A method for extracting key parameters of an enhancement-mode GaN device based on a depletion-mode GaN HEMT

Abstract

The application relates to a method for extracting key parameters of an enhancement-mode GaN device based on a depletion-mode GaN HEMT, belonging to the technical field of microelectronic research, and a same-size depletion-mode D-mode device is prepared beside an enhancement-mode E-mode device; since the size of the enhancement-mode E-mode device is completely same as that of the depletion-mode D-mode device, gate-source resistance and gate-drain resistance of the enhancement-mode device can be directly obtained through the depletion-mode device, and the key parameters of the enhancement-mode device can be quickly, conveniently and accurately extracted; since the depletion-mode device and the enhancement-mode device are adjacent, the gold-semiconductor contact resistance error value caused by uneven etching of P-GaN can be eliminated, and the accuracy of extraction of the key parameters of the device is improved; and the method for extracting the key parameters is realized based on a conventional structure and electrical test data, and does not need to introduce a complex structure and a destructive test.

Description

Technical Field

[0001] This invention relates to a method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT, belonging to the field of microelectronics research technology. Background Technology

[0002] With the continuous development of gallium nitride (GaN) power device technology, enhancement-mode AlGaN / GaN high electron mobility transistors (HEMTs) have gradually become an important development direction for GaN power devices due to their normally off characteristics, exhibiting higher safety and compatibility in power electronics and system-level applications. Among them, AlGaN / GaN HEMTs that achieve enhancement-mode characteristics using P-GaN gate structures have gained widespread attention in high-voltage power conversion, electric vehicles, and communication power supplies. In P-GaN AlGaN / GaN HEMT devices, key parameters such as sheet resistance, channel resistance, two-dimensional electron gas concentration, and electron mobility are closely related to the electrical transport characteristics of the device. These key parameters are important physical quantities in device structure optimization and performance optimization. However, most current methods for extracting key electrical parameters of GaN HEMT devices are based on physical models of depletion-mode devices, typically assuming that the channel sheet resistance is uniformly distributed along the channel direction and that the channel under the gate is fully conductive. This is difficult to directly apply to enhancement-mode P-GaN HEMT devices.

[0003] Therefore, there is an urgent need to develop a method to extract key parameters of enhanced gallium nitride devices without damaging the device structure or increasing process complexity, so as to provide technical support for a deeper understanding of the device's electrical transport mechanism and device performance optimization. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMTs. Since the dimensions of enhancement-mode E-mode devices and depletion-mode D-mode devices are exactly the same, the gate-source resistance and gate-drain resistance of enhancement-mode devices can be directly obtained from the depletion-mode devices, enabling rapid, convenient, and accurate extraction of key parameters of enhancement-mode devices.

[0005] The present invention adopts the following technical solution:

[0006] A method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT includes the following steps:

[0007] S1, fabricate an enhanced E-mode device, and fabricate a depletion-mode D-mode device of the same size next to the enhanced E-mode device;

[0008] S2, due to the gate length of the enhancement-mode E-mode device and the depletion-mode D-mode device , grid width , gate-source spacing Grid spacing The gate-source resistance R of the enhancement-mode E-mode device is equal to that of the other devices. GS1 and gate-drain resistance R GD1 The gate-source resistance R of the depletion-mode D-mode device is respectively compared with that of the other two devices. GS2 and gate-drain resistance R GD2 equal;

[0009] To test the output characteristic curve of a depletion-mode D-mode device, the gate-source voltage V is used. GS Set to 0V, drain-source voltage V DS Set to 0-10V, outputting the drain-source current I of the depletion-mode D-mode device. DS You can get V GS Output characteristic curve of the device at 0V;

[0010] For depletion-mode D-mode devices, V is taken at a low field. DS = 0.1 V current I DS - Voltage value V DS Total resistance R Z =V DS / I DS Based on the device structure, the total resistance R is obtained. Z = 2R C + R GS2 + R GD2 + R G2 (The ratio of drain-source current to drain-source voltage is the total drain-source channel resistance, which is the sum of the gold-semiconductor contact resistance between the source and the ohmic metal, the gold-semiconductor contact resistance between the drain and the ohmic metal, the channel resistance between the gate and source, the channel resistance under the gate, and the channel resistance between the gate and drain.) Where R C This represents the gold-semi contact resistance between the source and the ohmic metal, or the gold-semi contact resistance between the drain and the ohmic metal; both are equal. R GS2 R represents the channel resistance between the gate and source. GD2 R represents the channel resistance between the gate and drain. G2 Indicates the channel resistance under the gate;

[0011] For depletion-mode D-mode devices, the gate voltage V GS At 0 V, since the density of the two-dimensional electron gas under the gate and the gate source / drain are equal, the total resistance R is... Z - 2R C = R GS2+ R GD2 + R G2 = ,in The amount of electron charge. For V GS Two-dimensional electron gas at 0 V, For V GS Mobility at 0 V;

[0012] The capacitance-voltage (CV) characteristics of the depletion-mode D-mode device were tested at different gate voltages. The two-dimensional electron gas concentration at different gate voltages was obtained by integrating the capacitance-voltage characteristic curve (i.e., the CV curve). ,in, For the applied gate voltage, The point on the capacitance-voltage characteristic curve where the capacitance changes the most rapidly corresponds to... The value is obtained by differentiating the capacitance-voltage characteristic curve. The gate capacitance is being tested. The area of ​​the Schottky contact; the gold-semiconductor contact resistance R is obtained by TLM testing. C , will R C V GS Two-dimensional electron gas at 0 V , grid length Grid spacing , gate-source spacing and gate width Substitute R Z - 2R C = The solution yields the V of the depletion-mode D-mode device. GS Mobility at 0 V ;

[0013] The gate-source resistance and gate-drain resistance of enhancement-mode E-mode devices are equal to those of depletion-mode D-mode devices, which are respectively the gate-source resistance R0. GS1 =R GS2 = and gate-drain resistance R GD1 =R GD2 = , calculate , The gate-source resistance R can be solved iteratively by substituting the values. GS1 and gate-drain resistance R GD1 ;

[0014] S3, gate resistance:

[0015] drain-source voltage V DS Set to 0-10V, for different gate-source voltages VGS Lower output drain source current I DS That is, testing different gate-source voltages V GS The output characteristic curve of the enhancement-mode E-mode device is taken as the drain-source voltage V under low field. DS Current I at 0.1 V DS -Voltage V DS The data shows that the total source-drain resistance R of the enhancement-mode E-mode device is... Z =V DS / I DS The total resistance R under different gate voltages was obtained. Z Total resistance R under different gate voltages Z = 2R C + R GS1 + R G1 + R GD1 Gold-semiconductor contact resistance R C Gate-source resistance R GS1 and gate-drain resistance R GD1 The gate resistance R under different gate voltages has been obtained in step S2. G1 ;

[0016] S4, Gate bottom resistance:

[0017] The resistance below the gate is , bring in the gate width , grid length and V GS Gate resistance R at 0V G1 That is, the resistance below the gate is obtained ;

[0018] S5, Two-dimensional electron gas concentration under gate voltage:

[0019] Test the capacitance-voltage (CV) characteristics of the enhanced E-mode device at different gate voltages. For example... Figure 5 As shown, the concentration of the two-dimensional electron gas under different gate voltages can be obtained by integrating the capacitance-voltage characteristic curve (CV curve). ,in To apply a gate voltage in an enhancement-mode E-mode device, The point corresponding to the fastest capacitance change in the capacitance-voltage characteristic curve of the enhancement-mode E-mode device under different gate voltages. The value can be obtained by differentiating the capacitance-voltage characteristic curve. Gate capacitance tested in an enhanced E-mode device. The area of ​​the Schottky contact in the enhancement-mode device;

[0020] S6, under-gate electron mobility:

[0021] Gate electron mobility ,in For grid length, The amount of electron charge. For grid width, For the density of two-dimensional electron gas, The gate resistance; the two-dimensional electron gas density under the gate at different gate voltages in step S5. and the gate resistance under different gate voltages in step S3 After substituting the values ​​into the solution, the under-gate electron mobility under different gate voltages can be obtained;

[0022] S7, Two-dimensional electron gas concentration in the gate-source channel:

[0023] In enhancement-mode E-mode devices, the selective placement of the GaN cap layer on the AlGaN barrier layer beneath the gate causes the conduction band of the AlGaN barrier layer beneath the gate to rise, and the conduction band at the AlGaN / GaN heterojunction interface is located at the Fermi level E. F This process depletes the two-dimensional electron gas under the gate, achieving enhancement mode. However, since P-GaN is absent in the gate-source and gate-drain regions, two-dimensional electron gas still exists in the channel. Therefore, the gate-source two-dimensional electron gas of the enhancement-mode E-mode device can be directly obtained from the gate-source two-dimensional electron gas density of the depletion-mode D-mode device, which has the same device size. When the gate bias of the depletion-mode D-mode device is 0V, the gate-source two-dimensional electron gas density under a 0V gate bias can be obtained from step S2. (The two-dimensional electron gas concentration under different gate voltages in step S2 is obtained by integrating the capacitance-voltage characteristic curve, i.e., the CV curve:) The two-dimensional electron gas under the gate at 0V bias can be obtained. The gate-source two-dimensional electron gas density of the enhancement-mode E-mode device is then... = .

[0024] S8, gate-source channel electron mobility:

[0025] Gate-source channel electron mobility μ s = ,in For the gate-source spacing, It is a two-dimensional electron gas, obtained from step S7; Let μ be the gate-source resistance; substituting this into the solution yields the gate-source channel electron mobility μ. s ;

[0026] S9, gate-source sheet resistance:

[0027] Gate source sheet resistance is Substituting this into the gate-source sheet resistance yields... .

[0028] Preferably, in step S1, the enhancement-mode E-mode device and the depletion-mode D-mode device form an integrated structure, which, from bottom to top, includes a P-type doped silicon substrate, an AlN nucleation layer, a GaN buffer layer, an AlN insertion layer, and an AlGaN barrier layer. An ohmic metal electrode is disposed above the GaN buffer layer on one side of the integrated structure to form the source of the enhancement-mode E-mode device, and an ohmic metal electrode is disposed in the middle of the integrated structure to form the drain of the enhancement-mode E-mode device and the source of the depletion-mode D-mode device. An ohmic metal electrode is disposed above the GaN buffer layer on the other side of the integrated structure to form the drain of the depletion-mode D-mode device.

[0029] A p-type doped GaN cap layer and a Schottky metal electrode are sequentially disposed above the AlGaN barrier layer between the source and drain of the enhancement-mode E-mode device, and the Schottky metal electrode forms the gate of the enhancement-mode E-mode device.

[0030] A Schottky metal electrode is disposed above the AlGaN barrier layer between the source and drain of the depletion-mode D-mode device to form the gate of the depletion-mode D-mode device.

[0031] Preferably, the gate length L of the enhancement-mode E-mode device and the depletion-mode D-mode device G , gate width W, gate-source spacing L GS , grid spacing L GD They are all equal.

[0032] Preferably, in step S2, the depletion-mode D-mode device is in V GS =0V, i.e., under zero electric field, the polarization charge of the AlGaN barrier layer is uniformly distributed, the gate source, gate drain and the energy band under the gate have the same bending, and the two-dimensional electron gas density is equal.

[0033] For a two-dimensional electron gas thin layer with thickness approaching zero, ρ = = Where ρ is the surface resistivity, For the obstruction of the ditch, The density of the two-dimensional electron gas in the channel. The amount of electron charge. Because of mobility, therefore the total resistance R Z = = , The density of the two-dimensional electron gas in the channel. The length of the channel. This refers to the width of the channel.

[0034] For any details not covered in this invention, please refer to the prior art.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. Since the size of enhancement-mode E-mode devices and depletion-mode D-mode devices are exactly the same, the gate-source resistance and gate-drain resistance of enhancement-mode devices can be obtained directly from the depletion-mode devices, enabling the rapid, convenient, and accurate extraction of key parameters of enhancement-mode devices.

[0037] 2. In this invention, since the depletion-mode device and the enhancement-mode device are adjacent, the contact resistance error between the gold and semiconductor caused by uneven P-GaN etching can be eliminated, thereby improving the accuracy of extracting key device parameters.

[0038] 3. This invention establishes a more reasonable and accurate method for extracting key parameters of enhancement-mode P-GaN HEMT devices, providing theoretical support for the study of the electrical transport characteristics of enhancement-mode devices. The method for extracting key parameters in this invention is based on conventional structures and electrical test data, eliminating the need for complex structures and destructive testing.

[0039] 4. The device structure described in this invention is directly compatible with the mainstream manufacturing processes of existing P-GaN / AlGaN / GaN HEMT, making it easy to implement on existing production lines and reducing manufacturing costs. Attached Figure Description

[0040] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0041] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0042] Figure 2 The capacitance-voltage characteristic curve of a depletion-mode D-mode device;

[0043] Figure 3 Two-dimensional electron gas density of a depletion-type D-mode device at different gate voltages;

[0044] Figure 4 Capacitor-voltage characteristic curves for enhanced E-mode devices;

[0045] Figure 5 Two-dimensional electron gas density of enhancement-mode devices at different gate voltages;

[0046] Figure 6 The carrier mobility of the enhancement-mode device at different gate voltages;

[0047] In the figure, 1-silicon substrate, 2-AlN nucleation layer, 3-GaN buffer layer, 4-AlN insertion layer, 5-AlGaN barrier layer, 6-GaN cap layer, 7-source of enhancement-mode E-mode device, 8-ohmic metal electrode, 9-drain of depletion-mode D-mode device, 10-gate of enhancement-mode E-mode device, 11-gate of depletion-mode D-mode device. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. However, this is not the only description; all aspects not described in detail herein are based on conventional techniques in the art.

[0049] Example 1

[0050] A method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT includes the following steps:

[0051] S1, fabricate an enhanced E-mode device, and fabricate a depletion-mode D-mode device of the same size next to the enhanced E-mode device;

[0052] like Figure 1 As shown, the enhancement-mode E-mode device and the depletion-mode D-mode device form an integrated structure, which, from bottom to top, includes a P-type doped silicon substrate 1, an AlN nucleation layer 2, a GaN buffer layer 3, an AlN insertion layer 4, and an AlGaN barrier layer 5. An ohmic metal electrode is disposed above the GaN buffer layer 3 on one side of the integrated structure to form the source 7 of the enhancement-mode E-mode device. An ohmic metal electrode 8 is disposed in the middle of the integrated structure to form the drain of the enhancement-mode E-mode device and the source of the depletion-mode D-mode device. An ohmic metal electrode is disposed above the GaN buffer layer on the other side of the integrated structure to form the drain 9 of the depletion-mode D-mode device.

[0053] A p-type doped GaN cap layer 6 and a Schottky metal electrode are sequentially disposed above the AlGaN barrier layer 5 between the source and drain of the enhancement-mode E-mode device. The Schottky metal electrode forms the gate 10 of the enhancement-mode E-mode device.

[0054] A Schottky metal electrode is disposed above the AlGaN barrier layer between the source and drain of the depletion-mode D-mode device to form the gate 11 of the depletion-mode D-mode device.

[0055] Gate length L of enhancement-mode E-mode devices and depletion-mode D-mode devices G, gate width W, gate-source spacing L GS , grid spacing L GD They are all equal.

[0056] S2, due to the gate length of the enhancement-mode E-mode device and the depletion-mode D-mode device Grid width , gate-source spacing Grid spacing The gate-source resistance R of the enhancement-mode E-mode device is equal to that of the other devices. GS1 and gate-drain resistance R GD1 The gate-source resistance R of the depletion-mode D-mode device is respectively compared with that of the other two devices. GS2 and gate-drain resistance R GD2 equal;

[0057] To test the output characteristic curve of a depletion-mode D-mode device, the gate-source voltage V is used. GS Set to 0V, drain-source voltage V DS Set to 0-10V, outputting the drain-source current I of the depletion-mode D-mode device. DS You can get V GS Output characteristic curve of the device at 0V;

[0058] For depletion-mode D-mode devices, V is taken at a low field. DS = 0.1 V current I DS - Voltage value V DS Total resistance R Z =V DS / I DS Based on the device structure, the total resistance R is obtained. Z = 2R C + R GS2 + R GD2 + R G2 (The ratio of drain-source current to drain-source voltage is the total drain-source channel resistance, which is the sum of the gold-semiconductor contact resistance between the source and the ohmic metal, the gold-semiconductor contact resistance between the drain and the ohmic metal, the channel resistance between the gate and source, the channel resistance under the gate, and the channel resistance between the gate and drain.) Where R C This represents the gold-semi contact resistance between the source and the ohmic metal, or the gold-semi contact resistance between the drain and the ohmic metal; both are equal. R GS2 R represents the channel resistance between the gate and source. GD2 R represents the channel resistance between the gate and drain. G2 Indicates the channel resistance under the gate;

[0059] For depletion-mode D-mode devices, the gate voltage V GS At 0 V, since the density of the two-dimensional electron gas under the gate and the gate source / drain are equal, the total resistance R is...Z - 2R C = R GS2 + R GD2 + R G2 = ,in The amount of electron charge. For V GS Two-dimensional electron gas at 0 V, For V GS Mobility at 0 V;

[0060] like Figure 2 As shown, the capacitance-voltage (CV) characteristics of the depletion-mode D-mode device were tested at different gate voltages, such as... Figure 3 As shown, the concentration of the two-dimensional electron gas at different gate voltages is obtained by integrating the capacitance-voltage characteristic curve (i.e., the CV curve): ,in, For the applied gate voltage, The point on the capacitance-voltage characteristic curve where the capacitance changes the most rapidly corresponds to... The value is obtained by differentiating the capacitance-voltage characteristic curve. The gate capacitance is being tested. The area of ​​the Schottky contact; the gold-semiconductor contact resistance R is obtained by TLM testing. C , will R C V GS Two-dimensional electron gas at 0 V , grid length Grid spacing , gate-source spacing and gate width Substitute R Z - 2R C = The solution yields the V of the depletion-mode D-mode device. GS Mobility at 0 V ;

[0061] The gate-source resistance and gate-drain resistance of enhancement-mode E-mode devices are equal to those of depletion-mode D-mode devices, which are respectively the gate-source resistance R0. GS1 =R GS2 = and gate-drain resistance R GD1 =R GD2 = , calculate , The gate-source resistance R can be solved iteratively by substituting the values. GS1 and gate-drain resistance R GD1 ;

[0062] S3, gate resistance:

[0063] drain-source voltage V DS Set to 0-10V, for different gate-source voltages V GS Lower output drain source current I DS That is, testing different gate-source voltages V GS The output characteristic curve of the enhancement-mode E-mode device is taken as the drain-source voltage V under low field. DS Current I at 0.1 V DS -Voltage V DS The data shows that the total source-drain resistance R of the enhancement-mode E-mode device is... Z =V DS / I DS The total resistance R under different gate voltages was obtained. Z Total resistance R under different gate voltages Z = 2R C + R GS1 + R G1 + R GD1 Gold-semiconductor contact resistance R C Gate-source resistance R GS1 and gate-drain resistance R GD1 The gate resistance R under different gate voltages has been obtained in step S2. G1 ;

[0064] S4, Gate bottom resistance:

[0065] The resistance below the gate is , bring in the gate width , grid length and V GS Gate resistance R at 0V G1 That is, the resistance below the gate is obtained ;

[0066] S5, Two-dimensional electron gas concentration under gate voltage:

[0067] like Figure 4 The capacitance-voltage (CV) characteristics of the enhanced E-mode device under different gate voltages were tested. Figure 5 As shown, the concentration of the two-dimensional electron gas under different gate voltages can be obtained by integrating the capacitance-voltage characteristic curve (CV curve). ,in To apply a gate voltage in an enhancement-mode E-mode device, The point corresponding to the fastest capacitance change in the capacitance-voltage characteristic curve of the enhancement-mode E-mode device under different gate voltages. The value can be obtained by differentiating the capacitance-voltage characteristic curve. Gate capacitance tested in an enhanced E-mode device. The area of ​​the Schottky contact in the enhancement-mode device;

[0068] S6, under-gate electron mobility:

[0069] Gate electron mobility ,in For grid length, The amount of electron charge. For grid width, For the density of two-dimensional electron gas, The gate resistance; the two-dimensional electron gas density under the gate at different gate voltages in step S5. and the gate resistance under different gate voltages in step S3 After substituting the values ​​into the solution, the under-gate electron mobility under different gate voltages can be obtained, such as... Figure 6 As shown;

[0070] S7, Two-dimensional electron gas concentration in the gate-source channel:

[0071] In enhancement-mode E-mode devices, the selective placement of the GaN cap layer on the AlGaN barrier layer beneath the gate causes the conduction band of the AlGaN barrier layer beneath the gate to rise, and the conduction band at the AlGaN / GaN heterojunction interface is located at the Fermi level E. F This process depletes the two-dimensional electron gas under the gate, achieving enhancement mode. However, since P-GaN is absent in the gate-source and gate-drain regions, two-dimensional electron gas still exists in the channel. Therefore, the gate-source two-dimensional electron gas of the enhancement-mode E-mode device can be directly obtained from the gate-source two-dimensional electron gas density of the depletion-mode D-mode device, which has the same device size. When the gate bias of the depletion-mode D-mode device is 0V, the gate-source two-dimensional electron gas density under a 0V gate bias can be obtained from step S2. (The two-dimensional electron gas concentration under different gate voltages in step S2 is obtained by integrating the capacitance-voltage characteristic curve, i.e., the CV curve:) The two-dimensional electron gas under the gate at 0V bias can be obtained. The gate-source two-dimensional electron gas density of the enhancement-mode E-mode device is then... = .

[0072] S8, gate-source channel electron mobility:

[0073] Gate-source channel electron mobility μ s = ,in For the gate-source spacing, It is a two-dimensional electron gas, obtained from step S7; Let μ be the gate-source resistance; substituting this into the solution yields the gate-source channel electron mobility μ. s ;

[0074] S9, gate-source sheet resistance:

[0075] Gate source sheet resistance is Substituting this into the gate-source sheet resistance yields... .

[0076] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT, characterized in that, Includes the following steps: S1, fabricate an enhanced E-mode device, and fabricate a depletion-mode D-mode device of the same size next to the enhanced E-mode device; S2, due to the gate length of the enhancement-mode E-mode device and the depletion-mode D-mode device Grid width , gate-source spacing Grid spacing The gate-source resistance R of the enhancement-mode E-mode device is equal to that of the other devices. GS1 and gate-drain resistance R GD1 The gate-source resistance R of the depletion-mode D-mode device is respectively compared with that of the other two devices. GS2 and gate-drain resistance R GD2 equal; To test the output characteristic curve of a depletion-mode D-mode device, the gate-source voltage V is used. GS Set to 0V, drain-source voltage V DS Set to 0-10V, outputting the drain-source current I of the depletion-mode D-mode device. DS You can get V GS Output characteristic curve of the device at 0V; For depletion-mode D-mode devices, V is taken at a low field. DS = 0.1 V current I DS - Voltage value V DS Total resistance R Z =V DS / I DS Based on the device structure, the total resistance R is obtained. Z = 2R C + R GS2 + R GD2 + R G2 , where R C R represents the gold-semi contact resistance between the source and the ohmic metal, or the gold-semi contact resistance between the drain and the ohmic metal. GS2 R represents the channel resistance between the gate and source. GD2 R represents the channel resistance between the gate and drain. G2 Indicates the channel resistance under the gate; For depletion-mode D-mode devices, the gate voltage V GS At 0 V, since the density of the two-dimensional electron gas under the gate and the gate source / drain are equal, the total resistance R is... Z - 2R C = R GS2 + R GD2 + R G2 = ,in The amount of electron charge. For V GS Two-dimensional electron gas at 0 V, For V GS Mobility at 0 V; The capacitance-voltage characteristics of the depletion-mode D-mode device were tested at different gate voltages. The two-dimensional electron gas concentration at different gate voltages was obtained by integrating the capacitance-voltage characteristic curves. ,in, For the applied gate voltage, The point on the capacitance-voltage characteristic curve where the capacitance changes the most rapidly corresponds to... The value is obtained by differentiating the capacitance-voltage characteristic curve. The gate capacitance is being tested. The area of ​​the Schottky contact; the gold-semiconductor contact resistance R is obtained by TLM testing. C , will R C V GS Two-dimensional electron gas at 0 V , grid length Grid spacing , gate-source spacing and gate width Substitute R Z - 2R C = Solving for V yields V GS Mobility at 0 V ; The gate-source resistance and gate-drain resistance of enhancement-mode E-mode devices are equal to those of depletion-mode D-mode devices, which are respectively the gate-source resistance R0. GS1 =R GS2 = and gate-drain resistance R GD1 =R GD2 = , calculate , The gate-source resistance R can be solved iteratively by substituting the values. GS1 and gate-drain resistance R GD1 ; S3, gate resistance: drain-source voltage V DS Set to 0-10V, for different gate-source voltages V GS Lower output drain source current I DS That is, testing different gate-source voltages V GS The output characteristic curve of the enhancement-mode E-mode device is taken as the drain-source voltage V under low field. DS Current I at 0.1 V DS -Voltage V DS The data shows that the total source-drain resistance R of the enhancement-mode E-mode device is... Z =V DS / I DS The total resistance R under different gate voltages was obtained. Z Total resistance R under different gate voltages Z = 2R C + R GS1 + R G1 + R GD1 Gold-semiconductor contact resistance R C Gate-source resistance R GS1 and gate-drain resistance R GD1 The gate resistance R under different gate voltages has been obtained in step S2. G1 ; S4, Gate bottom resistance: The resistance below the gate is , bring in the gate width , grid length and V GS Gate resistance R at 0V G1 That is, the resistance below the gate is obtained ; S5, Two-dimensional electron gas concentration under gate voltage: The capacitance-voltage characteristics of the enhancement-mode E-mode device were tested at different gate voltages. The two-dimensional electron gas concentration under the gate at different gate voltages was obtained by integrating the capacitance-voltage characteristic curves. ,in To apply a gate voltage in an enhancement-mode E-mode device, The point corresponding to the fastest capacitance change in the capacitance-voltage characteristic curve of the enhancement-mode E-mode device under different gate voltages. value, Gate capacitance tested in an enhanced E-mode device. The area of ​​the Schottky contact in the enhancement-mode device; S6, under-gate electron mobility: Gate electron mobility ,in For grid length, The amount of electron charge. For grid width, For the density of two-dimensional electron gas, The gate resistance; the two-dimensional electron gas density under the gate at different gate voltages in step S5. and the gate resistance under different gate voltages in step S3 After substituting the values ​​into the solution, the under-gate electron mobility under different gate voltages is obtained; S7, Two-dimensional electron gas concentration in the gate-source channel: In enhancement-mode E-mode devices, the selective placement of the GaN cap layer on the AlGaN barrier layer beneath the gate causes the conduction band of the AlGaN barrier layer beneath the gate to rise, and the conduction band at the AlGaN / GaN heterojunction interface is located at the Fermi level E. F The above results in the depletion of the two-dimensional electron gas under the gate, achieving enhancement mode of the device. However, since P-GaN is not present in the gate-source and gate-drain regions, two-dimensional electron gas still exists in the channel. Therefore, the gate-source two-dimensional electron gas of the enhancement-mode E-mode device is directly obtained from the gate-source two-dimensional electron gas density of the depletion-mode D-mode device, which has the same device size. When the gate bias voltage of the depletion-mode D-mode device is 0V, the gate-source two-dimensional electron gas under the 0V gate bias voltage can be obtained from step S2. The gate-source two-dimensional electron gas density of the enhancement-mode E-mode device = ; S8, gate-source channel electron mobility: Gate-source channel electron mobility = ,in For the gate-source spacing, The two-dimensional electron gas density of the gate source is obtained from step S7; Let be the gate-source resistance; substituting this into the solution yields the gate-source channel electron mobility. ; S9, gate-source sheet resistance: Gate source sheet resistance is Substituting this into the gate-source sheet resistance yields... .

2. The method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT according to claim 1, characterized in that, In step S1, the enhancement-mode E-mode device and the depletion-mode D-mode device form an integrated structure, which, from bottom to top, includes a P-type doped silicon substrate, an AlN nucleation layer, a GaN buffer layer, an AlN insertion layer, and an AlGaN barrier layer. An ohmic metal electrode is disposed above the GaN buffer layer on one side of the integrated structure to form the source of the enhancement-mode E-mode device, and an ohmic metal electrode is disposed in the middle of the integrated structure to form the drain of the enhancement-mode E-mode device and the source of the depletion-mode D-mode device. An ohmic metal electrode is disposed above the GaN buffer layer on the other side of the integrated structure to form the drain of the depletion-mode D-mode device. A p-type doped GaN cap layer and a Schottky metal electrode are sequentially disposed above the AlGaN barrier layer between the source and drain of the enhancement-mode E-mode device, and the Schottky metal electrode forms the gate of the enhancement-mode E-mode device. A Schottky metal electrode is disposed above the AlGaN barrier layer between the source and drain of the depletion-mode D-mode device to form the gate of the depletion-mode D-mode device.

3. The method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT according to claim 2, characterized in that, Gate length L of enhancement-mode E-mode devices and depletion-mode D-mode devices G , gate width W, gate-source spacing L GS , grid spacing L GD They are all equal.

4. The method for extracting key parameters of enhancement-mode GaN devices based on depletion-mode GaN HEMT according to claim 3, characterized in that, In step S2, the depletion-mode D-mode device is in V GS =0V, i.e., under zero electric field, the polarization charge of the AlGaN barrier layer is uniformly distributed, the gate source, gate drain and the energy band under the gate have the same bending, and the two-dimensional electron gas density is equal. For a two-dimensional electron gas thin layer with thickness approaching zero, ρ = = Where ρ is the surface resistivity, For the obstruction of the ditch, The density of the two-dimensional electron gas in the channel. The amount of electron charge. Because of mobility, therefore the total resistance R Z = = , The density of the two-dimensional electron gas in the channel. The length of the channel. This refers to the width of the channel.

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