Power Devices

Abstract

The present invention discloses a power device that integrates both a main and auxiliary MOSFETs, with the auxiliary MOSFET serving as a current detection sensor. The pads of the main MOSFET include a gate pad and a main source pad located on the front, and a drain pad located on the back. The auxiliary MOSFET and the auxiliary source pad share a gate pad and drain pad with the main MOSFET. The power device layout structure includes a rectangular active area. The gate pad and the auxiliary source pad are located at the top of a selected area of ​​the active area near the first edge of the active area, with a gap between the gate pad and the auxiliary source pad. The main source pad is located at the top of the active area outside the gate pad and the auxiliary source pad. The area of ​​the main source pad is larger than that of the auxiliary source pad. The auxiliary MOSFET is located in the active area below the auxiliary source pad. The present invention can be integrated with sensors, improving device reliability without affecting the chip functionality of the power device, and ensuring the active area corresponding to the main chip is sufficient.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a power device. Background Art

[0002] The MOSFET corresponding to existing conventional power devices has only three ports: gate, source, and drain. The first two terminals, the bonding pads (PADs), are located on the front surface of the chip, while the third terminal, the PAD, is located on the back surface of the chip.

[0003] If it is necessary to further integrate sensors on the basis of existing power devices, then in addition to the three ports mentioned above, there will also be sensor ports. The placement of the lead-out terminal bonding pad involves the layout planning and the vertical and horizontal methods of the internal cellular structure units. It is necessary to consider obtaining as much active area as possible, and to determine the placement of each sensor device inside the main chip according to the design function and purpose. It is also necessary to consider the reasonable distribution of the positions of each lead-out terminal bonding pad. Finally, how to realize the integration of sensors in power devices and ultimately improve the performance of power devices is the topic to be studied in this application. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a power device that can be integrated with multiple sensors, so as to monitor the working status of the power device in real time and thereby improve the reliability of the device. At the same time, the introduction of the sensors does not affect the chip function of the power device, and the active area corresponding to the main chip can be guaranteed.

[0005] In order to solve the above technical problems, the power device provided by the present invention integrates a main MOSFET and an auxiliary MOSFET at the same time, and the auxiliary MOSFET serves as a current detection sensor.

[0006] The main MOSFET includes a first source region and a first gate structure formed on the front side of the semiconductor substrate and a first drain region formed on the back side of the semiconductor substrate. The first source region is connected to a main source pad composed of a front metal layer; the first gate is connected to a gate pad composed of a front metal layer, and the first drain region is connected to a drain pad composed of a back metal layer.

[0007] The auxiliary MOSFET includes a second source region and a second gate structure formed on the front surface of the semiconductor substrate and the first drain region, the second gate structure is connected to the gate pad, and the second source region is connected to an auxiliary source pad composed of a front metal layer.

[0008] The layout structure of power devices includes:

[0009] Rectangular active area.

[0010] The gate pad and the auxiliary source pad are disposed on a top portion of a selected region of the active region near a first edge of the active region, with a gap between the gate pad and the auxiliary source pad;

[0011] The main source pad is located on the top of the active area outside the gate pad and the auxiliary source pad;

[0012] An area of ​​the main source pad is larger than an area of ​​the auxiliary source pad.

[0013] The auxiliary MOSFET is located in the active area at the bottom of the auxiliary source pad.

[0014] A further improvement is that the power device is also integrated with a first temperature sensor (Temp sensor) and a second temperature sensor.

[0015] The main MOSFET also includes a body region doped with the second conductive type formed on the semiconductor substrate, a drift region doped with the first conductive type formed at the bottom of the body region, the drift region is composed of the semiconductor substrate doped with the first conductive type or a first epitaxial layer doped with the first conductive type formed on top of the semiconductor substrate, and the first drain region is formed on the back side of the drift region.

[0016] A body diode is formed between the body region and the drift region.

[0017] The first temperature sensor is formed by the body diode located in an edge region of the active area.

[0018] The second temperature sensor is formed by the body diode located in a central area of ​​the active region.

[0019] A selected corner area of ​​the active region is a circuit-free area.

[0020] The first temperature sensor is located in the circuit-free area. When the power device is turned on, no current flows in the circuit-free area. The body region of the body diode of the first temperature sensor is connected to a first anode pad composed of a front metal layer, and the cathode pad of the first temperature sensor adopts the drain pad.

[0021] The second temperature sensor is located at a selected position in the central area of ​​the active area, the top of the body region at the selected position of the second temperature sensor is connected to a first metal block composed of a front metal layer, the first metal block is connected to a second anode pad through a first metal lead, and the cathode pad of the second temperature sensor adopts the drain pad.

[0022] The second anode pad is disposed on a top portion of a selected region of the active region near a first edge of the active region, and a gap is formed between the second anode pad and the gate pad and the auxiliary source pad.

[0023] The covering area of ​​the main source pad is located outside the circuit-free area, the second anode pad, the first metal block, and the first metal lead.

[0024] A further improvement is that the power device also integrates a current-limited source-drain on-resistance (Current Limit Rdson, CL Rdson) sensor.

[0025] The current limiting source-drain on-resistance sensor is located at a selected position in the central area of ​​the active area, the surface of the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is exposed, and the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is isolated from the body region on the surrounding side.

[0026] The top of the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is connected to a second metal block composed of a front-side metal layer.

[0027] The second metal block is connected to the first resistance pad through a second metal lead, and the second resistance pad of the current-limiting source-drain on-resistance sensor adopts the drain pad.

[0028] The first resistor pad is located on a top portion of a selected region of the active region near a first edge of the active region, and spaces are provided between the first resistor pad, the second anode pad, the gate pad, and the auxiliary source pad.

[0029] There is a gap between the first metal block and the second metal block.

[0030] The covering area of ​​the main source pad is also located outside the first resistor pad and the second metal lead.

[0031] A further improvement is that the first vertex of the corner area corresponding to the circuit-free area is the first endpoint of the first edge.

[0032] A further improvement is that the gate pad is also arranged in the non-circuit area, the gate pad and the first anode pad are spaced apart, and a vertex of the first anode pad is located on a first vertex of the non-circuit area.

[0033] A further improvement is that the circuit-free area is rectangular.

[0034] One vertex of the gate pad is located on the second vertex of the non-circuit area, and the first vertex and the second vertex of the non-circuit area are two diagonal vertices.

[0035] A further improvement is that the first resistor pad, the first anode pad, the second anode pad, the gate pad and the auxiliary source pad are all rectangular.

[0036] One side of the first resistor pad, the second anode pad, and the auxiliary source pad are all located on the first edge.

[0037] A further improvement is that, in a direction from the first end point to the second end point of the first edge, the arrangement order of the first resistor pad, the second anode pad and the auxiliary source pad includes:

[0038] the auxiliary source pad, the first resistor pad, and the second anode pad.

[0039] the auxiliary source pad, the second anode pad, and the first resistor pad.

[0040] A further improvement is that one vertex of the first anode pad is located on the first vertex of the non-circuit area; and the gate pad is also arranged outside the non-circuit area.

[0041] A further improvement is that the circuit-free area is rectangular.

[0042] A further improvement is that the first resistor pad, the first anode pad, the second anode pad, the gate pad and the auxiliary source pad are all rectangular.

[0043] One side of the gate pad, the first resistor pad, the second anode pad, and the auxiliary source pad are all located on the first edge.

[0044] A side of the gate pad that is perpendicular to the first edge is located on a side of the non-circuit area.

[0045] A further improvement is that, in a direction from the first end point to the second end point of the first edge, the arrangement order of the first resistor pad, the second anode pad and the auxiliary source pad includes:

[0046] the auxiliary source pad, the first resistor pad, and the second anode pad.

[0047] the auxiliary source pad, the second anode pad, and the first resistor pad.

[0048] A further improvement is that the first metal lead and the second metal lead are parallel to a first middle line and are located on both sides of the first middle line, and the first middle line is a line passing through the midpoint of the first edge and perpendicular to the first edge.

[0049] A further improvement is that the size of the first metal block is larger than the size of the second metal block.

[0050] The top edge of the second metal block is located at the bottom of the bottom edge of the first metal block; or, the top edge and the bottom edge of the second metal block are located between the top edge and the bottom edge of the first metal block.

[0051] The top edge and the bottom edge of the first metal block and the top edge and the bottom edge of the second metal block are parallel to the first edge.

[0052] The bottom edge of the first metal block is closer to the first edge than the top edge, and the bottom edge of the second metal block is closer to the first edge than the top edge.

[0053] The bottom of the bottom edge of the second metal block is an area between the bottom edge of the second metal block and the first edge.

[0054] A further improvement is that the size of the formation area of ​​the current-limiting source-drain on-resistance sensor is 20 μm*20 μm.

[0055] The present invention can realize a current detection sensor by providing an auxiliary MOSFET on the basis of a main MOSFET. In terms of layout, the auxiliary MOSFET only needs to occupy a formation area of ​​an auxiliary source pad. The device structure of the auxiliary MOSFET formed on the semiconductor substrate is located at the bottom of the auxiliary source pad. The gate pad and the drain pad are shared by the auxiliary MOSFET and the main MOSFET. During the current detection process, the current detection function can be realized by comparing the current detection ratio of the main MOSFET and the auxiliary MOSFET. According to the current detection result, the main MOSFET is turned off in the event of overcurrent, thereby protecting the main MOSFET.

[0056] The present invention can also set up temperature sensors, wherein the first temperature sensor is set in the circuit-free area at the edge of the active area, and the second temperature sensor is set in the central area of ​​the active area. Since no current flows in the circuit-free area and current flows in the central area, the two temperature sensors can respectively detect the temperatures of the two types of areas and obtain the temperature difference between the two types of areas, thereby realizing protection control of the power device.

[0057] The present invention can also provide a current-limiting source-drain on-resistance sensor, which can obtain the corresponding current-limiting source-drain on-resistance by testing the voltage between the drift region and the first drain region at the bottom of the formation area of ​​the current-limiting source-drain on-resistance sensor when the source-drain current is fixed, and shut down the power device when the current-limiting source-drain on-resistance is large, that is, the measured voltage between the drift region and the first drain region at the bottom is large, thereby further protecting the power device.

[0058] The layout of the present invention enables the pads corresponding to each sensor to be located at the edge of the active area, thereby ensuring the area of ​​the active area corresponding to the main chip.

[0059] Therefore, the present invention can be integrated with multiple sensors, so as to monitor the working status of the power device in real time and thereby improve the reliability of the device, so that the power device has the characteristics of high avalanche and high reliability; at the same time, the introduction of the sensor will not affect the chip function of the power device, and the active area corresponding to the main chip can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0061] Figure 1 This is a first layout diagram of a power device according to an embodiment of the present invention;

[0062] Figure 2 This is a second layout diagram of a power device according to an embodiment of the present invention;

[0063] Figure 3 This is a third layout diagram of the power device according to an embodiment of the present invention;

[0064] Figure 4 This is the fourth layout diagram of the power device according to the embodiment of the present invention. DETAILED DESCRIPTION

[0065] like Figure 1 , which is a first layout diagram of a power device according to an embodiment of the present invention; the power device according to the embodiment of the present invention integrates a main MOSFET and an auxiliary MOSFET, and the auxiliary MOSFET serves as a current detection sensor.

[0066] The main MOSFET includes a first source region and a first gate structure formed on the front side of the semiconductor substrate and a first drain region formed on the back side of the semiconductor substrate. The first source region is connected to a main source pad 102 composed of a front metal layer; the first gate is connected to a gate pad 103 composed of a front metal layer, and the first drain region is connected to a drain pad composed of a back metal layer.

[0067] The auxiliary MOSFET includes a second source region, a second gate structure and a first drain region formed on the front surface of the semiconductor substrate. The second gate structure is connected to the gate pad 103, and the second source region is connected to the auxiliary source pad 104 composed of a front metal layer.

[0068] The layout structure of the power device includes:

[0069] The active area 101 is rectangular.

[0070] The gate pad 103 and the auxiliary source pad 104 are disposed on a top portion of a selected region of the active region 101 near a first edge of the active region 101 , with a space therebetween.

[0071] The main source pad 102 is located on top of the active area 101 outside the gate pad 103 and the auxiliary source pad 104 . Figure 1 In FIG. 1 , the main source pad 102 is also represented by Source3A and Source3B, the gate pad 103 is also represented by Gate Pad2, and the auxiliary source pad 104 is also represented by Source Pad4.

[0072] The area of ​​the main source pad 102 is larger than that of the auxiliary source pad 104 .

[0073] The auxiliary MOSFET is located in the active area 101 at the bottom of the auxiliary source pad 104 .

[0074] In the embodiment of the present invention, the power device is further integrated with a first temperature sensor and a second temperature sensor.

[0075] The main MOSFET also includes a body region doped with the second conductivity type formed on the semiconductor substrate, a drift region doped with the first conductivity type formed at the bottom of the body region, the drift region is composed of a semiconductor substrate doped with the first conductivity type or a first epitaxial layer doped with the first conductivity type formed on top of the semiconductor substrate, and the first drain region is formed on the back side of the drift region.

[0076] A body diode is formed between the body region and the drift region.

[0077] The first temperature sensor is formed by a body diode located in an edge region of the active area 101 .

[0078] The second temperature sensor is formed by a body diode located in the central region of the active area 101 .

[0079] A selected corner area of ​​the active area 101 is a circuit-free area 112 .

[0080] The first temperature sensor is located in the non-circuit area 112. When the power device is turned on, no current flows in the non-circuit area 112. The body region of the body diode of the first temperature sensor is connected to the first anode pad 105 composed of the front metal layer, and the cathode pad of the first temperature sensor adopts the drain pad.

[0081] The second temperature sensor is located at a selected position in the central area of ​​the active area 101. The top of the body region at the selected position of the second temperature sensor is connected to a first metal block 107 composed of a front metal layer. The first metal block 107 is connected to the second anode pad 106 through a first metal lead 108. The cathode pad of the second temperature sensor adopts a drain pad.

[0082] Figure 1 In FIG. 1 , the first anode pad 105 is also represented by Anode Pad1 , and the second anode pad 106 is also represented by Anode Pad6 .

[0083] The second anode pad 106 is disposed on the top of a selected region of the active area 101 near a first edge of the active area 101 , with a gap between the second anode pad 106 and the gate pad 103 and the auxiliary source pad 104 .

[0084] The coverage area of ​​the main source pad 102 is located outside the non-circuit area 112 , the second anode pad 106 , the first metal block 107 and the first metal lead 108 .

[0085] In the embodiment of the present invention, the power device also integrates a current-limited source-drain on-resistance sensor.

[0086] The current limiting source drain on-resistance sensor is located at a selected position in the central area of ​​the active area 101 . The surface of the drift region in the formation area of ​​the current limiting source drain on-resistance sensor is exposed and the drift region in the formation area of ​​the current limiting source drain on-resistance sensor is isolated from the surrounding body region.

[0087] The top of the drift region in the current-limiting source-drain on-resistance sensor formation area is connected to a second metal block 110 formed from a front-side metal layer. In some embodiments, the size of the current-limiting source-drain on-resistance sensor formation area is 20 μm by 20 μm. In other embodiments, the size of the current-limiting source-drain on-resistance sensor formation area can be adjusted as needed.

[0088] The second metal block 110 is connected to the first resistance pad 109 through a second metal lead 111 . The second resistance pad of the current-limiting source-drain on-resistance sensor is a drain pad.

[0089] Figure 1 In FIG. 1 , the first resistor pad 109 is also represented by Pad5.

[0090] The first resistor pad 109 is located on the top of a selected region of the active area 101 near a first edge of the active area 101 , with spaces between the first resistor pad 109 , the second anode pad 106 , the gate pad 103 and the auxiliary source pad 104 .

[0091] There is a gap between the first metal block 107 and the second metal block 110 .

[0092] The coverage area of ​​the main source pad 102 is also located outside the first resistor pad 109 and the second metal lead 111 .

[0093] In the embodiment of the present invention, the layout of the power device is flexibly configured. Figure 1 The first layout shown further has the following features:

[0094] The first vertex of the corner area corresponding to the non-circuit area 112 is the first end point of the first edge.

[0095] The gate pad 103 is also disposed in the non-circuit region 112 . There is a distance between the gate pad 103 and the first anode pad 105 . One vertex of the first anode pad 105 is located on a first vertex of the non-circuit region 112 .

[0096] The circuit-free area 112 is rectangular.

[0097] One vertex of the gate pad 103 is located on the second vertex of the non-circuit region 112, and the first vertex and the second vertex of the non-circuit region 112 are two diagonal vertices. Figure 1 As shown, by setting the circuits diagonally, the area of ​​the circuit-free region 112 can be reduced.

[0098] The first resistor pad 109 , the first anode pad 105 , the second anode pad 106 , the gate pad 103 and the auxiliary source pad 104 are all rectangular.

[0099] The first resistor pad 109, the second anode pad 106, and one side of the auxiliary source pad 104 are all located on the first edge. In other embodiments, the first resistor pad 109, the second anode pad 106, and one side of the auxiliary source pad 104 do not need to be completely located on the first edge; they can be aligned and close to the first edge.

[0100] In the direction from the first end point to the second end point of the first edge, the first resistor pad 109, the second anode pad 106, and the auxiliary source pad 104 are arranged in the following order: auxiliary source pad 104, first resistor pad 109, and second anode pad 106. In other embodiments, the following order can also be adopted: in the direction from the first end point to the second end point of the first edge, the first resistor pad 109, the second anode pad 106, and the auxiliary source pad 104 are arranged in the following order: auxiliary source pad 104, second anode pad 106, and first resistor pad 109.

[0101] In the embodiment of the present invention, the first metal lead 108 and the second metal lead 111 are parallel to the first middle line and are located on both sides of the first middle line. The first middle line is a line passing through the midpoint of the first edge and perpendicular to the first edge. Figure 1 As shown, the first metal lead 108 and the second metal lead 111 are both arranged close to the first middle line, so that the contact position of the first metal lead 108 and the second anode pad 106 is close to Figure 1 The left side of the second anode pad 106109 is close to the middle side, and the contact position of the second metal lead 111 and the first resistor pad 109 is close to Figure 1 The right side of the first resistor pad 109 is close to the middle side.

[0102] In the embodiment of the present invention, the size of the first metal block 107 is larger than the size of the second metal block 110 .

[0103] The top edge of the second metal block 110 is located below the bottom edge of the first metal block 107. In other embodiments, the top edge and bottom edge of the second metal block 110 can be located between the top edge and bottom edge of the first metal block 107.

[0104] The top and bottom sides of the first metal block 107 and the top and bottom sides of the second metal block 110 are parallel to the first edge.

[0105] The bottom side of the first metal block 107 is closer to the first edge than the top side, and the bottom side of the second metal block 110 is closer to the first edge than the top side.

[0106] The bottom of the bottom side of the second metal block 110 is an area between the bottom side of the second metal block 110 and the first edge.

[0107] The embodiment of the present invention can also adopt Figure 2 The second layout diagram shown is implemented as follows: Figure 2 As shown, the second layout diagram and Figure 1 The difference of the first layout diagram shown is that Figure 2In the embodiment, one vertex of the first anode pad 105 is located on a first vertex of the non-circuit region 112 ; the gate pad 103 is also disposed outside the non-circuit region 112 .

[0108] The embodiment of the present invention can also adopt Figure 3 The third layout diagram shown is implemented as follows: Figure 3 As shown, the third layout diagram and Figure 2 The difference of the second layout diagram shown is that Figure 3 In the embodiment, the top side and the bottom side of the second metal block 110 are located between the top side and the bottom side of the second metal block 110 .

[0109] The embodiment of the present invention can also adopt Figure 4 The fourth layout diagram shown is implemented as follows: Figure 4 As shown, the fourth layout diagram and Figure 3 The difference of the third layout diagram shown is that Figure 4 The first metal lead 108 and the second metal lead 111 are located on both sides of the first middle line. Figure 3 The one in the middle is exactly right, Figure 4 As shown in FIG, the first metal lead 108 and the connected first metal block 107 and the second anode pad 106 are all located on the left side of the first center line, and the second metal lead 111 and the connected second metal block 110 and the first resistor pad 109 are all located on the right side of the first center line.

[0110] The embodiment of the present invention can realize a current detection sensor by providing an auxiliary MOSFET on the basis of the main MOSFET. In terms of layout, the auxiliary MOSFET only needs to occupy a formation area of ​​an auxiliary source pad 104. The device structure of the auxiliary MOSFET formed on the semiconductor substrate is located at the bottom of the auxiliary source pad 104. The gate pad 103 and the drain pad are shared by the auxiliary MOSFET and the main MOSFET. During the current detection process, the current detection function can be realized by comparing the current detection ratio of the main MOSFET and the auxiliary MOSFET, and according to the current detection result, the main MOSFET is turned off when overcurrent occurs, thereby protecting the main MOSFET.

[0111] The embodiment of the present invention can also set up temperature sensors, wherein the first temperature sensor is set in the circuit-free area 112 at the edge of the active area 101, and the second temperature sensor is set in the central area of ​​the active area 101. Since no current flows in the circuit-free area 112 and current flows in the central area, the two temperature sensors can respectively detect the temperatures of the two types of areas and obtain the temperature difference between the two types of areas, thereby realizing protection control of the power device.

[0112] The embodiment of the present invention can also provide a current limiting source-drain on-resistance sensor, which can obtain the corresponding current limiting source-drain on-resistance by testing the voltage between the drift region and the first drain region at the bottom of the formation area of ​​the current limiting source-drain on-resistance sensor when the source-drain current is fixed, and shut down the power device when the current limiting source-drain on-resistance is large, that is, the measured voltage between the drift region and the first drain region at the bottom is large, thereby further protecting the power device.

[0113] The layout of the embodiment of the present invention enables the pads corresponding to each sensor to be located at the edge of the active area, thereby ensuring the area of ​​the active area corresponding to the main chip.

[0114] Therefore, the embodiment of the present invention can be integrated with multiple sensors, so as to monitor the working status of the power device in real time and thereby improve the reliability of the device, so that the power device has the characteristics of high avalanche and high reliability; at the same time, the introduction of the sensor does not affect the chip function of the power device, and the active area corresponding to the main chip can be guaranteed.

[0115] The working mode of each sensor in the embodiment of the present invention is further described below:

[0116] In an embodiment of the present invention, the auxiliary MOSFET is placed directly under the corresponding sense PAD, i.e., the auxiliary source pad 104. Combined with the drain pad, the gate pad 103 and the auxiliary source pad 104, the source-drain current of the auxiliary MOSFET can be detected. At the same time, combined with the drain pad, the gate pad 103 and the main source pad 102, the source-drain current of the main MOSFET can be detected. The two can realize the current detection ratio of the main MOSFET and the auxiliary MOSFET. When an overcurrent is detected, the main MOSFET is turned off in time.

[0117] In this embodiment of the present invention, a temp sensor is provided at the center and at the edge, respectively. These sensors are the first and second temperature sensors, both implemented using body diodes. The center temperature is checked to achieve shutdown at a maximum absolute temperature of 150°C. The edge temperature is checked to check the temperature difference with the center point. When the temperature difference (TSW) is equal to 60°C, thermal shock shutdown is achieved.

[0118] A current limit Rdson sensor, also known as a source-drain on-resistance sensor, measures current. The voltage across the sensing current is proportional to the measured current. A 20 x 20 μm area is isolated in the center of the chip to create the source-drain on-resistance sensor.

[0119] The N-type substrate (Nsub) resistor in the current-limiting source-drain on-resistance sensor formation area serves as the CLsense resistor of the power tube. Nsub includes the N-type region from the top surface of the drift region to the drain region. When the maximum current of 100A passes through, the voltage difference across Nsub is 150mV to achieve shutdown detection.

[0120] The embodiment of the present invention can make various changes to the chip layout, such as Figures 1 to 4 The four changes shown make the design more flexible without affecting the chip functionality.

[0121] The embodiments of the present invention have the following advantages:

[0122] There is a temp sensor at the outermost corner of the chip and at the center of the chip. When the chip is working, there is no current flowing through one area and current flowing through the other area. The junction temperatures of the two areas are different, and the electrical signals fed back by the two sensors are different. External sampling can quantify the temperature difference based on the different electrical signals.

[0123] Three different sensors can be integrated into a MOSFET chip.

[0124] Specific high avalanche and high reliability characteristics.

[0125] The present invention has been described in detail above by means of specific embodiments, but these do not constitute limitations of the present invention. Without departing from the principles of the present invention, those skilled in the art may make many variations and improvements, which should also be considered as the scope of protection of the present invention.

Claims

1. A power device, characterized in that: A main MOSFET and an auxiliary MOSFET are integrated at the same time, and the auxiliary MOSFET serves as a current detection sensor; The main MOSFET includes a first source region and a first gate structure formed on the front side of the semiconductor substrate and a first drain region formed on the back side of the semiconductor substrate, wherein the first source region is connected to a main source pad composed of a front side metal layer; The first gate is connected to a gate pad composed of a front metal layer, and the first drain region is connected to a drain pad composed of a back metal layer; The auxiliary MOSFET includes a second source region and a second gate structure and the first drain region formed on the front surface of the semiconductor substrate, the second gate structure is connected to the gate pad, and the second source region is connected to an auxiliary source pad composed of a front metal layer; The layout structure of power devices includes: Rectangular active area; The gate pad and the auxiliary source pad are disposed on a top portion of a selected region of the active region near a first edge of the active region, with a gap between the gate pad and the auxiliary source pad; The main source pad is located on the top of the active area outside the gate pad and the auxiliary source pad; The area of ​​the main source pad is larger than the area of ​​the auxiliary source pad; The auxiliary MOSFET is located in the active area at the bottom of the auxiliary source pad; The power device is also integrated with a first temperature sensor and a second temperature sensor; The main MOSFET further includes a body region doped with the second conductivity type formed on the semiconductor substrate, a drift region doped with the first conductivity type formed at the bottom of the body region, the drift region being composed of the semiconductor substrate doped with the first conductivity type or a first epitaxial layer doped with the first conductivity type formed on top of the semiconductor substrate, and the first drain region being formed on the back side of the drift region; A body diode is formed between the body region and the drift region; The first temperature sensor is formed by the body diode located in the edge area of ​​the active area; The second temperature sensor is formed by the body diode located in the central area of ​​the active region; A selected corner area of ​​the active area is a circuit-free area; The first temperature sensor is located in the circuit-free area. When the power device is turned on, no current flows in the circuit-free area. The body region of the body diode of the first temperature sensor is connected to a first anode pad composed of a front metal layer, and the cathode pad of the first temperature sensor is the drain pad. The second temperature sensor is located at a selected position in the central area of ​​the active region, the top of the body region at the selected position of the second temperature sensor is connected to a first metal block composed of a front metal layer, the first metal block is connected to a second anode pad through a first metal lead, and the cathode pad of the second temperature sensor adopts the drain pad; The second anode pad is located on a top portion of a selected region of the active region near a first edge of the active region, and a gap is formed between the second anode pad and the gate pad and the auxiliary source pad. The covering area of ​​the main source pad is located outside the circuit-free area, the second anode pad, the first metal block and the first metal lead; The power device also integrates a current-limited source-drain on-resistance sensor; The current limiting source-drain on-resistance sensor is located at a selected position in the central area of ​​the active area, the surface of the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is exposed, and the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is isolated from the body region on the peripheral side; The top of the drift region in the formation area of ​​the current limiting source-drain on-resistance sensor is connected to a second metal block composed of a front metal layer; The second metal block is connected to the first resistance pad via a second metal lead, and the second resistance pad of the current-limiting source-drain on-resistance sensor adopts the drain pad; The first resistor pad is located on a top portion of a selected region of the active region near a first edge of the active region, and there are spaces between the first resistor pad, the second anode pad, the gate pad, and the auxiliary source pad. There is a gap between the first metal block and the second metal block; The covering area of ​​the main source pad is also located outside the first resistor pad and the second metal lead; The first vertex of the corner area corresponding to the circuit-free area is the first endpoint of the first edge.

2. The power device according to claim 1, wherein: The gate pad is also disposed in the non-circuit region. There is a distance between the gate pad and the first anode pad. One vertex of the first anode pad is located on a first vertex of the non-circuit region.

3. The power device according to claim 2, wherein: The circuit-free area is rectangular; One vertex of the gate pad is located on the second vertex of the non-circuit area, and the first vertex and the second vertex of the non-circuit area are two diagonal vertices.

4. The power device according to claim 2, wherein: The first resistor pad, the first anode pad, the second anode pad, the gate pad and the auxiliary source pad are all rectangular; One side of the first resistor pad, the second anode pad, and the auxiliary source pad are all located on the first edge.

5. The power device according to claim 4, wherein: In a direction from a first end point to a second end point of the first edge, the first resistor pad, the second anode pad, and the auxiliary source pad are arranged in the following order: the auxiliary source pad, the first resistor pad, and the second anode pad; the auxiliary source pad, the second anode pad, and the first resistor pad.

6. The power device according to claim 1, wherein: One vertex of the first anode pad is located on a first vertex of the non-circuit area; and the gate pad is also arranged outside the non-circuit area.

7. The power device according to claim 6, wherein: The circuit-free area is rectangular.

8. The power device according to claim 7, wherein: The first resistor pad, the first anode pad, the second anode pad, the gate pad and the auxiliary source pad are all rectangular; One side of the gate pad, the first resistor pad, the second anode pad and the auxiliary source pad are all located on the first edge; A side of the gate pad that is perpendicular to the first edge is located on a side of the non-circuit area.

9. The power device according to claim 8, wherein: In a direction from a first end point to a second end point of the first edge, the first resistor pad, the second anode pad, and the auxiliary source pad are arranged in the following order: the auxiliary source pad, the first resistor pad, and the second anode pad; the auxiliary source pad, the second anode pad, and the first resistor pad.

10. The power device according to claim 5 or 9, wherein: The first metal lead and the second metal lead are both parallel to a first middle line and located on both sides of the first middle line. The first middle line is a line passing through the midpoint of the first edge and perpendicular to the first edge.

11. The power device according to claim 10, wherein: The size of the first metal block is larger than the size of the second metal block; The top edge of the second metal block is located at the bottom of the bottom edge of the first metal block; or, the top edge and bottom edge of the second metal block are located between the top edge and bottom edge of the first metal block; The top edge and the bottom edge of the first metal block and the top edge and the bottom edge of the second metal block are parallel to the first edge; The bottom edge of the first metal block is closer to the first edge than the top edge, and the bottom edge of the second metal block is closer to the first edge than the top edge; The bottom of the bottom edge of the second metal block is an area between the bottom edge of the second metal block and the first edge.

12. The power device according to claim 1, wherein: The size of the formation area of ​​the current-limiting source-drain on-resistance sensor is 20 μm*20 μm.

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