Electronic circuit and semiconductor device
By setting an electrostatic discharge (ESD) protection circuit at the gate-source port of a high-voltage gallium nitride (GaN) high electron mobility transistor, the problem of its weak ESD capability is solved, resulting in higher ESD capability and improved component utilization, while reducing cost and area.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-03
- Publication Date
- 2026-04-14
AI Technical Summary
High-voltage gallium nitride high electron mobility transistors have weak electrostatic discharge capability at their gate-source ports, making it difficult to meet the requirements of harsh application environments.
An electrostatic discharge protection circuit is set between the gate and source ports of the main transistor, including a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. They are turned on when the voltage exceeds or falls below the threshold, respectively, to achieve charge discharge.
This improved the electrostatic discharge capability of the gate-source ports of the main transistor, reduced component costs and footprint, and enabled low-cost, miniaturized semiconductor devices.
Smart Images
Figure CN224124499U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor technology, and in particular to an electronic circuit and a semiconductor device. Background Technology
[0002] Third-generation compound semiconductors are widely used in high-frequency, high-temperature, high-power, and radiation-resistant fields due to their wider bandgap, superior high-temperature performance, and higher electron mobility, in order to meet the needs that traditional silicon (Si)-based semiconductors cannot satisfy.
[0003] High-voltage gallium nitride (GaN) power devices of 600V and above are widely used in power supply applications due to their high electron mobility and relatively low production cost. Compared to low-voltage GaN transistors, high-voltage GaN transistors have more demanding operating environments (ESD levels). Furthermore, the ESD (electrostatic discharge) capabilities of the source-drain (DS) and gate-drain (GD) ports of high-voltage GaN high electron mobility transistors (HEMTs) are significantly higher than those of the gate-source (GS) port. Therefore, improving the ESD capability of the gate-source ports and protecting them is a problem that those skilled in the art are seeking to solve. Utility Model Content
[0004] The purpose of this invention is to provide an electronic circuit and semiconductor device to improve the ESD capability of the gate-source port.
[0005] To solve the above-mentioned technical problems, this utility model provides an electronic circuit, which includes: a main transistor and an electrostatic discharge (ESD) protection circuit connected between the gate and source ports of the main transistor. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. When the voltage at the gate and source ports of the main transistor is greater than a first threshold, the first discharge current branch is turned on; when the voltage at the gate and source ports of the main transistor is less than a second threshold, the second discharge current branch is turned on.
[0006] Optionally, in the electronic circuit, the main transistor is a high electron mobility transistor; the voltage divider element includes a resistor.
[0007] Optionally, in the electronic circuit, the electrostatic protection circuit has a symmetrical structure.
[0008] Optionally, in the electronic circuit, the first discharge current branch includes a first switch branch and the discharge tube. The opening of the discharge tube is controlled by the first switch branch. When the voltage at the gate-source port of the main transistor is greater than the first threshold, the first switch branch is turned on.
[0009] Optionally, in the electronic circuit, the first switching branch includes a plurality of first transistors connected in series, the voltage divider element, and the second transistor. The plurality of first transistors are used to determine the first threshold, and the voltage divider element and the second transistor are used to control the opening of the drain pipe.
[0010] Optionally, in the electronic circuit, the second discharge current branch includes a second switch branch and the discharge tube. The opening of the discharge tube is controlled by the second switch branch. When the voltage at the gate-source port of the main transistor is less than the second threshold, the second switch branch is turned on.
[0011] Optionally, in the electronic circuit, the second switching branch includes a plurality of third transistors connected in series, the voltage divider element, and a fourth transistor. The plurality of third transistors are used to determine the second threshold, and the voltage divider element and the fourth transistor are used to control the opening of the drain pipe.
[0012] Optionally, in the electronic circuit, the drain tube is a low-voltage gallium nitride transistor, one of the source and drain terminals of the drain tube is connected to the source terminal of the main transistor, the other of the source and drain terminals of the drain tube is connected to the gate terminal of the main transistor, the gate terminal of the drain tube is connected to the voltage divider element, the first threshold is a positive voltage value, and the second threshold is a negative voltage value.
[0013] The present invention also provides a semiconductor device, the semiconductor device comprising:
[0014] Semiconductor substrate; and,
[0015] A main transistor formed on the semiconductor substrate and an electrostatic discharge (ESD) protection circuit connected between the gate and source ports of the main transistor are provided. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. The first discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is greater than a first threshold, and the second discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is less than a second threshold.
[0016] Optionally, in the semiconductor device, the main transistor is a high electron mobility transistor; and the drain tube is a low-voltage gallium nitride transistor.
[0017] In the electronic circuit and semiconductor device provided by this utility model, an electrostatic discharge (ESD) protection circuit is provided between the gate and source ports of the main transistor. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. When the voltage at the gate and source ports of the main transistor is greater than a first threshold, the first discharge current branch is turned on; when the voltage at the gate and source ports of the main transistor is less than a second threshold, the second discharge current branch is turned on. Therefore, when the voltage at the gate and source ports of the main transistor is greater than the first threshold or less than the second threshold, that is, when the absolute value of the voltage at the gate and source ports of the main transistor is too large, current can be discharged through the ESD protection circuit, thereby improving the ESD capability of the gate and source ports of the main transistor.
[0018] In the electronic circuits and semiconductor devices provided by this utility model, the first discharge current branch and the second discharge current branch share the voltage divider element and the drain tube, thereby improving the utilization rate of the components, reducing the cost and area of the components, and thus forming a low-cost and miniaturized semiconductor device. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the electronic circuit structure of an embodiment of the present invention.
[0020] Figure 2 This is a schematic diagram of the structure of a semiconductor device according to an embodiment of the present invention.
[0021] The reference numerals in the attached figures are explained as follows:
[0022] 100 - Electronic circuit; 110 - Main transistor; 120 - Electrostatic protection circuit; 121 - First discharge current branch; 1210 - First switch branch; 122 - Second discharge current branch; 1220 - Second switch branch; R - Voltage divider element; M - Drain tube; M1, M11, M12, M13 - First transistor; M2 - Second transistor; M3, M31, M32, M33 - Third transistor; M4 - Fourth transistor.
[0023] 200 - Semiconductor device; 210 - Semiconductor substrate; 220 - Main transistor; 221 - Gate; 222 - Source region; 223 - Drain region; 230 - Drain tube; 231 - Gate; 232 - Source region; 233 - Drain region; 240 - Metal layer. Detailed Implementation
[0024] The electronic circuits and semiconductor devices proposed in this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.
[0025] The terminology used in this utility model is for the purpose of describing particular embodiments only and is not intended to limit the utility model. Unless otherwise defined in this application, the technical or scientific terms used in this utility model should be understood in their ordinary sense by one of ordinary skill in the art to which this utility model pertains. The words "first," "second," and similar terms used in this utility model specification and claims do not indicate any order, quantity, or importance, but are only used to distinguish different components. Similarly, the words "a" or "one" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the words "upper / upper layer" and / or "lower / lower layer" and similar terms are for ease of description only and are not limited to a location or spatial orientation. The words "comprising" or "including" and similar terms mean that the elements or structures preceding "comprising" or "including" cover the elements or structures listed after "comprising" or "including" and their equivalents, and do not exclude other elements or structures. The words "connected" or "linked" and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The singular forms “a,” “the,” and “the” used in this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0026] The core idea of this application is to provide an electronic circuit and semiconductor device in which an electrostatic discharge (ESD) protection circuit is provided between the gate and source ports of a main transistor. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. When the voltage at the gate and source ports of the main transistor is greater than a first threshold, the first discharge current branch is turned on; when the voltage at the gate and source ports of the main transistor is less than a second threshold, the second discharge current branch is turned on. Therefore, when the voltage at the gate and source ports of the main transistor is greater than the first threshold or less than the second threshold, i.e., when the absolute value of the voltage at the gate and source ports of the main transistor is too large, current can be discharged through the ESD protection circuit, thereby improving the bidirectional ESD capability of the gate and source ports of the main transistor.
[0027] Please refer to Figure 1 This is a schematic diagram of the electronic circuit structure of an embodiment of this utility model. Figure 1 As shown in this embodiment, the electronic circuit 100 includes a main transistor 110 and an electrostatic discharge (ESD) protection circuit 120 connected between the gate and source ports of the main transistor 110. In this embodiment, the main transistor 110 is a high electron mobility transistor (HEMT), and the ESD capability of the gate-source port of the main transistor 110 is lower than that of the source-drain port and the gate-drain port. The driving voltage Vgs of the main transistor 110 is, for example, between -7V and 7V.
[0028] The electrostatic protection circuit 120 includes a first discharge current branch 121 (e.g., ...). Figure 1 (as shown in the red line in the middle) and the second discharge current branch 122 (as shown in the red line in the middle) Figure 1 (As shown by the blue line in the middle), the first discharge current branch 121 and the second discharge current branch 122 share a voltage divider element R and a bleeder tube M; wherein, when the voltage at the gate-source port of the main transistor 110 is greater than a first threshold, the first discharge current branch 121 is turned on; when the voltage at the gate-source port of the main transistor 110 is less than a second threshold, the second discharge current branch 122 is turned on. This achieves discharge of the gate-source charge of the main transistor 110, improving the ESD capability of the gate-source port of the main transistor 110.
[0029] like Figure 1 As shown in the embodiments of this application, the voltage divider element R includes a resistor, for example, the voltage divider element R is a resistor with a suitable resistance value. In some embodiments of this application, the drain tube M can be a low-voltage gallium nitride transistor, for example, the withstand voltage of the drain tube M does not exceed 30V, and the drain tube M can have a symmetrical structure of source and drain terminals about the gate terminal. One of the source and drain terminals of the drain tube M is connected to the source terminal of the main transistor 110, and the other of the source and drain terminals of the drain tube M is connected to the gate terminal of the main transistor 110. The gate terminal of the drain tube M is connected to the voltage divider element R.
[0030] In some embodiments of this application, the first threshold is a positive voltage value, and the second threshold is a negative voltage value. For example, if the driving voltage Vgs of the main transistor 110 is between -7V and 7V, the first threshold can be greater than 7V, and the second threshold can be less than -7V. In some embodiments of this application, the first threshold can be, for example, 7.5V, and the second threshold can be, for example, -7.5V; or, for example, the first threshold can be, for example, 9V, and the second threshold can be -9V.
[0031] In some embodiments of this application, the electrostatic discharge protection circuit 120 has a symmetrical structure, that is, the first discharge current branch 121 and the second discharge current branch 122 are symmetrical. The first threshold and the second threshold can be opposites of each other to symmetrically achieve the discharge of gate-source charge and improve the symmetry of the ESD capability of the gate-source port of the main transistor 110. In other embodiments of this application, the electrostatic discharge protection circuit 120 can also be an asymmetrical structure, where the absolute values of the first threshold and the second threshold can be different. For example, the absolute value of the first threshold can be greater than the second threshold, or the absolute value of the first threshold can be set to be less than the absolute value of the second threshold to achieve different charge discharge control strategies for the gate-source of the main transistor 110 in the forward and reverse directions.
[0032] like Figure 1 As shown, the first discharge current branch 121 includes a first switch branch 1210 and the discharge tube M. The opening of the discharge tube M is controlled by the first switch branch 1210. When the voltage at the gate-source port of the main transistor 110 is greater than the first threshold, the first switch branch 1210 is turned on. Correspondingly, the discharge tube M is turned on, thereby discharging the gate-source charge of the main transistor 110 to improve the ESD capability of the gate-source port of the main transistor 110. The first threshold can be, for example, 7.5V, thus discharging current when the forward voltage is too high.
[0033] The first switch branch 1210 includes a plurality of first transistors M1 connected in series, a voltage divider element R, and a second transistor M2. The plurality of first transistors M1 are used to determine the first threshold, and the voltage divider element R and the second transistor M2 are used to control the opening of the drain tube M. In this embodiment, three first transistors M1 are schematically shown; in other embodiments of this application, more first transistors M1 can be connected in series, such as five or six, and correspondingly, the value of the first threshold can be increased. For example, if the threshold voltage of the first transistor M1 is 1.5V, three first transistors M1 connected in series result in a first threshold of 4.5V; five first transistors M1 connected in series result in a first threshold of 7.5V. The number of first transistors M1 can be m, and correspondingly, the first threshold V... GS1(th) For: V th(M11) +V th(M12) +V th(M13) +……V th(M1m) The value of the first threshold can be adjusted by selecting the threshold voltage and the number of the first transistor M1.
[0034] like Figure 1As shown in this embodiment, three first transistors M1 are connected in sequence. Each first transistor M1 can be a low-voltage gallium nitride transistor, and its source and drain terminals can be symmetrical about the gate. Specifically, one source / drain terminal (source or drain) of the first transistor M11 is connected to one source / drain terminal of the first transistor M12; the other source / drain terminal of the first transistor M12 is connected to one source / drain terminal of the first transistor M13; the gate terminal of the first transistor M11 is connected to its own source / drain terminal; the gate terminal of the first transistor M12 is connected to its own source / drain terminal; and the gate terminal of the first transistor M13 is connected to its own source / drain terminal. The other source / drain terminal of the first transistor M11 is connected to the gate terminal of the main transistor 110; the other source / drain terminal of the first transistor M13 is connected to one end of the voltage divider element R; the other end of the voltage divider element R is connected to the drain terminal of the second transistor M2; the source terminal of the second transistor M2 is connected to the source terminal of the main transistor 110; and the gate terminal of the second transistor M2 is connected to the gate terminal of the main transistor 110.
[0035] In this embodiment, the switching state of the second transistor M2 is consistent with the forward switching state of the main transistor 110; that is, when the main transistor 110 is forward-biased, the second transistor M2 is also on. When the voltage at the gate-source port of the main transistor 110 is greater than a first threshold, the first transistors M11, M12, and M13 are also turned on, and the first switching branch 1210 is conducted. At this time, the voltage divider element R and the second transistor M2 provide voltage to the drain tube M, causing the drain tube M to turn on. Thus, the gate-source charge of the main transistor 110 can be discharged through the drain tube M, thereby improving the forward ESD capability of the gate-source port of the main transistor 110.
[0036] In this embodiment, the second discharge current branch 122 and the first discharge current branch 121 are symmetrically arranged. For example... Figure 1 As shown, the second discharge current branch 122 includes a second switch branch 1220 and the discharge tube M. The opening of the discharge tube M is controlled by the second switch branch 1220. When the voltage at the gate-source port of the main transistor 110 is less than the second threshold, the second switch branch 1220 is turned on. Correspondingly, the discharge tube M is turned on, thereby discharging the gate-source charge of the main transistor 110 to improve the ESD capability of the gate-source port of the main transistor 110. The second threshold can be, for example, -7.5V, thus discharging current when the reverse voltage is too high.
[0037] The second switching branch 1220 includes multiple third transistors M3 connected in series, the voltage divider element R, and a fourth transistor M4. The multiple third transistors M3 are used to determine the second threshold, and the voltage divider element R and the fourth transistor M4 are used to control the opening of the drain pipe M. In this embodiment, three third transistors M3 are schematically shown; in other embodiments of this application, more third transistors M3 can be connected in series, such as five or six, which correspondingly increases the absolute value of the second threshold. For example, if the threshold voltage of the third transistor M3 is -1.5V, with three third transistors M3 connected in series, the second threshold is -4.5V; with five third transistors M3 connected in series, the second threshold is -7.5V. The number of third transistors M3 can be n, and correspondingly, the second threshold V... GS2(th) For: -(V th(M31) +V th(M32) +V th(M33) +……V th(M3n) The value of the second threshold can be adjusted by selecting the threshold voltage and number of the third transistor M3. In some embodiments of this application, the values of m and n can be the same, for example, both can be 5, 7, etc.; in other embodiments of this application, the values of m and n can also be different, for example, m can be 7 and n can be 5, or m can be 7 and n can be 9, etc., to achieve different gate-source charge discharge strategies.
[0038] like Figure 1 As shown in the embodiment of this application, the three third transistors M3 are connected in sequence. The third transistor M3 can be a low-voltage gallium nitride transistor, and the third transistor M3 can have a structure in which the source and drain terminals are symmetrical about the gate terminal. In this configuration, one source-drain terminal (source or drain terminal) of the third transistor M31 is connected to one source-drain terminal of the third transistor M32; the other source-drain terminal of the third transistor M32 is connected to one source-drain terminal of the third transistor M33; the gate terminal of the third transistor M31 is connected to its own source-drain terminal; the gate terminal of the third transistor M32 is connected to its own source-drain terminal; and the gate terminal of the third transistor M33 is connected to its own source-drain terminal. The other source-drain terminal of the third transistor M31 is connected to the source terminal of the main transistor 110. The other source-drain terminal of the third transistor M33 is connected to one end of the voltage divider element R. The other end of the voltage divider element R is connected to the drain terminal of the fourth transistor M4. The source terminal of the fourth transistor M4 is connected to the gate terminal of the main transistor 110, and the gate terminal of the fourth transistor M4 is connected to the source terminal of the main transistor 110.
[0039] In this embodiment, the activation of the fourth transistor M4 coincides with the reverse activation of the main transistor 110; that is, when the main transistor 110 is activated in reverse, the fourth transistor M4 is activated. When the voltage at the gate-source port of the main transistor 110 is less than a second threshold, the third transistors M31, M32, and M33 are also activated, and the second switching branch 1220 is turned on. At this time, the voltage divider element R and the fourth transistor M4 provide voltage to the bleeder M, causing the bleeder M to activate. Therefore, the gate-source charge of the main transistor 110 can be discharged through the bleeder M, thereby improving the reverse ESD capability of the gate-source port of the main transistor 110.
[0040] In this embodiment, when the forward voltage and / or reverse voltage of the gate-source port of the main transistor 110 is too large, the current can be discharged through the electrostatic discharge protection circuit 120, thereby improving the ESD capability of the gate-source port of the main transistor 110.
[0041] In this embodiment, the first transistor M1, the second transistor M2, the third transistor M3, and the fourth transistor M4 can all be low-voltage gallium nitride transistors, thereby facilitating the fabrication of the electronic circuit 100 on the same semiconductor substrate and simplifying the fabrication process of the electronic circuit 100.
[0042] This application also provides a semiconductor device, such as... Figure 2 As shown, the semiconductor device 200 includes: a semiconductor substrate 210; and a main transistor 220 formed on the semiconductor substrate 210 and an electrostatic discharge (ESD) protection circuit (not shown) connected between the gate and source ports of the main transistor 220, i.e., the ESD protection circuit is connected to the gate and source ports of the main transistor 220 respectively. The semiconductor substrate 210 may be made of, for example, gallium nitride.
[0043] The main transistor 220 is... Figure 1 The main transistor 110 in the circuit, and the structure of the electrostatic protection circuit can be referred to accordingly. Figure 1 The electrostatic discharge protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. The first discharge current branch is turned on when the voltage at the gate-source port of the main transistor is greater than a first threshold, and the second discharge current branch is turned on when the voltage at the gate-source port of the main transistor is less than a second threshold.
[0044] In this embodiment, the main transistor 220 is a high-voltage gallium nitride high electron mobility transistor; the drain tube 230 can be a low-voltage gallium nitride transistor, and the drain tube 230 is... Figure 1 The drain pipe M in the middle. For example... Figure 2 As shown in the embodiment of this application, the drain tube 230 has a symmetrical structure, that is, the distance from the gate 231 of the drain tube 230 to the source region 232 and the drain region 233 of the drain tube 230 is the same, so as to symmetrically drain the main transistor 220 and improve the ESD capability of the main transistor 220 in both forward and reverse directions. The main transistor 220 can be a common high electron mobility transistor, and the distance from the gate 221 of the main transistor 220 to the source region 222 of the main transistor 220 can be smaller than the distance from the gate 221 of the main transistor 220 to the drain region 223 of the main transistor 220. The first transistor M1, the second transistor M2, the third transistor M3, and the fourth transistor M4 can be common high electron mobility transistors or low-voltage gallium nitride transistors with a symmetrical structure; this application does not limit this. Figure 2 The main transistor 220 and the drain pipe 230 are mainly shown for clearer understanding. In this embodiment, the drain pipe 230 has a symmetrical structure. The connections between the main transistor 220 and the drain pipe 230, as well as the connections between other components in the electrostatic protection circuit, can be achieved through one or more metal layers 240 and plugs (…). Figure 2 The implementation (not shown in the text) is not described in detail in this application.
[0045] In the embodiments of this application, the electrostatic protection circuit reuses the voltage divider element and the drain tube, thereby improving the utilization rate of the components, reducing the cost and area of the components, and thus forming a low-cost, miniaturized semiconductor device.
[0046] In this application, references to "one embodiment" or "some embodiments" mean that a feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment or at least some embodiments of this application. Therefore, the appearance of the phrases "in one embodiment" or "in some embodiments" throughout this application does not necessarily refer to the same or the same embodiments. Furthermore, in one or more embodiments, features, structures, or characteristics can be combined in any suitable combination and / or sub-combination.
[0047] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of this application. The embodiments of this application can be combined in any way without departing from the spirit and scope of this application. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.
Claims
1. An electronic circuit, characterized in that, The electronic circuit includes a main transistor and an electrostatic discharge (ESD) protection circuit connected between the gate and source ports of the main transistor. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. The first discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is greater than a first threshold; the second discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is less than a second threshold.
2. The electronic circuit as described in claim 1, characterized in that, The main transistor is a high electron mobility transistor; the voltage divider element includes a resistor.
3. The electronic circuit as described in claim 1, characterized in that, The electrostatic protection circuit has a symmetrical structure.
4. The electronic circuit as described in claim 1, characterized in that, The first discharge current branch includes a first switch branch and the discharge tube. The opening of the discharge tube is controlled by the first switch branch. When the voltage at the gate-source port of the main transistor is greater than the first threshold, the first switch branch is turned on.
5. The electronic circuit as described in claim 4, characterized in that, The first switch branch includes a plurality of first transistors connected in series, the voltage divider element and the second transistor, the plurality of first transistors being used to determine the first threshold, and the voltage divider element and the second transistor being used to control the opening of the drain pipe.
6. The electronic circuit as described in claim 1, characterized in that, The second discharge current branch includes a second switch branch and the discharge tube. The opening of the discharge tube is controlled by the second switch branch. When the voltage at the gate-source port of the main transistor is less than the second threshold, the second switch branch is turned on.
7. The electronic circuit as described in claim 6, characterized in that, The second switching branch includes a plurality of third transistors connected in series, the voltage divider element and the fourth transistor, the plurality of third transistors being used to determine the second threshold, and the voltage divider element and the fourth transistor being used to control the opening of the drain pipe.
8. The electronic circuit according to any one of claims 1 to 7, characterized in that, The drain tube is a low-voltage gallium nitride transistor. One of the source and drain terminals of the drain tube is connected to the source terminal of the main transistor, and the other of the source and drain terminals of the drain tube is connected to the gate terminal of the main transistor. The gate terminal of the drain tube is connected to the voltage divider element. The first threshold is a positive voltage value, and the second threshold is a negative voltage value.
9. A semiconductor device, characterized in that, The semiconductor device includes: Semiconductor substrate; and, A main transistor formed on the semiconductor substrate and an electrostatic discharge (ESD) protection circuit connected between the gate and source ports of the main transistor are provided. The ESD protection circuit includes a first discharge current branch and a second discharge current branch, which share a voltage divider element and a drain tube. The first discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is greater than a first threshold, and the second discharge current branch is turned on when the voltage at the gate and source ports of the main transistor is less than a second threshold.
10. The semiconductor device as claimed in claim 9, characterized in that, The main transistor is a high electron mobility transistor; the drain tube is a low-voltage gallium nitride transistor.