semiconductor devices

Abstract

A semiconductor device with excellent reliability comprises a semiconductor element having a semiconductor layer and a wiring layer provided on the semiconductor element, the wiring layer comprising first to third electrodes, an insulating film, and first and second electrode pads, the first to third electrodes being located between the semiconductor element and the insulating film, the second electrode being insulated from the first electrode pad, the first electrode and the second electrode pad being insulated, the first electrode being electrically connected to the first electrode pad, the second electrode being electrically connected to the second electrode pad, the distance from the first surface of the first electrode pad at a portion where the first electrode and the first electrode pad are connected to the semiconductor layer being greater than the distance from the first surface of the first electrode pad at a portion where the second electrode and the first electrode pad are insulated from the first electrode pad to the semiconductor layer, and the distance from the first surface of the second electrode pad at a portion where the second electrode and the second electrode pad are connected to the semiconductor layer being greater than the distance from the first surface of the second electrode pad at a portion where the first electrode and the second electrode pad are insulated from the semiconductor layer.

Description

[0001] Related applications

[0002] This application claims the benefit of priority based on Japanese Patent Application No. 2020-159719 (filing date: September 24, 2020), the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to a semiconductor device. Background Art

[0004] Semiconductor elements such as transistors and diodes are used in circuits such as switching power supply circuits and inverter circuits. These semiconductor elements are required to have high withstand voltage and low on-resistance.

[0005] There is a method to reduce RonS (mΩcm) by providing pads on semiconductor elements and forming bonding wires on the pads for wiring. 2 However, when forming the pads and bonding wires, a large stress is applied to the semiconductor element, which may cause damage to the semiconductor element. Summary of the Invention

[0006] Embodiments of the present invention provide a highly reliable semiconductor device.

[0007] A semiconductor device according to an embodiment includes a semiconductor element having a semiconductor layer, and a wiring layer on the semiconductor element, the wiring layer having a first electrode on the semiconductor element, a second electrode on the semiconductor element, a third electrode on the semiconductor element, an insulating film on the first electrode, the second electrode, and the third electrode, a first electrode pad on the insulating film having a side opposite to the semiconductor element as a first surface, the wiring layer having a second electrode pad, the second electrode pad being adjacent to the first electrode pad on the insulating film, and having a side opposite to the semiconductor element as the first surface, the first electrode, the second electrode, and the third electrode being located between the semiconductor element and the insulating film, and the second electrode and the first electrode pad being connected via an insulating layer. The first electrode and the second electrode pad are insulated by the insulating film, the first electrode and the second electrode pad are insulated by the insulating film, the first electrode and the first electrode pad are electrically connected by being connected via a first opening provided in the insulating film, the second electrode and the second electrode pad are electrically connected by being connected via a second opening provided in the insulating film, the distance from the first surface of the first electrode pad at the portion where the first electrode and the first electrode pad are connected to the semiconductor layer is greater than the distance from the first surface of the first electrode pad at the portion where the second electrode and the first electrode pad are insulated to the semiconductor layer, and the distance from the first surface of the second electrode pad at the portion where the second electrode and the second electrode pad are connected to the semiconductor layer is greater than the distance from the first surface of the second electrode pad at the portion where the first electrode and the second electrode pad are insulated to the semiconductor layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a conceptual perspective view of a semiconductor device according to an embodiment.

[0009] Figure 2 This is a schematic cross-sectional view of a semiconductor device according to an embodiment.

[0010] Figure 3 This is a schematic cross-sectional view of a semiconductor device according to an embodiment.

[0011] Figure 4 This is a schematic cross-sectional view of a semiconductor device according to an embodiment.

[0012] Figure 5 This is a schematic cross-sectional view of a semiconductor device according to an embodiment.

[0013] Figure 6 This is a schematic cross-sectional view of a semiconductor device according to an embodiment. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same or similar components are denoted by the same reference numerals, and description of components that have already been described once may be omitted.

[0015] In this specification, the term “nitride semiconductor layer” includes a “GaN-based semiconductor.” “GaN-based semiconductor” is a general term for semiconductors including gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), and intermediate compositions thereof.

[0016] In this specification, “undoped” means that the impurity concentration is 2×10 16 cm -3 the following.

[0017] In this specification, the upper direction in the drawings is described as "upper," and the lower direction in the drawings is described as "lower" to indicate the positional relationship of components, etc. In this specification, the concepts of "upper" and "lower" are not necessarily terms that indicate the relationship with the direction of gravity.

[0018] (First embodiment)

[0019] The semiconductor device of the first embodiment includes a semiconductor element having a semiconductor layer and a wiring layer on the semiconductor element. A GaN-based semiconductor device is used as an example for the following description, but the semiconductor element may also be a lateral transistor other than a GaN-based one.

[0020] Figure 1 It is a schematic perspective view of the semiconductor device 100 according to the first embodiment. Figure 2 、 31 is a schematic cross-sectional view of the semiconductor device 100 according to the first embodiment. Figure 2 yes Figure 1 Partial cross-sectional view of section A-A'. Figure 3 This is a partial cross-sectional view of the BB' section. The semiconductor element 10 is, for example, a HEMT (High Electron Mobility Transistor) using a GaN-based semiconductor. The semiconductor element 10 has an element region that acts as a transistor and a non-element region that does not act as a transistor. Figure 1 The area surrounded by the dotted line 21 corresponds to the element area. The first pad electrode 22 and the second pad electrode 23 of the wiring layer are located on the element area of ​​the semiconductor element 10. The third pad electrode 24 of the wiring layer is located on the non-element area of ​​the semiconductor element 10. Figure 2 The wiring on the first electrode 5 side is shown in FIG. Figure 3 Schematic diagram showing the wiring on the second electrode 6 side.

[0021] The semiconductor element 10 includes a substrate 1 , a buffer layer 2 , a channel layer 3 (a first nitride semiconductor layer), and a barrier layer 4 (a second nitride semiconductor layer).

[0022] The substrate 1 is formed of, for example, silicon (Si). In addition to silicon, sapphire (Al 2 O 3 ) or silicon carbide (SiC) can also be used.

[0023] A buffer layer 2 is provided on the substrate 1. The buffer layer 2 has the function of alleviating the lattice mismatch between the substrate 1 and the channel layer 3. The buffer layer 2 is made of, for example, aluminum gallium nitride (AlGaN). W Ga 1-W A multilayer structure of N(0<W≤1)) is formed.

[0024] The channel layer 3 is provided on the buffer layer 2. The channel layer 3 is also called the electron transit layer (Japanese: electron running layer). The channel layer 3 is, for example, undoped aluminum gallium nitride (AlGaN). X Ga 1-X N (0≤X<1). More specifically, it is, for example, undoped gallium nitride (GaN). The thickness of the channel layer 3 is, for example, not less than 0.1 μm and not more than 10 μm. In the embodiment, the thickness is the length (height) of each component in the stacking direction of the channel layer 3 and the barrier layer 4, including the channel layer 3.

[0025] The barrier layer 4 is provided on the channel layer 3. The barrier layer 4 is also called an electron supply layer. The band gap of the barrier layer 4 is larger than the band gap of the channel layer 3. The barrier layer 4 is, for example, undoped aluminum gallium nitride (AlGaN). Y Ga 1-Y N (0<Y≤1, X<Y)). More specifically, for example, undoped Al0.25 Ga 0.75 N. The thickness of the barrier layer 4 is, for example, not less than 2 nm and not more than 100 nm.

[0026] A heterojunction interface is formed between the channel layer 3 and the barrier layer 4. A two-dimensional electron gas (2DEG) is formed at the heterojunction interface and becomes a carrier of the HEMT 100.

[0027] A wiring layer 20 is provided on the semiconductor element 10 of the semiconductor device 100. The wiring layer 20 includes a first electrode 5, a second electrode 6, a third electrode 7, an insulating film 8, a first electrode pad 22, a second electrode pad 23, a third electrode pad 24, a first bonding wire 25, a second bonding wire 26, and a third bonding wire 27. The first bonding wire 25, the second bonding wire 26, and the third bonding wire 27 are connected to the electrode terminals of the semiconductor device 100.

[0028] The first electrode 5 is, for example, a source electrode. The source electrode 5 is provided on the channel layer 3 and the barrier layer 4. The source electrode 5 is electrically connected to the channel layer 3 and the barrier layer 4. The source electrode 5 is, for example, directly in contact with the barrier layer 4.

[0029] The source electrode 5 is a metal electrode, for example. The source electrode 5 is, for example, an aluminum film mainly composed of aluminum, containing 50 wt% or more of aluminum, or a stacked structure of titanium (Ti) and aluminum (Al). The source electrode 5 is preferably in ohmic contact with the barrier layer 4.

[0030] The source electrode 5 may include a field plate electrode, and the field plate electrode is connected to the source electrode 5. A plurality of field plate electrodes may be connected to the source electrode 5. In this case, Figure 2 The source electrode 5 shown in the cross-sectional view of FIG. 1 is a member extending most toward the drain electrode 6 .

[0031] The second electrode 6 is a drain electrode. The drain electrode 6 is provided on the channel layer 3 and the barrier layer 4. The drain electrode 6 is electrically connected to the channel layer 3 and the barrier layer 4. For example, the drain electrode 6 is in contact with the barrier layer 4.

[0032] The drain electrode 6 is, for example, a metal electrode. It is, for example, an aluminum film containing aluminum as a main component and containing 50 wt% or more of aluminum, or a stacked structure of titanium (Ti) and aluminum (Al). The drain electrode 6 is preferably in ohmic contact with the barrier layer 4 .

[0033] The distance between the source electrode 5 and the drain electrode 6 is, for example, not less than 5 μm and not more than 30 μm.

[0034] Alternatively, the source electrode 5 and the drain electrode 6 may be directly in contact with the channel layer 3 .

[0035] The third electrode 7 is a gate electrode. The gate electrode 7 is disposed on the channel layer 3 and the barrier layer 4. The gate electrode 7 is electrically connected to the channel layer 3 and the barrier layer 4. For example, the gate electrode 7 is directly in contact with the barrier layer 4. The gate electrode 7 is disposed between the source electrode 5 and the drain electrode 6.

[0036] The gate electrode 7 is made of, for example, titanium nitride (TiN).

[0037] A gate insulating film (not shown) may be provided between the gate electrode 7 and the barrier layer, allowing the semiconductor device 100 to be a MIS (Metal Insulator Semiconductor) HEMT. The gate insulating layer may be made of, for example, an oxide or an oxynitride. Examples of the gate insulating layer include silicon oxide, aluminum oxide, silicon oxynitride, or aluminum oxynitride.

[0038] The gate electrode 7 may include a field plate electrode, and the field plate electrode is connected to the gate electrode 7 .

[0039] The insulating film 8 covers the source electrode 5, the drain electrode 6, and the gate electrode 7. The insulating film 8 is made of, for example, an oxide or a nitride. Examples of the insulating film 8 include silicon oxide (SiO2), silicon nitride (SiN), or a high-k dielectric material. Examples of high-k materials include hafnium oxide (HfO2).

[0040] The types and concentrations of elements in semiconductor layers and semiconductor regions can be measured, for example, by SIMS (Secondary Ion Mass Spectrometry) and EDX (Energy Dispersive X-ray Spectroscopy). In addition, the relative concentration of elements can also be determined, for example, based on the carrier concentration obtained by SCM (Scanning Capacitance Microscopy). In addition, the depth, thickness, width, spacing, and other distances of the impurity region can be obtained, for example, by SIMS. In addition, the depth, thickness, width, spacing, and other distances of the impurity region can also be obtained, for example, based on a comparison image of an SCM image and an atom probe image.

[0041] The first electrode pad 22 and the second electrode pad 23 of the wiring layer 20 are adjacent to each other on the device region of the semiconductor device 10. The first electrode pad 22 is a source electrode pad. The second electrode pad 23 is a drain electrode pad. In addition, the third electrode pad 24 is a gate electrode pad.

[0042] The source electrode pad 22 is, for example, a metal electrode. The source electrode pad 22 is, for example, an aluminum film mainly composed of aluminum and containing more than 50 wt% of aluminum, or a stacked structure of titanium (Ti) and aluminum (Al). The source electrode pad 22 has a first surface on the side opposite to the semiconductor element side. The source electrode pad 22 and the source electrode 5 are preferably in ohmic contact. The source electrode pad 22 is connected to the first bonding wire 25. In one bonding wire, if the source-drain is set as a unit cell, three unit cells are typically connected. At the position where the first bonding wire 25 is set, the positioning accuracy is improved by providing a recessed portion not shown in the figure on the source electrode pad 22. In order to provide the recessed portion, for example, the position where the first bonding wire 25 is formed is aligned with the portion (excluding its peripheral portion) Figure 2 The source power supply pad 22 (not shown) and the insulating film 8 are thickened as a whole. Thus, the region of the source power supply pad 22 connected to the first bonding wire 25 is recessed relative to the region of the source power supply pad 22 not connected to the first bonding wire 25.

[0043] The drain electrode pad 23 is, for example, a metal electrode. The drain electrode pad 23 is, for example, an aluminum film mainly composed of aluminum and containing more than 50 wt% of aluminum, or a stacked structure of titanium (Ti) and aluminum (Al). The drain electrode pad 23 has a first surface on the side opposite to the semiconductor element side. The source electrode pad 22 and the source electrode 5 are preferably in ohmic contact. The drain electrode pad 23 is connected to the second bonding wire 26. In one bonding wire, if the source-drain is set as a unit cell, three unit cells are typically connected. At the position where the second bonding wire 26 is set, the positioning accuracy is improved by providing a recessed portion not shown in the figure on the drain electrode pad 23. In order to provide the recessed portion, for example, the position where the second bonding wire 26 is formed is aligned with the portion (excluding its peripheral portion) Figure 3 The drain power supply pad 23 (not shown) and the insulating film 8 are thickened as a whole. Thus, the region of the drain power supply pad 23 connected to the second bonding wire 26 is recessed relative to the region of the source power supply pad 23 not connected to the second bonding wire 26.

[0044] Gate electrode pad 24 is, for example, a metal electrode. It may be, for example, primarily aluminum, an aluminum film containing at least 50 wt% aluminum, or a laminated structure of titanium (Ti) and aluminum (Al). Gate electrode pad 24 has a first surface on the side opposite the semiconductor element. Ohmic contact is preferably established between gate electrode pad 24 and gate electrode 7. Gate electrode pad 24 is connected to third bonding wire 27.

[0045] Reference Figure 2 and Figure 3The cross-sectional schematic diagram of FIG is used to explain the connection of the wiring around the source electrode pad 22. The source electrode 5, the drain electrode 6, and the gate electrode 7 are located between the semiconductor element 10 and the insulating film 8. The insulating film 8 is located between the source electrode pad 22 and the source electrode 5 and between the source electrode pad 22 and the drain electrode 6. Figure 2 、 3 In the figure, although the insulating film 8 is not separated, it may be a multi-layered insulating film.

[0046] A first opening A is provided in insulating film 8 between source electrode 5 and source electrode pad 22 on the source electrode 5 side. Source electrode 5 and source electrode pad 22 are connected via first opening A, and are electrically connected.

[0047] On the drain electrode 6 side below the source electrode pad 22 , there is no opening in the insulating film 8 , and the drain electrode 6 and the source electrode pad 22 are insulated from each other by the insulating film 8 .

[0048] The source electrode pad 22 has a concave and convex structure. The portion where the source electrode 5 and the source electrode pad 22 are in contact and electrically connected via the first opening A provided in the insulating film 8 is a convex portion, and the portion where the drain electrode 6 and the source electrode pad 22 are insulated from each other by the insulating film 8 is a concave portion. The electrically connected portion is convex, and the electrically unconnected portion is concave.

[0049] The distance from the first surface of the source electrode pad 22 at the portion where the source electrode 5 and the source electrode pad 22 are connected to the semiconductor layer (for example, the channel layer 3) of the semiconductor element is greater than the distance from the first surface of the source electrode pad 22 at the portion where the drain electrode 6 and the source electrode pad 22 are insulated to the channel layer.

[0050] This unevenness prevents short circuits between the drain electrode 6 and the source electrode pad 22. When forming the first bonding wire 25 on the source electrode pad 22, there is a risk that mechanical stress will be applied to the junction between the first bonding wire 25 and the source electrode pad 22, potentially damaging the insulating film 8. Since the source electrode 5 and the source electrode pad 22 are electrically conductive, the insulating film 8 is selectively broken between the source electrode 5 and the source electrode pad 22. If the first surface of the source electrode pad 22, which prevents short circuits, is flat, stress will be applied to the entire surface, making it more susceptible to overall damage. If there are protrusions on the source electrode pad 22, stress will concentrate on the protruding portion. Since there are no protrusions in the area where short circuits are undesirable, even if the insulating film 8 is broken and conductive components separated by the insulating film 8 come into contact, short circuits can be prevented by causing protrusions in areas where there are no electrical issues.

[0051] If the unevenness is small, there is a risk of damage to the insulating film 8 on the drain electrode 6 side. If the unevenness is too large, it is easy to cause poor bonding between the bonding wire and the source electrode pad 22. Therefore, the difference between the distance from the first surface of the source electrode pad 22 at the portion where the source electrode 5 and the source electrode pad 22 are connected to the channel layer 3 and the distance from the first surface of the source electrode pad 22 at the portion where the drain electrode 6 and the source electrode pad 22 are insulated from each other to the channel layer 3 is preferably 1 μm or more and 10 μm or less.

[0052] Furthermore, if the width of the recess is narrow, the stress relaxation effect is small. Therefore, the width of the recess is wider than the width of the drain electrode 6 , and is preferably at least twice the width of the drain electrode 6 .

[0053] On the source electrode pad 22 side, the width of the concave portion is narrower than the width of the convex portion due to the width of the electrode.

[0054] There are cases where a portion of the insulating film 8 between the source electrode 5 and the source electrode pad 22 is damaged, thereby generating a crack (first crack). If the insulating film 8 is sandwiched between the source electrode 5 and the source electrode pad 22, which are primarily made of aluminum, cracks are likely to form in the insulating film 8. It is preferable that the source electrode 5 and the source electrode pad 22 remain connected and conductive even in the resulting crack.

[0055] A second opening B is provided in insulating film 8 between drain electrode 6 and drain electrode pad 23 on the drain electrode pad 23 side. Drain electrode 6 and drain electrode pad 23 are connected via second opening B, and drain electrode 6 and drain electrode pad 23 are electrically connected.

[0056] There is no opening in the insulating film 8 on the source electrode 5 side below the drain electrode pad 23 side, and the source electrode 5 and the drain electrode pad 23 are insulated by the insulating film 8 .

[0057] The drain electrode pad 23 side has a concave and convex structure. The portion where the drain electrode 6 and the drain electrode pad 23 are in contact and electrically connected via the second opening B provided in the insulating film 8 is a convex portion, and the portion where the source electrode 5 and the drain electrode pad 23 side are insulated by the insulating film 8 is a concave portion. The electrically connected portion is convex, and the electrically unconnected portion is concave.

[0058] The distance from the first surface of the drain electrode pad 23 side of the portion where the drain electrode 6 and the drain electrode pad 23 side are connected to the semiconductor layer (for example, the channel layer 3) of the semiconductor element is greater than the distance from the first surface of the drain electrode pad 23 side of the portion where the source electrode 5 and the drain electrode pad 23 side are insulated to the channel layer.

[0059] This unevenness prevents short circuits between the source electrode 5 and the drain electrode pad 23. When forming the second bonding wire 26 on the drain electrode pad 23, there's a risk that mechanical stress will be applied to the junction between the first bonding wire 25 and the drain electrode pad 23, potentially damaging the insulating film 8. Since the drain electrode 6 and the drain electrode pad 23 are electrically connected, the insulating film 8 is selectively damaged between the drain electrode 6 and the drain electrode pad 23. If the first surface of the drain electrode pad 23, which prevents short circuits, is flat, stress will be applied to the entire surface, making it more susceptible to overall damage. If there are protrusions on the drain electrode pad 23, stress will concentrate on the protruding portion. Since there are no protrusions in areas where short circuits are undesirable, even if the insulating film 8 is damaged and conductive components separated by the insulating film 8 come into contact, short circuits can be prevented by protruding in areas where there are no electrical issues.

[0060] If the unevenness is small, there is a risk of damage to the insulating film 8 on the source electrode 5 side. If the unevenness is too large, it is easy to cause poor bonding between the bonding wire and the drain electrode pad 23 side. Therefore, the difference between the distance from the first surface on the drain electrode pad 23 side of the portion where the drain electrode 6 is connected to the drain electrode pad 23 side to the channel layer 3 and the distance from the first surface on the drain electrode pad 23 side of the portion where the source electrode 5 is insulated from the drain electrode pad 23 side to the channel layer 3 is preferably 1 μm or more and 10 μm or less.

[0061] Furthermore, if the width of the recess is narrow, the stress relaxation effect is small. Therefore, the width of the recess is preferably wider than the width of the source electrode 5 and is 1.2 times or more of the width of the source electrode 5 .

[0062] On the drain electrode pad 23 side, the width of the concave portion is wider than the width of the convex portion due to the width of the electrode.

[0063] There are cases where a portion of the insulating film 8 between the drain electrode 6 and the drain electrode pad 23 is damaged, causing a crack (second crack). If the insulating film 8 is sandwiched between the drain electrode 6, which is primarily made of aluminum, and the drain electrode pad 23, cracks are more likely to form in the insulating film 8. It is preferable that the drain electrode 6 and the drain electrode pad 23 remain connected and conductive even in the resulting crack.

[0064] (Second embodiment)

[0065] The semiconductor device of the second embodiment is a modified example of the semiconductor device of the first embodiment. Figure 4 、 5 , a schematic cross-sectional view of the semiconductor layer 101 according to the second embodiment is shown. Figure 4 The semiconductor device 101 of the second embodiment is Figure 1 A partial cross-sectional view of the section corresponding to the AA' section. Figure 5The semiconductor device 101 of the second embodiment is Figure 1 A partial cross-sectional view of the cross section corresponding to the BB' cross section. The semiconductor device 101 of the second embodiment is the same as the semiconductor device 100 of the first embodiment, except that the source electrode 5 under the source electrode pad 22 and the drain electrode 6 under the drain electrode pad 23 are thicker. In the embodiment including the modified example of the first embodiment, part or all of the changed or added structure can be adopted in other embodiments. The description of the common content between the embodiments is omitted. In the second embodiment, it is also possible to provide a semiconductor device 101 with excellent reliability in the same way as the first embodiment.

[0066] In the second embodiment, by changing the thickness of the electrodes, unevenness is formed on the surfaces of the source electrode pad 22 and the drain electrode pad 23. To change the thickness of the electrodes, different metals may be stacked on the thick electrodes.

[0067] By changing the thickness of the electrode, a short circuit between the source and the drain can be prevented, and a highly reliable semiconductor device 101 can be provided.

[0068] (Third embodiment)

[0069] The semiconductor device of the third embodiment is a modified example of the semiconductor device of the first embodiment. Figure 6 Schematic cross-sectional view of the semiconductor layer 102 according to the third embodiment is shown in FIG. Figure 6 The semiconductor device 101 of the third embodiment is Figure 1 A partial cross-sectional view of the cross section corresponding to the AA' cross section. The semiconductor device 102 of the third embodiment thickens the insulating film 8 on the source electrode 5 under the source electrode pad 22. Although not shown in the figure, it is the same as the semiconductor device 100 of the first embodiment except that the insulating film 8 on the drain electrode 6 under the drain electrode pad 23 is thickened. In an embodiment including a modified example of the first embodiment, part or all of the changed or added structure can be adopted in other embodiments. The description of the common content between the embodiments is omitted. In the third embodiment, it is also possible to provide a semiconductor device 102 with excellent reliability in the same way as the first embodiment.

[0070] In the third embodiment, unevenness is formed on the surfaces of the source electrode pad 22 and the drain electrode pad 23 by changing the thickness of the insulating film 8. To change the thickness of the insulating film, a different insulating film may be stacked on the thick insulating film.

[0071] By changing the thickness of the insulating film, a short circuit between the source and the drain can be prevented, and a highly reliable semiconductor device 102 can be provided.

[0072] Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways and can be omitted, replaced, or modified in various ways without departing from the main purpose of the invention. For example, the constituent elements of one embodiment can be replaced or modified with the constituent elements of other embodiments. These embodiments and their variations are included in the scope or main purpose of the invention and are included in the invention described in the claims and their equivalents.

Claims

1. A semiconductor device comprising: a semiconductor element having a semiconductor layer; and a wiring layer over the semiconductor element, the wiring layer having a first electrode over the semiconductor element, a second electrode over the semiconductor element, and a third electrode over the semiconductor element; an insulating film over the first, second, and third electrodes; a first electrode pad over the insulating film having a first surface opposite the semiconductor element; the wiring layer having a second electrode pad, the second electrode pad being adjacent to the first electrode pad on the insulating film and having a first surface opposite the semiconductor element; the first, second, and third electrodes being located between the semiconductor element and the insulating film; the second electrode and the first electrode pad being insulated from each other by the insulating film; the first electrode and the second electrode pad being insulated from each other by the insulating film; the first electrode and the first electrode pad being electrically connected to each other by contacting each other via a first opening provided in the insulating film; the second electrode and the second electrode pad being electrically connected to each other by contacting each other via a second opening provided in the insulating film; a first bonding wire being connected to the first electrode pad; a second bonding wire being connected to the second electrode pad; and a bonding wire being connected to the first electrode pad. In the region of the first bonding wire, the distance from the first surface of the first electrode pad at the portion where the first electrode and the first electrode pad are connected to the semiconductor layer is greater than the distance from the first surface of the first electrode pad at the portion where the second electrode and the first electrode pad are insulated from the first electrode pad to the semiconductor layer. In the region of the second electrode pad connected to the second bonding wire, the distance from the first surface of the second electrode pad at the portion where the second electrode and the second electrode pad are connected to the semiconductor layer is greater than the distance from the first surface of the second electrode pad at the portion where the first electrode and the second electrode pad are insulated from the first electrode pad to the semiconductor layer. The difference between the distance from the first surface of the first electrode pad at the portion where the first electrode and the first electrode pad are connected to the semiconductor layer and the distance from the first surface of the first electrode pad at the portion where the second electrode and the second electrode pad are insulated from the first electrode pad to the semiconductor layer is greater than 1 μm and less than 10 μm. The difference between the distance from the first surface of the second electrode pad at the portion where the second electrode and the second electrode pad are connected to the semiconductor layer and the distance from the first surface of the second electrode pad at the portion where the first electrode and the second electrode pad are insulated from the first electrode pad to the semiconductor layer is greater than 1 μm and less than 10 μm.

2. The semiconductor device according to claim 1, wherein the first electrode pad has a concave and convex portion, a portion where the first electrode and the first electrode pad are electrically connected via a first opening provided in the insulating film is a convex portion, and a portion where the second electrode and the first electrode pad are insulated via the insulating film is a concave portion, the second electrode pad has a concave and convex portion, a portion where the second electrode and the second electrode pad are electrically connected via a second opening provided in the insulating film is a convex portion, and a portion where the first electrode and the second electrode pad are insulated via the insulating film is a concave portion, the width of the concave portion of the first electrode pad is narrower than the width of the convex portion of the first electrode pad, and the width of the concave portion of the second electrode pad is wider than the width of the convex portion of the second electrode pad.

3. In the semiconductor device according to claim 1 or 2, the first electrode pad has a concave-convex portion, the portion where the second electrode and the first electrode pad are insulated by the insulating film is a concave portion, the width of the concave portion of the first electrode pad is more than twice the width of the second electrode, and the second electrode pad has a concave-convex portion, the portion where the first electrode and the second electrode pad are insulated by the insulating film is a concave portion, and the width of the concave portion of the second electrode pad is more than 1.2 times the width of the first electrode. 4 . The semiconductor device according to claim 1 , wherein the first electrode pad and the second electrode pad are provided on a semiconductor element region of the semiconductor element. 5 . The semiconductor device according to claim 1 , wherein the third electrode is connected to a third electrode pad via a wiring, the third electrode pad being provided on a non-semiconductor element region on the semiconductor element, and a third bonding wire is connected to the third electrode pad.

6. In the semiconductor device according to claim 1 or 2, the first electrode, the second electrode, the first electrode pad and the second electrode pad are mainly composed of Al, a first crack exists in a portion of the insulating film between the first electrode and the first electrode pad, the first electrode and the first electrode pad are connected via the first crack, a second crack exists in a portion of the insulating film between the second electrode and the second electrode pad, the second electrode and the second electrode pad are connected via the second crack.

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