An IGBT with programmable built-in resistor gate

Abstract

The present invention relates to an IGBT with a programmable built-in resistor gate. By setting several groups of programmable resistor gates between the gate metal PAD and the gate bus, the operator can program the several groups of programmable resistor gates by burning the PAD after the IGBT leaves the factory, and then adjust the built-in gate resistance to make it adapt to the corresponding application scenario.

Description

Technical Field

[0001] The present invention relates to an IGBT, in particular to an IGBT with a programmable built-in resistance gate. Background Art

[0002] The gate resistor Rg plays a crucial role in the IGBT's turn-on and turn-off processes. In particular, the IGBT's turn-on energy consumption is closely related to Rg. Gate resistor Rg is typically divided into an internal gate resistor Rgin placed on the chip and an external gate resistor Rgex used by system manufacturers at the system level. These resistors are generally difficult to change once set, especially Rgin, which is formed by the chip manufacturer during the chip fabrication process and cannot be changed due to device structure constraints. Fine-tuning Rg allows chip manufacturers to use the chip in a variety of application scenarios without changing the system-level settings.

[0003] Publication number CN216749899U, titled "IGBT Layout Structure with Built-in Adjustable Gate Resistor," discloses an IGBT layout that modifies the gate resistor value by changing the gate poly mask to adjust the width of the gate resistor area. While this IGBT layout allows the fabrication of IGBTs with varying gate resistors, the size of the built-in gate resistor cannot be changed after fabrication.

[0004] To this end, it is necessary to design a new IGBT chip, which can still reduce the built-in gate resistance through programming after preparation so that it can meet the needs of corresponding application scenarios. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an IGBT with a programmable built-in resistor gate and adjustable built-in gate resistance after preparation.

[0006] The IGBT with a programmable built-in resistor gate of the present invention includes a chip body, which includes a substrate, a gate metal PAD located above the substrate, and a gate bus. Several groups of programmable resistor gates are arranged between the gate metal PAD and the gate bus. The programmable resistor gate includes a polysilicon layer with a first doping type, an oxide layer is provided between the polysilicon layer and the substrate, one end of the polysilicon layer is connected to the gate metal PAD, and the other end is connected to the gate bus. A doped region with a second doping type is provided in the middle of the polysilicon layer. The IGBT with a programmable built-in resistor gate also includes several burning PADs, and the polysilicon layers of each programmable resistor gate are connected to the corresponding burning PAD via an electric fuse.

[0007] The advantage of this IGBT with programmable internal gate resistors is that, by providing several sets of programmable gate resistors between the gate metal PAD and the gate bus, operators can program these sets of programmable gate resistors by burning the PADs after the IGBT leaves the factory, thereby adjusting the internal gate resistors to suit the application scenario. Compared to existing IGBTs, this type of IGBT has a wider range of applications because its internal gate resistors can be adjusted programmably after leaving the factory.

[0008] Furthermore, in the IGBT with a programmable built-in resistance gate of the present invention, the polysilicon layer is an N-type polysilicon layer, and the doped region is a P-type doped region.

[0009] The arrangement of an N-type polysilicon layer and a P-type doped region creates multiple back-to-back diodes to disconnect the programmable internal resistor from the parallel connection. The number of diodes depends on the gate voltage and the breakdown voltage of a single set of back-to-back diodes, generally ensuring that the total breakdown voltage is higher than the gate voltage. Alternatively, a P-type polysilicon layer and an N-type doped region can be used, in which case multiple face-to-face diodes are formed.

[0010] Furthermore, in the IGBT with a programmable built-in resistance gate of the present invention, the electric fuse is a polysilicon electric fuse.

[0011] The electric fuse is formed of polysilicon with corners, and its width and number of corners are set according to the size of the fuse current.

[0012] Furthermore, in the IGBT with programmable built-in resistance gate of the present invention, a dielectric layer is provided on the surface of the polysilicon layer, and the gate metal PAD and the gate bus are respectively connected to the polysilicon layer through contact holes penetrating the dielectric layer.

[0013] The dielectric layer isolates the polysilicon layer from the gate metal PAD and the gate bus. The gate metal PAD and the gate bus are connected to the polysilicon layer through two contact holes respectively.

[0014] Furthermore, the IGBT with a programmable built-in resistor gate of the present invention further includes a test PAD connected to the gate bus.

[0015] The setting of the test PAD realizes the detection function of the programmable resistor gate. The above-mentioned burning PAD, test PAD, gate metal PAD and gate bus are all made of metal materials such as aluminum, gold or copper.

[0016] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement them in accordance with the contents of the specification, the embodiments of the present invention are described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a planar schematic diagram of an IGBT with a programmable built-in resistor gate;

[0018] Figure 2 yes Figure 1 A local plan view of a set of programmable resistor gates;

[0019] Figure 3 yes Figure 2 Partial cross-sectional view along the AA direction;

[0020] Figure 4 yes Figure 3 A partial enlarged view of part B in the middle;

[0021] Figure 5 This is the circuit model diagram of the programmable resistor grid before burning;

[0022] Figure 6 This is a circuit model diagram of the programmable resistor grid after burning.

[0023] In the figure, substrate 1, gate metal PAD 2, gate bus 3, polysilicon layer 4, oxide layer 5, doped region 6, burn PAD 7, electric fuse 8, dielectric layer 9, contact hole 10, test PAD 11. DETAILED DESCRIPTION

[0024] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0025] See also Figures 1 to 6 The IGBT with a programmable built-in resistor gate of this embodiment includes a chip body, which includes a substrate 1, a gate metal PAD 2 located above the substrate, and a gate bus 3. Several groups of programmable resistor gates are arranged between the gate metal PAD and the gate bus. The programmable resistor gate includes a polysilicon layer 4 with a first doping type, an oxide layer 5 is provided between the polysilicon layer and the substrate, one end of the polysilicon layer is connected to the gate metal PAD, and the other end is connected to the gate bus. A doped region 6 with a second doping type is provided in the middle of the polysilicon layer. The IGBT with a programmable built-in resistor gate also includes several burning PADs 7. The polysilicon layers of each programmable resistor gate are connected to the corresponding burning PAD via an electric fuse 8.

[0026] The IGBT with programmable internal gate resistors of the present invention incorporates several sets of programmable gate resistors between the gate metal pad and the gate bus. This allows operators to program these sets of programmable gate resistors after the IGBT leaves the factory by burning the pads, thereby adjusting the internal gate resistors to suit the application scenario. Compared to existing IGBTs, this new IGBT's internal gate resistors can be adjusted programmably after leaving the factory, thus extending its application range.

[0027] The gate bus is used to connect to the gate in the cell area of ​​the chip body, and the gate can be a planar gate or a trench gate.

[0028] The polysilicon layer of the programmable resistor gate is used to connect the gate metal PAD and the gate bus, and has a first doping type. In this embodiment, the polysilicon layer is an N-type polysilicon layer.

[0029] The doping region in the middle of the polysilicon layer is of the second doping type, such as P-type doping. In this embodiment, the doping region is formed by performing P-type implantation in the middle of the gate polysilicon to form the P-type doping region.

[0030] The P-type doped region in the middle of the polysilicon layer enables the formation of multiple back-to-back diodes in the middle of the gate polysilicon to disconnect the polysilicon layer, thereby making it have R G0 resistance.

[0031] The burning PAD is used to burn the programmable built-in resistor gate through the electric fuse via an external burning program to adjust the resistance value of the programmable resistor gate, thereby adjusting the resistance value of the IGBT built-in gate resistor. It can be set on the surface of the chip body.

[0032] Specifically, the external programming program applies a high voltage to the polysilicon layer through the programming PAD and the electric fuse. Since the connection between the electric fuse and the polysilicon layer is located on one side of the doped region, the back-to-back diodes are reverse biased. The high reverse bias voltage can cause the diodes to fail and become permanently short-circuited. Moreover, the large failure current will cause the electric fuse to blow. This can, on the one hand, play a current limiting role to protect the programming circuit, and on the other hand, it can indicate that the back-to-back diodes have been burned.

[0033] After short circuit, the built-in resistor R G1 R G0 By connecting the two resistors in parallel, the resistance of the polysilicon layer and the programmable resistor gate is reduced. The operator can adjust the resistance of the IGBT's built-in gate resistor by burning the corresponding number of programmable resistor gates.

[0034] Preferably, in the IGBT with a programmable built-in resistor gate of this embodiment, the polysilicon layer is an N-type polysilicon layer, and the doped region is a P-type doped region.

[0035] The arrangement of an N-type polysilicon layer and a P-type doped region creates multiple back-to-back diodes (i.e., two diodes connected at the P-terminal end) to disconnect the programmable internal resistor from the parallel connection. The number of diodes depends on the gate voltage and the breakdown voltage of a single set of back-to-back diodes, generally ensuring that the total breakdown voltage is higher than the gate voltage. Alternatively, a P-type polysilicon layer and an N-type doped region can be used, in which case multiple face-to-face diodes are formed.

[0036] Preferably, in the IGBT with a programmable built-in resistance gate of this embodiment, the electric fuse is a polysilicon electric fuse.

[0037] The electric fuse is formed of polysilicon with corners, and its width and number of corners are set according to the size of the fuse current.

[0038] Preferably, in the IGBT with programmable built-in resistor gate of this embodiment, a dielectric layer 9 is provided on the surface of the polysilicon layer, and the gate metal PAD and the gate bus are respectively connected to the polysilicon layer through contact holes 10 penetrating the dielectric layer.

[0039] The dielectric layer isolates the polysilicon layer from the gate metal PAD and the gate bus. The gate metal PAD and the gate bus are connected to the polysilicon layer through two contact holes respectively.

[0040] Preferably, the IGBT with a programmable built-in resistor gate in this embodiment further includes a test PAD11 connected to the gate bus.

[0041] The setting of the test PAD realizes the detection function of the programmable resistor gate. The above-mentioned burning PAD, test PAD, gate metal PAD and gate bus are all made of metal materials such as aluminum, gold or copper.

[0042] One end of the gate bus is connected to the source region, and the other end is connected to the test PAD. The operator can detect the status of the fuse by applying voltage between the programming PAD and the test PAD, or can blow the fuse through these two PADs to prevent the short circuit of the corresponding back-to-back diodes.

[0043] Specifically, by applying voltage to the test PAD and the programming PAD and measuring current, it can be determined whether the electric fuse has been programmed. If it has been programmed, the circuit between the test PAD and the programming PAD is in an open circuit state.

[0044] If you need to prevent the back-to-back diodes from short-circuiting, you can pressurize the test PAD and the programming PAD to blow the fuse in advance. This will destroy the programming circuit of the back-to-back diodes, thereby preventing the back-to-back diodes from performing normal programming procedures.

[0045] The above are only preferred embodiments of the present invention, which are used to assist those skilled in the art to implement the corresponding technical solutions, and are not used to limit the scope of protection of the present invention, which is defined by the appended claims. It should be pointed out that for those skilled in the art, a number of equivalent improvements and variations can be made based on the technical solutions of the present invention, and these improvements and variations should also be regarded as the scope of protection of the present invention. At the same time, it should be understood that although this specification is described in accordance with the above-mentioned embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions of each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An IGBT with a programmable built-in resistor gate, comprising a chip body, wherein the chip body comprises a substrate (1), a gate metal PAD (2) located above the substrate, and a gate bus (3), characterized in that: A plurality of programmable resistance gates are provided between a gate metal PAD and a gate bus. The programmable resistance gates include a polysilicon layer (4) having a first doping type, an oxide layer (5) is provided between the polysilicon layer and a substrate, one end of the polysilicon layer is connected to the gate metal PAD, and the other end is connected to the gate bus. A doping region (6) having a second doping type is provided in the middle of the polysilicon layer. The IGBT with programmable built-in resistance gates also includes a plurality of burning PADs (7), and the polysilicon layers of each programmable resistance gate are connected to the corresponding burning PAD via an electric fuse (8).

2. The IGBT with a programmable built-in resistor gate according to claim 1, characterized in that: The polysilicon layer is an N-type polysilicon layer, and the doped region is a P-type doped region.

3. The IGBT with a programmable built-in resistor gate according to claim 1, characterized in that: The electric fuse is a polysilicon electric fuse.

4. The IGBT with a programmable built-in resistor gate according to claim 1, characterized in that: A dielectric layer (9) is provided on the surface of the polysilicon layer, and the gate metal PAD and the gate bus are respectively connected to the polysilicon layer through contact holes (10) penetrating the dielectric layer.

5. The IGBT with a programmable built-in resistor gate according to claim 1, characterized in that: Also included is a test PAD (11) connected to the gate bus.

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