Semiconductor device

Abstract

A semiconductor device includes: a semiconductor substrate having a first surface on which a first electrode is disposed; a first semiconductor region of a first conductivity type disposed on the second surface of the semiconductor substrate; a plurality of second semiconductor regions of a second conductivity type disposed on the first semiconductor region and extending in the first direction; a third semiconductor region of the second conductivity type disposed on the first semiconductor region, the third semiconductor region defining a portion of a trench extending in a second direction traversing the first direction; a second electrode disposed in the trench; a first insulating film disposed in the trench and between a sidewall of the third semiconductor region defining the portion of the trench and the second electrode; and a fourth semiconductor region of the first conductivity type disposed on the third semiconductor region.

Description

[0001] Related Applications

[0002] This application claims the benefit of Japanese Priority Patent Application JP 2022-134837 filed on Aug. 26, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a semiconductor device. Background Art

[0004] In recent years, in order to cope with more various applications, there has been an increasing demand for high breakdown voltage transistors that can handle large currents.

[0005] For example, the following PTL1 discloses a trench transistor having a drift layer between a channel formed on the side of a gate electrode vertically embedded from the front side and a drain provided on the back side. The trench transistor disclosed in PTL1 can have a depletion layer in the thickness direction of the semiconductor substrate, so that a high withstand voltage can be achieved.

[0006] Reference List

[0007] Patent Literature

[0008] PTL 1: JP 2010-258328A Summary of the invention

[0009] Technical issues

[0010] However, in the trench transistor disclosed in the above-mentioned PTL 1, there is a possibility that a high electric field is applied to a gate insulating film provided on the bottom surface of the gate electrode embedded in the vertical direction, thereby destroying the gate insulating film.

[0011] Therefore, in trench transistors, the reliability against high electric fields may need to be further improved.

[0012] Solution to the problem

[0013] According to the present disclosure, a semiconductor device is provided, comprising: a semiconductor substrate having a first surface on which a first electrode is arranged; a first semiconductor region; a plurality of second semiconductor regions of a first conductivity type arranged on the second surface of the semiconductor substrate, a plurality of second semiconductor regions of a second conductivity type arranged on the first semiconductor region and extending along a first direction, a third semiconductor region of a second conductivity type arranged on the first semiconductor region, the third semiconductor region defining a portion of a groove extending along a second direction across the first direction, a second electrode arranged in the groove; a first insulating film arranged in the groove and between the sidewall of the third semiconductor region defining the portion of the groove and the second electrode; and a fourth semiconductor region arranged on the third semiconductor region, the first conductivity type, wherein the first portion of the second electrode has a first depth shallower than a second depth of the second portion of the second electrode, and the second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode. A vehicle control system is also provided, which includes an electronic controller, which includes a semiconductor device, wherein the semiconductor device includes: a semiconductor substrate, which has a first surface, on which a first electrode is arranged; a first semiconductor region of a first conductivity type, which is arranged on a second surface of the semiconductor substrate; a plurality of second semiconductor regions of a second conductivity type, which are arranged on the first semiconductor region and extend along a first direction; a third semiconductor region of the second conductivity type, which is arranged on the first semiconductor region, and which defines a portion of a groove extending along a second direction transverse to the first direction; a second electrode, which is arranged in the groove; a first insulating film, which is arranged in the groove and between the sidewall of the third semiconductor region defining the portion of the groove and the second electrode; and a fourth semiconductor region of the first conductivity type, which is arranged on the third semiconductor region, wherein

[0014] The first portion of the second electrode has a first depth that is shallower than a second depth of the second portion of the second electrode, and the second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a semiconductor device according to a first configuration example.

[0016] Figure 2 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a semiconductor device according to a second configuration example.

[0017] Figure 3A are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0018] Figure 3B are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0019] Figure 3C are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0020] Figure 3D are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0021] Figure 3E are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0022] Figure 3F are explanatory diagrams showing steps of a method for manufacturing a semiconductor device according to a second configuration example.

[0023] Figure 4 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a modification of the semiconductor device according to the first configuration example.

[0024] Figure 5 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a modification of the semiconductor device according to the second configuration example.

[0025] Figure 6 is a block diagram showing an embodiment of a schematic configuration of a vehicle control system.

[0026] Figure 7 It is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection portion and the imaging unit. DETAILED DESCRIPTION

[0027] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0028] Note that the description will be given in the following order.

[0029] 1. Implementation Method

[0030] 1.1. First configuration embodiment

[0031] 1.2. Second configuration example

[0032] 1.3. Manufacturing method

[0033] 1.4. Modifications

[0034] 2. Application Examples

[0035] <1. Implementation Method>

[0036] (1.1. First Configuration Example)

[0037] First, refer to Figure 1 A first configuration example of a semiconductor device according to an embodiment of the present disclosure is described. Figure 1 1 and 2 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a semiconductor device 1 according to a first configuration example. Figure 1 The middle left, lower left and upper right cross-sectional views respectively show cross sections taken along the line AA, BB or CC described in the upper left plan view.

[0038] like Figure 1 As shown, the semiconductor device 1 includes a first electrode 110, a semiconductor substrate 120, a first semiconductor region 130, a second semiconductor region 131, a third semiconductor region 140, a second electrode 151, a first insulating film 152, a fourth semiconductor region 160, and a third electrode 170. The semiconductor device 1 is a vertical metal oxide semiconductor field effect transistor (MOSFET) having a so-called trench structure.

[0039] exist Figure 1 In the upper left plan view of FIG. 1 , the first electrode 110 , the semiconductor substrate 120 , the first semiconductor region 130 , the third semiconductor region 140 , and the third electrode 170 are omitted in order to clarify the arrangement of other configurations.

[0040] Hereinafter, “first conductivity type” means one of “p type” and “n type”, and “second conductivity type” means the other of “p type” and “n type” different from the “first conductivity type”.

[0041] The first electrode 110 includes a conductive material and is disposed on a first main surface of the semiconductor substrate 120. The first electrode 110 serves as a drain electrode of the vertical MOSFET by being electrically connected to the semiconductor substrate 120 via an ohmic junction, etc. For example, the first electrode 110 may include copper (Cu), nickel (Ni), aluminum (Al), titanium (Ti), tantalum (Ta), tungsten (W), gold (Au), silver (Ag), or a combination of these metals.

[0042] The semiconductor substrate 120 is a substrate including a semiconductor material of a first conductivity type. For example, the semiconductor substrate 120 may be n + type SiC substrate. Note that the thickness of the semiconductor substrate 120 may be 100 μm to 350 μm. The concentration of the first conductive type impurity (eg, nitrogen (N) or phosphorus (P)) of the semiconductor substrate 120 may be approximately 1.0×10 18 cm -3Up to 3.0×10 19 cm -3 .

[0043] The first semiconductor region 130 includes a semiconductor material of a first conductivity type and is disposed on an upper surface of the semiconductor substrate 120. For example, the first semiconductor region 130 may include n - The concentration of the first conductive type impurity (e.g., nitrogen (N) or phosphorus (P)) in the first semiconductor region 130 may be about 5.0×10 15 cm -3 to 1.2×10 16 cm -3 .

[0044] The second semiconductor region 131 includes a semiconductor material of a second conductivity type, and a plurality of second semiconductor regions are arranged in a first direction (for example, when viewed from the front) Figure 1 The second semiconductor region 131 is provided in a strip shape extending in the first direction in parallel with each other in the first semiconductor region 130. With this arrangement, at the depth where the second semiconductor region 131 is provided, the second semiconductor region 131 and the first semiconductor region 130 are in a second direction orthogonal to the first direction (for example, when viewed from the front). Figure 1 The second semiconductor region 131 is alternately arranged in a strip shape (in a vertical direction when the second semiconductor region 131 is in ...

[0045] Since the second semiconductor region 131 is of the second conductivity type, a high electric field can be prevented from being applied to the region near the first insulating film 152. In addition, a depletion layer extending from the second semiconductor region 131 is formed in the first semiconductor region 130 existing between the second semiconductor regions 131. Therefore, by utilizing the depletion layer, the second semiconductor region 131 can prevent a high electric field from being applied even to a non-nearby region, which is a region other than the region near the first insulating film 152. Therefore, the second semiconductor region 131 can suppress the first insulating film 152 from being damaged due to the high electric field.

[0046] The concentration of the second conductive type impurity (e.g., aluminum (Al)) in the second semiconductor region 131 is set so that the first semiconductor region 130 present between the second semiconductor regions 131 is not completely depleted by the voltage applied to the first electrode 110 during normal operation. For example, the concentration of the second conductive type impurity in the second semiconductor region 131 may be set to about 1.0×10 18 cm-3 Up to 3.0×10 19 cm -3 With this arrangement, even when the depletion layer diffuses from the second semiconductor region 131 , the first semiconductor region 130 can ensure a current path passing between the second semiconductor region 131 in the first semiconductor region 130 .

[0047] The third semiconductor region 140 includes a semiconductor material of the second conductivity type and is disposed on the first semiconductor region 130. For example, the third semiconductor region 140 may include p-type SiC. The concentration of the second conductivity type impurity (e.g., aluminum (Al)) in the third semiconductor region 140 may be about 1.0×10 16 cm -3 Up to 5.0×10 17 cm -3 .

[0048] The second electrode 151 includes a conductive material and is provided to the third semiconductor region 140 as a trench-type electrode embedded from the third semiconductor region 140. Specifically, the second electrode 151 may be provided to be embedded in a trench provided in the third semiconductor region 140 in a second direction orthogonal to the first direction (e.g., when viewed from the front). Figure 1 For example, the second electrode 151 may include polysilicon introduced with conductive type impurities. The second electrode 151 may be used as a gate electrode of the semiconductor device 1.

[0049] The second electrode 151 is embedded in a region near the second semiconductor region 131 so as to reach the first semiconductor region 130, and is embedded to a shallower depth and does not reach the first semiconductor region 130 in a region not near the second semiconductor region 131. More specifically, the second electrode 151 may be embedded in a region near just above the second semiconductor region 131 so as to reach the first semiconductor region 130, and may be embedded to a shallower depth and does not reach the first semiconductor region 130 in a region other than the region near just above the second semiconductor region 131. For example, in order not to form an inversion layer in the third semiconductor region 140 on the side, the second electrode 151 in the non-nearby region may be embedded to a depth similar to the depth at which the fourth semiconductor region 160 is provided. With this arrangement, the second electrode 151 is provided so that the extended cross section in the second direction has a comb-tooth shape.

[0050] The first insulating film 152 includes an insulating material and is disposed between the side of the trench where the second electrode 151 is disposed and the second electrode 151. Specifically, the first insulating film 152 may extend in the second direction between the side and bottom of the trench and the second electrode 151 and be embedded in the third semiconductor region 140. For example, the first insulating film 152 may include silicon oxide (SiO x ).

[0051] In a region near the second semiconductor region 131, the first insulating film 152 may be embedded to a depth in contact with the second semiconductor region 131, so as to more effectively obtain the effect of blocking the electric field by the second semiconductor region 131. In addition, in a region not near the second semiconductor region 131, the first insulating film 152 may be embedded to the same depth as that of the region near the second semiconductor region, so as to simplify the manufacturing process.

[0052] The fourth semiconductor region 160 is a semiconductor region of the first conductivity type and is disposed in the third semiconductor region 140. Specifically, the fourth semiconductor region 160 may be disposed in the third semiconductor region 140 on both sides of the second electrode 151 to sandwich a groove extending in a second direction orthogonal to the first direction. More specifically, the fourth semiconductor region 160 may extend in the second direction on the upper surface of the third semiconductor region 140 while sandwiching a groove extending in the second direction orthogonal to the first direction. For example, the fourth semiconductor region 160 may be n + The concentration of the first conductive type impurity (eg, nitrogen (N) or phosphorus (P)) in the fourth semiconductor region 160 may be approximately 7.0×10 18 cm -3 to 7.0×10 19 cm -3 .

[0053] The third electrode 170 includes a conductive material and is disposed on the third semiconductor region 140. The third electrode 170 serves as a source electrode of the vertical MOSFET by being electrically connected to the fourth semiconductor region 160 via an ohmic junction, etc. The third electrode 170 may include, for example, copper (Cu), nickel (Ni), aluminum (Al), titanium (Ti), tantalum (Ta), tungsten (W), gold (Au), silver (Ag), or a combination of these metals.

[0054] In the semiconductor device 1, when a voltage is applied to the second electrode 151 to turn on, an inversion layer is formed in the third semiconductor region 140 on the side of the second electrode 151, and a channel serving as a current path is formed. With this arrangement, since the fourth semiconductor region 160 and the first semiconductor region 130 are electrically connected to each other, the semiconductor device 1 can flow current between the third electrode 170 and the first electrode 110. On the other hand, in the semiconductor device 1, the application of voltage to the second electrode 151 is stopped and turned off, so that the channel formed in the third semiconductor region 140 on the side of the second electrode 151 is lost. With this arrangement, since the fourth semiconductor region 160 and the first semiconductor region 130 are non-conductive, the semiconductor device 1 can stop the flow of current between the third electrode 170 and the first electrode 110.

[0055] The semiconductor device 1 according to the present embodiment can prevent a high electric field from being applied to the first insulating film 152 by providing the second semiconductor region 131 in a region near the first insulating film 152 provided between the trench and the second electrode 151. Furthermore, in the semiconductor device 1, when the second semiconductor region 131 and the second electrode 151 extend in directions orthogonal to each other, the second electrode 151 can be more easily positioned in a region near the second semiconductor region 131.

[0056] Furthermore, in the semiconductor device 1 according to the present embodiment, the embedding depth of the second electrode 151 in the region not near the second semiconductor region 131 is configured to be shallower than the embedding depth of the second electrode 151 in the region near the second semiconductor region. With this arrangement, since the semiconductor device 1 can reduce the volume between the second electrode 151 and the first electrode 110 in the non-nearby region, the switching characteristics can be further improved.

[0057] In addition, in the semiconductor device 1, the second electrode 151 is configured so that a channel is not formed in a region not near the second semiconductor region 131. With this arrangement, the semiconductor device 1 can reduce the amount of saturation current at the time of failure. In addition, since the semiconductor device 1 can avoid applying a voltage to the first insulating film 152 in a non-nearby region, the withstand voltage of the first insulating film 152 can be further improved.

[0058] (1.2. Second Configuration Example)

[0059] Next, we will refer to Figure 2 A second configuration example of the semiconductor device according to the present embodiment is described. Figure 2 2 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a semiconductor device 2 according to a second configuration example. Figure 2The middle left, lower left and upper right cross-sectional views respectively show cross sections taken along the line AA, BB or CC described in the upper left plan view.

[0060] like Figure 2 As shown, the semiconductor device 2 is arranged so that the ratio of the thickness of the first semiconductor region 130 and the third semiconductor region 140 is different between a region near the second semiconductor region 131 and a region not near the second semiconductor region 131. With this arrangement, the semiconductor device 2 can form an inversion layer and a channel in the third semiconductor region 140 on the side of the second electrode 151 even in a region not near the second semiconductor region 131.

[0061] Specifically, the first semiconductor region 130 is set to be thicker in a region not near the second semiconductor region 131 than in a region near the second semiconductor region, and the third semiconductor region 140 is set to be thinner in a non-near region than in a near region thereof. That is, the interface between the first semiconductor region 130 and the third semiconductor region 140 has a periodic protrusion-recess shape in the second direction in a region near the second semiconductor region 131 and a region not near the second semiconductor region 131.

[0062] With this arrangement, the second electrode 151 in the non-nearby region, which is set so that the embedding depth is shallower than the embedding depth in the nearby region, can reach the first semiconductor region 130. Therefore, the second electrode 151 in the non-nearby region can form an inversion layer in the third semiconductor region 140 on the side by voltage application to form a channel serving as a current path between the fourth semiconductor region 160 and the first semiconductor region 130.

[0063] The semiconductor device 2 according to the second configuration example can have a channel serving as a current path not only in a region near the second semiconductor region 131 but also in a region not near the second semiconductor region, so that the on-resistance can be further reduced.

[0064] (1.3. Manufacturing method)

[0065] Next, we will refer to FIG. 3A to FIG. 3F A method of manufacturing the semiconductor device 2 according to the second configuration example is described. FIG. 3A to FIG. 3F 2 are explanatory diagrams showing steps of a method for manufacturing the semiconductor device 2 according to the second configuration example. FIG. 3A to FIG. 3F The middle left, lower left and upper right cross-sectional views respectively show cross sections taken along the line AA, BB or CC described in the upper left plan view.

[0066] like Figure 3AAs shown, first, SiC is deposited on the second main surface of the semiconductor substrate 120 using a chemical vapor deposition (CVD) method while introducing nitrogen (N) serving as a first conductive type impurity, thereby forming the first semiconductor region 130. For example, n formed by a sublimation method may be used. + A type SiC substrate is used as the semiconductor substrate 120 .

[0067] Next, if Figure 3B As shown, aluminum (Al) serving as a second conductive type impurity is introduced into the first semiconductor region 130 at about 200 nm to 500 nm using ion implantation, and then annealing is performed at about 1800° C. for several hours, thereby forming the second semiconductor region 131 in the first semiconductor region 130. For example, the plurality of second semiconductor regions 131 may be formed in a strip shape so as to be parallel to each other in a first direction (for example, when viewed from the front) Figure 3B The left-right direction when the

[0068] Then, if Figure 3C As shown, SiC is deposited on the second semiconductor region 131 using a CVD method while nitrogen (N) serving as a first conductive type impurity is introduced, thereby further forming the first semiconductor region 130 .

[0069] Afterwards, if Figure 3D As shown, aluminum (Al) serving as a second conductive type impurity is introduced into the upper portion of the first semiconductor region 130 by ion implantation, and then annealing is performed at about 1800° C. for several hours, thereby converting the upper portion of the first semiconductor region 130 into the third semiconductor region 140 .

[0070] At this time, the ratio of the thickness of the first semiconductor region 130 to the third semiconductor region 140 can be changed by changing the implantation depth of the second conductive type impurity between the region near the second semiconductor region 131 and the region not near the second semiconductor region 131. For example, the third semiconductor region 140 can be formed so that the region near the second semiconductor region 131 has a greater thickness than the non-nearby region.

[0071] Then, if Figure 3E As shown, the trenches formed by etching the third semiconductor region 140 and the first semiconductor region 130 are surface oxidized and then filled with polysilicon introduced with conductive type impurities, thereby forming the first insulating film 152 and the second electrode 151 .

[0072] Specifically, first, by using a hard mask to form a second direction (for example, when viewed from the front side) Figure 3EThe third semiconductor region 140 and the first semiconductor region 130 are etched in the region extending in the vertical direction (in the vertical direction) until the second semiconductor region 131 is exposed to form a trench. Next, the trench in the region not near the second semiconductor region 131 is partially filled with silicon oxide (SiO x ) after which the embedded SiO x The interface between the third semiconductor region 140 and the first semiconductor region 130 is etched to a desired height. Next, after oxidizing the SiC on the bottom and side surfaces of the trench, an interface modification process is performed using nitric oxide (NO) gas to form a silicon oxide (SiO x ) of the first insulating film 152. Subsequently, the remaining portion of the trench is filled with polysilicon introduced with conductive type impurities, thereby forming the second electrode 151.

[0073] Afterwards, if Figure 3F As shown in , the fourth semiconductor region 160 is formed in the third semiconductor region 140 by ion implantation, and then the third electrode 170 and the first electrode 110 are formed. Note that the third semiconductor region 140 may further have a contact region of the second conductivity type using ion implantation in order to reduce the contact resistance between the third semiconductor region 140 and the third electrode 170.

[0074] Specifically, first, nitrogen (N) serving as a first conductive type impurity is introduced into the third semiconductor region 140 on both sides of the groove extending in the second direction orthogonal to the first direction by ion implantation, thereby forming the fourth semiconductor region 160. Next, the second electrode 151 is protected by an insulating layer, and then nickel (Ni) and aluminum (Al) sequentially deposited on the upper surface of the third semiconductor region 140 are patterned to form a third electrode 170 electrically connected to the fourth semiconductor region 160. Subsequently, nickel (Ni), titanium (Ti), nickel (Ni), and gold (Au) are sequentially deposited on the first main surface of the semiconductor substrate 120, thereby forming the first electrode 110 electrically connected to the semiconductor substrate 120.

[0075] Through the above steps, the semiconductor device 2 according to the present embodiment is manufactured.

[0076] (1.4. Modification)

[0077] In addition, reference will be made to Figure 4 and Figure 5 Modifications of the semiconductor device according to the present embodiment are described. Figure 4 1 and 2 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a modification of the semiconductor device 1 according to the first configuration example. Figure 5 1 and 2 are explanatory diagrams showing a planar configuration and a cross-sectional configuration of a modification of the semiconductor device 2 according to the second configuration example.

[0078] like Figure 4 and Figure 5 As shown in , the first insulating film 152 can be set by changing the depth of the first insulating film 152 embedded in each of the region near the second semiconductor region 131 and the region not near the second semiconductor region 131. Specifically, corresponding to the embedding depth of the second electrode 151, the first insulating film 152 can be set so that the embedding depth in the non-nearby region is shallower than the embedding depth in the nearby region.

[0079] For example, Figure 4 As shown in , in the semiconductor device 1 according to the first configuration embodiment, the first insulating film 152 can be embedded in the vicinity region to reach the second semiconductor region 131, while being embedded more shallowly in the non-nearby region to the same depth as that of the fourth semiconductor region 160. With this arrangement, in the semiconductor device 1, it is not necessary to backfill the trenches formed in the third semiconductor region 140 and the first semiconductor region 130 with an insulating material in the non-nearby region of the trench, and therefore, the manufacturing process can be further simplified.

[0080] Even in this case, the switching characteristics can be further improved because the semiconductor device 1 can reduce the volume between the second electrode 151 and the first electrode 110 in the non-nearby region. In addition, in the semiconductor device 1, the third semiconductor region 140 on the side of the second electrode 151 in the non-nearby region may not have a channel, so that the amount of saturation current flowing at the time of a fault can be reduced.

[0081] For example, Figure 5 As shown in , in the semiconductor device 2 according to the second configuration example, the first insulating film 152 can be embedded in the vicinity region to reach the second semiconductor region 131, and can be embedded in the non-vicinity region to reach the interface of the first semiconductor region 130 set shallower. With this arrangement, the semiconductor device 2 can control the etching end point of the trench in a self-aligned manner using the interface between the third semiconductor region 140 and the first semiconductor region 130. Therefore, the manufacturing process of the semiconductor device 2 can be further simplified.

[0082] Even in this case, the switching characteristics can be further improved because the semiconductor device 2 can reduce the volume between the second electrode 151 and the first electrode 110 in the non-nearby region. In addition, since the semiconductor device 2 can have a channel serving as a current path not only in the region near the second semiconductor region 131 but also in the region not near the second semiconductor region, the on-resistance can be further reduced.

[0083] <2. Application Examples>

[0084] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any type of mobile body (such as, a car, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility tool, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor)).

[0085] Figure 6 is a block diagram showing a schematic configuration example of a vehicle control system which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0086] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. Figure 6 In the illustrated embodiment, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. In addition, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are illustrated.

[0087] The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 serves as a control device for a drive force generating device (such as an internal combustion engine or a drive motor) that generates the drive force of the vehicle, a drive force transmitting mechanism that transmits the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device such as a braking device that generates the braking force of the vehicle.

[0088] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 is used as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as a headlight, a backup light, a brake light, a flasher light, or a fog light. In this case, a radio wave transmitted from a portable device that replaces the key or a signal of various switches may be input to the body system control unit 12020. The body system control unit 12020 receives input of these radio waves or signals, and controls the door lock device, the power window device, the lights, etc. of the vehicle.

[0089] The vehicle exterior information detection unit 12030 detects external information of the vehicle on which the vehicle control system 12000 is installed. For example, the imaging unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The vehicle exterior information detection unit 12030 can perform object detection processing or distance detection processing of a person, a vehicle, an obstacle, a sign, text on the road surface, etc. based on the received image.

[0090] The imaging unit 12031 is an optical sensor that receives light to output an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, and can output the electrical signal as distance measurement information. In addition, the light received by the imaging unit 12031 can be visible light or invisible light such as infrared light.

[0091] The in-vehicle information detection unit 12040 detects the interior information of the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that images the driver, and the in-vehicle information detection unit 12040 can calculate the driver's fatigue or concentration based on the detection information input from the driver state detection unit 12041, or can determine whether the driver is dozing off.

[0092] The microcomputer 12051 can calculate the control target value of the driving force generation device, the steering mechanism or the braking device based on the internal and external information of the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output the control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control for the purpose of realizing the functions of the advanced driver assistance system (ADAS), and the functions of the advanced driver assistance system include collision avoidance or impact mitigation of the vehicle, follow-up driving based on the vehicle-to-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0093] In addition, the microcomputer 12051 can control the driving force generating device, steering mechanism, braking device, etc. based on the surrounding information of the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, thereby performing coordinated control for purposes such as automatic driving that enables the vehicle to drive autonomously without relying on the driver's operation.

[0094] In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the vehicle exterior information acquired by the vehicle exterior information detection unit 12030. For example, the microcomputer 12051 can perform coordinated control for the purpose of preventing glare, such as switching from a high beam to a low beam, by controlling the headlights according to the position of a preceding vehicle or an oncoming vehicle detected by the vehicle exterior information detection unit 12030.

[0095] The sound / image output unit 12052 sends an output signal of at least one of sound or image to an output device capable of visually or auditorily notifying the occupants of the vehicle or the outside of the vehicle of information. Figure 6 In the embodiment of the present invention, an audio speaker 12061, a display unit 12062, and a dashboard 12063 are shown as output devices. For example, the display unit 12062 may include at least one of an on-board display or a head-up display.

[0096] Figure 7 is a diagram showing an embodiment of the installation position of the imaging unit 12031.

[0097] exist Figure 7 In the imaging unit 12031, imaging units 12101, 12102, 12103, 12104 and 12105 are included.

[0098] The imaging units 12101, 12102, 12103, 12104, and 12105 are, for example, disposed at locations of the vehicle 12100 such as the front nose, side mirrors, rear bumper, rear door, and the upper portion of the windshield in the vehicle compartment. The imaging unit 12101 disposed at the front nose and the imaging unit 12105 disposed at the upper portion of the windshield in the vehicle compartment mainly acquire images in front of the vehicle 12100. The imaging units 12102 and 12103 disposed at the side mirrors mainly acquire images on the sides of the vehicle 12100. The imaging unit 12104 disposed at the rear bumper or rear door mainly acquires images behind the vehicle 12100. The imaging unit 12105 disposed at the upper portion of the windshield in the vehicle compartment is mainly used to detect vehicles ahead, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

[0099] Notice, Figure 7An embodiment of the imaging ranges of the imaging units 12101 to 12104 is shown. The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided at the front nose, the imaging ranges 12112 and 12113 respectively indicate the imaging ranges of the imaging units 12102 and 12103 provided at the side mirrors, and the imaging range 12114 indicates the imaging range of the imaging unit 12104 provided at the rear bumper or the rear door. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above is obtained.

[0100] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0101] For example, the microcomputer 12051 obtains the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the time change of the distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, thereby extracting a three-dimensional object traveling at a predetermined speed (for example, 0 km / h or more) in the same direction as the vehicle 12100 as the leading vehicle, specifically, the three-dimensional object closest to the vehicle 12100 on the driving path of the vehicle 12100. In addition, the microcomputer 12051 can pre-set the inter-vehicle distance to be ensured in front of the leading vehicle, and can perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. As described above, coordinated control for the purpose of automatic driving, etc., in which the vehicle is driven autonomously without relying on the operation of the driver, can be performed.

[0102] For example, the microcomputer 12051 can classify the three-dimensional object data related to the three-dimensional object into two-wheeled vehicles, standard-sized vehicles, large vehicles, pedestrians, and other three-dimensional objects such as utility poles based on the distance information obtained from the imaging units 12101 to 12104, extract these three-dimensional objects, and use these three-dimensional objects for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that the driver of the vehicle 12100 can visually identify and obstacles that the driver cannot visually identify. Then, the microcomputer 12051 determines the collision risk indicating the risk level of collision with each obstacle, and when the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can perform driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062 or performing forced deceleration or evasive steering via the drive system control unit 12010.

[0103] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 may identify a pedestrian by determining whether a pedestrian exists in the captured images of the imaging units 12101 to 12104. This recognition of the pedestrian is performed by, for example, a process of extracting feature points in the captured images of the imaging units 12101 to 12104 used as infrared cameras and a process of performing pattern matching processing on a series of feature points indicating the outline of the object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian exists in the captured images of the imaging units 12101 to 12104 and identifies the pedestrian, the sound / image output unit 12052 causes the display unit 12062 to superimpose and display a square outline for emphasizing the recognized pedestrian. In addition, the sound / image output unit 12052 may cause the display unit 12062 to display an icon indicating a pedestrian at a desired position, etc.

[0104] An embodiment of a vehicle control system to which the technology according to the present disclosure can be applied is described above. The technology according to the present invention can be applied to electronic control devices such as a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050 in the above configuration. Specifically, each of the semiconductor device 1 according to the first configuration embodiment or the semiconductor device 2 according to the second configuration embodiment can be applied to a transistor included in the above electronic control unit. The technology according to the present disclosure can further improve the withstand voltage and reliability of the transistor, and therefore can be more preferably applied to a vehicle control system using a higher voltage. In accordance with the technology according to the present disclosure, the vehicle control system can improve the reliability of the system for high voltage and reduce the impact when a transistor fails.

[0105] Although the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such embodiments. Obviously, for those skilled in the art of the present disclosure, various modifications and improvements can be conceived within the scope of the technical concept described in the claims, and it should be naturally understood that these modifications and improvements also belong to the technical scope of the present disclosure.

[0106] In addition, the effects described in this specification are merely illustrative or exemplary, and not restrictive. That is, together with or instead of the above effects, the technology according to the present disclosure may show other effects that are obvious to those skilled in the art from the description of this specification.

[0107] Note that the following configurations also belong to the technical scope of the present disclosure.

[0108] (1) A semiconductor device comprising:

[0109] A semiconductor substrate having a first main surface, wherein a first electrode is disposed on the first main surface;

[0110] A first semiconductor region of a first conductivity type is disposed on the second main surface of the semiconductor substrate;

[0111] A plurality of second semiconductor regions of a second conductivity type are arranged in the first semiconductor region and extend in parallel in a first direction;

[0112] A third semiconductor region of the second conductivity type is disposed on the first semiconductor region;

[0113] a trench disposed in the third semiconductor region and extending in a second direction orthogonal to the first direction;

[0114] a second electrode disposed in the groove;

[0115] a first insulating film disposed between a side wall of the trench and the second electrode; and

[0116] A fourth semiconductor region of the first conductivity type is disposed in the third semiconductor region, wherein

[0117] The second electrode in a non-nearby region, which is a region other than the nearby region in the second semiconductor region, has an embedded depth shallower than that of the second electrode in the nearby region. (2)

[0119] The semiconductor device according to (1), wherein, in the vicinity, the first insulating film is further provided between the bottom surface of the trench and the second electrode. (3)

[0121] The semiconductor device according to (2), wherein, in the vicinity, the second electrode is embedded so as to reach the first semiconductor region from the third semiconductor region. (4)

[0123] The semiconductor device according to (3), wherein, in the non-nearby region, the second electrode is embedded to a depth reaching the fourth semiconductor region from the third semiconductor region. (5)

[0125] The semiconductor device according to any one of (1) to (4), wherein the second electrode has a comb-teeth shape in the second direction. (6)

[0127] The semiconductor device according to any one of (1) to (5), wherein a thickness of the third semiconductor region in the non-nearby region is thinner than a thickness of the third semiconductor region in the nearby region. (7)

[0129] The semiconductor device according to (6), wherein in the vicinity region and the non-vicinity region, the second electrode is embedded so as to reach the first semiconductor region from the third semiconductor region. (8)

[0131] The semiconductor device according to any one of (1) to (7), wherein an embedding depth of the first insulating film in the vicinity region is the same as an embedding depth of the first insulating film in the non-vicinity region. (9)

[0133] The semiconductor device according to any one of (1) to (7), wherein an embedding depth of the first insulating film in the non-nearby region is shallower than an embedding depth of the first insulating film in the nearby region. (10)

[0135] The semiconductor device according to any one of (1) to (9), wherein the second semiconductor region and the third semiconductor region are electrically connected at an equal potential.

[0136] (11) A semiconductor device comprising:

[0137] A semiconductor substrate having a first surface, and a first electrode is disposed on the first surface;

[0138] A first semiconductor region of a first conductivity type is disposed on the second surface of the semiconductor substrate;

[0139] A plurality of second semiconductor regions of a second conductivity type, disposed on the first semiconductor region and extending along the first direction;

[0140] a third semiconductor region of a second conductivity type disposed on the first semiconductor region, the third semiconductor region defining a portion of the trench extending in a second direction transverse to the first direction;

[0141] a second electrode disposed in the groove;

[0142] a first insulating film provided in the trench and between a side wall of the third semiconductor region defining the portion of the trench and the second electrode; and

[0143] A fourth semiconductor region of the first conductivity type is disposed on the third semiconductor region, wherein:

[0144] The first portion of the second electrode has a first depth that is shallower than a second depth of the second portion of the second electrode, and

[0145] The second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode. (12)

[0147] The semiconductor device according to (11), wherein the first insulating film is further provided between the bottom surface of the trench and the second electrode. (13)

[0149] The semiconductor device of (12), wherein the first semiconductor region further defines a second portion of the trench, and wherein the second portion of the second electrode extends from the portion of the trench to the second portion of the trench. (14)

[0151] The semiconductor device of (13), wherein the fourth semiconductor region further defines a third portion of the trench, and wherein the first portion of the second electrode and the second portion of the second electrode extend from the portion of the trench to the third portion of the trench. (15)

[0153] The semiconductor device according to any one of (11) to (14), wherein the second electrode has a comb-teeth shape in the second direction. (16)

[0155] A semiconductor device according to any one of (11) to (15), wherein the thickness of the first portion of the third semiconductor region is thinner than the thickness of the second portion of the third semiconductor region, and wherein the second portion of the third semiconductor region is closer to the second semiconductor region than the first portion of the third semiconductor region. (17)

[0157] The semiconductor device according to (16), wherein the first portion of the second electrode extends from the portion of the trench to a third portion of the trench, and the second portion of the second electrode extends from the portion of the trench to the second portion of the trench. (18)

[0159] The semiconductor device according to any one of (11) to (17), wherein the second electrode and the first insulating film are combined to have a single thickness across the length of the trench. (19)

[0161] The semiconductor device according to any one of (11) to (18), wherein the embedding depth of the first insulating film is substantially the same throughout the trench. (20)

[0163] The semiconductor device according to any one of (11) to (19), wherein the first insulating film extends to the second semiconductor region and contacts the second semiconductor region. (twenty one)

[0165] The semiconductor device according to any one of (11) to (20), wherein the second semiconductor region and the third semiconductor region are electrically connected at an equal potential. (twenty two)

[0167] The semiconductor device according to any one of (11) to (22), wherein the second electrode and the first insulating film are combined to have a plurality of different thicknesses over the length of the trench.

[0168] (23) A vehicle control system comprising:

[0169] Electronic controllers, including semiconductor devices,

[0170] The semiconductor device includes:

[0171] A semiconductor substrate having a first surface, and a first electrode is disposed on the first surface;

[0172] A first semiconductor region of a first conductivity type is disposed on the second surface of the semiconductor substrate;

[0173] A plurality of second semiconductor regions of a second conductivity type, disposed on the first semiconductor region and extending along the first direction;

[0174] a third semiconductor region of a second conductivity type disposed on the first semiconductor region, the third semiconductor region defining a portion of the trench extending in a second direction transverse to the first direction;

[0175] a second electrode disposed in the groove;

[0176] a first insulating film provided in the trench and between a side wall of the third semiconductor region defining the portion of the trench and the second electrode; and

[0177] A fourth semiconductor region of the first conductivity type is disposed on the third semiconductor region, wherein:

[0178] The first portion of the second electrode has a first depth that is shallower than a second depth of the second portion of the second electrode, and

[0179] The second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode. (twenty four)

[0181] The vehicle control system according to (23), wherein the first insulating film is further provided between the bottom surface of the groove and the second electrode. (25)

[0183] The vehicle control system of (24), wherein the first semiconductor region further defines a second portion of the trench, and wherein the second portion of the second electrode extends from the portion of the trench to the second portion of the trench. (26)

[0185] The vehicle control system of (25), wherein the fourth semiconductor region further defines a third portion of the trench, and wherein the first portion of the second electrode and the second portion of the second electrode extend from the portion of the trench to the third portion of the trench. (27)

[0187] A vehicle control system according to any one of (23) to (26), wherein the second electrode has a comb-teeth shape in the second direction. (28)

[0189] A vehicle control system according to any one of (23) to (27), wherein the thickness of the first portion of the third semiconductor region is thinner than the thickness of the second portion of the third semiconductor region, and wherein the second portion of the third semiconductor region is closer to the second semiconductor region than the first portion of the third semiconductor region. (29)

[0191] A vehicle control system according to (28), wherein the first portion of the second electrode extends from the portion of the groove to a third portion of the groove, and the second portion of the second electrode extends from the portion of the groove to the second portion of the groove. (30)

[0193] A vehicle control system according to any one of (23) to (29), wherein the second electrode and the first insulating film are combined to have a single thickness across the length of the groove.

[0194] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

[0195] Reference Numbers List

[0196] 1.2 Semiconductor devices

[0197] 110 first electrode

[0198] 120 Semiconductor substrate

[0199] 130 first semiconductor region

[0200] 131 Second semiconductor region

[0201] 140 Third semiconductor region

[0202] 151 Second electrode

[0203] 152 first insulating film

[0204] 160 Fourth semiconductor region

[0205] 170 The third electrode.

Claims

1. A semiconductor device comprising: A semiconductor substrate having a first surface, and a first electrode is disposed on the first surface; A first semiconductor region of a first conductivity type is disposed on the second surface of the semiconductor substrate; a plurality of second semiconductor regions of a second conductivity type, disposed on the first semiconductor region and extending along a first direction; a third semiconductor region of the second conductivity type disposed on the first semiconductor region, the third semiconductor region defining a portion of a trench extending along a second direction transverse to the first direction; a second electrode disposed in the groove; a first insulating film provided in the trench and between a side wall of the third semiconductor region defining the portion of the trench and the second electrode; as well as The fourth semiconductor region of the first conductivity type is disposed on the third semiconductor region, wherein: The first portion of the second electrode has a first depth that is shallower than a second depth of the second portion of the second electrode, and The second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode.

2. The semiconductor device according to claim 1, wherein The first insulating film is further provided between the bottom surface of the trench and the second electrode.

3. The semiconductor device according to claim 2, wherein: The first semiconductor region further defines a second portion of the trench, and wherein a second portion of the second electrode extends from the portion of the trench to the second portion of the trench.

4. The semiconductor device according to claim 3, wherein: The fourth semiconductor region further defines a third portion of the trench, and wherein the first portion of the second electrode and the second portion of the second electrode extend from the portion of the trench to the third portion of the trench.

5. The semiconductor device according to claim 1, wherein The second electrode has a comb-teeth shape in the second direction.

6. The semiconductor device according to claim 1, wherein A first portion of the third semiconductor region has a thickness thinner than a second portion of the third semiconductor region, wherein the second portion of the third semiconductor region is closer to the second semiconductor region than the first portion of the third semiconductor region.

7. The semiconductor device according to claim 6, in, A first portion of the second electrode extends from the portion of the trench to a third portion of the trench, and a second portion of the second electrode extends from the portion of the trench to the second portion of the trench.

8. The semiconductor device according to claim 1, wherein The second electrode and the first insulating film are combined to have a single thickness across the length of the trench.

9. The semiconductor device according to claim 1, wherein: The embedding depth of the first insulating film is substantially the same throughout the trench.

10. The semiconductor device according to claim 1, wherein The first insulating film extends to and contacts the second semiconductor region.

11. The semiconductor device according to claim 1, wherein The second semiconductor region and the third semiconductor region are electrically connected to each other at the same potential.

12. The semiconductor device according to claim 1, wherein The second electrode and the first insulating film are combined to have a plurality of different thicknesses over the length of the trench.

13. A vehicle control system, comprising: Electronic controllers, including semiconductor devices, Wherein, the semiconductor device comprises: A semiconductor substrate having a first surface, and a first electrode is disposed on the first surface; A first semiconductor region of a first conductivity type is disposed on the second surface of the semiconductor substrate; a plurality of second semiconductor regions of a second conductivity type, disposed on the first semiconductor region and extending along a first direction; a third semiconductor region of the second conductivity type disposed on the first semiconductor region, the third semiconductor region defining a portion of a trench extending along a second direction transverse to the first direction; a second electrode disposed in the groove; a first insulating film provided in the trench and between a side wall of the third semiconductor region defining the portion of the trench and the second electrode; and The fourth semiconductor region of the first conductivity type is disposed on the third semiconductor region, wherein: The first portion of the second electrode has a first depth that is shallower than a second depth of the second portion of the second electrode, and The second portion of the second electrode is closer to the second semiconductor region than the first portion of the second electrode.

14. The vehicle control system according to claim 13, wherein: The first insulating film is further provided between the bottom surface of the trench and the second electrode.

15. The vehicle control system according to claim 14, wherein: The first semiconductor region further defines a second portion of the trench, and wherein a second portion of the second electrode extends from the portion of the trench to the second portion of the trench.

16. The vehicle control system according to claim 15, wherein: The fourth semiconductor region further defines a third portion of the trench, and wherein the first portion of the second electrode and the second portion of the second electrode extend from the portion of the trench to the third portion of the trench.

17. The vehicle control system according to claim 13, in, The second electrode has a comb-teeth shape in the second direction.

18. The vehicle control system according to claim 13, wherein: A first portion of the third semiconductor region has a thickness thinner than a second portion of the third semiconductor region, wherein the second portion of the third semiconductor region is closer to the second semiconductor region than the first portion of the third semiconductor region.

19. The vehicle control system according to claim 18, in, A first portion of the second electrode extends from the portion of the trench to a third portion of the trench, and a second portion of the second electrode extends from the portion of the trench to the second portion of the trench.

20. The vehicle control system according to claim 13, wherein: The second electrode and the first insulating film are combined to have a single thickness across the length of the trench.

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