Integrated temperature measuring device and power semiconductor device

Abstract

The present invention relates to the field of semiconductor technology, and discloses an integrated temperature measuring device and a power semiconductor device. The integrated temperature measuring device includes: a cathode, where the cathode includes a target cathode comb bar in the 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, where the comb bar missing area is at least in communication with 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, where the anode is the gate of the power semiconductor device, where there is a gap between the cathode and the cathode molybdenum sheet, and the integrated temperature measuring device is used to measure the junction temperature of the PN junction through an electrical signal between the cathode and the anode. The present invention can realize the on-line measurement of the operating junction temperature of the PN junction of the device through a temperature measuring device integrated inside the device.

Description

Technical Field

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

[0002] In the actual application process, power semiconductor devices (especially high-voltage high-power semiconductor devices, such as Figure 1A or Figure 1B as shown) generate a large amount of heat during the large current conduction and switching processes, causing the device temperature to work at a relatively high temperature (typically 90 °C), which is generally referred to as the operating junction temperature. When the device is working, the operating junction temperature will affect the service life of the device. At present, the device case temperature is mainly measured, the junction temperature of the device is obtained through the thermal resistance, and the service life of the device is estimated through the life model.

[0003] However, the 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 purpose of the present invention is to provide an integrated temperature measuring device and a power semiconductor device, which can realize the online measurement of the operating junction temperature of the PN junction of the device through the temperature measuring device integrated inside the power semiconductor device.

[0005] To achieve the above purpose, in the first aspect of the present invention, an integrated temperature measuring device is provided. The integrated temperature measuring device includes: a cathode, the cathode includes a target cathode comb bar in the 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, where 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, 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 the 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 bar is 10%-60% of the thickness of the other cathode comb bars.

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

[0009] Preferably, 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 less 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 further 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 disposed 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 further 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 disposed 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 solution, the present invention creatively, on the basis of the existing PN junction structure of the device, sets the cathode as: the target cathode comb-bar in the power semiconductor device and the metal wiring connected to the target cathode comb-bar, or the metal wiring connected to the 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; sets the anode as the gate of the power semiconductor device, thereby forming a temperature measuring device integrated inside the power semiconductor device, and realizing the on-line measurement of the operating junction temperature of the PN junction of the device through the temperature measuring device.

[0015] The second aspect of the present invention provides a power semiconductor device, which includes: a plurality of the above integrated temperature measuring devices.

[0016] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation part. Brief Description of the Drawings

[0017] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and form a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not limit the embodiments of the present invention. In the accompanying drawings:

[0018] Figure 1A is a schematic diagram of a unit cell structure in a conventional power semiconductor device;

[0019] Figure 1B is a top view of a conventional power semiconductor device;

[0020] Figure 2 is a schematic diagram of the structure of an integrated temperature measuring device provided by an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of the structure of an integrated temperature measuring device provided by an embodiment of the present invention;

[0022] Figure 4 is a diagram showing the positional relationship between the integrated temperature measuring device provided by an embodiment of the present invention and the cathode molybdenum sheet;

[0023] Figure 5 is a three-dimensional schematic diagram of the metal wiring of the integrated temperature measuring device provided by an embodiment of the present invention; and

[0024] Figure 6 is a planar (xz) schematic diagram of the metal wiring of the integrated temperature measuring device provided by an embodiment of the present invention. Detailed Description of the Embodiments

[0025] The following describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0026] Figure 2 is a schematic diagram of the structure of an integrated temperature measuring device provided by an embodiment of the present invention. As Figure 2 shown, the integrated temperature measuring device includes: a cathode 1, a PN junction 2, and an anode 3. Among them, 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 the PN junction with the smallest junction depth in the power semiconductor device through the electrical signal between the cathode 1 and the anode 3.

[0027] Among them, the cathode 1 includes a target cathode comb bar 10 in the power semiconductor device and a metal wiring 12 connected to the target cathode comb bar 10, as Figure 2 shown. Alternatively, in another embodiment, the cathode 1 is a metal wiring 12 connected to the comb bar missing area 16 in the target cathode comb bar 10, as Figure 3As 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.

[0028] 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.

[0029] 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. Figures 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.

[0030] Wherein, the anode 3 is the gate of the power semiconductor device, such as Figures 2-4 That is to say, the gate metal of the power semiconductor device is also the anode of the temperature sensitive diode.

[0031] 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 .

[0032] 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 shown, Figure 3The cathode 1 shown only utilizes a partial area of the target cathode comb bar, so the non-missing part can still bear the cathode of the power semiconductor device together with other cathode comb bars.

[0033] In Figure 2 the structure shown, the metal wiring is not connected to any other cathode comb bar; in Figure 3 the structure shown, the metal wiring is not connected to any cathode comb bar (including the target cathode comb bar).

[0034] This embodiment can realize the on-line measurement of the junction temperature of the power semiconductor device, without the need for additional measurement devices such as infrared and temperature patches, and without relying on the thermal resistance of the device.

[0035] In one embodiment, when the cathode includes the target cathode comb bar in the power semiconductor device and the 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.

[0036] As Figure 2 shown, in order to ensure the insulation between the cathode of the temperature-sensitive diode and other cathodes in the device, it is necessary to make their heights different. Specifically, the thickness of the target cathode comb bar 10 can be reduced so that when the chip is press-packaged, the target cathode comb bar 10 is insulated from other cathode comb bars (such as the cathode comb bar 14, and the thicknesses of all cathode comb bars of a conventional power semiconductor device are equal, but in this embodiment, the thickness of the target cathode comb bar 10 is less than the thickness of other cathode comb bars 14), and the electrical signal of the cathode 1 is led out to the chip edge through the metal wiring 12, where the thickness of the metal wiring 12 is less than or equal to the thickness of the target cathode comb bar 10, so a gap can be formed between the cathode 1 formed by the target cathode comb bar 10 and the cathode molybdenum sheet 4.

[0037] 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, as Figure 2 shown in the cathode region (i.e., the n 2 region) and the P+ base region (i.e., the P 2 + region) to form a PN junction.

[0038] Among them, the thickness of the target cathode comb bar is 10%-60% of the thickness of the other cathode comb bars. This can not only reduce the voltage drop of the cathode metal wiring of the temperature-sensitive diode and improve the compatibility with the gate metal thickness of the power semiconductor device (such as GCT), but also ensure the insulation between the cathode of the temperature-sensitive diode and the cathode of the power semiconductor device (such as GCT). Preferably, the thickness of the target cathode comb bar is 35%-45% of the thickness of the other cathode comb bars.

[0039] As Figure 2 shown, the left sub - figure is a device cross - section corresponding to the position of the conventional cathode comb bar, which represents the conventional unit cell structure of the power semiconductor device; the right sub - figure represents the device cross - section of the target cathode comb bar position, which represents the temperature - sensitive diode structure, and the two structures are designed as two different chip unit structures.

[0040] 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 less than the thickness of the target cathode comb bar.

[0041] As Figure 3 shown, part of the target cathode comb bar can be removed by various existing methods to obtain a comb - bar missing area 16 connected to both edges of the target cathode comb bar, and the temperature - sensitive diode is arranged at the comb - bar missing area 16. Specifically, a 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 press - fit 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 (for example, other cathode comb bars 14, and the thickness of all cathode comb bars of a conventional power semiconductor device is equal); and, the cathode signal of the nearest PN - junction (such as the J3 - junction) below the comb - bar missing area 16 is led out to the chip edge through the metal wiring 12, so a gap can be formed between the cathode 1 formed by the metal wiring 12 and the cathode molybdenum sheet 4.

[0042] In this embodiment, taking IGCT as an example, the PN - junction 2 is the J3 - junction below the target cathode comb bar, as Figure 3 shown in the cathode region (i.e., the n 2 region) and the P + base region (i.e., the P 2 + region) form a PN - junction.

[0043] 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.

[0044] Preferably, the center of the comb - bar missing area is aligned with the center of the target cathode comb bar. In this embodiment, arranging the temperature - sensitive diode structure in the middle of the cathode comb bar can further make the measurement point closer to the high - temperature area where the current is concentrated, so that the junction temperature of the PN - junction (such as the J3 - junction in the IGCT device) at this place can be measured more effectively, and the measurement accuracy is higher.

[0045] As Figure 5As shown, the right sub - figure shows a schematic structural diagram of the target cathode comb 10 with a missing comb - bar region 16 and its metal wiring 12. Among them, the black region is the target cathode comb 10 / cathode metal, the red region is the cathode 1 of the temperature - sensitive diode, the blue stripes are the gates (which are also the anodes 3 of the temperature - sensitive diodes), the blue region is the isolation oxide layer, and the yellow region is the cathode region (i.e., the cathode - doped n - type silicon region, abbreviated as n 2 region); the upper - left sub - figure is a device cross - sectional view corresponding to the position of the cathode comb, which represents the conventional unit cell structure of the power semiconductor device; the lower - left sub - figure is a device cross - sectional view corresponding to the missing comb - bar region, which represents the temperature - sensitive diode structure. The two are integrated on a chip unit structure, with a higher integration degree.

[0046] In one embodiment, the integrated temperature - measuring device further includes: a first metal pad 18 (as shown in Figure 2 or Figure 3 ), 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.

[0047] In another embodiment, the integrated temperature - measuring device further includes: a first metal pad 18 (as shown in Figure 2 or Figure 3 ), 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.

[0048] 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 the actual on - line measurement of the junction temperature and not depending on the thermal resistance of the device.

[0049] In the above - mentioned various embodiments, the cathode of the power semiconductor device is vertically led out to the outside through a metal molybdenum plate; while the integrated temperature - measuring device (i.e., the temperature - sensitive diode) needs to be led out to the edge of the chip by means of a lateral metal wiring (as shown in Figure 5 or Figure 6 ), and an independent metal pad is designed. Finally, it is connected out to the outside through wire bonding or spring probes, and the external integrated control system realizes the on - line measurement of the junction temperature.

[0050] In each of the above embodiments, the target cathode comb bars can be one or more, which can be set according to actual needs. For example, Figure 2 or Figure 3 as shown, 4 target cathode comb bars can be selected as measurement points. For the specific structure of each temperature-sensitive diode, reference can be made to the above description, which will not be elaborated here.

[0051] In summary, the present invention creatively, on the basis of the existing PN junction structure of the device, sets the cathode as: the target cathode comb bars in the power semiconductor device and the metal wiring connected to the target cathode comb bars, or the metal wiring connected to the comb bar missing area in the target cathode comb bars, where the comb bar missing area is at least connected to one edge of the target cathode comb bars; sets the anode as the gate of the power semiconductor device, thereby forming a temperature measurement device integrated inside the power semiconductor device, and realizes the on-line measurement of the working junction temperature of the PN junction of the device through this temperature measurement device.

[0052] An embodiment of the present invention provides a power semiconductor device, which includes: a plurality of the above integrated temperature measurement devices.

[0053] According to needs, multiple temperature measurement points can be set inside the chip (for example, Figure 2 or Figure 3 the 4 measurement points shown), to realize the temperature measurement at different positions inside the chip.

[0054] In each of the above embodiments, mainly IGCT (Integrated Gate Commutated Thyristor) is taken as an example for explanation and illustration. Among them, the IGCT device includes not only reverse-blocking IGCT devices, but also asymmetric IGCT devices. Of course, the present invention is not only applicable to GCT devices, but also applicable 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 distributions in the cathode region. The substrate material of the power device is not limited to silicon, and can also be a third-generation semiconductor material such as silicon carbide or gallium nitride.

[0055] In each of the above embodiments, the power semiconductor device includes: an IGCT device, an IGBT device, a MOSFET device, and a GTO device.

[0056] 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 achieve on-line measurement of the operating junction temperature of the device.

[0057] The preferred embodiments of the present invention have been 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 scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0058] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination manners.

[0059] Furthermore, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content 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. When the cathode includes a target cathode comb bar in the 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.

2. The integrated temperature measuring device according to claim 1, characterized in that: The thickness of the target cathode comb bars is 10%-60% of the thickness of the other cathode comb bars.

3. The integrated temperature measuring device according to claim 1, characterized in that: The thickness of the target cathode comb bars is 35%-45% of the thickness of the other cathode comb bars.

4. 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.

5. The integrated temperature measuring device according to claim 4, 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.

6. The integrated temperature measuring device according to claim 4, characterized in that: The center of the comb bar missing area is aligned with the center of the target cathode comb bar.

7. 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.

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 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.

9. 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 1-8.

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