Integrated temperature measuring device and power semiconductor device

Abstract

The invention relates to the technical field of semiconductors, and discloses an integrated temperature measuring device and a power semiconductor device. The integrated temperature measuring device comprises a cathode, the cathode comprises a target cathode comb in the power semiconductor device and a metal wire connected with the target cathode comb, or the cathode is a metal wire connected with a comb missing area in the target cathode comb, wherein the sliver missing area is at least communicated with one edge of the target cathode sliver; the PN junction is positioned below the target cathode sliver and is closest to the target cathode sliver; the anode is a gate pole of the power semiconductor device, a gap exists between the cathode and the cathode molybdenum sheet, and the integrated temperature measuring device is used for measuring the junction temperature of the PN junction through an electric signal between the cathode and the anode. On-line measurement of the working junction temperature of the PN junction of the device can be realized through the temperature measuring device integrated in the device.

Description

Technical Field

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

[0002] In practical applications, power semiconductor devices (especially high-voltage and high-power semiconductor devices, such as Figure 1A or Figure 1B As shown in the figure, due to the large current flow and the large amount of heat generated during the switching process, the device temperature works at a relatively high temperature (typically 90°C), which is generally called the working junction temperature. When the device is working, the working junction temperature will affect the working life of the device. At present, the working life of the device is mainly estimated by testing the device case temperature, the junction temperature of the thermal resistance device, and the life model.

[0003] However, existing measurement methods have disadvantages such as difficulty in online detection and only being able to obtain the average junction temperature of the device. Summary of the invention

[0004] The object of the present invention is to provide an integrated temperature measuring device and a power semiconductor device, which can realize online measurement of the working junction temperature of the PN junction of the device through the temperature measuring device integrated inside the power semiconductor device.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides an integrated temperature measuring device, which includes: a cathode, wherein the cathode includes a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, or the cathode is a metal wiring connected to a comb bar missing area in the target cathode comb bar, wherein the comb bar missing area is at least connected to one edge of the target cathode comb bar; a PN junction located below the target cathode comb bar and closest to the target cathode comb bar; and an anode, wherein the anode is the gate of the power semiconductor device, wherein there is a gap between the cathode and the cathode molybdenum sheet in the power semiconductor device, and the integrated temperature measuring device is used to measure the junction temperature of the PN junction through the electrical signal between the cathode and the anode.

[0006] Preferably, when the cathode includes a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, the thickness of the target cathode comb bar is less than the thickness of other cathode comb bars, and the thickness of the metal wiring is less than or equal to the thickness of the target cathode comb bar.

[0007] Preferably, the thickness of the target cathode comb bars is 10%-60% of the thickness of the other cathode comb bars.

[0008] Preferably, the thickness of the target cathode comb bars is 35%-45% of the thickness of the other cathode comb bars.

[0009] Preferably, in the case where the cathode is a metal wiring connected to the comb bar missing area in the target cathode comb bar, the thickness of the metal wiring is smaller than the thickness of the target cathode comb bar.

[0010] Preferably, the length of the comb bar missing area is less than or equal to 1 / 2 of the length of the target cathode comb bar.

[0011] Preferably, the center of the comb bar missing area is aligned with the center of the target cathode comb bar.

[0012] Preferably, the integrated temperature measuring device also includes: a first metal pad connected to the cathode; a second metal pad connected to the anode, wherein the first metal pad and the second metal pad are arranged at the edge of the power semiconductor device; a first metal lead connected to the first metal pad for leading out the electrical signal of the cathode; and a second metal lead connected to the second metal pad for leading out the electrical signal of the anode.

[0013] Preferably, the integrated temperature measuring device also includes: a first metal pad connected to the cathode; a second metal pad connected to the anode, wherein the first metal pad and the second metal pad are arranged at the edge of the power semiconductor device; a first spring probe connected to the first metal pad for leading out the electrical signal of the cathode; and a second spring probe connected to the second metal pad for leading out the electrical signal of the anode.

[0014] Through the above technical scheme, the present invention creatively sets the cathode as: a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, or a metal wiring connected to a comb bar missing area in the target cathode comb bar, based on the existing PN junction structure of the device, wherein the comb bar missing area is at least connected to one edge of the target cathode comb bar; the anode is set as the gate of the power semiconductor device, thereby forming a temperature measuring device integrated inside the power semiconductor device, and the online measurement of the working junction temperature of the PN junction of the device is achieved through the temperature measuring device.

[0015] A second aspect of the present invention provides a power semiconductor device, the power semiconductor device comprising: a plurality of the above-mentioned integrated temperature measuring devices.

[0016] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1A is a schematic diagram of a unit cell structure in a conventional power semiconductor device; Figure 1B It is a top view of a conventional power semiconductor device; Figure 2 is a schematic structural diagram of an integrated temperature measuring device provided by an embodiment of the present invention; Figure 3 is a schematic structural diagram of an integrated temperature measuring device provided by an embodiment of the present invention; Figure 4 is a positional relationship diagram between the integrated temperature measuring device and the cathode molybdenum sheet provided in one embodiment of the present invention; Figure 5 is a three-dimensional schematic diagram of metal wiring of an integrated temperature measurement device provided by an embodiment of the present invention; and Figure 6 Schematic diagram of the plane (xz) of the metal wiring of the integrated temperature measurement device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0019] Figure 2 FIG. 1 is a schematic diagram of the structure of an integrated temperature measuring device provided by an embodiment of the present invention. Figure 2 As shown, the integrated temperature measuring device includes: a cathode 1, a PN junction 2, and an anode 3, wherein the integrated temperature measuring device is a temperature-sensitive diode integrated inside a power semiconductor device, and is used to measure the junction temperature of a PN junction with the smallest junction depth in the power semiconductor device through an electrical signal between the cathode 1 and the anode 3.

[0020] The cathode 1 includes a target cathode comb bar 10 in a power semiconductor device and a metal wiring 12 connected to the target cathode comb bar 10. Figure 2 Alternatively, in another embodiment, the cathode 1 is a metal wiring 12 connected to the target cathode comb strip 10 in the comb strip missing region 16, as shown in FIG. Figure 3 As shown, the comb strip missing area 16 is at least connected to one edge of the target cathode comb strip 10. Of course, the present invention is not limited to Figure 3 The comb bar missing area 16 shown is connected to two edges of the target cathode comb bar 10 and can be set according to actual needs.

[0021] There is a gap g between the cathode 1 and the cathode molybdenum sheet 4 in the power semiconductor device, such as Figure 4 shown.

[0022] The PN junction 2 is a PN junction below the target cathode comb bar and closest to the target cathode comb bar. Taking the IGCT device as an example, the PN junction is the original IGCT device. Figure 2-4 The cathode region (i.e. n 2 region) and P+ base region (i.e. P 2 + region) formed by a PN junction (i.e., J3 junction); taking MOSFET and IGBT as examples, the PN junction is the PN junction between the P-well region and the n-drift region.

[0023] Wherein, the anode 3 is the gate of the power semiconductor device, such as Figure 2-4 That is to say, the gate metal of the power semiconductor device is also the anode of the temperature sensitive diode.

[0024] In this embodiment, the integrated temperature measuring device is used to measure the junction temperature of the PN junction through the electrical signal between the cathode 1 and the anode 3 .

[0025] The following are Figure 2 and Figure 3 We analyze two situations. (1) For Figure 2 For the cathode 1 shown, since there is a gap between the cathode 1 and the cathode molybdenum sheet 4 and the cathode 1 includes the entire target cathode comb bar 10, when the chip is crimped and packaged, the target cathode comb bar 10, the metal wiring 12 and other cathode comb bars in the device are insulated, so that the PN junction under the target cathode comb bar can be used to form a PN junction of a temperature-sensitive diode, and it can be led out to the edge of the chip through the metal wiring 12. (2) For Figure 3 As for the cathode 1 shown in the figure, since there is a gap between the cathode 1 and the cathode molybdenum sheet 4, the target cathode comb 10 itself is provided with a comb missing area 16, and the metal wiring 12 is connected to the comb missing area 16, when the chip is crimped and packaged, the metal wiring 12 is insulated from all cathode combs in the device (including the target cathode comb), so that the PN junction under the target cathode comb can be used to form a PN junction of a temperature-sensitive diode, and it can be led out to the edge of the chip through the metal wiring 12. Figure 2 Compared to cathode 1, Figure 3 The cathode 1 shown only utilizes a partial area in the target cathode comb bar, so the remaining portion can still serve as the cathode of the power semiconductor device together with other cathode comb bars.

[0026] exist Figure 2 In the structure shown, the metal wiring is not connected to any other cathode comb bars; Figure 3 In the structure shown, the metal wiring is not connected to any cathode comb bar (including the target cathode comb bar).

[0027] This embodiment can realize the online measurement of the junction temperature of the power semiconductor device, without the need for additional infrared, temperature patch and other measuring devices, and without relying on the thermal resistance of the device.

[0028] In one embodiment, when the cathode includes a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, the thickness of the target cathode comb bar is less than the thickness of other cathode comb bars, and the thickness of the metal wiring is less than or equal to the thickness of the target cathode comb bar.

[0029] like Figure 2 As shown, in order to ensure the insulation of the temperature-sensitive diode cathode from other cathodes in the device, the heights of the two need to be different. Specifically, the thickness of the target cathode comb bar 10 can be reduced so that the target cathode comb bar 10 and other cathode comb bars (such as cathode comb bar 14, for conventional power semiconductor devices, all cathode comb bars have the same thickness, but in this embodiment, the thickness of the target cathode comb bar 10 is less than the thickness of other cathode comb bars 14) are insulated when the chip is crimped and packaged, and the electrical signal of the cathode 1 is led out to the edge of the chip through the metal wiring 12, wherein the thickness of the metal wiring 12 is less than or equal to the thickness of the target cathode comb bar 10, so the cathode 1 formed by the target cathode comb bar 10 and the metal wiring 12 can form a gap with the cathode molybdenum sheet 4.

[0030] In this embodiment, taking the IGCT device as an example, the PN junction 2 is the J3 junction below the target cathode comb bar 10, such as Figure 2 The cathode region (i.e. n 2 region) and P+ base region (i.e. P 2 + region) to form a PN junction.

[0031] The target cathode comb strip thickness is 10%-60% of the thickness of the other cathode comb strips, thereby not only reducing the voltage drop of the cathode metal wiring of the temperature-sensitive diode and improving the compatibility with the gate metal thickness of the power semiconductor device (such as GCT), but also ensuring the insulation between the cathode of the temperature-sensitive diode and the cathode of the power semiconductor device (such as GCT). Preferably, the target cathode comb strip thickness is 35%-45% of the thickness of the other cathode comb strips.

[0032] like Figure 2As shown, the left sub-figure is a cross-sectional view of the device corresponding to the conventional cathode comb position, which represents the conventional unit cell structure of the power semiconductor device; the right sub-figure represents a cross-sectional view of the device at the target cathode comb position, which represents the temperature-sensitive diode structure. The two structures are designed as two different chip unit structures.

[0033] In another embodiment, when the cathode is a metal wiring connected to the comb bar missing area in the target cathode comb bar, the thickness of the metal wiring is smaller than the thickness of the target cathode comb bar.

[0034] like Figure 3 As shown, a part of the target cathode comb bar can be removed by various existing methods to obtain a comb bar missing area 16 connected to the two edges of the target cathode comb bar, and the temperature sensitive diode is set at the comb bar missing area 16. Specifically, the comb bar missing area 16 can be formed on the target cathode comb bar 10, and the thickness of the metal wiring 12 is set to be less than the thickness of the target cathode comb bar, so that when the chip is crimped and packaged: the metal wiring 12 connected to the comb bar missing area 16 is insulated from other areas in the target cathode comb bar 10 and other cathode comb bars (such as other cathode comb bars 14, the thickness of all cathode comb bars for conventional power semiconductor devices is equal); and the cathode signal of the nearest PN junction (such as J3 junction) below the comb bar missing area 16 is led out to the edge of the chip through the metal wiring 12, so that the cathode 1 formed by the metal wiring 12 can form a gap with the cathode molybdenum sheet 4.

[0035] In this embodiment, taking IGCT as an example, the PN junction 2 is the J3 junction below the target cathode comb bar. Figure 3 The cathode region (i.e. n 2 region) and P+ base region (i.e. P 2 + region) to form a PN junction.

[0036] Wherein, the length of the comb bar missing area is less than or equal to 1 / 2 of the length of the target cathode comb bar.

[0037] Preferably, the center of the comb strip missing area is aligned with the center of the target cathode comb strip. In this embodiment, the temperature-sensitive diode structure is arranged in the middle of the cathode comb strip, which can further bring the measurement point closer to the high temperature area where the current is concentrated, thereby more effectively measuring the junction temperature of the PN junction (such as the J3 junction in the IGCT device) there, with higher measurement accuracy.

[0038] like Figure 5As shown, the right sub-figure shows the structural schematic diagram of the target cathode comb 10 and its metal wiring 12 containing the comb missing area 16, wherein the black area is the target cathode comb 10 / cathode metal, the red area is the cathode 1 of the temperature sensitive diode, the blue stripe is the gate (also the anode 3 of the temperature sensitive diode), the blue area is the isolation oxide layer, and the yellow area is the cathode area (i.e., the cathode doped n-type silicon area, abbreviated as n 2 area); the upper left sub-figure is a cross-sectional view of the device corresponding to the cathode comb position, which represents the conventional unit cell structure of the power semiconductor device; the lower left sub-figure is a cross-sectional view of the device corresponding to the comb missing area, which represents the temperature sensitive diode structure. The two are integrated on a chip unit structure with a higher degree of integration.

[0039] In one embodiment, the integrated temperature measuring device further includes: a first metal pad 18 (such as Figure 2 or Figure 3 as shown), connected to the cathode 1; a second metal pad (not shown), connected to the anode 3, wherein the first metal pad 18 and the second metal pad are arranged at the edge of the power semiconductor device; a first metal lead (not shown), connected to the first metal pad 18, for leading out the electrical signal of the cathode 1; and a second metal lead (not shown), connected to the second metal pad, for leading out the electrical signal of the anode 3.

[0040] In another embodiment, the integrated temperature measuring device further includes: a first metal pad 18 (such as Figure 2 or Figure 3 as shown), connected to the cathode 1; a second metal pad (not shown), connected to the anode 3, wherein the first metal pad 18 and the second metal pad are arranged at the edge of the power semiconductor device; a first spring probe (not shown), connected to the first metal pad 18, for leading out the electrical signal of the cathode 1; and a second spring probe (not shown), connected to the second metal pad, for leading out the electrical signal of the anode 3.

[0041] The present invention can measure the junction temperature of the PN junction of the power semiconductor device through the electrical signal between the cathode and the anode, thereby realizing actual online measurement of the junction temperature without relying on the thermal resistance of the device.

[0042] In the above embodiments, the cathode of the power semiconductor device is vertically connected to the outside through the metal molybdenum plate; while the integrated temperature measuring device (i.e., the temperature sensitive diode) needs to be connected with the help of horizontal metal wiring (such as Figure 5 or Figure 6 As shown in the figure, it is led out to the edge of the chip, and an independent metal pad is designed. Finally, it is connected to the outside through metal bonding or spring probes, and the external integrated control system realizes the online measurement of junction temperature.

[0043] In the above embodiments, the target cathode comb bar can be one or more, and can be set according to actual needs. Figure 2 or Figure 3 As shown, four target cathode combs can be selected as measurement points. The specific structure of each temperature-sensitive diode can be found in the above description, which will not be repeated here.

[0044] To summarize, the present invention creatively sets the cathode as: a target cathode bar in a power semiconductor device and a metal wiring connected to the target cathode bar, or a metal wiring connected to a bar missing area in the target cathode bar, based on the existing PN junction structure of the device, wherein the bar missing area is connected to at least one edge of the target cathode bar; the anode is set as the gate of the power semiconductor device, thereby forming a temperature measuring device integrated inside the power semiconductor device, and the online measurement of the working junction temperature of the PN junction of the device is achieved through the temperature measuring device.

[0045] An embodiment of the present invention provides a power semiconductor device, and the power semiconductor device includes: a plurality of the above-mentioned integrated temperature measurement devices.

[0046] As needed, multiple temperature measurement points can be set inside the chip (for example, Figure 2 or Figure 3 The 4 measurement points shown in the figure can be used to measure the temperature at different locations inside the chip.

[0047] In the above-mentioned embodiments, IGCT (Integrated Gate Commutated Thyristor) is mainly used as an example for explanation and description, wherein the IGCT device includes not only a reverse-blocking IGCT device, but also an asymmetric IGCT device. Of course, the present invention is not only applicable to GCT devices, but also to IGBT (Insulate-Gate Bipolar Transistor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), GTO (gate turn-off thyristor), and other power devices with radial and annular distribution of cathode regions. The substrate material of the power device is not limited to silicon, but can also be a third-generation semiconductor material such as silicon carbide or gallium nitride.

[0048] In each of the above embodiments, the power semiconductor device includes: an IGCT device, an IGBT device, a MOSFET device, and a GTO device.

[0049] In power semiconductor devices (such as IGCT, GTO, etc.), an integrated temperature-sensitive diode is designed by utilizing the existing PN junction structure of the device to realize online testing of the working junction temperature of the device.

[0050] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0052] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An integrated temperature measuring device, characterized in that: The integrated temperature measuring device comprises: A cathode, the cathode comprising a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, or the cathode is a metal wiring connected to a comb bar missing region in the target cathode comb bar, wherein the comb bar missing region is at least connected to one edge of the target cathode comb bar; a PN junction located below the target cathode comb bar and closest to the target cathode comb bar; and an anode, wherein the anode is a gate of the power semiconductor device, There is a gap between the cathode and the cathode molybdenum sheet in the power semiconductor device, and the integrated temperature measuring device is used to measure the junction temperature of the PN junction through the electrical signal between the cathode and the anode.

2. The integrated temperature measuring device according to claim 1, characterized in that: In the case where the cathode includes a target cathode comb bar in a power semiconductor device and a metal wiring connected to the target cathode comb bar, the thickness of the target cathode comb bar is less than the thickness of other cathode comb bars, and the thickness of the metal wiring is less than or equal to the thickness of the target cathode comb bar.

3. The integrated temperature measuring device according to claim 2, characterized in that: The thickness of the target cathode comb bars is 10%-60% of the thickness of the other cathode comb bars.

4. The integrated temperature measuring device according to claim 2, characterized in that: The thickness of the target cathode comb bars is 35%-45% of the thickness of the other cathode comb bars.

5. The integrated temperature measuring device according to claim 1, characterized in that: In the case where the cathode is a metal wiring connected to the comb bar missing region in the target cathode comb bar, the thickness of the metal wiring is smaller than the thickness of the target cathode comb bar.

6. The integrated temperature measuring device according to claim 5, characterized in that: The length of the comb bar missing area is less than or equal to 1 / 2 of the length of the target cathode comb bar.

7. The integrated temperature measuring device according to claim 5, characterized in that: The center of the comb bar missing area is aligned with the center of the target cathode comb bar.

8. The integrated temperature measuring device according to claim 1, characterized in that: The integrated temperature measuring device also includes: A first metal pad connected to the cathode; A second metal pad connected to the anode, wherein the first metal pad and the second metal pad are arranged at the edge of the power semiconductor device; A first metal lead, connected to the first metal pad, for leading out an electrical signal of the cathode; and The second metal lead is connected to the second metal pad and is used to lead out the electrical signal of the anode.

9. The integrated temperature measuring device according to claim 1, characterized in that: The integrated temperature measuring device also includes: A first metal pad connected to the cathode; A second metal pad connected to the anode, wherein the first metal pad and the second metal pad are arranged at the edge of the power semiconductor device; A first spring probe, connected to the first metal pad, for extracting an electrical signal from the cathode; and The second spring probe is connected to the second metal pad and is used to lead out the electrical signal of the anode.

10. A power semiconductor device, characterized in that: The power semiconductor device comprises: a plurality of integrated temperature measuring devices according to any one of claims 1-9.

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