside the through-hole 210. The tungsten portion 230 can be formed of tungsten or an alloy containing tungsten. The upper end of the tungsten portion 230 contacts the gate pad 50. The lower end of the tungsten portion 230 can contact the wiring layer 51 or be connected to the wiring layer 51 via other conductive components. Inside the through-hole 210, the tungsten portion 230 can contact the interlayer insulating film 38 or other conductive components.

[0089] The barrier metal layer 220 at least covers the upper surface 221 of the interlayer insulating film 38 below the connection region 206. The barrier metal layer 220 is formed of a material containing titanium. The barrier metal layer 220 may also be made of different materials. As an example, the barrier metal layer 220 is a laminate with a titanium nitride layer stacked on a titanium layer. By making the barrier metal layer 220 a laminate with a titanium nitride layer stacked on a titanium layer, the titanium layer reacts with the wiring layer 51 made of polysilicon to form titanium silicide, which can reduce the contact resistance between the wiring layer 51 and the barrier metal layer 220. In addition, by forming titanium silicide, the titanium layer is thinned to, for example, a few nm or less, so hydrogen can pass through the barrier metal layer 220 to the underlying layer. Therefore, damage formed inside the semiconductor device 100 during the manufacturing process can be recovered by annealing in a hydrogen atmosphere. Here, damage may be, for example, dangling bonds at the interface between the insulating film 44 and the semiconductor substrate 10. When the titanium layer is thick, for example, around 20 nm or more, even with annealing in a hydrogen atmosphere, hydrogen will be adsorbed by the titanium layer, preventing it from reaching the layer below the titanium layer. Therefore, damage formed inside the semiconductor device 100 cannot be restored by annealing in a hydrogen atmosphere. The thickness of the barrier metal layer 220, which includes the titanium layer and the titanium nitride layer, on the upper surface 221 of the interlayer insulating film 38, can be around 50 nm or more and about 200 nm or less.

[0090] The barrier metal layer 220 can also be disposed in an area that does not overlap with the connection area 206 when viewed from above. The barrier metal layer 220 can also be disposed below the protective member 240. Alternatively, the barrier metal layer 220 can be disposed inside the through-hole 210. The barrier metal layer 220 can cover the sidewalls and bottom surface of the through-hole 210. In this case, the barrier metal layer 220 is disposed between the tungsten portion 230 and the wiring layer 51 and the interlayer insulating film 38.

[0091] In the event of a partial defect in an electrode such as the emitter electrode 52 or the gate pad 50, resin ions contained in the sealing resin reach the wiring layer 51 or the insulating film 44 from the upper surface side of the semiconductor device 100 due to the electric field inside the semiconductor device 100. Especially in the active portion 120, the resin ions are captured by the insulating film 44, resulting in a greater tunneling current than usual, thus causing adverse effects on the characteristics of the semiconductor device 100, such as a decrease in the threshold voltage.

[0092] To address this, by providing a barrier metal layer 220, resin ions can be suppressed from reaching layers lower than the barrier metal layer 220. The barrier metal layer 220 can be provided not only in the active portion 120 but also below the pad portion. More preferably, the barrier metal layer 220 is provided on the entire lower surface of the pad portion. The entire lower surface of the pad portion refers to the area below the pad portion that overlaps with the pad portion when viewed from above. Therefore, it is possible to suppress resin ions from reaching the wiring layer 51 or the insulating film 44 in the event of a partial defect in the electrode of the pad portion, and it is also possible to suppress resin ions from penetrating the active portion 120 adjacent to the pad portion, preventing threshold voltage reduction and other issues.

[0093] However, the adhesion between the titanium-containing barrier metal layer 220 and the interlayer insulating film 38 is relatively low. For example, the adhesion is reduced because the titanium in the barrier metal layer 220 reacts with materials such as boron in the interlayer insulating film 38.

[0094] If the adhesion between the barrier metal layer 220 and the interlayer insulating film 38 decreases, the barrier metal layer 220 and the interlayer insulating film 38 will easily peel off when the wiring portion 202 is stretched. The reason for this easy peeling is that when the wiring portion 202 is stretched, especially below the connection region 206, stress is applied between the barrier metal layer 220 and the interlayer insulating film 38 in the vertical direction. If the adhesion between the barrier metal layer 220 and the interlayer insulating film 38 at the interface parallel to the XY plane (referred to as the XY interface) decreases, and if no structure is formed at the XY interface, the barrier metal layer 220 and the interlayer insulating film 38 will easily peel off in the vertical direction. The absence of a structure at the interface refers to the absence of through-holes, as described later. If the barrier metal layer 220 and the interlayer insulating film 38 peel off when the wiring portion 202 is stretched, the gate pad 50 located above the barrier metal layer 220 will also detach along with the wiring portion 202.

[0095] In this example, a through-hole 210 and a tungsten portion 230 are provided below the connection region 206. Therefore, the area of ​​the XY interface between the interlayer insulating film 38 and the barrier metal layer 220 can be reduced below the connection region 206. This helps to suppress the peeling of the barrier metal layer 220 from the interlayer insulating film 38. It should be noted that the adhesion between the tungsten portion 230 and the barrier metal layer 220 is better than the adhesion between the interlayer insulating film 38 and the barrier metal layer 220.

[0096] Figure 3 This is a diagram showing an example of the configuration of the tungsten section 230 when viewed from above. Figure 3 In the middle, will be with Figure 2AThe overlapping area of ​​the connecting area 206 shown is designated as the connecting lower area 208. The size and shape of the connecting lower area 208 in top view are the same as those of the connecting area 206. Additionally, in Figure 3 In the diagram, the opening area 201 is represented by a dashed line. The inner side of the rectangle marked by the dashed line is the opening area 201. A protective component 240 is provided on the outer side of the rectangle marked by the dashed line, but... Figure 3 Omitted in .

[0097] exist Figure 3 In this embodiment, each tungsten portion 230 extends along the Y-axis direction. The length of each tungsten portion 230 in the Y-axis direction is greater than its length in the X-axis direction. The shape of the tungsten portion 230 when viewed from above can be strip-shaped. By making the shape of the tungsten portion 230 strip-shaped when viewed from above, it is easier to increase the area of ​​the tungsten portion 230 compared to the case where it is circular when viewed from above. In this example, the tungsten portion 230 can be provided from one end of the gate pad 50 to the other end in the Y-axis direction. In another example, the tungsten portion 230 can be provided in a region that is inside the end of the gate pad 50. In addition, the tungsten portion 230 can also extend beyond the end of the gate pad 50 along the Y-axis direction. The tungsten portion 230 can also extend in the X-direction. The tungsten portions 230 extending in the X-axis direction and the tungsten portions 230 extending in the Y-axis direction can also intersect in a grid pattern.

[0098] exist Figure 2A In this process, the width X1 of each through-hole 210 in the X-axis direction can be 0.5 μm or more and 0.8 μm or less. Each width X1 can be approximately the same. The width X1 can be measured at the upper end of the through-hole 210. By setting the width X1 to 0.5 μm or more, when a barrier metal layer 220 is formed on the interlayer insulating film 38, a barrier metal layer 220 of a specified thickness can also be formed at the bottom of the through-hole 210. Furthermore, by setting the width X1 to 0.8 μm or less, tungsten can be sufficiently retained inside the through-hole 210 during etching back. An overview of the etching back process will be described later. The width at the upper end of the through-hole 210 can be greater than the width at the lower end. Since the width at the upper end of the through-hole 210 is greater than the width at the lower end, and the sidewalls of the through-hole 210 are tapered, the thickness of the barrier metal layer 220 on the sidewalls of the through-hole 210 can be increased. Setting the sidewall of the through hole 210 to be tapered means that the width of the through hole 210 continuously narrows from the top to the bottom. For example, the width X1 at the top of the through hole 210 can be 0.5 μm, and the width at the bottom of the through hole 210 can be 0.3 μm.

[0099] In this example, multiple through holes 210 forming multiple tungsten portions 230 are arranged at predetermined intervals along the X-axis direction. The distance X2 between two adjacent through holes 210 can be, for example, 0.5 μm or more and 3.2 μm or less. The distance X2 can be measured at the upper end of the through hole 210. Each distance X2 can be approximately the same. The distance X2 can be greater than or equal to the width X1. By making the width X1 and distance X2 of the through holes 210 as described above, deviations in the manufacturing process can be suppressed, and the tungsten portions 230 can be easily formed. In addition, by setting the width, i.e., the distance X2, where the interlayer insulating film 38 and the barrier metal layer 220 meet at the XY interface to 3.2 μm or less, the effect of suppressing the peeling of the interlayer insulating film 38 and the barrier metal layer 220 is achieved.

[0100] The method for forming the tungsten portion 230 can be described as follows. First, a through-hole 210 is formed in the interlayer insulating film 38 by photolithography and dry etching. Next, a barrier metal layer 220 is formed inside the through-hole 210 and on the interlayer insulating film 38. Next, a tungsten film is formed inside the through-hole 210 and on the interlayer insulating film 38, filling the through-hole 210 with tungsten. Next, the tungsten portion 230 is formed by etching back. Here, etching back refers to the process of removing the tungsten film on the interlayer insulating film 38 by etching away the tungsten remaining inside the through-hole 210. This is one example of the method for forming the tungsten portion 230. It should be noted that the formation of the tungsten portion 230 of the gate pad 50 can be the same as described later. Figure 16 The formation of the tungsten portion 230 in the active region shown occurs simultaneously.

[0101] exist Figure 3 In this configuration, the width along the X-axis connecting the lower region 208 is set to X3. The width X6 of each tungsten unit 230 along the X-axis is less than the width X3. Width X6 can be less than half or less than one-third of width X3. The distance X7 between adjacent tungsten units 230 along the X-axis is less than the width X3. Distance X7 can be less than half or less than one-third of width X3. For example... Figure 2A and Figure 3 As shown, the lower region 208 may include a plurality of tungsten portions 230 arranged along the X-axis.

[0102] In the connection lower region 208, the area of the region where the through hole 210 is formed when viewed from above is set as S1, and the area of the entire connection lower region 208 is set as S. The area S1 of the through hole 210 is preferably 20% or more of the area S of the connection lower region 208. That is, in the connection lower region 208, the area of the XY interface between the barrier metal layer 220 and the gate pad 50 is affected by the thickness of the barrier metal layer 220 on the side wall of the through hole 210, but can be about 0% or more and about 80% or less of the area S of the connection lower region 208. By providing the through hole 210, the area of the XY interface between the interlayer insulating film 38 with weak adhesion and the barrier metal layer 220 can be reduced, so that the interlayer insulating film 38 and the barrier metal layer 220 do not peel off, preventing the occurrence of the defect that the gate pad 50 falls off due to peeling.

[0103] Figure 4 It is a diagram showing an example of the results of a tensile test for a plurality of semiconductor devices 100. In the tensile test, the wire wiring portion 202 is pulled upward to test whether the gate pad 50 peels off from the interlayer insulating film 38. In the tensile test, a case where a break occurs in the wire wiring portion 202 or the connection portion 204 before the gate pad 50 peels off is determined as a qualified product. The ratio of the gate pad 50 falling off before a break occurs in the wire wiring portion 202 or the connection portion 204 is set as the peeling incidence rate. In Figure 4 it, the vertical axis represents the peeling incidence rate, and the horizontal axis represents the area ratio S1 / S of the area of the region where the through hole 210 is formed in the connection lower region 208 to the area of the connection lower region 208 in percentage. The diameter of the wire used in the tensile test is 400 μm or 500 μm. In the tensile test, tests using wires of other diameters were also conducted, but no significant dependence on the wire diameter was observed. The wire can be made of aluminum or can also be made of a compound mainly composed of aluminum. For example, silicon can be added to the wire.

[0104] As Figure 4 shown, if the area ratio S1 / S is 20% or more, the peeling incidence rate is 0%. Therefore, the area ratio S1 / S is preferably 20% or more. By setting the area ratio S1 / S to 20% or more, the occurrence of the defect that the gate pad 50 falls off is eliminated. This area ratio can be 50% or more or can also be 100%.

[0105] In addition, the area of the opening region 201 when viewed from above is set as S 201 . In the region below the opening region 201, the area of the tungsten portion 230 when viewed from above is set as S1'. The area ratio S1' / S 201It can be 20% or more, 50% or more, or even 100%. When the wire wiring section 202 is joined to the opening area 201, the position of the lower connection area 208 may sometimes deviate; therefore, the area ratio S1' / S 201 Setting the area ratio S1 / S to 20% or higher is effective in suppressing the occurrence of gate pad detachment defects. That is, even if the position of the area 208 below the lead bonding connection deviates, setting the area ratio S1 / S to 20% or higher is always effective in suppressing the occurrence of gate pad detachment defects.

[0106] Additionally, the area of ​​the gate pad 50 when viewed from above is set to S. 50 Additionally, in the area below the gate pad 50, the area of ​​the tungsten portion 230 when viewed from above is set to S1”, with an area ratio of S1” / S 50 The area ratio S1 / S can be 0.3% or more, 20% or more, 50% or more, or even 100%. That is, to suppress the defect of gate pad 50 detachment, it is important that the area ratio S1 / S is 20% or more, and the area of ​​the tungsten portion can be relatively small, except for the region below the connection 208, for example, except for the opening region 201. An area ratio S1 / S of 20% or more is effective in suppressing the defect of gate pad 50 detachment, therefore... Figure 2A In the case of the through hole 210, the width X1 and the distance X2 can satisfy the relationship X1 / (X1+X2)≥0.2 so that the area ratio S1 / S is more than 20%.

[0107] Figure 5 This is a diagram showing another example of the AA cross-section. This example shows a cross-sectional structure where the width X1 of the through-hole 210 in the X-axis direction is greater than 0.8 μm. The through-hole 210 can be the same as in the previous example, a strip extending along the Y-axis. Alternatively, in the lower connecting region 208, the area ratio S1 / S is greater than 50% when the area of ​​the region where the through-hole 210 is formed is set as S1 in top view and the area of ​​the entire lower connecting region 208 is set as S. The structure of the tungsten portion 230, through-hole 210, barrier metal layer 220, and interlayer insulating film 38 of the semiconductor device 100 in this example is similar to... Figure 2A The examples differ. Other structures are different. Figure 2A The examples are the same.

[0108] Figure 6 It means Figure 5 This diagram shows a top view of an example configuration of the tungsten section 230 in the semiconductor device 100. Figure 5 and Figure 6In this example, a tungsten portion 230 is integrally provided when viewed from above the lower region 208. The width of the tungsten portion 230 in the X-axis direction is greater than the width x3 of the lower region 208. In this example, the end of the tungsten portion 230 is located below the gate pad 50 and is disposed on the barrier metal layer 220 in the area excluding the lower region 208. Below the gate pad 50 refers to the area disposed below the gate pad 50 and overlapping with the gate pad 50 when viewed from above. The barrier metal layer 220 is provided between the tungsten portion 230 and the upper surface 221 of the interlayer insulating film 38. When viewed from above, the tungsten portion 230 can cover the entire area below the opening region 201 or the entire area below the gate pad 50. In this example, by providing a through-hole 210 in the interlayer insulating film 38 connecting the lower region 208, the XY interface between the upper surface 221 of the interlayer insulating film 38 and the barrier metal layer 220 is reduced compared to the case where no through-hole 210 is provided. This suppresses peeling between the interlayer insulating film 38 and the barrier metal layer 220, preventing the gate pad 50 from detaching.

[0109] In this example, the width X1 of the through-hole 210 is greater than 0.8 μm. Therefore, in the above-described method for forming the tungsten portion 230, sufficient tungsten cannot be retained within the through-hole 210 during tungsten etch-back. This is because the tungsten inside the through-hole 210 is also etched during tungsten etch-back. Furthermore, tungsten residue that cannot be removed during etch-back may remain inside the through-hole 210, potentially causing defects in subsequent processes. Defects in subsequent processes include, for example, tungsten remaining in the through-hole 210 due to etch-back peeling off from the barrier metal layer 220 and becoming foreign matter. Therefore, when the width X1 is greater than 0.8 μm, it is preferable not to perform tungsten etch-back. In the region below the gate pad 50, by not etching back tungsten after deposition, a [structure / structure] can be formed. Figure 5 and Figure 6 The structure is shown. Furthermore, in the region where the gate channel surrounding the active portion 120 is formed, the tungsten on the interlayer insulating film 38 can be etched together with the gate pad 50 and the barrier metal layer 220. This prevents the gate pad 50 from being electrically connected to the emitter electrode 52.

[0110] exist Figure 5 and Figure 6In this example, the width X1 can be larger than the distance X2 between two adjacent through holes 210. The width X1 can be more than twice or more than three times the distance X2. Additionally, the width X1 can be larger than the width of the interlayer insulating film 38 in the X-axis direction. Furthermore, the width X1 can be smaller or larger than the width X3 of the lower region 208. In this example, a plurality of through holes 210 arranged along the X-axis are provided below the connecting portion 204. In other examples, only one of the plurality of through holes 210 arranged along the X-axis may be included below the connecting portion 204.

[0111] Figure 7 This is a diagram illustrating another example of a cross-section AA. In this example, the area of ​​the region where the through-hole 210 is formed in the lower region 208 is defined as S1 (top view), and the area of ​​the entire lower region 208 is defined as S, where the area ratio S1 / S is 100%. The structure of the tungsten portion 230, through-hole 210, barrier metal layer 220, and interlayer insulating film 38 of the semiconductor device 100 in this example is similar to... Figure 2A The examples differ. Other structures are different. Figure 2A The examples are the same.

[0112] Figure 8 It means Figure 7 This diagram shows a top view of an example configuration of the tungsten section 230 in the semiconductor device 100. Figure 7 and Figure 8 In this example, the lower connection region 208 is provided with a tungsten portion 230 and a through-hole 210 in a top view. The width of the tungsten portion 230 in the X-axis direction is greater than the width of the lower connection region 208 by 3. In this example, no interlayer insulating film 38 is provided in the lower connection region 208. Therefore, there is no XY interface between the upper surface 221 of the interlayer insulating film 38 and the barrier metal layer 220 in the lower connection region 208, which can suppress the gate pad 50 from falling off due to the peeling of the upper surface 221 of the interlayer insulating film 38 from the XY interface of the barrier metal layer 220.

[0113] In the examples described in this specification, the tungsten portion 230 may also cover a portion of the upper surface 221 of the interlayer insulating film 38. In this case, a barrier metal layer 220 may be provided between the tungsten portion 230 and the upper surface 221 of the interlayer insulating film 38. In this example, the tungsten portion 230 is disposed below the gate pad 50 and above the interlayer insulating film 38 in the area excluding the lower connection region 208. When viewed from above, the tungsten portion 230 may cover the entire area below the opening region 201, or it may cover the entire area below the gate pad 50.

[0114] The through-hole 210 is disposed in a region below the gate pad 50, including a portion of the lower connection region 208. The through-hole 210 can be disposed in a region smaller than the opening region 201 when viewed from above, or in the same region as the opening region 201, or in a region larger than the opening region 201. Below the gate pad 50, a through-hole 210 can be disposed in a region including the lower connection region 208, or it can be disposed in regions other than the lower connection region 208.

[0115] The tungsten portion 230 disposed inside the through-hole 210 and the tungsten portion 230 disposed above the interlayer insulating film 38 can be continuous. After forming the through-hole 210 in the interlayer insulating film 38 and stacking the barrier metal layer 220, tungsten is deposited inside the through-hole 210 and above the interlayer insulating film 38. In the region below the gate pad 50, by not etching back the tungsten after deposition, a [missing information - likely a specific structure or feature] can be formed. Figure 7 and Figure 8 The structure is shown. Furthermore, in the region where the gate channel surrounding the active portion 120 is formed, the tungsten on the interlayer insulating film 38 can be etched together with the gate pad 50 and the barrier metal layer 220. This prevents the gate pad 50 from being electrically connected to the emitter electrode 52.

[0116] Figure 9 This is a diagram showing another example of a cross-section AA. In this example, the semiconductor device 100 and... Figures 1 to 8 The difference in the example is that, in this cross-section, the tungsten portion 230 and the through-hole 210 are only provided below the connection region 206 or the opening region 201, and not in other areas below the gate pad 50. The area of ​​the gate pad 50 in top view is set as S50. Additionally, in the region below the gate pad 50, the area of ​​the tungsten portion 230 in top view is set as S1”. This can be a case where the area ratio S1” / S50 is 0.3% or more. Other structures are similar to... Figures 1 to 8 The same applies to any of the examples. According to this example, it is also possible to reduce the XY interface between the barrier metal layer 220 and the interlayer insulating film 38 in the connection area 208 that is prone to peeling, and to suppress the situation where the gate pad 50 falls off due to the peeling of the upper surface 221 of the interlayer insulating film 38 and the XY interface between the barrier metal layer 220.

[0117] Figure 10 It means Figure 9 This diagram shows a top view of an example configuration of the tungsten portions 230 in the semiconductor device 100. As described above, each tungsten portion 230 is configured to overlap with the lower connection region 208 or the opening region 201. However, as... Figure 10As shown, each tungsten portion 230 may extend in the Y-axis direction to the outside of the lower connection region 208 or the opening region 201. The tungsten portion 230 may extend to a position overlapping with the end of the gate pad 50 in the Y-axis direction. In other examples, each tungsten portion 230 may also be provided only in the region overlapping with the lower connection region 208 or the opening region 201 in the Y-axis direction.

[0118] Figure 11 This is a diagram showing another example of the AA section. In this example, the density of the tungsten portion 230 and the through hole 210 differs from other areas in the region below the connecting region 206 or the opening region 201. Other structures are similar to... Figures 1 to 10 The same as any of the examples in it.

[0119] In this example, the density of the tungsten portion 230 and the through hole 210 in the region below the connection region 206 or the opening region 201 is higher than that in other regions. That is, the region below the connection region 206 or the opening region 201 has a higher area ratio of tungsten portion 230 and through hole 210.

[0120] In this example, the widths of each through-hole 210 and tungsten portion 230 in the X-axis direction are equal. In the region below the connection region 206 or the opening region 201, the period of the tungsten portion 230 and through-hole 210 in the X-axis direction is shorter than that in other regions. In this example, the XY interface between the barrier metal layer 220 and the interlayer insulating film 38 in the connection region 208, which is prone to peeling, can also be reduced, and the detachment of the gate pad 50 due to peeling of the upper surface 221 of the interlayer insulating film 38 and the XY interface of the barrier metal layer 220 can be suppressed.

[0121] Figure 12 It means Figure 11 This diagram shows a top view of an example configuration of the tungsten portion 230 in the semiconductor device 100. As described above, the period in the X-axis direction of the tungsten portion 230 that overlaps with the connection region 206 or the opening region 201 is shorter than the period of the other regions.

[0122] Figure 13This is an enlarged cross-sectional view of the vicinity of the through-hole 210. The width of the lower end of the through-hole 210 can be narrower than the width of the upper end. A depression formed by etch-back can be present at the upper end of the tungsten portion filling the through-hole 210. If the thickness of the barrier metal layer 220 disposed on the upper surface 221 of the interlayer insulating film 38 is set as Z1, the thickness of the barrier metal layer 220 disposed on the side of the through-hole 210 is set as Z2, and the thickness of the barrier metal layer 220 disposed at the lower end of the through-hole 210 is set as Z3, then the relationship Z1>Z2>Z3 holds true. Thicknesses Z1 and Z3 are lengths in the Z-axis direction. Z2 is the length in the direction perpendicular to the sidewall of the through-hole 210. Even if the barrier metal layers 220 on the side and bottom of the through-hole 210 are thin, they can prevent resin ions from reaching below the barrier metal layer 220 in the event of defects in the gate pad 50. This is because a tungsten portion 230 is present within the through-hole 210. A portion of the titanium deposited on the bottom surface of the through-hole 210 is bonded to the silicon contained in the wiring layer 51, thereby forming an alloy of titanium and silicon under the barrier metal layer 220 on the bottom surface of the through-hole 210.

[0123] Figure 14 This diagram shows an example configuration of the connection region 206 on the upper surface of the gate pad 50. As described above, the connection region 206 is the region where the connection portion 204 is provided. In this example, multiple strip-shaped tungsten portions 230 extending along a first direction (the Y-axis direction in this example) and through holes 210 are provided. Furthermore, the major axis of the connection region 206 is indicated by a dashed line 209. The major axis of the connection region 206 is the axis with the longest length of the connection region 206 in the XY plane. The direction in which the dashed line 209 extends is designated as the second direction.

[0124] When viewed from above, the angle θ between the first direction and the second direction can be less than 10 degrees. The angle θ can be less than 5 degrees or 0 degrees. That is, the major axis of the connecting region 206 can be approximately parallel to the extension direction of the tungsten portion 230.

[0125] like Figure 14 As shown, if a strip of tungsten portion 230 is provided, unevenness along the pattern of the tungsten portion 230 may sometimes occur on the upper surface of the gate pad 50. If the angle θ is large, the connector 204 spans more of the tungsten portion 230. In this case, if the connector 204 is to be joined to the upper surface of the gate pad 50 by ultrasonic bonding, there is a situation where the force applied by the ultrasonic waves is difficult to be transmitted to the connector 204. To address this, by setting the angle θ to 10 degrees or less, the connector 204 can be easily joined to the gate pad 50 by ultrasonic bonding.

[0126] Figure 15This diagram shows another configuration example of the connection area 206 on the upper surface of the gate pad 50. In this example, the angle θ between the first direction and the second direction is 30 degrees or more. The angle θ can be 45 degrees or more, or it can be 60 degrees or more. In this example, the number of tungsten portions 230 spanned by the connection portion 204 can be increased. In this case, the upper surface of the gate pad 50 in contact with the connection portion 204 has more irregularities, thus increasing the contact area between the connection portion 204 and the gate pad 50. In addition, when the connection portion 204 is a fixing component such as solder, the bonding between the connection portion 204 and the gate pad 50 can be made more secure.

[0127] Figure 16 This diagram shows an example of the XZ cross-section in the active section 120. The semiconductor substrate 10 has N-type regions such as emitter regions, P-type regions such as collector regions, gate electrodes, gate insulating films, etc., but... Figure 16 The details are omitted. In the active part 120, an interlayer insulating film 38, a through hole 210, a barrier metal layer 220, and a tungsten portion 230 may also be provided between the emitting electrode 52 and the upper surface 21 of the semiconductor substrate 10. For example, the barrier metal layer 220 and the tungsten portion 230 can electrically connect the emitting electrode 52 to the upper surface 21 of the semiconductor substrate 10.

[0128] The width of the tungsten portion 230 or the through hole 210 in the active part 120 in the X-axis direction is set to X4. The width X4 of the tungsten portion 230 or the through hole 210 in the active part 120 can be... Figures 1-15 The width X1 of the tungsten portion 230 or the through-hole 210 in the lower region 208 described herein is different. Furthermore, the distance X5 in the X-axis direction of the through-hole 210 in the active portion 120 can be different from the distance X2 of the through-hole 210 in the lower region 208. For example, the width X1 of the through-hole 210 in the lower region 208 can be smaller than the width X4 of the through-hole 210 below the emitter electrode 52. The reason why the width X1 can be smaller than the width X4 is that, since no element structures such as the gate electrode and gate insulating film are formed in the gate pad 50, it has better flatness than the active portion 120 and is easier to micro-process.

[0129] The tungsten portion 230 and the through-hole 210 in the active portion 120 have a width X4 and a distance X5 suitable for carrier extraction. The tungsten portion 230 and the through-hole 210 in the lower region 208 have a width X1 and a distance X2 suitable for connecting the gate pad 50 and the wiring layer 51, and for suppressing the peeling of the gate pad 50. It should be noted that the interlayer insulating film 38, the through-hole 210, the barrier metal layer 220, and the tungsten portion 230 can be formed in the region below the active portion 120 and the gate pad 50 through the same manufacturing process.

[0130] The ratio of the area S1 of the tungsten portion 230 disposed in the active portion 120 to the total area S of the active portion 120, S1 / S, is the same as that of the gate pad 50 and is set to 20% or more. Alternatively, the S1 / S of the active portion 120 may be around 25%.

[0131] Figure 17 This diagram shows another configuration example of the tungsten portion 230 and the through-hole 210 from a top view. In this example, the tungsten portion 230 and the through-hole 210 are arranged in a vortex shape in the area overlapping with the gate pad 50. The center (or end point) of this vortex can be configured in the lower region 208. Figure 17 The description of the through-hole 210 is omitted, but the through-hole 210 is formed in a region substantially the same as the tungsten portion 230. In the lower connecting region 208, the area of ​​the region where the through-hole 210 is formed is set as S1 when viewed from above, and the area of ​​the entire lower connecting region 208 is set as S, such that the area ratio S1 / S is 20% or more. This prevents the interlayer insulating film 38 from peeling off from the XY interface of the barrier metal layer 220. Furthermore, in Figure 17 In this version, the through hole 210 is omitted. As a variation, the tungsten portion 230 and the through hole 210 may not be arranged on the outside of the opening region 201.

[0132] Figure 18 This is a diagram showing other configuration examples of the tungsten section 230 and the through hole 210 when viewed from above. Figures 1 to 16 In the example, the tungsten portion 230 and the through hole 210 are discretely arranged in the X-axis direction and continuously arranged in the Y-axis direction. In this example, the tungsten portion 230 and the through hole 210 are discretely arranged in the Y-axis direction. Other structures are similar. Figures 1 to 16 The same applies to any of the examples. The tungsten portion 230 and the through hole 210 can also be discretely arranged in two directions, such as the X-axis and Y-axis directions. Figure 18 The description of the through-hole 210 is omitted, but the through-hole 210 is formed in a region that is approximately the same as the tungsten portion 230. In the lower connection region 208, the area of ​​the region where the through-hole 210 is formed when viewed from above is set to S1, and the area of ​​the entire lower connection region 208 is set to S. The area ratio S1 / S is more than 20%. As a result, the XY interface between the interlayer insulating film 38 and the barrier metal layer 220 can be prevented from peeling off.

[0133] Figure 19 It means Figure 18 A diagram showing an example of a CC cross-section. The CC cross-section is the XZ plane through the gate pad 50 and the connection portion 204. Figure 19 To and Figure 2AThe same structure. The length of the through-hole 210 in the X-axis direction is set to the width X1. Furthermore, in this example, multiple tungsten portions 230 are arranged at predetermined intervals along the X-axis direction. The distance between two adjacent through-holes 210 in the X-axis direction is set to X2.

[0134] Figure 20 It means Figure 18 A diagram illustrating an example of a DD cross-section. The DD cross-section is the YZ plane passing through the gate pad 50 and the connection portion 204. The length of the through-hole 210 in the Y-axis direction is defined as the width Y1. In this example, multiple tungsten portions 230 are arranged at predetermined intervals along the Y-axis direction. The distance between two adjacent through-holes 210 in the Y-axis direction is defined as Y2. At this time, in the connection-below region 208, the relationship (X1×Y1) / ((X1+X2)×(Y1+Y2))≥0.2 can be satisfied, such that the area ratio S1 / S obtained by setting the top view area of ​​the region where the through-hole 210 is formed as S1 and the total area of ​​the connection-below region 208 as S is 20% or more. For example, X1 can be 0.5μm, X2 can be 1.5μm, Y1 can be 5.0μm, and Y2 can be 1.0μm. It should be noted that in Figure 18 In this version, the through hole 210 is omitted. As a variation, the tungsten portion 230 and the through hole 210 may not be arranged on the outside of the opening region 201.

[0135] exist Figures 1 to 20 In any of the examples described herein, the interlayer insulating film 38 can be a BPSG film or a BSG film. The boron concentration in the interlayer insulating film 38 can be 2.6 wt% or more and 5 wt% or less. More preferably, the boron concentration in the interlayer insulating film 38 can be 2.7 wt% or more and 4.0 wt% or less. It should be noted that wt% represents the weight percentage concentration. If the boron concentration is too low, it is difficult to manufacture the interlayer insulating film 38. The reason why the manufacture of the interlayer insulating film 38 becomes difficult is that, for example, during heat treatment of the interlayer insulating film 38, it is difficult for deformation caused by flow to occur, and the interlayer insulating film 38 above the trench gate will have residual depressions, and tungsten is likely to remain in these depressions during etch-back of the tungsten film. In addition, if the boron concentration is too high, the reaction between titanium and boron in the barrier metal layer 220 is likely to occur, the adhesion of the barrier metal layer 220 and the interlayer insulating film 38 will be reduced, and it will be easy to peel off at the interface.

[0136] Figure 21 This is a diagram showing other configuration examples of the tungsten section 230 and the through hole 210 when viewed from above. Figure 21 In the text, the opening region 201 and the connecting lower region 208 are omitted, but in relation to... Figures 1 to 20 The example has an opening area 201 and a connecting area 208 at the same location.

[0137] exist Figures 1 to 20 In one example, at least a portion of the through-hole 210 and the tungsten portion 230 are provided along a first extending direction (e.g., the Y-axis direction) parallel to the upper surface 21 of the semiconductor substrate 10. In this example, a portion of the through-hole 210 and the tungsten portion 230 are provided along a second extending direction (e.g., the X-axis direction) parallel to the upper surface 21 of the semiconductor substrate 10 and different from the first extending direction. Other structures are similar. Figures 1 to 20 The same as any of the examples in [the text]. Figure 21 The image shows a tungsten section 230, but a through hole 210 is also provided at a position corresponding to the tungsten section 230.

[0138] The semiconductor device 100 in this example has tungsten portions 230-1 and 230-2 extending in different directions in the XY plane. In this example, tungsten portion 230-1 extends along the Y-axis direction. For example, tungsten portion 230-1 is a strip-shaped portion with a long side in the Y-axis direction. In this example, tungsten portion 230-2 extends along the X-axis direction. For example, tungsten portion 230-2 is a strip-shaped portion with a long side in the X-axis direction.

[0139] Tungsten section 230-1 and tungsten section 230-2 can be connected. In this case, the through hole 210 has a through hole connection portion 231 at the location where the tungsten section 230-1 and tungsten section 230-2 are connected. In this example, the through hole connection portion 231 is the portion formed by the merging of the through hole 210 provided along the Y-axis direction and the through hole 210 provided along the X-axis direction.

[0140] Tungsten portions 230-1 and 230-2 may intersect in the XY plane. In other words, tungsten portions 230-1 and 230-2 may be configured to penetrate each other in the XY plane. Tungsten portion 230-1 may be arranged at a predetermined period in the X-axis direction. Tungsten portion 230-2 may be arranged at a predetermined period in the Y-axis direction. Tungsten portions 230-1 and 230-2 may be arranged in a grid pattern in the XY plane. In this case, the through-hole connecting portions 231 are arranged at predetermined periods in the X-axis and Y-axis directions, respectively.

[0141] Figure 22 yes Figure 21Enlarged views of tungsten portions 230-1 and 230-2 are shown. In this example, the spacing of the through-hole connecting portions 231 arranged along the X-axis is set as 'a', the spacing of the through-hole connecting portions 231 arranged along the Y-axis is set as 'b', the width of the through-hole 210 arranged along the X-axis is set as 'c', and the width of the through-hole 210 arranged along the Y-axis is set as 'd'. The width of the through-hole 210 can be the width of the tungsten portion 230. Furthermore, the spacing of the through-hole connecting portions 231 can be the period of the tungsten portions 230. The spacing between two through-hole connecting portions 231 is the distance between corresponding positions in each through-hole connecting portion 231. The distance between the centers of the through-hole connecting portions 231 can be set as the spacing of the through-hole connecting portions 231. Additionally, as... Figure 22 As shown, the distance between the end edges of the through-hole connecting portions 231 on the same side can also be defined as the interval of the through-hole connecting portions 231. These widths and intervals can be measured at the height position of the upper end of the through hole 210.

[0142] The intervals a and b and the widths c and d can satisfy the following formula:

[0143] ((a×c)+(bc)×d) / (a×b)≥0.2.

[0144] That is, in a unit area a×b, the area occupied by the through hole 210 or the tungsten portion 230 (a×c)+(bc)×d can be 20% or more. This area ratio can be 25% or more, or it can be 30% or more. Figures 1 to 20 The same applies to the examples described.

[0145] Figure 23 This diagram illustrates other shape examples of the through-hole 210 and the tungsten portion 230. In this example, the through-hole 210 and the tungsten portion 230 may have a curved portion 232 in the XY plane parallel to the upper end of the through-hole 210. When the through-hole 210 is formed by etching the interlayer insulating film 38, the portion where the through-holes 210 meet is easily etched. Therefore, there are cases where the width of the through-hole connection portion 231 is larger than the width of other portions of the through-hole 210. For example, as... Figure 23 As shown, etching is performed in the XY plane near the through-hole connection portion 231, resulting in a curved portion 232 appearing in the upper surface shape of the through-hole 210 and the tungsten portion 230. Consequently, the width of the through-hole 210 and the tungsten portion 230 at the through-hole connection portion 231 is larger than the width of the through-hole 210 and the tungsten portion 230 at other locations.

[0146] Figure 24 It means Figure 23 A diagram showing an example of the EE section. The EE section is the YZ plane intersecting the tungsten section 230-2 at a location different from that of the tungsten section 230-1. Figure 24In the original text, the connecting portion 204 and other components provided on the gate pad 50 are omitted, but they are similar to... Figure 20 Similarly, in this example, a connection portion 204, a wiring portion 202, and a protective component 240 are provided on the gate pad 50. In other figures, the connection portion 204, the wiring portion 202, and the protective component 240 are sometimes omitted. According to this example, the area of ​​the XY interface between the interlayer insulating film 38 and the barrier metal layer 220 can also be reduced. Therefore, peeling between the barrier metal layer 220 and the interlayer insulating film 38 can be suppressed.

[0147] Figure 25 It means Figure 23 The figure shows an example of the FF cross section. The FF cross section is the YZ plane along the tungsten portion 230-1 through the through-hole connection portion 231. The upper end of the tungsten portion 230 provided in the through-hole connection portion 231 is positioned lower than the upper end of the tungsten portion 230 provided in the through-hole 210 other than the through-hole connection portion 231. That is, the upper surface of the tungsten portion 230 is recessed in the through-hole connection portion 231 toward the upper surface 21 of the semiconductor substrate 10. As shown in Figure 23 As explained, the width of the through-hole 210 increases near the through-hole connection portion 231. Therefore, when tungsten is filled into the through-hole 210, a depression is easily generated at the through-hole connection portion 231. By providing a step on the upper surface of the tungsten portion 230, the contact area between the gate pad 50 and the tungsten portion 230 is increased, thereby improving the adhesion between the gate pad 50 and the tungsten portion 230.

[0148] The thickness of the tungsten portion 230 in the area excluding the through-hole connection portion 231 is set to z2. Thickness z2 can be the maximum value of the tungsten portion 230 thickness. The depth of the recess in the tungsten portion 230 at the through-hole connection portion 231 is set to z1. Depth z1 can be the height difference between the apex of the top surface and the bottom surface of the adjacent top surface of the tungsten portion 230. Depth z1 can be 5% or more, 10% or more, or 20% or more of the thickness z2. Depth z1 can be less than 50% or less of the thickness z2, or less than 30%. This allows the thickness of the tungsten portion 230 to be maintained at a certain level, and improves the adhesion between the tungsten portion 230 and the gate pad 50. The width of the recess on the upper surface of the tungsten portion 230 is set to c'. In this example, width c' is the width in the Y-axis direction. Width c' can be larger than the width c of the tungsten portion 230-2.

[0149] Figure 26 This diagram shows another configuration example of the tungsten section 230 and the through hole 210 as viewed from above. In this example, the tungsten section 230-1 is connected to the tungsten section 230-2, but does not penetrate the tungsten section 230-2. That is, the tungsten section 230-1 and the tungsten section 230-2 are connected in a T-shape. Other structures are similar to... Figure 21The example is the same. In this example, a through hole connection portion 231 is also provided at the connection portion between the tungsten portion 230-1 and the tungsten portion 230-2.

[0150] Figure 27 yes Figure 26 Enlarged views of tungsten sections 230-1 and 230-2 are shown. In this example, tungsten sections 230-1 and 230-2 are connected in a T-shape. Other structures are similar to... Figure 22 or Figure 23 same.

[0151] In this example, the spacing of the through-hole connecting portions 231 arranged along the X-axis direction is set to a, the spacing of the through-hole connecting portions 231 arranged along the Y-axis direction is set to b, the width of the through-hole 210 arranged along the X-axis direction is set to c, and the width of the through-hole 210 arranged along the Y-axis direction is set to d.

[0152] and Figure 22 Similarly, the intervals a and b and the widths c and d can satisfy the following formula:

[0153] ((a×c)+(bc)×d) / (a×b)≥0.2.

[0154] That is, in a unit area a×b, the area occupied by the through hole 210 or the tungsten part 230 (a×c)+(bc)×d can be 20% or more. This area ratio can be 25% or more, or it can be 30% or more.

[0155] Figure 28 This is a diagram showing another configuration example of the tungsten section 230 and the through hole 210 in a top view. In this example, at least one of the tungsten sections 230-1 and 230-2 is discretely configured in its extending direction. Figure 28 In the example, the tungsten section 230-2 is discretely arranged along the X-axis direction. The tungsten section 230-2 is also discretely arranged along the Y-axis direction.

[0156] As in Figure 2B As described, the groove 25 is provided extending along the Y-axis direction. Figure 28 In one example, the tungsten portion 230-1 extending along the Y-axis and the through-hole 210 are continuously provided on the gate pad 50 along the Y-axis. On the other hand, the tungsten portions 230-2 are discretely arranged in the X-axis direction. With this structure, the unevenness of the upper surface of the tungsten portion 230 can be reduced in the direction parallel to the trench 25, and the deviation in the connection between the trench 25 and the gate pad 50 can be reduced. In other examples, the tungsten portion 230-2 may be continuously provided in the X-axis direction, and the tungsten portion 230-1 may be discretely provided in the Y-axis direction.

[0157] The tungsten section 230-2 can be arranged at a predetermined period in the X-axis direction. The tungsten section 230-2 can be connected to or separated from the tungsten section 230-1. When the tungsten section 230-2 is connected to the tungsten section 230-1, a through-hole connection portion 231 can be provided at the connection point. For example... Figure 28 As shown, a tungsten section 230-2 can be arranged between two tungsten sections 230-1 in the X-axis direction. In other examples, more than two tungsten sections 230-2 can also be arranged between two tungsten sections 230-1 in the X-axis direction.

[0158] Figure 29 yes Figure 28 Enlarged views of tungsten sections 230-1 and 230-2 are shown. In this example, tungsten section 230-1 is separate from tungsten section 230-2. Other structures are similar to... Figure 22 or Figure 23 same.

[0159] In this example, the spacing of the through-hole connecting portions 231 arranged along the X-axis is set as 'a', the spacing of the through-hole connecting portions 231 arranged along the Y-axis is set as 'b', the width of the through-hole 210 filled with tungsten portion 230-2 in the Y-axis direction is set as 'c', and the width of the through-hole 210 arranged along the Y-axis direction is set as 'd'. Furthermore, the width of the through-hole 210 filled with tungsten portion 230-2 in the X-axis direction is set as 'e', ​​and the distance in the X-axis direction between the through-hole 210 filled with tungsten portion 230-1 and the through-hole 210 filled with tungsten portion 230-2 is set as 'f'. Distance f is the shortest distance between tungsten portion 230-1 and tungsten portion 230-2.

[0160] The intervals a, b, widths c, d, e, and distance f can satisfy the following formula:

[0161] ((b×d)+(e×c)) / (a×b)≥0.2.

[0162] That is, in a unit area a×b, the area occupied by the through hole 210 or the tungsten part 230 (b×d)+(e×c) can be 20% or more. This area ratio can be 25% or more, or it can be 30% or more.

[0163] Figure 30 It means Figure 28 An enlarged view of another example of tungsten portions 230-1 and 230-2 shown. In this example, each tungsten portion 230-2 has a longer side in the X-axis direction. That is, the width e is greater than the width c. In other examples, the width e may be the same as the width c, or the width e may be less than the width c.

[0164] In this example, the tungsten section 230-1 positioned along the Y-axis and the tungsten section 230-2 positioned along the X-axis can also be configured separately. The width e can be greater than the distance f.

[0165] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Various modifications or improvements can be made to the above embodiments, which will be apparent to those skilled in the art. As can be seen from the claims, such modifications or improvements can also be included within the technical scope of the present invention.

Claims

1. A semiconductor device, characterized by comprising: The semiconductor device includes a semiconductor substrate and comprises: An emission electrode is disposed above the upper surface of the semiconductor substrate; The pad portion is disposed above the upper surface of the semiconductor substrate and is separated from the emitter electrode; The wire routing section is connected to the connection area on the upper surface of the pad section; A wiring layer is disposed between the semiconductor substrate and the pad portion, and includes a region overlapping the connection region; An interlayer insulating film is disposed between the wiring layer and the pad portion, and has a through hole below the connection area; A tungsten portion, disposed inside the through-hole, electrically connecting the wiring layer and the pad portion, the tungsten portion comprising tungsten; and A barrier metal layer is configured to cover the upper surface of the interlayer insulating film, and the barrier metal layer comprises titanium.

2. The semiconductor device according to claim 1, characterized in that, In the region below the connection that overlaps with the connection area when viewed from above, the area where the tungsten portion is located is more than 20% of the area of ​​the region below the connection.

3. The semiconductor device according to claim 2, characterized in that, The area of ​​the region where the tungsten portion is located is more than 50% of the area of ​​the region below the connection.

4. The semiconductor device according to claim 2, characterized in that, The tungsten portion is disposed in the area below the entire connection.

5. The semiconductor device according to claim 2, characterized in that, The tungsten portion covers a portion of the upper surface of the interlayer insulating film.

6. The semiconductor device according to claim 5, characterized in that, The tungsten portion covers the upper surface of the interlayer insulating film in the area excluding the region below the connection.

7. The semiconductor device according to claim 1, characterized in that, The tungsten portion is configured to overlap with the entire pad portion when viewed from above.

8. The semiconductor device according to claim 1, characterized in that, The width of the through hole is greater than 0.5 μm and less than 0.8 μm.

9. The semiconductor device according to claim 8, characterized in that, The interlayer insulating film has a plurality of through holes. The distance between two adjacent through holes is greater than 0.5 μm and less than 3.2 μm.

10. The semiconductor device according to claim 9, characterized in that, The width of the through hole and the distance between the through holes satisfy the following relationship: X1 / (X1+X2)≥0.2, where X1 is the width of the through hole and X2 is the distance between two adjacent through holes.

11. The semiconductor device according to claim 1, characterized in that, The barrier metal layer is also disposed on the bottom surface of the through hole. The barrier metal layer covering the upper surface of the interlayer insulating film is thicker than the barrier metal layer disposed on the bottom surface of the through hole.

12. The semiconductor device according to claim 1, characterized in that, A plurality of tungsten portions extending along a first direction are provided on the upper surface of the interlayer insulating film. The connecting region has a major axis in the second direction when viewed from above. The angle between the first direction and the second direction is less than 10 degrees.

13. The semiconductor device according to claim 2, characterized in that, The interlayer insulating film, the through-hole, and the tungsten portion are also disposed below the emitting electrode. The spacing of the through holes in the region below the connection is different from the spacing of the through holes below the transmitting electrode.

14. The semiconductor device according to claim 2, characterized in that, The interlayer insulating film, the through-hole, and the tungsten portion are also disposed below the emitting electrode. The width of the through hole in the region below the connection is smaller than the width of the through hole below the transmitting electrode.

15. The semiconductor device according to claim 1, characterized in that, The interlayer insulating film is a BPSG film or a BSG film. The boron concentration in the interlayer insulating film is above 2.6 wt% and below 5 wt%.

16. The semiconductor device according to claim 1, characterized in that, The through hole and at least a portion of the tungsten portion are arranged along a first extending direction parallel to the upper surface of the semiconductor substrate.

17. The semiconductor device according to claim 16, characterized in that, The through hole and a portion of the tungsten portion are arranged along a second extending direction that is parallel to the upper surface of the semiconductor substrate and different from the first extending direction.

18. The semiconductor device according to claim 17, characterized in that, The semiconductor device has a through-hole connection portion that connects the through-hole disposed along the first extension direction to the through-hole disposed along the second extension direction.

19. The semiconductor device according to claim 18, characterized in that, When the interval between the through-hole connecting portions arranged along the second extending direction is set to 'a', the interval between the through-hole connecting portions arranged along the first extending direction is set to 'b', the width of the through-hole arranged along the second extending direction is set to 'c', and the width of the through-hole arranged along the first extending direction is set to 'd', the following formula is satisfied: ((a×c)+(bc)×d) / (a×b)≥0.

2.

20. The semiconductor device according to claim 18, characterized in that, The upper end of the tungsten portion disposed at the through-hole connection is positioned lower than the upper end of the tungsten portion disposed in the through hole other than the through-hole connection.

21. The semiconductor device according to claim 17, characterized in that, The through holes are discretely arranged in at least one of the first extension direction and the second extension direction.

22. The semiconductor device according to claim 21, characterized in that, The semiconductor device includes: A trench, which is disposed on the upper surface of the semiconductor substrate along the first extending direction; and A gate electrode is disposed inside the trench; The through holes are discretely arranged in the second extension direction.

23. The semiconductor device according to claim 17, characterized in that, The tungsten portion disposed along the first extending direction and the tungsten portion disposed along the second extending direction are configured off the ground.

24. The semiconductor device according to any one of claims 1 to 3, characterized in that, The plurality of through holes are arranged along the arrangement direction. The width of the through hole in the arrangement direction is greater than the distance between two adjacent through holes.

25. The semiconductor device according to any one of claims 1 to 3, characterized in that, In the region overlapping with the pad portion, the density of through holes in the region below the connection region is higher than the density of through holes in the region other than the connection region.

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