IGBT device

Abstract

This invention provides an IGBT device. A temperature sensor is integrated on one side of the cell region within the IGBT device to monitor the device's actual temperature in real time. Multiple diodes are connected in series within the temperature sensor to amplify the temperature sensing signal, improving measurement accuracy and sensitivity, and enhancing the anti-interference capability of the temperature sensing. Each diode is located on the field oxide layer to achieve electrical isolation. Furthermore, the field oxide layer has a specific size to prevent high-voltage breakdown and enhance device reliability. Each diode also has an N-type doped region and a P-type doped region; the N-type and P-type doped regions are respectively connected to metal plugs for electrode leads. Furthermore, the metal plugs are of a specific size to reduce contact resistance and further enhance device performance.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to an IGBT device. Background Technology

[0002] An Insulated Gate Bipolar Transistor (IGBT) is a composite, fully controllable, voltage-driven power semiconductor device composed of a Bipolar Junction Transistor (BJT) and a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). IGBTs combine the advantages of both MOS and BJTs. They possess the high input impedance, low control power, simple drive circuitry, fast switching speed, and low switching losses of MOS, while also exhibiting the high current density, low saturation voltage drop, and strong current handling capability of BJTs.

[0003] IGBTs are highly temperature-sensitive; increased internal temperature leads to a larger on-state voltage drop, increased power consumption and heat generation, potentially causing thermal runaway. Furthermore, high temperatures reduce the reverse withstand voltage and surge protection, making them more susceptible to breakdown. Therefore, to ensure safe operation, current technology integrates temperature sensors within the IGBT for real-time temperature monitoring, facilitating overheat protection. However, the measurement accuracy and reliability of existing temperature sensors integrated into the IGBT are limited, failing to achieve the desired monitoring effect.

[0004] Therefore, a new temperature sensor is urgently needed to solve the above-mentioned technical problems. Utility Model Content

[0005] The purpose of this invention is to provide an IGBT device that addresses at least one of the following problems: how to improve the temperature measurement accuracy and sensitivity of the temperature sensor integrated within the IGBT, and how to improve the reliability of the IGBT device.

[0006] To address the aforementioned technical problems, this utility model provides an IGBT device, comprising: a cell region and a temperature sensor located on one side of the cell region; wherein,

[0007] The temperature sensor includes multiple diodes connected in series, and each diode is located on an oxide layer; each diode has an N-type doped region and a P-type doped region; the N-type doped region and the P-type doped region are respectively connected to metal plugs for electrode lead-out.

[0008] Optionally, in the IGBT device, the dimensions of the metal plug satisfy the following formula:

[0009] 1 / 2*Z>d>1 / 3*Z;

[0010] Where Z is the sum of the lengths of the N-type doped region and the P-type doped region; d is the diameter of the metal plug.

[0011] Optionally, in the IGBT device, a portion of the metal plug structure is inserted into the corresponding N-type doped region or the corresponding P-type doped region, and the dimensions of the portion structure satisfy the following formula:

[0012] L<1 / 10H;

[0013] Wherein, L is the thickness of the partial structure, and H is the thickness of the corresponding N-type doped region or the corresponding P-type doped region.

[0014] Optionally, in the IGBT device, the IGBT device has a substrate; the field oxide layer is formed in a portion of the substrate, and the top surface of the field oxide layer is flush with the top surface of the remaining portion of the substrate.

[0015] Optionally, in the IGBT device, the size of the field oxide layer satisfies the following formula:

[0016] X>k*BV;

[0017] (YZ) / 2>Z;

[0018] Where X is the maximum thickness of the field oxide layer, and the unit is nm;

[0019] BV is the reverse breakdown voltage of the temperature sensor, and its unit is V;

[0020] k is a coefficient;

[0021] Y is the maximum length of the field oxide layer;

[0022] Z is the sum of the lengths of the N-type doped region and the P-type doped region.

[0023] Optionally, in the IGBT device, the IGBT device further includes an interlayer dielectric layer; the interlayer dielectric layer covers the N-type doped region and the P-type doped region, as well as a portion of the exposed top surface of the substrate and a portion of the top surface of the field oxide layer;

[0024] One end of the metal plug is connected to the corresponding N-type doped region or the corresponding P-type doped region, and the other end penetrates a portion of the interlayer dielectric layer and extends to the top surface of the interlayer dielectric layer.

[0025] Optionally, in the IGBT device, the temperature sensor further includes a first metal wire and a second metal wire; the first metal wire and the second metal wire are spaced apart on the interlayer dielectric layer and are respectively connected to the metal plugs in each of the diodes to connect the diodes in series.

[0026] In this configuration, the metal plug connected to the N-type doped region in the same diode is connected to one of the first metal line and the second metal line; the metal plug connected to the P-type doped region is connected to the other of the first metal line and the second metal line.

[0027] Optionally, in the IGBT device, the spacing between the first metal line and the second metal line is greater than 5 micrometers.

[0028] Optionally, in the IGBT device, the temperature sensor further includes a first pad and a second pad; the first pad and the second pad are spaced apart on one side of the plurality of series-connected diodes, and the first metal line and the second metal line are respectively connected to the first pad and the second pad along at least a straight line.

[0029] Optionally, in the IGBT device, the temperature sensor includes 4 to 6 diodes; wherein the forward voltage drop of each diode is less than or equal to 0.7V, and the forward voltage drop of the temperature sensor is in the range of 2V to 4V.

[0030] In summary, this invention provides an IGBT device. Compared to existing technologies, the IGBT device integrates a temperature sensor on one side of its internal cell region to monitor the device's actual temperature in real time. Multiple diodes are connected in series within the temperature sensor to amplify the temperature sensing signal, improving measurement accuracy and sensitivity, and enhancing the anti-interference capability of temperature sensing. Furthermore, each diode is located on the field oxide layer to achieve electrical isolation. The field oxide layer has a specific size to prevent high-voltage breakdown and enhance device reliability. Each diode also has an N-type doped region and a P-type doped region; the N-type and P-type doped regions are respectively connected to metal plugs for electrode leads. Furthermore, the metal plugs are of a specific size to reduce contact resistance and further enhance device performance. Therefore, the IGBT device provided by this invention can accurately monitor device temperature in real time, which is beneficial for improving device reliability. Attached Figure Description

[0031] Those skilled in the art will understand that the accompanying drawings are provided to better understand the present invention and do not constitute any limitation on the scope of the present invention.

[0032] Figure 1 This is a planar schematic diagram of the IGBT device in an embodiment of this utility model.

[0033] Figure 2 This is a cross-sectional schematic diagram of the temperature sensor in an embodiment of this utility model.

[0034] Figure 3 This is a circuit diagram of six diodes connected in series in an embodiment of this utility model.

[0035] Figure 4 This is a cross-sectional schematic diagram of two metal plugs corresponding to the N-type doped region and the P-type doped region in an embodiment of this utility model.

[0036] And, in the attached image:

[0037] 100 - Substrate; 101 - Field oxide layer; 102 - N-type doped region; 103 - P-type doped region; 104 - Metal plug; 105 - Interlayer dielectric layer; 106 - First metal line; 107 - Second metal line; 108 - First pad; 109 - Second pad;

[0038] C - Cell region; S - Temperature sensor; D - Diode. Detailed Implementation

[0039] To make the objectives, advantages, and features of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clearly illustrate the purpose of the embodiments of this utility model. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may emphasize different aspects and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0040] Furthermore, in this specification, the x-axis, y-axis, and z-axis are three mutually perpendicular directions in three-dimensional space. Length refers to the dimension along the x-axis, and thickness refers to the dimension along the z-axis.

[0041] Please see Figures 1 to 3This embodiment provides an IGBT device, including: a cell region C and a temperature sensor S located on one side of the cell region C; wherein, the temperature sensor S includes a plurality of diodes D connected in series, and each of the diodes D is located on a field oxide layer 101; each of the diodes D has an N-type doped region 102 and a P-type doped region 103; the N-type doped region 102 and the P-type doped region 103 are respectively connected to metal plugs 104 for electrode lead-out.

[0042] Based on this, the IGBT device provided in this embodiment integrates a temperature sensor S on one side of the cell region C to monitor the actual temperature of the device in real time. Multiple diodes are connected in series within the temperature sensor S to amplify the temperature sensing signal, improve measurement accuracy and sensitivity, and enhance the anti-interference capability of temperature sensing. Furthermore, each diode is located on the field oxide layer 101 to achieve electrical isolation. Further, the field oxide layer 101 in this embodiment has a specific size to prevent high-voltage breakdown and enhance device reliability. Each diode also has an N-type doped region 102 and a P-type doped region 103; the N-type doped region 102 and the P-type doped region 103 are respectively connected to metal plugs 104 for electrode lead-out. Further, the metal plugs 104 in this embodiment are set with a specific size to reduce contact resistance and further enhance device performance.

[0043] The IGBT device provided in this embodiment will be described in detail below with reference to the accompanying drawings.

[0044] Please continue reading. Figure 1 and Figure 2 In this embodiment, the IGBT device integrates the temperature sensor S on one side of the cell region C to monitor the temperature within the IGBT device. The cell region C within the IGBT device is a critical component area, and placing the temperature sensor S close to the cell region C allows for a more accurate reflection of the device's actual temperature.

[0045] Furthermore, the IGBT device has a substrate 100. The substrate 100 is the base structure of the device, and various device layers are disposed on and stacked on the substrate 100. The temperature sensor S is located on the substrate 100, and a portion of the substrate 100 in contact with the temperature sensor S is formed with a field oxide layer 101 using Local Oxidation of Silicon (LOCOS) technology to provide local shielding and isolation. The top surface of the field oxide layer 101 is flush with the top surface of the remaining unoxidized areas of the substrate 100, and the temperature sensor S is located on the field oxide layer 101 to prevent the temperature sensor S from affecting other device structures in the IGBT device.

[0046] like Figure 2 and Figure 3 As shown, the temperature sensor S includes multiple diodes D connected in series. It should be noted that the temperature signal of a single diode D is very weak, and its forward voltage drop is less than or equal to 0.7V. Connecting multiple diodes D in series amplifies the temperature sensing signal, improves measurement accuracy and sensitivity, and enhances the anti-interference capability of the temperature sensing. Preferably, 4 to 6 diodes D are connected in series within the temperature sensor S, so that the forward voltage drop range of the temperature sensor S is 2V to 4V, thereby amplifying the signal and reducing measurement errors.

[0047] Based on this, each diode D is spaced apart on the field oxide layer 101. Each diode D includes an N-type doped region 102 and a P-type doped region 103; the N-type doped region 102 and the P-type doped region 103 are respectively connected to metal plugs 104 for electrode lead-out. The N-type doped region 102 and the P-type doped region 103 are prepared by doping a polycrystalline silicon layer with N-type and P-type ions respectively to form a PN junction. The metal plugs 104 are formed by filling metal contact holes. Specifically, the IGBT device also includes an interlayer dielectric layer 105. The interlayer dielectric layer 105 covers the N-type doped region 102 and the P-type doped region 103, as well as the exposed surfaces of the substrate 100 and the field oxide layer 101. Optionally, the interlayer dielectric layer 105 is made of silicon nitride, which not only achieves electrical isolation between device layers but also protects the covered device layers from external environmental interference. Therefore, multiple contact holes (CTs) can be formed on the interlayer dielectric layer 105. Each contact hole penetrates a portion of the interlayer dielectric layer 105 and exposes a portion of the surface of the N-type doped region 102 and a portion of the surface of the P-type doped region 103 in each diode D. The metal plug 104 can be formed by filling it with a metal material. Optionally, the filling material is tungsten.

[0048] like Figure 2 and Figure 4 As shown, one end of the metal plug 104 is connected to the corresponding N-type doped region 102 or the corresponding P-type doped region 103, and the other end penetrates a portion of the interlayer dielectric layer 105 and extends to the top surface of the interlayer dielectric layer 105 for easy electrical lead-out. Since the forward voltage drop of each diode D is very low, the contact resistance formed by the metal plug 104 must be sufficiently small to ensure optimal device characteristics. Therefore, in this embodiment, the dimensions of the metal plug 104 satisfy the following formula:

[0049] 1 / 2*Z>d>1 / 3*Z;

[0050] Where Z is the sum of the lengths of the N-type doped region 102 and the P-type doped region 103; d is the diameter of the metal plug 104; that is, the maximum dimension of the metal plug 104 in the x-axis direction.

[0051] Furthermore, a portion of the structure of the metal plug 104 is inserted into the corresponding N-type doped region 102 or the corresponding P-type doped region 103 to ensure good electrical contact. However, to avoid penetrating the N-type doped region 102 or the P-type doped region 103 during etching to form the contact hole, this embodiment limits the size of the portion of the metal plug 104 inserted into the corresponding N-type doped region 102 or the corresponding P-type doped region 103 to satisfy the following formula:

[0052] L<1 / 10H;

[0053] Wherein, L represents the thickness of the partial structure, and H represents the thickness of the corresponding N-type doped region 102 or the corresponding P-type doped region 103. It can be understood that L also corresponds to the thickness of the polysilicon layer etched away during the etching of the contact hole.

[0054] Furthermore, such as Figure 2 As shown, to prevent the temperature sensor S from being broken down by high voltage, the size of the field oxide layer 101 satisfies the following formula:

[0055] X>k*BV;

[0056] (YZ) / 2>Z;

[0057] Wherein, X is the maximum thickness of the field oxide layer 101, in nm; BV is the reverse breakdown voltage of the temperature sensor S, in V; and k is a coefficient. It should be noted that the value of k is related to the product type, and this embodiment does not specifically limit it. For example, in some products, k = 1 nm / V; that is, for every 1V increase in the reverse breakdown voltage of the temperature sensor S, the maximum thickness of the field oxide layer 101 increases by 1 nm. Y is the maximum length of the field oxide layer 101; Z is the sum of the lengths of the N-type doped region 102 and the P-type doped region 103. It should be noted that in this embodiment, setting X > k * BV aims to prevent longitudinal breakdown of the temperature sensor S; and setting (YZ) / 2 > Z aims to prevent lateral breakdown of the temperature sensor S, thereby comprehensively improving the reliability of the temperature sensor S.

[0058] Please continue reading. Figure 2The temperature sensor S further includes a first metal line 106 and a second metal line 107. The first metal line 106 and the second metal line 107 are spaced apart on the interlayer dielectric layer 105 and are respectively connected to the metal plugs 104 in each of the diodes D, thus connecting the diodes in series. Specifically, the metal plug 104 in the same diode D connected to the N-type doped region 102 is connected to one of the first metal line 106 and the second metal line 107; the metal plug 104 connected to the P-type doped region 103 is connected to the other of the first metal line 106 and the second metal line 107. In short, the N-type doped region 102 and the P-type doped region 103 in each diode D are connected to one of the first metal line 106 and the second metal line 107 via corresponding metal plugs 104, ensuring that the diodes D are connected in series.

[0059] Furthermore, to avoid short-circuiting diode D, the first metal line 106 and the second metal line 107 in the same diode D are spaced apart, and the spacing 'a' is greater than 5 micrometers. Optionally, the method for forming the first metal line 106 and the second metal line 107 includes, but is not limited to: forming a metal layer on the surface of the interlayer dielectric layer 105, and then using an etching process to etch multiple gaps in the metal layer, so that a portion of the metal layer serves as the first metal line 106 and another portion of the metal layer serves as the second metal line 107. The material of the metal layer includes, but is not limited to, copper, aluminum, gold, silver, and their alloys.

[0060] Please continue reading. Figure 1 and Figure 2 The temperature sensor S further includes a first pad 108 and a second pad 109. The first pad 108 and the second pad 109 are dedicated test interfaces for the temperature sensor S, enabling the extraction of temperature signals and facilitating connection to external measurement circuits for accurate measurement of temperature changes. Therefore, as... Figure 1 As shown, the first pad 108 and the second pad 109 are spaced apart on one side of the plurality of series-connected diodes, and are respectively connected to the first metal line 106 and the second metal line 107. Furthermore, to reduce signal transmission interference and loss, and lower the risk of short circuits, the first metal line 106 and the second metal line 107 are routed in straight lines, avoiding excessively long or winding routes, and are directly connected to the first pad 108 and the second pad 109 respectively, thus enabling signal transmission to the series-connected diodes.

[0061] In summary, the IGBT device provided in this embodiment integrates a temperature sensor S on one side of the cell region C for real-time monitoring of the device's actual temperature. Multiple diodes D are connected in series within the temperature sensor S to amplify the temperature sensing signal, improve measurement accuracy and sensitivity, and enhance the anti-interference capability of the temperature sensing. Furthermore, each diode D is located on the field oxide layer 101, and the field oxide layer 101 has a specific size, which not only achieves electrical isolation but also prevents high-voltage breakdown, effectively enhancing device reliability. Each diode D also has an N-type doped region 102 and a P-type doped region 103; the N-type doped region 102 and the P-type doped region 103 are respectively connected to metal plugs 104 for electrode lead-out. The metal plugs 104 are set with specific dimensions to reduce contact resistance and further enhance device performance. In addition, the first pad 108 and the second pad 109 in the temperature sensor S are directly disposed above the diodes D, which helps reduce the routing of the first metal line 106 and the second metal line 107 and avoids the risk of short circuits.

[0062] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the present invention's technical solutions using the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention's technical solutions. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention's technical solutions, shall still fall within the protection scope of the present invention's technical solutions.

Claims

1. An IGBT device, characterized in that, include: A cell region and a temperature sensor located on one side of the cell region; wherein, The temperature sensor includes multiple diodes connected in series, and each diode is located on an oxide layer; each diode has an N-type doped region and a P-type doped region; the N-type doped region and the P-type doped region are respectively connected to metal plugs for electrode lead-out.

2. The IGBT device according to claim 1, characterized in that, The dimensions of the metal plug satisfy the following formula: 1 / 2*Z>d>1 / 3*Z; Where Z is the sum of the lengths of the N-type doped region and the P-type doped region; d is the diameter of the metal plug.

3. The IGBT device according to claim 1 or 2, characterized in that, The portion of the metal plug is inserted into the corresponding N-type doped region or the corresponding P-type doped region, and the dimensions of the portion of the structure satisfy the following formula: L<1 / 10H; Wherein, L is the thickness of the partial structure, and H is the thickness of the corresponding N-type doped region or the corresponding P-type doped region.

4. The IGBT device according to claim 1, characterized in that, The IGBT device has a substrate; a field oxide layer is formed in a portion of the substrate, and the top surface of the field oxide layer is flush with the top surface of the remaining portion of the substrate.

5. The IGBT device according to claim 1 or 4, characterized in that, The size of the field oxide layer satisfies the following formula: X>k*BV; (YZ) / 2>Z; Where X is the maximum thickness of the field oxide layer, and the unit is nm; BV is the reverse breakdown voltage of the temperature sensor, and its unit is V; k is a coefficient; Y is the maximum length of the field oxide layer; Z is the sum of the lengths of the N-type doped region and the P-type doped region.

6. The IGBT device according to claim 4, characterized in that, The IGBT device further includes an interlayer dielectric layer; the interlayer dielectric layer covers the N-type doped region and the P-type doped region, as well as a portion of the exposed top surface of the substrate and a portion of the top surface of the field oxide layer; One end of the metal plug is connected to the corresponding N-type doped region or the corresponding P-type doped region, and the other end penetrates a portion of the interlayer dielectric layer and extends to the top surface of the interlayer dielectric layer.

7. The IGBT device according to claim 6, characterized in that, The temperature sensor further includes a first metal wire and a second metal wire; the first metal wire and the second metal wire are spaced apart on the interlayer dielectric layer and are respectively connected to the metal plugs in each of the diodes to connect the diodes in series. In this configuration, the metal plug connected to the N-type doped region in the same diode is connected to one of the first metal line and the second metal line; the metal plug connected to the P-type doped region is connected to the other of the first metal line and the second metal line.

8. The IGBT device according to claim 7, characterized in that, The spacing between the first metal wire and the second metal wire is greater than 5 micrometers.

9. The IGBT device according to claim 7, characterized in that, The temperature sensor further includes a first pad and a second pad; the first pad and the second pad are spaced apart on one side of the plurality of diodes connected in series, and the first metal line and the second metal line are connected to the first pad and the second pad respectively along a straight line.

10. The IGBT device according to claim 1, characterized in that, The temperature sensor includes 4 to 6 diodes; the forward voltage drop of each diode is less than or equal to 0.7V, and the forward voltage drop range of the temperature sensor is 2V to 4V.

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