JP4910304B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device in which a temperature rise is suppressed. In particular, the present invention relates to a semiconductor device that can suppress an increase in temperature by dissipating heat generated when the semiconductor device is operating to the outside of the semiconductor device.

In order to increase the reliability of the semiconductor device, it is important to suppress a temperature rise during the operation of the semiconductor device. For example, in a semiconductor device used for switching a large current, such as an in-vehicle inverter, there is a problem that the semiconductor device easily rises to an excessive temperature due to heat generated by the semiconductor device itself, and a stable operation cannot be realized. is doing.
In Patent Document 1, a trench is formed that extends from the surface of an SOI (Silicon on Insulator) substrate to both the active layer and the buried insulating layer and reaches the back substrate, and has a high thermal conductivity and conductivity. A structure is disclosed that is filled with a material that is conductive. According to the semiconductor device of Patent Document 1, heat generated when the semiconductor device is operating is transferred to the back substrate of the SOI substrate through the trench, and the temperature rise of the semiconductor device is suppressed. Furthermore, the resistance characteristics of the semiconductor device are improved by using a conductive material.
JP 11-354807 A

However, as in Patent Document 1, if a conductive material is filled as it is into a trench reaching from the surface of the active layer to the back substrate, the trench causes substantially the same potential from the surface to the back surface of the semiconductor device. For this reason, a sufficient region for holding the electric field cannot be secured, and the breakdown voltage of the semiconductor device is significantly reduced. Also, if a conductive material that extends in the thickness direction of the semiconductor substrate is embedded in a semiconductor device (vertical semiconductor device) that has main electrodes on both the front and back surfaces of the semiconductor substrate and switches the current flowing between them, the thickness of the semiconductor substrate increases. The flowing current cannot be switched.
An object of the present invention is to realize a structure capable of suppressing an increase in temperature of a semiconductor device without reducing the breakdown voltage of the semiconductor device.
The present invention is particularly effective in the case of a vertical semiconductor device. In this case, a structure capable of suppressing the temperature rise of the semiconductor device while maintaining the switch function is realized.

  The feature of the present invention is not to fill the trench with the heat conductive member as it is, but to fill the trench with the insulating film. The thermally conductive member is electrically separated from the surrounding semiconductor region by an insulating film. Therefore, the potential difference between the surrounding semiconductor region and the heat conductive member is held by the insulating film, so that a region for ensuring a withstand voltage can be formed in the surrounding semiconductor region. For this reason, even if the trench is formed, the breakdown voltage of the semiconductor device does not substantially decrease. On the other hand, the heat generated when the semiconductor device is operating can be dissipated to the surface side of the semiconductor device through the heat conductive member filled in the trench.

The semiconductor device of the present invention includes a cell region including a plurality of switching elements and provided with a trench. The semiconductor device of the present invention includes a drift semiconductor region containing a first conductivity type impurity at a low concentration, a body semiconductor region containing a second conductivity type impurity at a low concentration and in contact with the drift semiconductor region, and a first conductivity type impurity. And a plurality of emitter semiconductor regions separated from the drift semiconductor region by the body semiconductor region, and a buffer semiconductor containing the first conductivity type impurity at a high concentration and separated from the body semiconductor region by the drift semiconductor region a region, a collector semiconductor region in contact with the buffer semiconductor region with a second conductive type impurity at a high concentration, so as to face via the insulating film in the body the semiconductor region separating the drift semiconductor region and the emitter semiconductor region A plurality of gate electrodes . The back main electrode is in contact with the collector semiconductor region, and the front main electrode is in contact with the emitter semiconductor region. The emitter semiconductor region and the gate electrode are formed for each switching element. Trenches of the present invention, along with extending toward the drift semiconductor region side from the emitter semiconductor region side on the surface of the body the semiconductor region, the heat conductive member which is coated with an insulating film that has been filled. The thermal conductivity of the thermally conductive member filled in the trench is larger than the thermal conductivity of the material forming each semiconductor region and the gate electrode. Further, the trench is characterized by penetrating the body semiconductor region and the drift semiconductor region and entering the buffer semiconductor region. Furthermore, the trench is not provided for each switching element.
By making the thermal conductivity of the thermal conductive member larger than the material that forms each surrounding semiconductor region and gate electrode, the degree of heat dissipation is improved compared to the case where no trench is formed. Thus, the temperature rise of the semiconductor device can be suppressed. Furthermore, since the heat conductive member is covered with the insulating film, the breakdown voltage of the semiconductor device is not substantially reduced. Further, when a vertical semiconductor device having the above-described elements is configured, the temperature rise of the semiconductor device can be suppressed while maintaining the switch function.
The semiconductor device in this case is generally referred to as a punch-through vertical IGBT (Insulated Gate Bipolar Transistor).
Since the trench is formed up to a deep position of the semiconductor device, the heat dissipation is greatly improved.

Each semiconductor region and the gate electrode are preferably formed using silicon as a main material. Furthermore, the heat conductive member is preferably formed using aluminum (Al) or copper (Cu) as a main material.
Aluminum or copper is a material having a higher thermal conductivity than silicon, and can suppress an increase in temperature of the semiconductor device. Furthermore, aluminum or copper is also a material that can be easily filled in the trench, and is preferable in terms of easy manufacture.

The heat conductive member is preferably conductive and in contact with the surface main electrode.
By fixing the thermally conductive member to the same potential as the surface main electrode, the pn junction surface of the drift semiconductor region and the body semiconductor region with respect to the inside of the body semiconductor region adjacent to the trench when the semiconductor device is turned off Thus, the depletion layer can be effectively extended. Since the trench is entering the buffer semiconductor region through the body the semiconductor region and the drift semiconductor region when the semiconductor device is turned off, against drift semiconductor region adjacent to the trench, and the drift semiconductor region The depletion layer can be effectively extended from the pn junction surface of the body semiconductor region, and substantially complete depletion of the drift semiconductor region can be easily achieved. Therefore, the breakdown voltage of the semiconductor device can be improved. The breakdown voltage of the semiconductor device can be improved and the temperature rise of the semiconductor device can be suppressed.

It is preferable that the trench is also formed in the termination region located around the cell region in which the gate electrode is formed.
The temperature rise in the termination region can be suppressed, and the reliability of the semiconductor device can be improved.

  According to the present invention, by filling the trench with the thermally conductive member covered with the insulator, it is possible to suppress an increase in the temperature of the semiconductor device without lowering the breakdown voltage of the semiconductor device. The present invention is particularly effective in the case of a vertical semiconductor device. In this case, it is possible to obtain a structure in which the temperature rise of the semiconductor device is suppressed while maintaining the switch function.

The main features of the examples are listed.
(1st form) The planar pattern of the trench for thermal radiation can utilize stripe shape, lattice shape, or dot shape.
(2nd form) Silver, copper, gold | metal | money, aluminum, magnesium, tungsten etc. can be utilized for a heat conductive member. In consideration of workability, corrosion resistance, mechanical strength, and cost, it is preferable to use copper or aluminum.
(3rd form) It is preferable to comprise so that a heat conductive member is electroconductivity and a grounding potential or a negative potential is applied when a semiconductor device turns off.
(Fourth Mode) The first semiconductor region is a region that ensures a breakdown voltage by forming a depletion region when the semiconductor device is turned off. In general, the first semiconductor region is a region having a low impurity concentration, but a super junction structure may be employed as necessary.

FIG. 1 schematically shows a longitudinal sectional view of a main part of the semiconductor device 10. The semiconductor device 10 is a punch-through vertical IGBT that performs bipolar operation.
The semiconductor device 10 includes an n ⁻ type drift region 26 (an example of a first semiconductor region). A p ⁻ type body region 28 (an example of a second semiconductor region) is formed in contact with the surface of drift region 26. On the surface portion of the body region 28, a plurality of n ⁺ -type emitter regions 36 (an example of a third semiconductor region) and a plurality of p ⁺ -type body contact regions 39 are selectively formed. The emitter region 36 and the body contact region 39 are separated from the drift region 26 by the body region 28. The emitter region 36 and the body contact region 39 are in contact with an emitter electrode 52 (an example of a surface main electrode) made of aluminum. A gate electrode 34 is opposed to a body region 28 that separates the drift region 26 and the emitter region 36 through a gate insulating film 32 made of silicon oxide. The gate electrode 34 has a planar pattern formed in a stripe shape when viewed in plan. The gate electrode 34 and the emitter electrode 52 are separated by an interlayer insulating film 38.
On the surface of the emitter electrode 52, a nickel layer 54, a gold thin layer 56, a solder layer 57, and a heat sink 58 are laminated. The heat sink 58 is connected to an emitter electrode terminal (not shown). Furthermore, the heat sink 58 is in contact with a cooling device (not shown) (for example, a water cooling device).
The nickel layer 54, the gold thin layer 56, the solder layer 57, and the heat sink 58 are not constituent elements of the semiconductor device 10, but are required when the semiconductor device 10 is mounted on, for example, an in-vehicle inverter device. Note that it is another member.

An n ⁺ -type buffer region 24 (an example of a fourth semiconductor region) is formed in contact with the back surface of the drift region 26. The buffer region 24 is separated from the body region 28 by the drift region 26. A p ⁺ -type collector region 22 (an example of a fifth region) is formed in contact with the back surface of the buffer region 24. The collector region 22 is separated from the drift region 26 by the buffer region 24. The collector region 22 may be formed so as to be in contact with the drift region 26. In this case, for example, the buffer region 24 is formed in a dispersed state, and the collector region 22 and the drift region 26 are in contact with each other using the adjacent buffer region 24 (generally referred to as a collector short type). You can also. A collector electrode 21 (an example of a back main electrode) made of aluminum is formed on the back surface of the collector region 22.

The semiconductor device 10 further includes a heat radiation trench 40 that penetrates the body region 28 and the drift region 26 and enters the buffer region 24 from the surface of the body region 28 on the emitter region 36 side. A heat conductive member 44 covered with a trench insulating film 42 is filled in the heat radiation trench 40. The thermally conductive member 44 is made of aluminum and is integral with the emitter electrode 52. The heat radiation trench 40 has a planar pattern formed in a stripe shape when viewed in plan.
The collector region 22, the buffer region 24, the drift region 26, the body region 28, the emitter region 36, and the body contact region 39 are formed using single crystal silicon, and the gate electrode 34 is formed using polycrystalline silicon. Yes. Since the heat conductive member 44 of the heat radiating trench 40 is formed using aluminum, the heat conductivity of the heat conductive member 44 is larger than the heat conductivity of each semiconductor region and the gate electrode 34.

Next, the operation of the semiconductor device 10 will be described.
When a positive voltage is applied to the collector electrode 21, the emitter electrode 52 is grounded, and a gate-on voltage is applied to the gate electrode 34, the semiconductor device 10 is turned on. When the semiconductor device 10 is turned on, an inversion layer is formed in the body region 28 opposed to the gate electrode 34, and electrons are injected from the emitter region 36 into the drift region 26 through the inversion layer. At the same time, holes are injected from the collector region 22 into the drift region 26 via the buffer region 24. Conductivity modulation occurs due to electrons injected from the emitter region 36 and holes injected from the collector region 22, and the semiconductor device 10 operates at a low on-voltage.

When the semiconductor device 10 is operating, heat is generated in the semiconductor device 10. In particular, a large amount of heat is generated in the drift region 26 where conduction modulation is activated, particularly in the vicinity of the pn junction surface 27 of the body region 28 and the drift region 26. If the temperature of the semiconductor device 10 rises excessively due to this heat, the operation of the semiconductor device 10 becomes unstable.
In the semiconductor device 10, the generated heat is transferred to the surface side of the semiconductor device 10 through the heat conductive member 44 of the heat radiation trench 40. The heat transferred to the surface side is radiated to a cooling device (not shown) via the emitter electrode 52, the nickel layer 54, the thin gold layer 56, the solder layer 57, and the heat radiating plate 58. For this reason, the semiconductor device 10 suppresses an increase in temperature and realizes a stable operation.
In the semiconductor device 10, since the heat radiation trench 40 is formed beyond the pn junction interface 27 between the drift region 26 and the body region 28, the heat generated at the pn junction interface 27 can be effectively used for the semiconductor device 10. Heat can be transferred to the surface side. The temperature rise of the semiconductor device 10 can be effectively suppressed.

When the gate-on voltage is turned off, the semiconductor device 10 is turned off. When the semiconductor device 10 is turned off, a depletion layer is formed from the pn junction interface 27 between the drift region 26 and the body region 28 toward the drift region 26. At this time, since the heat conductive member 44 of the heat radiation trench 40 is fixed to the ground potential, the depletion layer is effectively extended from the pn junction interface 27 between the drift region 26 and the body region 28 into the drift region 26. And substantially complete depletion of the drift region 26 can be easily achieved. Therefore, the breakdown voltage of the semiconductor device 10 can be improved. Note that when the equivalent breakdown voltage is ensured, the impurity concentration of the drift region 26 can be increased, so that it can be said that the on-voltage can be reduced by providing the heat radiation trench 40.
Further, the heat radiation trench 40 penetrates into the buffer region 24. Progress of the depletion layer extending from the pn junction interface 27 between the drift region 26 and the body region 28 is stopped by the interface 25 between the drift region 26 and the buffer region 24. Therefore, by allowing the heat radiation trench 40 to penetrate into the buffer region 24, the depletion layer is reliably prevented from proceeding to the corner 41 on the bottom surface of the heat radiation trench 40. If the corner 41 on the bottom surface of the heat radiating trench 40 is present in the drift region 26, there is a concern that the electric field is excessively concentrated in the corner 41. Neither will happen.
That is, the heat dissipation trench 40 can suppress the temperature rise of the semiconductor device 10 and can also improve the breakdown voltage of the semiconductor device 10.

(Manufacturing method of the semiconductor device 10)
Next, a method for manufacturing the semiconductor device 10 will be described with reference to FIGS.
First, as shown in FIG. 2, a semiconductor substrate in which a collector region 22, a buffer region 24, and a drift region 26 are stacked is prepared.
Next, the body region 28 is formed on the surface of the drift region 26 using an ion implantation technique and a thermal diffusion technique.

  Next, as shown in FIG. 3, after forming a mask (not shown) on the surface of the body region 28, the emitter region 36 and the body contact region 39 are formed using a lithography technique, an ion implantation technique, and a thermal diffusion technique. Selectively form. Next, using a reactive ion etching (RIE) technique, a trench reaching the drift region 26 from the surface of the body region 28 is formed, and the gate electrode 34 is formed. Specifically, after the trench is formed, the sidewall of the trench is thermally oxidized to form the gate oxide film 32, and then the polysilicon is filled into the trench by using a CVD (Chemical Vapor Deposition) method. To do. An interlayer insulating film 38 is formed so as to cover the surface of the gate electrode 34.

  Next, as shown in FIG. 4, a mask film 62 made of silicon oxide is formed on the surface of the body region 28 using the CVD method. The mask film 62 is patterned using a lithography technique and a dry etching technique to form an opening 63.

Next, as shown in FIG. 5, a trench 46 reaching from the body region 28 exposed in the opening 63 to the buffer region 24 is formed by using a dry etching technique using a high-speed dry etching apparatus. As will be described later, the trench 46 needs to be filled with a heat conductive member, so that the width 47 is formed relatively wide. For example, it is formed wider than the width 37 of the gate electrode 34.
Further, when the trench 46 is formed by dry etching, the mask film 62 is also removed although the etching speed is slow. If the thickness of the mask film 62 is adjusted in advance in consideration of the etching speed at which the trench 46 is formed and the etching speed at which the mask film 62 is removed, the timing at which the trench 46 is formed and the mask film 62 The removal timing can be matched. In this case, the process for removing the mask film 62 can be omitted, and the number of manufacturing processes can be reduced.

  Next, as shown in FIG. 6, a trench insulating film 42 is formed on the side wall that defines the trench 46 by using a thermal oxidation technique. The trench insulating film 42 formed on the surfaces of the emitter region 36 and the body contact region 39 is removed using a dry etching technique.

Next, as shown in FIG. 7, the trench 46 is filled with a heat conductive member 44 made of aluminum by using a CVD method or a sputtering method. At this time, the CVD method or the sputtering method is performed until the surface of the body region 28 is covered after the heat conductive member 44 is filled in the trench 46, thereby continuously connecting the heat radiation trench 40 and the emitter electrode 52. Can be formed.
The semiconductor device 10 can be obtained through these steps.

The heat conductive member 44 may be made of copper instead of aluminum. Since copper has a property of easily diffusing into single crystal silicon and silicon oxide, when copper is used for the heat conductive member 44, as shown in FIG. 8, after the trench insulating film 42 is formed, a sputtering method is used. It is preferable to form the barrier metal film 48 for preventing the diffusion of copper using the above. As the barrier metal film 48, for example, tantalum (Ta), tantalum nitride (TaN), silicon tantalum nitride (TaSiN), silicon tungsten nitride (WSiN), or tungsten nitride (WN ₂ ) can be suitably used.
Copper can also be filled into the trenches using CVD or sputtering. Further, the CVD method or the sputtering method at this time is also carried out until the surface of the body region 28 is covered after the thermal conductive member 44 made of copper is filled in the trench, thereby the heat dissipation trench 40 and The emitter electrode 53 made of copper can be formed continuously.

When the semiconductor device 10 is mounted on, for example, an in-vehicle inverter device, the following process is further performed.
As shown in FIG. 1, a nickel layer 54 containing nickel as a main component is formed using an electroless plating method or the like. Next, in order to ensure wettability, a gold thin layer 56 containing gold as a main component is formed on the surface of the nickel layer 54 using an electroless plating method or the like.
Next, the heat radiating plate 58 is prepared, and the heat radiating plate 58 and the gold thin layer 56 are bonded via the solder layer 57.
Through these steps, the semiconductor device 10 can be mounted on, for example, an in-vehicle inverter device.

(First modification)
FIG. 9 schematically shows a cross-sectional view of the main part of the semiconductor device 100. FIG. 9 shows the boundary between the cell region 12 where the semiconductor switching element group is formed and the termination region 14 where the semiconductor switching element group is not formed. The basic structure of the cell region 12 of the semiconductor device 100 is the same as that of the semiconductor device 10 described above. However, the heat radiation trench 40 is not formed in the cell region 12. Note that the same number is assigned to a semiconductor region having the same function as the semiconductor region of the semiconductor device 10, and the description thereof is omitted.
In the semiconductor device 100 shown in FIG. 9, a termination side heat radiation trench 70 corresponding to the heat radiation trench 40 of the semiconductor device 10 is formed only in the termination region 14. By providing the termination-side heat dissipation trench 70 in the termination region 14, the temperature rise in the termination region 14 can be suppressed, and the reliability of the semiconductor device 100 can be improved.
Further, similarly, the termination side heat radiation trench 70 promotes substantially complete depletion of the drift region 26 when the semiconductor device 100 is turned off. Therefore, the breakdown voltage of the termination region 14 can be improved. In addition, it can be said that the area of the termination | terminus area | region 14 can be made small when ensuring an equivalent pressure | voltage resistance. Therefore, the entire area of the semiconductor device 100 can be reduced, and the number of chips obtained for each wafer can be increased. Manufacturing costs can be reduced.

  Note that the heat radiation trench 40 of the semiconductor device 10 and the terminal heat radiation trench 70 of the semiconductor device 100 may be provided simultaneously in one semiconductor device. As described above, the characteristics can be improved in both the cell region and the termination region. In addition, since the heat radiation trenches in the cell region and the termination region can have the same structure, they can be manufactured in the same manufacturing process.

(Second modification)
FIG. 10 schematically shows a cross-sectional view of the main part of the semiconductor device 110. The semiconductor device 110 is a punch-through lateral IGBT that operates in a bipolar manner. Note that the same number is assigned to a semiconductor region having the same function as the semiconductor region of the semiconductor device 10, and the description thereof is omitted.
Also in this case, similarly to the semiconductor device 10 of the first embodiment, by providing the heat radiation trench 40, the drift region 26 in which conduction modulation is activated, in particular, the pn junction surface 27 between the body region 28 and the drift region 26 is provided. Heat generated in the vicinity can be transferred to the surface side of the semiconductor device 10 through the heat conductive member 44 of the heat radiating trench 40. The heat transferred to the surface side is radiated to a cooling device (not shown) via the emitter electrode 52, the nickel layer 54, the thin gold layer 56, the solder layer 57, and the heat radiating plate 58. The semiconductor device 10 suppresses a rise in temperature and realizes a stable operation.
Furthermore, when the semiconductor device 110 is turned off, a depletion layer can be effectively extended from the pn junction interface 27 between the drift region 26 and the body region 28 into the drift region 26, thereby substantially depleting the drift region 26. Can be easily achieved. Therefore, the breakdown voltage of the semiconductor device 110 can be improved.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In the above embodiment, an example of a vertical IGBT has been described. However, it is useful to apply the technology of the present invention to other semiconductor devices such as MOSFETs and thyristors.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The principal part sectional drawing of the semiconductor device of 1st Example is typically shown. The manufacturing process of the semiconductor device of 1st Example is shown (1). The manufacturing process of the semiconductor device of 1st Example is shown (2). The manufacturing process of the semiconductor device of 1st Example is shown (3). The manufacturing process of the semiconductor device of 1st Example is shown (4). The manufacturing process of the semiconductor device of 1st Example is shown (5). The manufacturing process of the semiconductor device of 1st Example is shown (6). The manufacturing process of the modification of the semiconductor device of 1st Example is shown. Sectional drawing of the principal part of the modification of the semiconductor device of 1st Example is shown. Sectional drawing of the principal part of the semiconductor device of 2nd Example is shown.

Explanation of symbols

21: collector electrode 22: collector region 24: buffer region 26: drift region 28: body region 32: gate insulating film 34: gate electrode 36: emitter electrode 38: interlayer insulating film 39: body contact region 40: heat dissipation trench 42: Trench insulating film 44: thermal conductive member 48: barrier metal layers 52, 53: emitter electrode 54: nickel layer 56: thin gold layer 57: solder layer 58: heat sink

Claims (5)

A semiconductor device including a cell region including a plurality of switching elements and provided with a trench,
A drift semiconductor region containing a first conductivity type impurity in a low concentration;
A body semiconductor region containing a second conductivity type impurity in a low concentration and in contact with the drift semiconductor region;
A plurality of emitter semiconductor regions containing a high concentration of the first conductivity type impurity and separated from the drift semiconductor region by the body semiconductor region;
A buffer semiconductor region containing a high concentration of the first conductivity type impurity and separated from the body semiconductor region by the drift semiconductor region;
A collector semiconductor region containing the second conductivity type impurity in a high concentration and in contact with the buffer semiconductor region;
A plurality of gate electrodes facing the body semiconductor region separating the drift semiconductor region and the emitter semiconductor region via an insulating film;
A back main electrode in contact with the collector semiconductor region;
A main surface electrode in contact with the emitter semiconductor region ,
The emitter semiconductor region and the gate electrode are formed for each switching element,
The trench is filled with a thermally conductive member extending from the surface of the body semiconductor region on the emitter semiconductor region side toward the drift semiconductor region side and covered with an insulating film ,
The thermal conductivity of the thermally conductive member is greater than the thermal conductivity of the material forming each semiconductor region and the gate electrode,
The trench penetrates the buffer semiconductor region through the body semiconductor region and the drift semiconductor region ,
The semiconductor device is characterized in that the trench is not provided for each switching element . Each semiconductor region and the gate electrode are formed using silicon as a main material,
2. The semiconductor device according to claim 1, wherein the heat conductive member is formed using aluminum (Al) or copper (Cu) as a main material.   3. The semiconductor device according to claim 1, wherein the heat conductive member is conductive and is in contact with the surface main electrode.   4. The semiconductor device according to claim 1, wherein the trench is also formed in a terminal region located around a cell region in which a gate electrode is formed. A semiconductor device comprising a cell region including a plurality of switching elements, and having a trench provided in the cell region,
A drift semiconductor region containing a first conductivity type impurity in a low concentration;
A body semiconductor region containing a second conductivity type impurity in a low concentration and in contact with the drift semiconductor region;
A plurality of emitter semiconductor regions containing a high concentration of the first conductivity type impurity and separated from the drift semiconductor region by the body semiconductor region;
A buffer semiconductor region containing a high concentration of the first conductivity type impurity and separated from the body semiconductor region by the drift semiconductor region;
A collector semiconductor region containing the second conductivity type impurity in a high concentration and in contact with the buffer semiconductor region;
A plurality of gate electrodes facing the body semiconductor region separating the drift semiconductor region and the emitter semiconductor region via an insulating film;
A back main electrode in contact with the collector semiconductor region;
A main surface electrode in contact with the emitter semiconductor region,
The emitter semiconductor region and the gate electrode are formed for each switching element,
The trench is filled with a thermally conductive member extending from the surface of the body semiconductor region on the emitter semiconductor region side toward the drift semiconductor region side and covered with an insulating film,
The thermal conductivity of the thermally conductive member is greater than the thermal conductivity of the material forming each semiconductor region and the gate electrode,
The semiconductor device is characterized in that the trench is not provided for each switching element.

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