Anti-device self-excitation biaser, method and device test system

Abstract

The present invention provides an anti-device self-excitation biaser, a method and a device testing system, comprising: a radio frequency signal input module, a direct current signal input module, a first comparison and triggering module, a second comparison and triggering module, and a tuning module; the radio frequency signal input module outputs a radio frequency output signal; the direct current signal input module outputs a direct current output signal; the first comparison and triggering module samples and detects the radio frequency output signal, and generates a first trigger signal when signal self-excitation is detected; the second comparison and triggering module samples and detects the direct current output signal, and generates a second trigger signal when signal self-excitation is detected; the tuning module adjusts the impedance value of the direct current signal input module after receiving any one of the first trigger signal and the second trigger signal. The present invention uses an adaptive active anti-device self-excitation biaser to ensure that when anti-device self-excitation occurs, parameter adjustment can be directly implemented based on the detected self-excitation state of the signal, so as to suppress or even eliminate signal self-excitation.

Description

Technical Field

[0001] The present invention relates to the technical field of microelectronic test and measurement, and particularly to an anti-device self-excitation bias device, method and device test system. Background Art

[0002] In the production process of semiconductor wafers, accurate measurement of their electrical characteristics is crucial. This is not only used to evaluate and verify the wafer manufacturing and R & D processes, but for high electron mobility transistor (HEMT) devices used in radio frequency and microwave technologies, it also involves constructing device models through performance testing and parameter extraction to provide the necessary process design kits for chip design. Therefore, precise measurement of the electrical performance of wafers is an essential step in the manufacturing process.

[0003] When measuring the electrical characteristics of wafers, differences between different wafer batches, devices at different positions within the same batch, and devices of different sizes must be considered. For HEMT devices, the accuracy of their test results may be affected by various factors, including production batches, device positions, and sizes. Issues such as process consistency, design structure, and probe contact may cause the device to self-oscillate during the test, which not only reduces the test efficiency but may also damage the device under test, the probe, or the test equipment.

[0004] When performing radio frequency or current-voltage (CV) characteristic tests on active devices, an external bias tee is usually used to supply power and isolate DC signals to avoid interfering with the test equipment. However, the performance of the bias tee, the stability and uniformity of the process platform, defects in the epitaxial layer, defects in the device structure, low on-resistance (Ron) of large-size devices, inconsistent probe contact caused by wafer bending, and impedance discontinuities caused by poor contact may all be the causes of self-oscillation.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art section of the present application. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide an anti-device self-excitation bias device, method and device test system for solving the problems such as the device under test being prone to self-oscillation due to the presence of the bias device in the prior art.

[0007] To achieve the above object and other related objects, the present invention provides an anti-device self-excitation bias device, comprising:

[0008] RF signal input module, DC signal input module, first comparison trigger module, second comparison trigger module, and tuning module;

[0009] The RF signal input module receives an RF signal and outputs an RF output signal to the output end of the anti-device self-excitation biasing device;

[0010] The DC signal input module receives a DC signal and outputs a DC output signal to the output end of the anti-device self-excitation biasing device;

[0011] The first comparison trigger module samples and detects the RF output signal to generate a first trigger signal when self-excitation occurs in the RF output signal;

[0012] The second comparison trigger module samples and detects the DC output signal to generate a second trigger signal when self-excitation occurs in the DC output signal;

[0013] The tuning module is connected to the output ends of the first comparison trigger module and the second comparison trigger module, and outputs a tuning signal to the DC signal input module after receiving any one of the first trigger signal and the second trigger signal to adjust the impedance value of the DC signal input module, thereby avoiding self-excitation of the RF output signal and the DC output signal and causing a self-excitation signal to be output to the output end of the anti-device self-excitation biasing device.

[0014] Optionally, the RF signal input module includes a first capacitor; the first electrode plate of the first capacitor is connected to the RF signal, and the second electrode plate is connected to the output end of the anti-device self-excitation biasing device.

[0015] Optionally, the first comparison trigger module includes a detection unit and a comparison unit; the detection unit receives the RF output signal and outputs the RF output signal to the first input end of the comparison unit; the second input end of the comparison unit is connected to a first preset voltage, and outputs the first trigger signal when the amplitude of the RF output signal is greater than or equal to the amplitude of the first preset voltage.

[0016] Optionally, the second comparison trigger module includes a second comparison trigger unit; the first input end of the second comparison trigger unit is connected to the DC output signal, the second input end is connected to a second preset voltage, and outputs the second trigger signal when the amplitude of the DC output signal is greater than or equal to the amplitude of the second preset voltage.

[0017] Optionally, the DC signal input module includes a first inductor, a first resistor, a second resistor, a first variable resistor, and a first variable capacitor; the DC signal sequentially passes through the first variable resistor, the first resistor, and the first inductor and is connected to the output end of the anti-device self-excitation biasing device; a node connected between the first variable resistor and the first resistor sequentially passes through the second resistor and the first variable capacitor and is connected to the reference ground; wherein, both the first variable resistor and the first variable capacitor are connected to the tuning signal of the tuning module.

[0018] Optionally, the anti-device self-excitation biasing device further includes a DC input detection module arranged in parallel with the DC signal input module for detecting the working state of the DC signal input module; wherein, the output signal of the DC input detection module is set in proportion to the RF output signal.

[0019] Optionally, the anti-device self-excitation biasing device further includes a third comparison trigger module; the third comparison trigger module samples and detects the output signal of the DC input detection module to generate a third trigger signal and output it to the tuning module to generate the tuning signal when self-excitation occurs in the output signal of the DC input detection module.

[0020] Optionally, the DC input detection module includes a second inductor, a third resistor, a fourth resistor, a second variable resistor, and a second variable capacitor; the DC signal sequentially passes through the second variable resistor, the third resistor, and the second inductor and is connected to the output end of the anti-device self-excitation biasing device; a node connected between the second variable resistor and the third resistor sequentially passes through the fourth resistor and the second variable capacitor and is connected to the reference ground; wherein, both the second variable resistor and the second variable capacitor are connected to the tuning signal of the tuning module.

[0021] Optionally, when the DC signal input module includes a first inductor, a first resistor, a second resistor, a first variable resistor, and a first variable capacitor, the inductance value of the second inductor is equal to the inductance value of the first inductor; the resistance value of the third resistor is equal to the resistance value of the first resistor; the resistance value of the fourth resistor is equal to the resistance value of the second resistor.

[0022] Optionally, the anti-device self-excitation biasing device further includes a voltage stabilization module for supplying power to the first comparison trigger module, the second comparison trigger module, and the tuning module.

[0023] Optionally, the anti-device self-excitation biaser further includes a DC input detection module and a third comparison and triggering module; the DC input detection module is arranged in parallel with the DC signal input module and is used to detect the working state of the DC signal input module, wherein the output signal of the DC input detection module is set in proportion to the RF output signal; the third comparison and triggering module samples and detects the DC input detection module to generate a third trigger signal when self-excitation occurs in the output signal of the DC input detection module and outputs the third trigger signal to the tuning module to generate the tuning signal;

[0024] At this time, the voltage stabilization module is further used to supply power to the third comparison and triggering module.

[0025] To achieve the above and other related purposes, the present invention provides an anti-device self-excitation method, which is implemented based on the above anti-device self-excitation method and includes:

[0026] Collect the RF output signal and the DC output signal, and when self-excitation occurs in any output signal, adjust the impedance value of the DC signal input module, thereby avoiding self-excitation of the RF output signal and the DC output signal and causing the self-excitation signal to be output to the output end of the anti-device self-excitation biaser.

[0027] Optionally, when the anti-device self-excitation biaser further includes a DC input detection module arranged in parallel with the DC signal input module, set the output signal of the DC input detection module to be in a preset proportion to the RF output signal.

[0028] Optionally, when the anti-device self-excitation biaser further includes a third comparison and triggering module, the tuning signal is output to at least one of the DC signal input module and the DC input detection module to adjust the impedance value of the corresponding module.

[0029] To achieve the above and other related purposes, the present invention provides a device test system, which is implemented based on the above anti-device self-excitation method and includes: an RF signal generator, a DC signal generator, a test probe, and the above anti-device self-excitation biaser;

[0030] The RF signal generator is used to generate an RF signal and is connected to the RF signal input module of the anti-device self-excitation biaser;

[0031] The DC signal generator is used to generate a DC signal and is connected to the DC signal input module of the anti-device self-excitation biaser;

[0032] The input end of the test probe is connected to the output end of the anti-device self-excitation biaser, and the output end is connected to the position to be measured of the device to be tested for device testing.

[0033] As described above, the anti-device self-excitation biaser, method, and device testing system of the present invention have the following beneficial effects:

[0034] 1. The anti-device self-excitation biaser, method, and device testing system of the present invention adopt an adaptive anti-device self-excitation biaser. Thus, when the device is anti-self-excited, parameter adjustment can be directly based on the self-excitation state of the detected signal to avoid device signal self-excitation. There is no need to adjust the parameters by adjusting the external devices of the anti-device self-excitation biaser, nor is it necessary to repeatedly adjust, avoiding human intervention.

[0035] 2. The anti-device self-excitation biaser, method, and device testing system of the present invention ensure that even if the device self-excites under different test conditions, it can be detected and directly suppressed or even eliminated, avoiding manual troubleshooting after finding that the test results do not meet the test requirements or the need for manual inspection every time the test conditions are adjusted, and avoiding the phenomenon of device damage during the tuning process. At the same time, the tuning range of the anti-device self-excitation biaser, method, and device testing system of the present invention can be larger and the adjustment is more efficient.

[0036] 3. The anti-device self-excitation biaser and device testing system of the present invention have a simple structure and a simple method. And due to the provision of an independent active power supply module, the accuracy of data detection during device detection is ensured, and it can be applied to the parameter testing of, including but not limited to, radio frequency HEMT devices, pHEMT devices, and power electronic devices, having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It shows a schematic structural diagram of a biaser.

[0038] Figure 2 It shows a schematic framework diagram of the anti-device self-excitation biaser of the present invention.

[0039] Figure 3 It shows a first schematic structural diagram of the anti-device self-excitation biaser of the present invention.

[0040] Figure 4 It shows a second schematic structural diagram of the anti-device self-excitation biaser of the present invention.

[0041] Figure 5 It shows a third schematic structural diagram of the anti-device self-excitation biaser of the present invention.

[0042] Figure 6 It shows Figure 1 The signal waveform diagram of device testing of the biaser under the first preset condition.

[0043] Figure 7 It shows Figure 1Signal waveform diagram of the biaser under the second preset condition for device testing.

[0044] Figure 8 Shown is the signal waveform diagram of the anti-device self-excitation biaser of the present invention under the second preset condition for device testing.

[0045] Description of component labels

[0046] 0 Biaser

[0047] 1 Anti-device self-excitation biaser

[0048] 11 RF signal input module

[0049] 12 DC signal input module

[0050] 13 First comparison and trigger module

[0051] 131 Detection unit

[0052] 132 Comparison unit

[0053] 14 Second comparison and trigger module

[0054] 15 Tuning module

[0055] 16 Voltage stabilization module

[0056] 2 Anti-device self-excitation biaser

[0057] 21 DC input detection module

[0058] 22 Third comparison and trigger module Specific implementation manners

[0059] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0060] Please refer to Figures 1 to 8 . It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0061] In the process of wafer manufacturing, for the HEMT device process applied to the radio frequency and microwave fields, it is necessary to test the performance of each device on the wafer, and device modeling is carried out through parameter extraction and fitting, so as to generate a process design and development package for chip design. Therefore, accurate measurement of wafer electrical performance parameters is an essential step. For HEMT devices, devices of different batches, different positions, and different sizes may cause self-oscillation of the device during the test due to process stability, structural design, probe contact, etc., which directly affects the accuracy of the test results, greatly affects the efficiency of the test work, and may further cause damage to the device under test, probe damage, or even test instrument failure.

[0062] In the process of radio frequency performance testing or CV performance testing of active devices, an external bias tee is often used to feed the device and isolate the influence of DC signals on the test equipment. However, the bias tee may cause self-oscillation, which is often detected outside the bias tee, resulting in too long self-oscillation time of the device, which may cause damage to the device performance or even damage the device. At the same time, when the device undergoes self-oscillation, usually the way and position of the probe contact are corrected, or other impedance matching networks are set outside the bias tee to improve it, or some links with magnetic rings or parallel capacitors are added outside to eliminate self-oscillation. However, the parameters of devices of different sizes or different positions are not balanced. Therefore, during the test, it may be necessary to frequently confirm the device status, and still cannot adjust the device in a timely and rapid manner, resulting in a complex test process and the need to repeatedly verify the validity of the test data.

[0063] Based on this, in order to quickly identify the possible self-oscillation conditions at the input and output ends of the device under test and make an adaptive adjustment to the self-oscillation state, the present invention provides an anti-device self-oscillation bias tee, method, and device test system.

[0064] Comparative example

[0065] As Figure 1 shown, this comparative example provides a bias tee 0, including: a first capacitor C01, a second capacitor C02, a third capacitor C03, an inductor L01, and a resistor R01.

[0066] Specifically, the radio frequency input signal RFIN passes through the first capacitor C01 and the second capacitor C02 in sequence and is output to the output end of the bias tee 0. The DC input signal DCIN passes through the resistor R01 and the inductor L01 in sequence and is output to the node connected between the first capacitor C01 and the second capacitor C02. The third capacitor C03 is connected to the node where the resistor R01 receives the DC input signal DCIN and is output to the reference ground.

[0067] A bias device 0 provided in this comparative example may cause self-excited oscillation in the face of its own performance, the stable uniformity of the process platform, the defects of the epitaxial layer, the defects of the device structure, the too low Ron parameter of large-size devices, the inconsistency of needle insertion caused by wafer warping, and the impedance discontinuity caused by poor contact, and it cannot be solved. It can only be adjusted manually. Moreover, the parameters of devices of different sizes or at different positions are not balanced. Therefore, it may be necessary to frequently confirm the device status and verify the validity of the test data during the test process.

[0068] Embodiment 1

[0069] Based on the above existing problems, as Figure 2 shown, this embodiment provides an anti-device self-excitation bias device 1, including: a radio frequency signal input module 11, a direct current signal input module 12, a first comparison trigger module 13, a second comparison trigger module 14, and a tuning module 15.

[0070] As Figure 2 shown, the radio frequency signal input module 11 receives a radio frequency signal RF IN and outputs a radio frequency output signal to the output end of the anti-device self-excitation bias device 1.

[0071] Specifically, the radio frequency signal input module 11 includes a first capacitor C1; the first electrode plate of the first capacitor C1 is connected to the radio frequency signal, and the second electrode plate is connected to the output end of the anti-device self-excitation bias device 1.

[0072] In this embodiment, when the anti-device self-excitation bias device 1 is applied to device testing, the first capacitor C1 can isolate the direct current component and only allow the alternating current signal to pass through, thereby ensuring the accuracy of the test result and protecting the device port.

[0073] As Figure 2 shown, the direct current signal input module 12 receives a direct current signal DC IN and outputs a direct current output signal to the output end of the anti-device self-excitation bias device 1.

[0074] Specifically, as Figure 3 shown, the direct current signal input module 12 includes a first inductor L1, a first resistor R1, a second resistor R2, a first variable resistor R V 1, and a first variable capacitor C V 1.

[0075] As an example, as Figure 3 shown, the direct current signal sequentially passes through the first variable resistor R V 1, the first resistor R1, and the first inductor L1 and is connected to the output end of the anti-device self-excitation bias device 1; the first variable resistor R VThe node connected between 1 and the first resistor R1 sequentially passes through the second resistor R2 and the first variable capacitor C V 1 and is connected to the reference ground GND; wherein, the first variable resistor R V 1 and the first variable capacitor C V 1 are both connected to the tuning signal of the tuning module 15.

[0076] In this embodiment, the first inductor L1 is set as a high-Q (Quality Factor) inductor. When the anti-device self-excitation biasing device 1 is applied to device testing, the first inductor L1 can isolate the AC signal, thereby ensuring the accuracy of the test result and protecting the device port; the Q factor is an important parameter for measuring the performance of the resonant circuit, which is defined as the ratio of the stored energy in the circuit at the resonant frequency to the dissipated energy in one cycle, and takes dozens to one hundred in this embodiment. The first resistor R1 is set as a precision resistor to amplify and output the input DC signal. The first variable capacitor C V 1 is a varactor diode.

[0077] Based on the varactor diode and the first variable resistor R V 1, an RC network, a radio frequency choke circuit and a decoupling circuit are reconstructed to increase the tuning range.

[0078] In this embodiment, the tuning signal of the tuning module 15 is divided into two paths, one path is input to the first variable resistor R V 1, and one path is input to the first variable capacitor C V 1. In this embodiment, the tuning signal of the tuning module 15 is set as a voltage value, one path outputs the first adjustment voltage Vc1, and the other path outputs the second adjustment voltage Vc2, which respectively change the resistance value of the first variable resistor R V 1 and the capacitance value of the first variable capacitor C V 1 to achieve the phase tuning of the DC signal input module 12.

[0079] It should be noted that, compared with the method of selecting and replacing the resistors outside or inside the anti-device self-excitation biasing device 1 and setting the repeatedly replaced capacitors to set parameters in some examples, the anti-device self-excitation biasing device 1 of this embodiment is provided with a first comparison trigger module 13 and a second comparison trigger module 14, which can directly track the self-excitation change of the signal in the anti-device self-excitation biasing device 1, avoiding the problems of time-consuming, easy damage to the device and inaccurate detection results existing in the methods of repeatedly replacing resistors, capacitors, etc.; at the same time, because this method can continuously and stably track the self-excitation signal, it can ensure that even if the device self-excites under different test conditions, it can be detected and directly suppressed or even eliminated, avoiding the problems of manual elimination after finding that the test results do not meet the test, or the need to check again whether the biasing device conditions have self-excited after each adjustment of the test conditions. Therefore, the anti-device self-excitation biasing device 1 of this embodiment can realize the test of multiple devices or even multiple wafers in one connection, and can adaptively detect without repeated debugging.

[0080] In addition, since the anti-device self-excitation biasing device 1 of this embodiment directly regulates the variable resistor and the variable capacitor according to the trigger signal, the reaction is faster. Compared with the methods of replacing resistors and replacing capacitors, it can quickly avoid the influence of self-excitation on the subsequent device and avoid the phenomenon of damage to the device during the tuning process. At the same time, since the variable capacitor and the variable resistor can be directly adjusted based on the tuning signal, the tuning range is larger and the adjustment is more efficient than the variable range of only mechanically replacing resistors and / or replacing capacitors.

[0081] It should be further noted that the specific setting of the radio frequency signal input module 11 is not limited to this embodiment. Any setting with a variable resistor and a variable capacitor connected to the tuning signal and adjusting the impedance by adjusting the phase relationship to prevent device self-excitation is within the protection scope of this embodiment.

[0082] As Figure 2 shown, the first comparison trigger module 13 samples and detects the radio frequency output signal to generate a first trigger signal when the radio frequency output signal self-excites.

[0083] Specifically, as Figure 3 shown, the first comparison trigger module 13 includes a detection unit 131 and a comparison unit 132; the detection unit 131 receives the radio frequency output signal and outputs the radio frequency output signal to the first input end of the comparison unit 132; the second input end of the comparison unit 132 is connected to a first preset voltage Vcc1, and outputs the first trigger signal when the amplitude of the radio frequency output signal is greater than or equal to the amplitude of the first preset voltage Vcc1.

[0084] In this embodiment, the detection unit 131 is set as an envelope detector, which acquires the amplitude of the RF output signal based on a diode or other rectifying device, and is used to sense self-oscillation caused by low-frequency oscillation, facilitating subsequent comparison. In other embodiments, the detection unit 131 can also be set as other types of detectors of broadband detectors to achieve the effect of sampling. If self-oscillation occurs in the RF output signal, its amplitude will increase correspondingly (as when self-oscillation occurs as shown in Figure 6 , Figure 7 , a part of the voltage of the signal will become larger). In this embodiment, the comparison unit 132 is set to judge the amplitude of the RF output signal. When it exceeds the first preset voltage Vcc1, it is determined that self-oscillation has occurred and the DC signal input module 12 needs to be adjusted to change the self-oscillation state. In this embodiment, when the RF output signal continuously self-oscillates, the first comparison trigger module 13 will continuously trigger, forming a cyclic trigger until the self-oscillation state ends and the trigger cycle ends.

[0085] As shown in Figure 2 , the second comparison trigger module 14 samples and detects the DC output signal, and generates a second trigger signal when self-oscillation occurs in the DC output signal.

[0086] Specifically, as shown in Figure 3 , the second comparison trigger module 14 includes a second comparison trigger unit; the first input terminal of the second comparison trigger unit is connected to the DC output signal, the second input terminal is connected to the second preset voltage Vcc2, and the second trigger signal is output when the amplitude of the DC output signal is greater than or equal to the amplitude of the second preset voltage Vcc2.

[0087] In this embodiment, as shown in Figure 3 , it is preferably set that the first input terminal of the second comparison trigger unit 14 is connected to the node where the first inductor L1 and the first resistor R1 are connected, and the voltage signal that does not flow through the inductor is acquired, so that the waveform change induction is more accurate and timely, and self-oscillation generation can be better suppressed. In addition, since the first resistor R1 is provided in this embodiment and amplified by a precision resistor, it can ensure that the collected DC signal fluctuates more, is easy to collect and accurate.

[0088] In this embodiment, the second comparison trigger unit 14 is set to judge the amplitude of the DC output signal. When it exceeds the second preset voltage Vcc2, it is determined that the DC characteristic has mutated (i.e., self-oscillation has occurred) and the DC signal input module 12 needs to be adjusted to avoid the signal continuously being in the self-oscillation state. In this embodiment, when the DC output signal continuously self-oscillates, the second comparison trigger module 14 will continuously trigger, forming a cyclic trigger until the self-oscillation state ends and the trigger cycle ends.

[0089] It should be noted that in this embodiment, the second comparison trigger module 14 is set to collect the DC output signal, that is, to collect the signal inside the DC signal input module 12 to determine whether self-excitation has occurred, especially the self-excitation signal output to the external circuit where it is located. Therefore, in fact, the second comparison trigger module 14 is set to collect the first variable resistor R V 1. It is possible to connect to the node of any two devices among the first resistor R1 and the first inductor L1, and the output terminal node of the first inductor L1 connected to the anti-device self-excitation biasing device 1. It does not mean that the signal can only be collected by connecting to the output terminal of the anti-device self-excitation biasing device 1.

[0090] It should be further noted that the setting of the second comparison trigger module 14 is not limited to this embodiment. Any setting that can collect the signal inside the DC signal input module to determine whether self-excitation has occurred in the DC output signal is within the protection scope of this embodiment.

[0091] As Figure 2 shown, the tuning module 15 is connected to the output terminal of the first comparison trigger module 13 and the output terminal of the second comparison trigger module 14, and outputs a tuning signal to the DC signal input module 12 after receiving any one of the first trigger signal and the second trigger signal, so as to adjust the impedance value of the DC signal input module 12, thereby avoiding self-excitation of the RF output signal and the DC output signal and causing the self-excitation signal to be output to the output terminal of the anti-device self-excitation biasing device 1.

[0092] Specifically, in this embodiment, the tuning module 15 is set as a numerically controlled tuning circuit. The numerically controlled tuning circuit converts a digital signal (any one of the first trigger signal and the second trigger signal) and generates the required tuning signals (the first tuning voltage Vc1 and the second tuning voltage Vc2), and outputs them to the corresponding variable capacitor and variable resistor respectively to adjust the phase of the DC signal, thereby making the phase difference between the DC signal and the RF signal not meet the self-excitation condition.

[0093] In this embodiment, the numerically controlled tuning circuit includes a watchdog program to prevent getting into a closed loop in the case where self-excitation cannot be eliminated.

[0094] It should be noted that the first tuning voltage Vc1 and the second tuning voltage Vc2 can be set based on actual requirements and can be set independently. That is, when the first tuning voltage Vc1 changes, the second tuning voltage Vc2 can change simultaneously or not, as long as the phase in the final DC signal input module 12 changes, thereby avoiding the self-excited state.

[0095] Specifically, as Figure 3As shown, the anti-device self-excitation biaser 1 further includes a voltage stabilization module 16, and the voltage stabilization module 16 is used to supply power to the first comparison trigger module 13, the second comparison trigger module 14, and the tuning module 15.

[0096] As an example, the first preset voltage Vcc1 and the second preset voltage Vcc2 in the first comparison trigger module 13 and the second comparison trigger module 14 are both provided by the voltage stabilization module 16, and the tuning module 15 is also powered based on the voltage stabilization module 16. Among them, by adopting a separate power supply path, the influence on device characteristics caused by series connection is avoided.

[0097] In this embodiment, the voltage stabilization module 16 adopts a broadband linear voltage stabilization circuit, which is used to adapt to different power supply systems and avoid low-frequency interference introduced by a switching voltage stabilization circuit.

[0098] As Figure 2 shown, this embodiment also provides an anti-device self-excitation method, which is implemented based on the above-mentioned anti-device self-excitation biaser 1 and includes: collecting the radio frequency output signal and the direct current output signal, and when any output signal undergoes self-excitation, adjusting the impedance value of the direct current signal input module 12, thereby avoiding self-excitation of the radio frequency output signal and the direct current output signal and causing a self-excitation signal to be output to the output end of the anti-device self-excitation biaser.

[0099] In this embodiment, an adaptive anti-device self-excitation biaser 1 is adopted, so as to ensure that when anti-device self-excitation occurs, parameter adjustment can be directly performed based on the self-excitation state of the detected signal, without the need to adjust parameters by adjusting external devices of the anti-device self-excitation biaser 1, nor repeated adjustment, avoiding human intervention.

[0100] This embodiment also provides a device test system, including: a radio frequency signal generator (not shown in the figure), a direct current signal generator (not shown in the figure), a test probe (not shown in the figure), and the above-mentioned anti-device self-excitation biaser 1.

[0101] Specifically, the radio frequency signal generator is used to generate a radio frequency signal and is connected to the radio frequency signal input module 11 of the anti-device self-excitation biaser 1. The direct current signal generator is used to generate a direct current signal and is connected to the direct current signal input module 12 of the anti-device self-excitation biaser 1. The input end of the test probe is connected to the output end of the anti-device self-excitation biaser 1, and the output end is connected to the position to be measured of the device to be tested for device testing.

[0102] In this embodiment, the output ends of the radio frequency signal input module 11 and the anti-device self-excitation biaser 1 are also connected to instruments such as a network analyzer; the DC signal input module 12 is also connected to DC instruments such as a semiconductor parameter analyzer, a source meter, and a power supply; the anti-device self-excitation biaser 1 is connected to the device under test and is used to conduct both DC and radio frequency signals simultaneously.

[0103] The device test system of this embodiment supports the active parameter testing of radio frequency HEMT devices, pHEMT devices, and power electronic devices simultaneously. Similarly, this embodiment can also be applied to the electrical performance parameter testing of higher frequency bands, and has high versatility and practicality.

[0104] Embodiment Two

[0105] As Figure 4 shown, this embodiment provides an anti-device self-excitation biaser 2, which is basically the same as Embodiment One. The difference is that the anti-device self-excitation biaser 2 of this embodiment further includes a DC input detection module 21 arranged in parallel with the DC signal input module 12.

[0106] As Figure 4 shown, the DC input detection module 21 is used to detect the working state of the DC signal input module; wherein, the output signal of the DC input detection module 21 is set in proportion to the radio frequency output signal.

[0107] Specifically, the DC input detection module 21 includes a second inductor L2, a third resistor R3, a fourth resistor R4, a second variable resistor Rv2, and a second variable capacitor Cv2.

[0108] As an example, the DC signal sequentially passes through the second variable resistor Rv2, the third resistor R3, and the second inductor L2 and is connected to the output end of the anti-device self-excitation biaser 1; the node connected between the second variable resistor Rv2 and the third resistor R3 sequentially passes through the fourth resistor R4 and the second variable capacitor Cv2 and is connected to the reference ground GND; wherein, both the second variable resistor Rv2 and the second variable capacitor Cv2 are connected to the tuning signal of the tuning module 15.

[0109] In this embodiment, when the DC signal input module 12 includes a first inductor L1, a first resistor R1, a second resistor R2, a first variable resistor RV1, and a first variable capacitor CV1, the inductance value of the second inductor L2 is equal to the inductance value of the first inductor L1; the resistance value of the third resistor R3 is equal to the resistance value of the first resistor R1; the resistance value of the fourth resistor R4 is equal to the resistance value of the second resistor R2. The DC signal input module 12 is used as an application end to provide the current or voltage required for testing. Then, the DC input detection module 21 is used as a detection end to measure the response (current or voltage) passing through the device, so as to ensure that the DC input detection module 21 can work properly. In this embodiment, the application end provides a current signal, and the detection end detects the voltage with the current signal applied, and then, according to the resistance relationship between the DC signal input module 12 and the DC input detection module 21, it is determined whether the DC signal input module 12 is working properly. Therefore, it is very important to ensure the precise cooperation between the application end and the detection end, because they jointly determine the accuracy and reliability of the test.

[0110] In this embodiment, it is further provided that the second comparison trigger module 14 further includes a current detection unit (not shown in the figure) for detecting the current of the DC signal input module 12.

[0111] It should be noted that in this embodiment, it is preferably set that the components in the DC signal input module 12 and the DC input detection module 21 are correspondingly equal to ensure the accuracy of the simulation. In actual use, the internal settings of the DC signal input module 12 and the DC input detection module 21 can be different, as long as the currents output by the DC input detection module 21 and the DC input detection module 21 are relatively consistent and change in a preset ratio for better detection. The specific settings are not limited to this embodiment. Based on this, when controlling the variable capacitors and variable resistors in the DC signal input module 12 and the DC input detection module 21 through the tuning signal, in addition to changing the impedance of the DC signal input module 12, it is also necessary to ensure that the internal device parameters of the DC signal input module 12 and the DC input detection module 21 are adjusted accordingly, and the internal current is always maintained in a preset ratio state.

[0112] In addition, the specific component settings of the DC input detection module 21 in this embodiment can refer to the internal component settings of the DC signal input module 12, and will not be elaborated here one by one.

[0113] Specifically, such as Figure 5As shown, the anti-device self-excitation biasing device 2 further includes a third comparison and triggering module 22; the third comparison and triggering module 22 samples and detects the output signal of the DC input detection module 21, and generates a third trigger signal to the tuning module 15 to generate the tuning signal when the output signal of the DC input detection module 21 undergoes self-excitation.

[0114] It should be noted that, in this embodiment, since the DC input detection module 21 is actually used to detect the DC signal input module 12, actually only a very small voltage difference is output at the output end of the anti-device self-excitation biasing device 2 to obtain the loss of the entire link, that is: the output signal of the DC input detection module 21 has little effect on the output end of the subsequent anti-device self-excitation biasing device 2. Therefore, the influence of the self-excitation of the DC input detection module 21 is also small. In actual use, the third comparison and triggering module 22 can be set or not set. In addition, when controlling the tuning module 15 to generate the tuning signal based on the third trigger signal, it includes a fifth tuning voltage Vc5 and a sixth tuning voltage Vc6. In this embodiment, the fifth tuning voltage Vc5 and the sixth tuning voltage Vc6 can be directly connected to the variable capacitor and variable resistor of the DC input detection module 21; in another embodiment, the fifth tuning voltage Vc5 and the sixth tuning voltage Vc6 can be connected to the variable capacitor and variable resistor of the DC signal input module 12. Actually, when controlling the tuning module 15 to generate the tuning signal based on the third trigger signal, the corresponding tuning voltage can be connected to at least one variable resistor or variable capacitor in the DC input detection module 21 and the DC signal input module 12, as long as it can ensure that the phase of the final DC signal input module 12 is adjusted and the internal current of the DC input detection module 21 changes accordingly. Such settings are within the protection scope of this embodiment.

[0115] It should be further noted that, compared with some examples of selecting and replacing the resistors outside or inside the anti-device self-excitation biasing device 1 and setting repeatedly replaced capacitors to set parameters, in addition to the feature that the self-excitation of the anti-device self-excitation biasing device 1 in this embodiment under different test conditions can be detected and directly suppressed or even eliminated, the anti-device self-excitation biasing device 2 of this embodiment can also perform electro-tuning of the DC input detection module 21 and the DC signal input module 12 based on the first trigger comparison module and the second trigger comparison module at the same time, which can complete high-precision consistency adjustment, reduce the deviation between links, and further ensure the accuracy and reliability of the anti-device self-excitation biasing device 2 of this embodiment.

[0116] As an example, in this embodiment, when the anti-device self-excitation biasing device 2 further includes a voltage stabilization module 16, the voltage stabilization module 16 is also used to supply power to the third comparison and triggering module 22.

[0117] In this embodiment, modules other than the radio frequency signal input module 11 and the direct current signal input module 12 are independently powered by the voltage stabilizing module 16, ensuring the stability of the anti-device self-excitation biasing device 2 and making it less susceptible to interference.

[0118] This embodiment also provides an anti-device self-excitation method, which is implemented based on the anti-device self-excitation biasing device 2 provided in this embodiment and is basically the same as the anti-device self-excitation method in Embodiment 1. The difference is that a direct current input detection module 21 is provided in this embodiment.

[0119] Specifically, in this embodiment, when the anti-device self-excitation biasing device further includes a direct current input detection module 21, the output signal of the direct current input detection module 21 is set to be in a preset ratio to the radio frequency output signal. The specific principle here has been described in the previous text and will not be elaborated again here.

[0120] In this embodiment, when the anti-device self-excitation biasing device 2 further includes a third comparison trigger module 22, the tuning signal is output to at least one of the direct current signal input module 12 and the direct current input detection module 21 to adjust the impedance value of the corresponding module. The specific setting has been described in the previous text and will not be elaborated again here.

[0121] This embodiment also provides a device testing system, including: a radio frequency signal generator (not shown in the figure), a direct current signal generator (not shown in the figure), a test probe, and the anti-device self-excitation biasing device 2 provided in this embodiment. The specific setting is basically the same as that in Embodiment 1. The difference is that it is different from the anti-device self-excitation biasing device 1 in Embodiment 1. Its specific connection relationship has been described before and will not be elaborated again here.

[0122] In this embodiment, the radio frequency signal generator is used to send W-band signals up to 120 GHz. Among them, the device testing system in this embodiment can be used for testing electrical parameters such as direct current IV characteristics, transconductance characteristics, alternating current CV characteristics, radio frequency S parameters, gain, noise figure, and phase characteristics, and covers high and low temperature characteristic tests; at the same time, the device testing system in this embodiment can be used for various platforms such as manual probe stations, semi-automatic probe stations, and fully automatic probe stations.

[0123] As Figures 6 to 8 shown, where Figure 6 and Figure 7 are the signals detected by the biasing device 0 in Comparative Example 1 under different test conditions respectively. Its signal waveform oscillates significantly and is difficult to solve. However, for the waveform signals tested by the biasing devices provided in Embodiment 1 and this embodiment under the corresponding conditions, self-excited oscillation is effectively avoided, and it can quickly suppress or even eliminate the oscillation after the signal oscillates, as Figure 8 shown.

[0124] The anti-device self-excitation biaser of the present invention focuses on being adaptive and tunable, relying on the parameter characterization of a semiconductor parameter analyzer or a precision source meter, and is used to solve the problems that it is difficult to eliminate or improve the self-excitation of devices at different positions and of different sizes at one time during the in-wafer on-chip testing process of device testing, especially HEMT device testing, so as to achieve fast, automatic, and highly accurate testing of multiple parameters of device testing, and avoid frequent adjustment of the test link and data verification caused by self-excitation.

[0125] In summary, the present invention provides an anti-device self-excitation biaser, method, and device testing system, including: a radio frequency signal input module, a direct current signal input module, a first comparison and triggering module, a second comparison and triggering module, and a tuning module; the radio frequency signal input module outputs a radio frequency output signal; the direct current signal input module outputs a direct current output signal; the first comparison and triggering module samples and detects the radio frequency output signal, and generates a first trigger signal when signal self-excitation is detected; the second comparison and triggering module samples and detects the direct current output signal, and generates a second trigger signal when signal self-excitation is detected; the tuning module adjusts the impedance value of the direct current signal input module after receiving any one of the first trigger signal and the second trigger signal. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0126] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An anti-device self-excitation biaser, characterized in that, The anti-device self-excitation biaser at least includes: a radio frequency signal input module, a direct current signal input module, a first comparison trigger module, a second comparison trigger module, and a tuning module; The radio frequency signal input module receives a radio frequency signal and outputs a radio frequency output signal to the output end of the anti-device self-excitation biaser; The direct current signal input module receives a direct current signal and outputs a direct current output signal to the output end of the anti-device self-excitation biaser; The first comparison trigger module samples and detects the radio frequency output signal to generate a first trigger signal when self-excitation occurs in the radio frequency output signal; The second comparison trigger module samples and detects the direct current output signal to generate a second trigger signal when self-excitation occurs in the direct current output signal; The tuning module is connected to the output end of the first comparison trigger module and the output end of the second comparison trigger module, and outputs a tuning signal to the direct current signal input module after receiving any one of the first trigger signal and the second trigger signal to adjust the impedance value of the direct current signal input module, thereby avoiding self-excitation of the radio frequency output signal and the direct current output signal and causing a self-excitation signal to be output to the output end of the anti-device self-excitation biaser.

2. The anti-device self-excitation biaser according to claim 1, characterized in that: The radio frequency signal input module includes a first capacitor; a first electrode plate of the first capacitor is connected to the radio frequency signal, and a second electrode plate is connected to the output end of the anti-device self-excitation biaser.

3. The anti-device self-excitation biaser according to claim 1, characterized in that: The first comparison trigger module includes a detection unit and a comparison unit; The detection unit receives the radio frequency output signal and outputs the radio frequency output signal to a first input end of the comparison unit; A second input end of the comparison unit is connected to a first preset voltage, and outputs the first trigger signal when the amplitude of the radio frequency output signal is greater than or equal to the amplitude of the first preset voltage.

4. The anti-device self-excitation biasing device according to claim 1, characterized in that: The second comparison trigger module includes a second comparison trigger unit; A first input end of the second comparison trigger unit is connected to the direct current output signal, a second input end is connected to a second preset voltage, and outputs the second trigger signal when the amplitude of the direct current output signal is greater than or equal to the amplitude of the second preset voltage.

5. The anti-device self-excitation biasing device according to claim 1, characterized in that: The direct current signal input module includes a first inductor, a first resistor, a second resistor, a first variable resistor, and a first variable capacitor; The direct current signal sequentially passes through the first variable resistor, the first resistor, and the first inductor and is connected to the output end of the anti-device self-excitation biaser; A node connected between the first variable resistor and the first resistor sequentially passes through the second resistor and the first variable capacitor and is connected to the reference ground; Wherein, both the first variable resistor and the first variable capacitor are connected to the tuning signal of the tuning module.

6. The anti-device self-excitation biaser according to any one of claims 1 to 5, characterized in that: The anti-device self-excitation biaser further includes a direct current input detection module arranged in parallel with the direct current signal input module for detecting the working state of the direct current signal input module; wherein, the output signal of the direct current input detection module is set in proportion to the radio frequency output signal.

7. The anti-device self-excitation biasing device according to claim 6, characterized in that: The anti-device self-excitation biaser further includes a third comparison and triggering module; the third comparison and triggering module samples and detects the output signal of the DC input detection module to generate a third trigger signal and output it to the tuning module to generate the tuning signal when self-excitation occurs in the output signal of the DC input detection module.

8. The anti-device self-excitation biaser according to claim 6, characterized in that: The DC input detection module includes a second inductor, a third resistor, a fourth resistor, a second variable resistor, and a second variable capacitor; The DC signal sequentially passes through the second variable resistor, the third resistor, and the second inductor and is connected to the output end of the anti-device self-excitation biaser; The node connected between the second variable resistor and the third resistor sequentially passes through the fourth resistor and the second variable capacitor and is connected to the reference ground; Wherein, both the second variable resistor and the second variable capacitor are connected to the tuning signal of the tuning module.

9. The anti-device self-excitation biaser according to claim 8, wherein: When the DC signal input module includes a first inductor, a first resistor, a second resistor, a first variable resistor, and a first variable capacitor, the inductance value of the second inductor is equal to the inductance value of the first inductor; the resistance value of the third resistor is equal to the resistance value of the first resistor; The resistance value of the fourth resistor is equal to the resistance value of the second resistor.

10. The anti-device self-excitation biasing device according to claim 1, characterized in that: The anti-device self-excitation biaser further includes a voltage stabilization module for supplying power to the first comparison and triggering module, the second comparison and triggering module, and the tuning module.

11. The anti-device self-excitation bias device according to claim 10, wherein: The anti-device self-excitation biaser further includes a DC input detection module and a third comparison and triggering module; the DC input detection module is arranged in parallel with the DC signal input module and is used for detecting the working state of the DC signal input module. Wherein, the output signal of the DC input detection module is set in proportion to the RF output signal; the third comparison and triggering module samples and detects the DC input detection module to generate a third trigger signal and output it to the tuning module to generate the tuning signal when self-excitation occurs in the output signal of the DC input detection module; At this time, the voltage stabilization module is further used for supplying power to the third comparison and triggering module.

12. An anti-device self-excitation method implemented based on the anti-device self-excitation biaser according to any one of claims 1 to 11, characterized in that: Collect the RF output signal and the DC output signal, and when self-excitation occurs in any output signal, adjust the impedance value of the DC signal input module, thereby avoiding self-excitation of the RF output signal and the DC output signal and causing a self-excitation signal to be output to the output end of the anti-device self-excitation biaser.

13. The anti-self-excitation method of a device according to claim 12, characterized in that: When the anti-device self-excitation biaser further includes a DC input detection module arranged in parallel with the DC signal input module, set the output signal of the DC input detection module to be in a preset proportion to the RF output signal.

14. The anti-self-excitation method of a device according to claim 13, characterized in that: When the anti-device self-excitation biaser further includes a third comparison and triggering module, The tuning signal is output to at least one of the DC signal input module and the DC input detection module to adjust the impedance value of the corresponding module.

15. A device testing system, characterized in that: The device test system includes: a radio frequency signal generator, a direct current signal generator, a test probe, and the anti-device self-excitation biaser according to any one of claims 1 to 11; The radio frequency signal generator is used to generate a radio frequency signal and is connected to the radio frequency signal input module of the anti-device self-excitation biaser; The direct current signal generator is used to generate a direct current signal and is connected to the direct current signal input module of the anti-device self-excitation biaser; The input end of the test probe is connected to the output end of the anti-device self-excitation biaser, and the output end is connected to the position to be tested of the device to be tested for device testing.

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