Compound semiconductor device RF thermal distribution test system

Abstract

The invention discloses a compound semiconductor device radio frequency heat distribution test system, comprising a signal source, a coupler, an isolator, a heat stage, a load regulator and an infrared thermal imager; the device is arranged on the heat stage, and a fixed ambient temperature is set by the heat stage; the infrared thermal imager collects the background heat radiation signal of the device when no microwave excitation signal and direct current excitation signal are applied; the direct current excitation signal is applied to the device so that the device works in a conducting or pinching-off working state; the signal source is connected to the radio frequency input end of the device through a coupler and an isolator to provide a microwave excitation signal; the load regulator is connected to the radio frequency output end of the device to adjust the standing wave ratio and phase of the microwave signal at the radio frequency output end, thereby changing the heat radiation signal of the device; the infrared thermal imager collects the heat radiation signal of the device in real time to generate a radio frequency heat distribution diagram of the device in a working state, and the system of the invention can more easily grasp the evolution mechanism of the device power distribution with the change of the working environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of compound power semiconductors. Background Art

[0002] Wide-bandgap compound semiconductor materials feature large bandgap widths, high breakdown voltages, fast electron drift velocities, and strong radiation resistance. Devices exhibit high-temperature and high-voltage resistance, as well as excellent high-frequency and high-power properties. During operation, compound semiconductor devices convert some electrical power into thermal radiation, the intensity of which is dependent on the device's operating state. Based on the Stefan-Boltzmann law and Planck's blackbody radiation formula, small changes in the blackbody's temperature can result in significant changes in the total radiated power.

[0003] To meet the demands of high-voltage, high-power applications, compound semiconductor devices are typically designed with multiple gates in parallel. As device power density continues to increase, self-heating near the gate becomes increasingly pronounced. Excessively high junction temperatures can reduce the device's peak power density and even impact its long-term reliability.

[0004] When the device is powered by DC, the power density flowing through each gate in its multi-gate parallel structure is similar, resulting in minimal temperature differences between the gates and a relatively uniform thermal distribution across the device. However, when the device is powered by RF, the DC and RF signals act as a superposition on each gate. The RF signal's effect on each gate varies in both the frequency and time domains, leading to varying junction temperatures across the device. Therefore, accurately determining the device's thermal distribution during RF operation presents a challenge. Summary of the Invention

[0005] Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the present invention provides a radio frequency heat distribution test system for compound semiconductor devices.

[0006] Technical solution: The present invention provides a radio frequency heat distribution test system for compound semiconductor devices, including a signal source, a coupler, an isolator, a heat stage, a load regulator, and an infrared thermal imager; the compound semiconductor device is placed on the heat stage, and a fixed ambient temperature is set by the heat stage;

[0007] An infrared thermal imager is used to collect background thermal radiation signals of a compound semiconductor device when no microwave excitation signals and direct current excitation signals are applied. A direct current excitation signal is then applied to the compound semiconductor device so that the compound semiconductor device operates in an on or off state. According to the operating state of the compound semiconductor device, a signal source is adjusted, and the signal source is connected to the radio frequency input end of the compound semiconductor device through a coupler and an isolator to provide a microwave excitation signal to the compound semiconductor device. The load regulator is connected to the radio frequency output end of the compound semiconductor device to adjust the standing wave ratio and phase of the microwave signal output from the radio frequency output end, thereby changing the thermal radiation signal of the compound semiconductor device. The infrared thermal imager collects the thermal radiation signals of the compound semiconductor device in real time, and generates a radio frequency thermal distribution map of the compound semiconductor device in the operating state based on the collected background thermal radiation signals and the real-time collected thermal radiation signals.

[0008] Furthermore, the system also includes a first attenuator, a second attenuator, a first power meter and a second power meter; the coupler is connected to the first power meter through the first attenuator; the load regulator is connected to the second power meter through the second attenuator; the first attenuator attenuates the microwave excitation signal input from the signal source to the compound semiconductor device through the coupler to a range that can be monitored by the first power meter, the load regulator transmits the signal output from the RF output end of the compound semiconductor device to the second attenuator, and the second attenuator attenuates the signal to a range that can be monitored by the second power meter; and whether the working state of the semiconductor compound is normal is judged based on the difference between the monitoring values ​​of the first power meter and the second power meter.

[0009] Furthermore, when a DC excitation signal is applied to the compound semiconductor device, the source is grounded, a gate DC power supply is connected to the gate of the compound semiconductor device, and a drain DC power supply is connected to the drain of the compound semiconductor device, so that the compound semiconductor device operates in an on or off state.

[0010] Furthermore, the material of the compound semiconductor device is indium phosphide, gallium arsenide, gallium nitride, silicon carbide or gallium oxide.

[0011] Furthermore, the compound semiconductor device is of a type of MOSFET, MISFET, MESFET, HFET, PHEMT, HEMT, SBD or HBT.

[0012] Furthermore, the load regulator has an operating frequency of DC to 1 THz and a standing wave ratio of 1:1 to 100:1.

[0013] Beneficial effects: The present invention realizes an analysis system for the thermal distribution of compound semiconductor devices, innovatively realizes a method for visualizing the thermal distribution of devices, combines the microwave working state of the device with the principle of thermal radiation, and constructs a dynamic capture of the thermal distribution of solid-state microwave devices under different working environments, making it easier to grasp the evolution mechanism of the device's thermal distribution as the working environment changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a system block diagram of the present invention.

[0015] Figure 2 RF thermal distribution diagram of compound semiconductor devices in operation. DETAILED DESCRIPTION

[0016] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0017] like Figure 1 As shown, the present invention provides a radio frequency heat distribution test system for compound semiconductor devices, including a signal source, a coupler, an isolator, a heat stage, a load regulator and a universal platform for infrared thermal imagers, and all hardware have a good common ground.

[0018] The source of the compound semiconductor device (hereinafter referred to as the device) is grounded, and the gate and drain are respectively connected to a DC power supply to provide a DC excitation signal for the device.

[0019] The signal source is connected to the device through a coupler and an isolator to provide the device with a microwave excitation signal.

[0020] The hot stage can achieve precise temperature control in the temperature range of -55℃~400℃. It is placed under the device and has good contact with the bottom of the device, providing a relative ambient temperature for the device.

[0021] The load regulator adjusts the standing wave ratio and phase of the signal output from the RF output port of the device; the load regulator operates at a frequency of DC to 1THz, a standing wave ratio of 1:1 to 100:1, and a phase of 0 ° ~360 ° .

[0022] The device is placed in a universal platform of infrared thermal imager, which captures the thermal radiation generated when the device is working and forms a radio frequency power distribution map after data processing.

[0023] This embodiment also includes a first attenuator, a second attenuator, a first power meter and a second power meter; the coupler is connected to the first power meter through the first attenuator to monitor the microwave input signal; the load regulator is connected to the second power meter through the second attenuator; the first attenuator attenuates the microwave excitation signal input from the signal source to the compound semiconductor device to a range that can be monitored by the first power meter, preventing the first power meter from burning due to excessive monitored power signals.

[0024] The load regulator transmits the signal output from the radio frequency output end of the compound semiconductor device to the second attenuator, and the second attenuator attenuates the signal to a range that can be monitored by the second power meter to monitor the microwave output signal.

[0025] In this embodiment, the material of the compound semiconductor device is indium phosphide, gallium arsenide, gallium nitride, silicon carbide or gallium oxide.

[0026] In this embodiment, the compound semiconductor device type is MOSFET, MISFET, MESFET, HFET, PHEMT, HEMT, SBD or HBT.

[0027] The method of using the system in this embodiment includes the following steps:

[0028] a. The system is precisely calibrated and has good common ground;

[0029] b. The hot stage performs precise temperature control to set the ambient temperature of the device;

[0030] c. The infrared thermal imager universal platform collects background thermal radiation signals when the device is not powered on;

[0031] d. The source of the device is grounded, and the gate and drain are powered by a DC power supply in sequence. It can operate in the on state or the off state. The operating state of the device must match the subsequent microwave signal;

[0032] e. Set the parameters of the signal source and turn on the microwave signal;

[0033] f. The microwave signal of the signal source is divided into the main signal and the bypass signal through the coupler;

[0034] g. The main signal is transmitted to the device through a coupler and an isolator. After being processed by the device, the signal is transmitted to the load regulator, attenuator, and second power meter. The bypass signal is transmitted to the input of the first power meter through a coupler and attenuator.

[0035] h. The load regulator adjusts the microwave signal output from the RF output of the device to a predetermined standing wave ratio and phase;

[0036] i. The first power meter and the second power meter monitor the input signal and output signal of the device respectively, and determine whether the working state of the device is normal based on the difference between the monitoring values ​​of the two power meters;

[0037] j. The device generates a thermal radiation signal under the combined action of a DC signal and a microwave signal;

[0038] k. The infrared thermal imager universal platform collects the thermal radiation signal of the device under working state, and forms the RF thermal distribution map of the device under working state through data processing.

[0039] In one embodiment, the compound semiconductor device uses GaN HEMT, the load regulator uses MMT-1808, the coupler uses 87031E, the hot stage temperature is set to 70°C, the gate and drain are powered by a DC power supply in sequence, the gate voltage Vg is -3.0V, the drain voltage Vd is 45V, the leakage current Id is 100mA, the signal source parameters are set to a frequency f of 4.6GHz, an input power Pin of 40.7dBm, a pulse working mode, a pulse width of 10us, a period of 1ms, and a duty cycle of 1%; the standing wave ratio of the load regulator is 5:1, and the phase is 60 O The attenuation of the second attenuator is 30dBm, and the attenuation of the first attenuator is 20dB. The RF thermal distribution diagram of the compound semiconductor device in the working state collected by the infrared thermal imager is as follows: Figure 2 shown.

[0040] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A compound semiconductor device radio frequency heat distribution test system, characterized in that: It includes a signal source, a coupler, an isolator, a heat stage, a load regulator and an infrared thermal imager; the compound semiconductor device is arranged on the heat stage, and a fixed ambient temperature is set by the heat stage; An infrared thermal imager is used to collect a background thermal radiation signal of a compound semiconductor device when no microwave excitation signal and direct current excitation signal are applied; a direct current excitation signal is then applied to the compound semiconductor device so that the compound semiconductor device operates in an on or off state; a signal source is adjusted according to the working state of the compound semiconductor device, and the signal source is connected to a radio frequency input end of the compound semiconductor device through a coupler and an isolator to provide a microwave excitation signal to the compound semiconductor device; The load regulator is connected to the radio frequency output terminal of the compound semiconductor device to adjust the standing wave ratio and phase of the microwave signal output from the radio frequency output terminal, thereby changing the thermal radiation signal of the compound semiconductor device; The infrared thermal imager collects the thermal radiation signal of the compound semiconductor device in real time, and generates a radio frequency thermal distribution map of the compound semiconductor device in a working state according to the collected background thermal radiation signal and the real-time collected thermal radiation signal; The system also includes a first attenuator, a second attenuator, a first power meter and a second power meter; the coupler is connected to the first power meter through the first attenuator; the load regulator is connected to the second power meter through the second attenuator; the first attenuator attenuates the microwave excitation signal output by the coupler to a range that can be monitored by the first power meter, the load regulator transmits the signal output by the radio frequency output end of the compound semiconductor device to the second attenuator, and the second attenuator attenuates the signal to a range that can be monitored by the second power meter; and whether the working state of the semiconductor compound is normal is judged according to the difference between the monitoring values ​​of the first power meter and the second power meter; When a DC excitation signal is applied to the compound semiconductor device, the source is grounded, a gate DC power supply is used to connect the gate of the compound semiconductor device, and a drain DC power supply is used to connect the drain of the compound semiconductor device, so that the compound semiconductor device works in an on or off working state.

2. The compound semiconductor device radio frequency heat distribution test system according to claim 1, characterized in that: The material of the compound semiconductor device is indium phosphide, gallium arsenide, gallium nitride, silicon carbide or gallium oxide.

3. The compound semiconductor device radio frequency heat distribution test system according to claim 1, characterized in that: The compound semiconductor device type is MOSFET, MISFET, MESFET, HFET, PHEMT, HEMT, SBD or HBT.

4. The compound semiconductor device radio frequency heat distribution test system according to claim 1, characterized in that: The load regulator has an operating frequency of DC to 1 THz and a standing wave ratio of 1:1 to 100:1.

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