High-sensitivity palladium-gold semiconductor test probe system

Abstract

The invention relates to the technical field of semiconductor test probes, discloses a high-sensitivity palladium-gold semiconductor test probe system, and aims to solve the problems of signal attenuation, test fluctuation, short service life and the like caused by high material resistivity, unstable contact resistance and easy oxidation of a traditional probe. The system comprises a palladium-gold alloy probe main body, a contact interface enhancement module integrated with an amorphous carbon protection layer and a noble metal transition layer, a signal transmission optimization module comprising an impedance matching and signal conditioning circuit, and a system control unit for monitoring contact resistance, pressure and temperature in real time, through material optimization, interface enhancement and closed-loop monitoring, low-resistance and high-stability contact is realized, the test sensitivity and precision are remarkably improved, and the service life of the probe is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of semiconductor test probe technology, specifically a high-sensitivity palladium-gold semiconductor test probe system. Background Technology

[0002] In the field of semiconductor manufacturing and testing, high-precision and high-reliability electrical performance testing is a crucial step in ensuring chip quality and yield. Among these components, the test probe, as the core interface connecting the testing equipment and the chip pads, directly impacts the integrity of signal transmission, the accuracy of test results, and the control of testing costs.

[0003] Among them, the semiconductor test probe system is a precision component specifically designed for testing the electrical parameters of integrated circuit wafers or packaged chips. This system establishes an electrical path through physical contact between the probe and the chip pads, thereby applying test signals and acquiring response data to complete functional verification and performance grading.

[0004] Existing test probes are generally made of nickel alloys or tungsten copper, which, while possessing a certain degree of mechanical strength, exhibit significant limitations in high-frequency, high-current testing scenarios. The high resistivity of the probe materials leads to signal attenuation and increased power consumption; insufficient contact resistance stability causes fluctuations in test results; and the mismatch between material hardness and chip pads can easily cause pad damage or premature probe wear. Furthermore, traditional probe materials are prone to surface oxidation after prolonged use, further degrading contact performance and shortening lifespan. As semiconductor process nodes continue to shrink and chip pin pitches continue to decrease, the aforementioned material defects leading to decreased test sensitivity, insufficient reliability, and rising maintenance costs are becoming increasingly prominent, representing a technological bottleneck restricting the improvement of advanced semiconductor testing performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of existing semiconductor test probes, such as signal attenuation, test result fluctuation, pad damage and short service life caused by high material resistivity, unstable contact resistance, hardness mismatch and easy oxidation, and to provide a high-sensitivity palladium semiconductor test probe system.

[0006] The technical solution of this invention is: a high-sensitivity palladium-gold semiconductor test probe system, comprising a probe body structure, a contact interface enhancement module, a signal transmission optimization module, and a system control and monitoring unit. The probe body structure is made of a palladium-gold alloy material with palladium as the matrix and uniformly doped with a specific proportion of gold. This alloy material has a volume resistivity of less than 2.5 microohm-cm and a Vickers hardness between 450 HV and 550 HV. The contact interface enhancement module is integrated into the probe tip and consists of an amorphous carbon protective layer formed by physical vapor deposition and a noble metal transition layer beneath the amorphous carbon protective layer. This module is used to establish and maintain a low-resistance and highly stable electrical connection between the probe and the chip pads. The signal transmission optimization module is electrically connected to the probe body structure and internally includes an impedance matching network and signal conditioning circuitry for optimizing the impedance of the transmission path and improving signal integrity of the high-frequency test signal passing through the probe. The system control and monitoring unit is communicatively connected to the probe body structure, the contact interface enhancement module, and the signal transmission optimization module. This unit is configured to collect probe working status data in real time and perform online evaluation and early warning of contact resistance drift and probe wear status based on a preset algorithm.

[0007] Furthermore, in the palladium-gold alloy material of the probe body structure, the gold doping ratio is controlled within the range of 8% to 12% by weight. This palladium-gold alloy material with specific composition is prepared through vacuum melting and rapid solidification processes, and its microstructure is a fine equiaxed crystal structure with a grain size of no more than 5 micrometers. This material combination and process enable the probe body to maintain the necessary mechanical strength while significantly reducing bulk resistance and enhancing resistance to arc erosion.

[0008] Furthermore, the noble metal transition layer in the contact interface enhancement module is made of iridium-ruthenium alloy, with a thickness between 0.1 micrometers and 0.3 micrometers. The thickness of the amorphous carbon protective layer is controlled within the range of 0.05 micrometers to 0.15 micrometers, and its surface energy is reduced to below 25 dynes / cm through plasma treatment, thereby reducing the adhesion between the probe and the chip pads and minimizing material transfer during the contact process.

[0009] Furthermore, the impedance matching network in the signal transmission optimization module employs a distributed parameter design, incorporating a series of miniature inductors and capacitors integrated onto a multilayer substrate using low-temperature co-fired ceramic technology. The impedance matching network aims to match the characteristic impedance between the probe tip and the test instrument input to 50 ohms, operating over a frequency range from DC to 40 GHz. The signal conditioning circuit integrates a low-noise amplifier and a programmable filter to amplify the acquired weak test signal and suppress out-of-band noise.

[0010] Furthermore, the system control and monitoring unit includes a high-precision four-wire Kelvin measurement circuit, a micro-force sensor for monitoring the axial force of the probe, and an embedded signal processor. The four-wire Kelvin measurement circuit is configured to monitor the contact resistance between the probe and the chip pad in real time, with a measurement resolution of 0.1 milliohms. The micro-force sensor monitors the pressure during probe contact in real time, ensuring it remains within a preset safety window of 50 millinewtons to 200 millinewtons. The embedded signal processor periodically analyzes the time-series data of contact resistance and contact pressure, and by comparing historical data with preset thresholds, it predicts the trend of probe performance degradation and determines the maintenance cycle.

[0011] Furthermore, the geometry of the probe's main body is specially designed, with its body being a multi-tiered stepped cylinder. The diameter of the finest end can be configured to be 15 micrometers, 25 micrometers, or 35 micrometers depending on the spacing of the test pads. The probe tip is shaped into a polygonal cone formed through precision grinding, with its apex angle between 15 and 30 degrees to ensure precise point contact on the tiny pads and to pierce any surface oxide layers that may be present.

[0012] Furthermore, the system control and monitoring unit also integrates a temperature compensation algorithm. This algorithm receives data from a temperature sensor located in the vicinity of the probe card and dynamically compensates and corrects the real-time measured contact resistance value based on the temperature coefficient of resistance of the probe material, thereby eliminating the impact of ambient temperature fluctuations on test accuracy.

[0013] Furthermore, the entire test probe system is designed to operate in an inert gas environment or within a vacuum chamber. The system is equipped with a sealed interface for connecting to an external gas source, continuously purging dry nitrogen or argon gas into the probe's working area to effectively isolate oxygen and thus fundamentally inhibit the oxidation process on the probe and pad surfaces. Compared with the prior art, the beneficial effects achieved by the present invention are: 1. This invention utilizes a palladium alloy with a specific composition as the probe body material, combined with optimized microstructure control, to achieve a significant reduction in probe resistivity and an ideal match between mechanical hardness. This directly results in a substantial reduction in signal attenuation and power consumption during testing. Furthermore, because its hardness is closer to that of the chip pad material, it effectively avoids the pad damage problems easily caused by traditional hard probes, thus improving testing safety and chip reliability.

[0014] 2. The contact interface enhancement module integrated in this invention constructs a highly stable, low-contact-resistance, and anti-adhesion electrical contact interface through the synergistic effect of a noble metal transition layer and an amorphous carbon protective layer. The low surface energy of the amorphous carbon layer reduces material adhesion and transfer during the contact process, while the noble metal transition layer ensures excellent conductivity and bonding strength. The combination of the two significantly improves the long-term stability of the contact resistance, reduces the fluctuation of test results, and extends the service life of the probe under frequent contact conditions.

[0015] 3. The signal transmission optimization module and system control and monitoring unit introduced in this invention constitute a closed-loop test quality assurance system. Impedance matching networks and signal conditioning circuits ensure the integrity of high-frequency signal transmission, while real-time online monitoring of contact resistance, contact pressure, and temperature compensation enable the system to promptly detect and correct changes in its operating state. This proactive monitoring and compensation mechanism significantly improves the accuracy and repeatability of test data. Furthermore, by predictively assessing probe wear conditions, it enables a shift from periodic maintenance to on-demand maintenance, reducing the overall operating and maintenance costs of the system.

[0016] 4. This invention, through its inert gas-protected working environment design, fundamentally suppresses the oxidation reaction between the probe and the pad surface, solving the problem of continuous degradation of contact performance caused by surface oxidation in traditional probes. This design further consolidates the long-term stability of the contact interface performance, ensuring that the test probe system maintains its initial high sensitivity and reliability during long-term operation, making it particularly suitable for advanced semiconductor manufacturing and testing scenarios with extremely stringent testing environment requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall technical architecture of the high-sensitivity palladium semiconductor test probe system proposed in this invention; Figure 2 This is a schematic diagram illustrating the core principle framework of the synergistic effect between the palladium alloy probe body material and the contact interface enhancement module in this invention. Figure 3 This is a schematic diagram of the multi-level interaction relationship and data flow of the closed-loop test quality assurance system composed of the signal transmission optimization module and the system control and monitoring unit in this invention; Figure 4 This is a flowchart illustrating the logic of the system control and monitoring unit in this invention, which performs online assessment and early warning of contact resistance drift and probe wear status. Figure 5 This is a schematic diagram comparing the core principle of this invention with existing technologies in terms of contact resistance stability and signal transmission integrity. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Please refer to the attached document. Figure 1 The high-sensitivity palladium semiconductor test probe system consists of four core functional modules: the probe body structure, the contact interface enhancement module, the signal transmission optimization module, and the system control and monitoring unit. These four modules are coupled together through precise mechanical interfaces and electrical connections, forming a collaborative whole. The probe body structure, as the physical execution end of the system, directly contacts and electrically connects to the pads of the semiconductor chip under test. The contact interface enhancement module, integrated at the tip of the probe body structure, primarily optimizes the physical and electrical characteristics of the contact interface. The signal transmission optimization module, electrically connected to the probe body structure via a high-frequency coaxial cable, is responsible for processing test signals in the transmission path. The system control and monitoring unit, acting as the intelligent hub of the system, communicates bidirectionally with the operating status monitoring points of the probe body structure, the contact interface enhancement module, and the control port of the signal transmission optimization module via multiple sensor and control lines, enabling real-time acquisition, analysis, and control of the entire system's operating status.

[0020] The probe's main structure forms the mechanical and electrical foundation of the entire system. Its core material is a palladium-gold alloy with a palladium matrix and a uniform doping ratio of gold. The gold doping ratio in this alloy is precisely controlled within the range of 8% to 12% by weight. This compositional design is the result of extensive experimental verification and optimization, aiming to minimize its volume resistivity while ensuring sufficient mechanical strength. This palladium-gold alloy, prepared through vacuum melting and rapid solidification, exhibits a volume resistivity below 2.5 microohm-cm and a Vickers hardness value consistently between 450 and 550. Please refer to the appendix. Figure 2This process also results in a fine equiaxed grain structure in the alloy, with grain size strictly controlled to no more than five micrometers. This uniform and fine grain structure not only helps to further improve the conductivity uniformity of the material but also significantly enhances its resistance to fatigue and arc erosion. The geometry of the probe body structure has been optimized through joint simulation of fluid dynamics and structural mechanics, with its body exhibiting a multi-level stepped cylindrical shape. This design effectively disperses the stress borne by the probe at the moment of contact, avoiding plastic deformation or fracture caused by stress concentration. The diameter of the finest end is configured according to the spacing of the target test pads, providing three standard specifications: 15 micrometers, 25 micrometers, or 35 micrometers. The probe tip is not a simple cone but a polygonal cone formed by five-axis precision grinding technology, with its apex angle precisely machined to between 15 and 30 degrees. This polygonal cone tip has multiple tiny edges, which can generate higher local pressure upon contact, thereby effectively piercing the natural oxide layer that may exist on the chip pad surface, ensuring direct metal-to-metal contact and laying the foundation for low-resistance connections.

[0021] The contact interface enhancement module is crucial for ensuring long-term stable contact performance. This module is directly constructed into the tip region of the probe body structure and is a multilayer thin-film composite structure. Please refer to the appendix. Figure 2 The bottom layer is a noble metal transition layer directly bonded to the probe's main structure. This transition layer is made of iridium-ruthenium alloy, and its thickness is precisely controlled between 0.1 and 0.3 micrometers using a film thickness monitoring system in the physical vapor deposition process. The iridium-ruthenium alloy possesses extremely high chemical stability and excellent conductivity. As a functional layer, it forms a strong metallurgical bond with the underlying palladium substrate, preventing interlayer delamination; furthermore, it provides an ideal deposition substrate for the upper thin film. Above the noble metal transition layer is an amorphous carbon protective layer formed by physical vapor deposition. The thickness of the amorphous carbon protective layer is controlled within the range of 0.05 to 0.15 micrometers. This amorphous carbon layer itself possesses extremely high hardness and chemical inertness. After the deposition process, its surface undergoes a specific plasma treatment. This treatment uses fluorine-containing process gases to reduce the surface energy of the amorphous carbon layer to below 25 dynes / cm. This ultra-low surface energy characteristic greatly reduces material adhesion and transfer caused by interatomic forces when the probe tip separates from the chip pad, thus maintaining the original morphology and compositional stability of the contact interface. The synergistic effect of the noble metal transition layer and the amorphous carbon protective layer together constructs an ideal electrical contact interface that combines low contact resistance, high mechanical stability, and anti-adhesion properties.

[0022] The core task of the signal transmission optimization module is to ensure the integrity of test signals, especially high-frequency signals, throughout the transmission path. This module achieves electrical connection to the tail of the probe body via a precision coaxial connector. Its internal core is an impedance matching network. Please refer to the appendix. Figure 3 This impedance matching network employs a distributed parameter design, rather than a traditional lumped parameter design, to handle operating frequencies up to 40 GHz. The network contains a series of miniature inductors and capacitors, whose layout and parameters have been rigorously optimized using full-wave electromagnetic field simulation software. These miniature inductors and capacitors are integrated into a multilayer ceramic substrate using cryogenic co-fired ceramic technology. Cryogenic co-fired ceramic technology allows for the formation of complex three-dimensional interconnect structures within the substrate, directly embedding passive components. This not only significantly reduces the physical size of the module but, more importantly, avoids parasitic parameters introduced by discrete component leads, improving the consistency of high-frequency performance. The impedance matching network is designed to stably match the characteristic impedance of the entire transmission path from the probe tip to the test instrument input to a standard impedance of 50 ohms across a frequency range from DC to 40 GHz. In addition to the impedance matching network, the module also integrates signal conditioning circuitry. At the core of the signal conditioning circuitry is a low-noise amplifier and a programmable filter. The first stage of the low-noise amplifier uses a junction field-effect transistor design, with an equivalent input noise voltage density of less than one nanovolt per ohm. The programmable filter is a bandpass filter based on a switched capacitor architecture. Its passband range can be programmed between 1 / 100 GHz and 40 GHz via digital commands sent by the system control and monitoring unit. It is used to suppress out-of-band noise and interference and improve the signal-to-noise ratio.

[0023] The system control and monitoring unit is the intelligent brain of the entire test probe system, realizing a closed loop of state perception, data processing, and control decision-making. Please refer to the appendix. Figure 3This unit is tightly connected to the rest of the system via multiple signal lines. Its hardware core is an embedded signal processor, typically a high-performance microcontroller or digital signal processor with a floating-point unit. To accurately measure the most critical parameter—contact resistance—the unit integrates a high-precision four-wire Kelvin measurement circuit. This circuit uses independent drive and sensing lines connected to the probe, fundamentally eliminating the influence of test cable and connector resistance on the measurement results, achieving a contact resistance measurement resolution of 0.1 milliohms. Simultaneously, a micro-force sensor is integrated into the probe's clamping mechanism to monitor the axial force on the probe in real time. This sensor, manufactured using microelectromechanical systems (MEMS) technology, has a range of 0 to 500 millinewtons and an accuracy better than 1%, ensuring that the contact pressure between the probe and the chip pad is always monitored within a preset safety window of 50 to 200 millinewtons, guaranteeing reliable contact while preventing excessive pressure from damaging the pad. The embedded signal processor synchronously acquires timing data of contact resistance and contact pressure at a sampling rate of 100 Hz.

[0024] Please refer to the attached document. Figure 4 One of the core algorithms of the system control and monitoring unit is the online assessment and early warning of contact resistance drift and probe wear status. The embedded signal processor performs real-time analysis on the acquired contact resistance sequence. The algorithm first performs digital filtering on the raw data to eliminate random noise. Then, it calculates a moving average of one hundred sampling points as a stable estimate of the current contact resistance. The algorithm maintains a historical baseline value for the contact resistance, which is learned after the probe is initially used and stabilized. The early warning logic is based on the following relationship: if the relative change of the current moving average value relative to the historical baseline value exceeds five percent and continues for more than ten sampling periods, it is determined that the contact resistance has significantly drifted, and the system will generate a level one early warning signal. In addition to absolute threshold judgment, the algorithm also performs trend analysis. It uses the least squares method to linearly fit the most recent one thousand contact resistance data points to obtain the slope of the resistance change over time. This slope is defined as the probe performance degradation rate. The performance degradation rate is calculated as follows: the performance degradation rate equals the slope value obtained from the linear fit. If the calculated performance degradation rate is positive and its value exceeds 0.1 milliohms per hour for three consecutive calculation cycles, it indicates that probe wear is accelerating, and the system will generate a level-two warning signal, prompting the need for preventative maintenance. Simultaneously, contact pressure data is also used to assist in the judgment. If the contact pressure is within a preset safety window, but the contact resistance continues to rise abnormally, it may indicate probe tip contamination or oxidation; if the contact pressure itself fluctuates significantly or exceeds the safety window, it may indicate a mechanical fault or misalignment in the probe mechanism. All these warning messages, along with raw data, timestamps, etc., are uploaded to the main control computer via the communication interface.

[0025] The system control and monitoring unit also integrates a temperature compensation algorithm to address the impact of ambient temperature fluctuations on test accuracy. At least one high-precision digital temperature sensor, with a measurement accuracy of ±0.5 degrees Celsius, is installed near the probe card. This temperature sensor sends ambient temperature data to the embedded signal processor once per second. The temperature compensation algorithm dynamically compensates and corrects the real-time measured contact resistance value based on the temperature coefficient of resistance of the palladium alloy material in the probe's main structure. The temperature coefficient of resistance of the palladium alloy is a pre-calibrated constant stored in the processor's non-volatile memory. The compensation formula is based on a linear model of metal resistance changing with temperature. The compensated contact resistance value is equal to the measured contact resistance value divided by one, plus the temperature coefficient of resistance multiplied by the difference between the current ambient temperature and the reference temperature. The reference temperature is typically set to 25 degrees Celsius. This real-time compensation effectively eliminates the drift in contact resistance measurements caused by changes in ambient temperature, ensuring the consistency and comparability of test data under different temperature environments.

[0026] The entire high-sensitivity palladium semiconductor test probe system is designed to operate in a controlled atmosphere to maximize its long-term stability. The system features a standardized sealed interface, typically employing a metal-sealed vacuum feedthrough or a high-performance polymer-sealed quick-connect gas path. This interface connects to an external high-purity gas source, such as a high-purity nitrogen or argon cylinder. During system operation, dry inert gas is continuously purged onto the probe's working area, creating a localized positive pressure protective environment. This gas flow effectively isolates oxygen and water vapor from the contact area, fundamentally inhibiting oxidation of the probe tip and chip pad surface. The gas flow rate is precisely controlled by a mass flow controller, typically set between 0.5 and 2 liters per minute, ensuring effective protection without interfering with precise probe positioning or introducing vibrations due to excessive gas flow. This inert gas protection design, combined with the antioxidant properties of the probe material itself and the protective effect of the contact interface enhancement module, constitutes multiple layers of protection, ensuring the system maintains its initial high sensitivity and reliability throughout long-term, continuous testing tasks.

[0027] The system's workflow begins with the main control computer issuing a test command. Upon receiving the command, the system control and monitoring unit first performs a self-check to confirm the normal operation of all sensors, communication links, and power supplies. Then, it controls the precision positioning platform to move the probe above the target chip pads. During the contact phase, the system control and monitoring unit reads data from the micro-force sensor in real time and precisely controls the probe's downward displacement using a closed-loop control algorithm, ensuring that the contact pressure is smoothly established and stabilized at a preset value, such as 100 millinewtons. After contact is established, the four-wire Kelvin measurement circuit immediately activates, measuring the initial contact resistance value and comparing it with a historical baseline. Simultaneously, a test signal is generated by an external test instrument and transmitted to the probe through a signal transmission optimization module. The impedance matching network in the signal transmission optimization module ensures minimal signal reflection during transmission, while the signal conditioning circuit performs low-noise amplification and filtering on the returned response signal to improve signal quality. Throughout the test, the system control and monitoring unit continuously monitors the contact resistance, contact pressure, and ambient temperature, and executes the aforementioned online evaluation, temperature compensation, and early warning logic. After the test, the probe smoothly lifts under the command of the control unit, completing one test cycle. All process data, including compensated contact resistance, contact pressure curves, and warning status, are recorded and can be used for subsequent statistical analysis and equipment health management. This highly integrated, intelligent, and proactive monitoring design enables this palladium semiconductor test probe system to not only possess superior electrical performance but also the condition awareness and predictive maintenance capabilities that traditional probe systems lack.

[0028] Example 2: This invention provides a specific implementation of a high-sensitivity palladium semiconductor test probe system for ultra-high frequency applications. The core of this embodiment lies in the targeted enhancement design of the signal transmission optimization module and the expansion of the data processing capabilities of the system control and monitoring unit to meet testing requirements at frequencies exceeding 40 GHz up to 67 GHz.

[0029] In Example 2, the basic materials and geometry of the probe body structure remain consistent with those in Example 1 to ensure fundamental mechanical and electrical properties. However, to reduce the additional losses caused by the skin effect at ultra-high frequencies, higher requirements are placed on the surface finish of the palladium alloy material. The probe body surface, especially the area traversed by the signal transmission path, requires additional electropolishing to reduce its surface roughness arithmetic mean to below 0.05 micrometers. This ultra-smooth surface can significantly reduce the path resistance when high-frequency current flows.

[0030] The signal transmission optimization module is the key improvement in this embodiment. Please refer to the appendix. Figure 3Based on the distributed parameter design of Example 1, the impedance matching network incorporates a transmission line structure based on thin-film technology. The microstrip line design on the low-temperature co-fired ceramic substrate is no longer merely a means of connecting components; it becomes an important part of the impedance matching network itself. The width, spacing, and dielectric thickness relative to the ground plane of the microstrip lines are precisely calculated and simulated to achieve a flatter impedance characteristic in the 50 GHz to 67 GHz frequency band. The capacitors and inductors integrated into the substrate employ a planar design of interdigitated capacitors and spiral inductors, further reducing parasitic parameters. Simultaneously, the low-noise amplifier in the signal conditioning circuit is replaced with an ultra-wideband amplifier based on indium phosphide semiconductor technology, extending its -3dB bandwidth to 70 GHz to ensure sufficient gain and linearity in the target frequency band. The programmable filter employs a cavity filter design based on a liquid crystal polymer substrate, dynamically adjusting the physical dimensions of the resonant cavity through a microelectromechanical system actuator to achieve rapid electrical tuning of the passband frequency.

[0031] The system control and monitoring unit needs to handle higher-speed data streams and more complex calibration tasks. The embedded signal processor has been upgraded to a high-performance digital signal processor with a multi-core architecture, its clock frequency exceeding one gigahertz, and it is equipped with a larger-capacity cache. To calibrate signal path phase errors at ultra-high frequencies, a vector error correction algorithm is integrated within the unit. This algorithm requires a calibration process before testing: the control unit drives probes to sequentially contact a set of standard impedance components (such as short circuit, open circuit, and load), recording the response data of the test instrument under each state. The system uses this data to construct an error model containing twelve error terms, corresponding to systematic errors such as directivity, isolation, source matching, and load matching. In subsequent actual chip testing, all raw measurement data are corrected in real time based on this error model to eliminate measurement uncertainties introduced by the system itself. This is crucial for accurately measuring the S-parameters and other vector network characteristics of the chip.

[0032] Furthermore, for ultra-high frequency (UHF) applications, even minute fluctuations in ambient temperature have a significant impact on the transmission line electrical length. Therefore, the temperature compensation algorithm has been enhanced. In addition to compensating for contact resistance, the algorithm also compensates for temperature-dependent phase changes in the signal transmission path. Temperature sensors are additionally mounted on critical internal nodes of the signal transmission optimization module, such as the surface of the low-temperature co-fired ceramic substrate. The system experimentally pre-calibrates the phase temperature coefficient of the entire signal path (from the probe tip to the module output port). After vector error correction, the system further compensates and corrects the signal phase based on the currently measured internal module temperature, ensuring the accuracy of the phase measurement results. The warning logic of the system control and monitoring unit has also been expanded accordingly, adding monitoring of return loss in addition to contact resistance drift. If the measured return loss continues to deteriorate within a certain frequency band, indicating that the impedance matching state may have changed due to probe wear or contamination, the system will trigger a specific high-frequency performance warning. This enables the palladium semiconductor test probe system to meet the stringent requirements of UHF testing of semiconductor devices in cutting-edge fields such as 5G mobile communication technology and millimeter-wave radar.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-sensitivity palladium-gold semiconductor test probe system, characterized in that, include: The main structure of the probe is made of palladium alloy material with palladium as the base and uniformly doped with 8% to 12% by weight of gold. The contact interface enhancement module, integrated into the tip of the probe body structure, includes an amorphous carbon protective layer formed by physical vapor deposition and a noble metal transition layer located beneath the amorphous carbon protective layer. The signal transmission optimization module is electrically connected to the probe body structure and includes an impedance matching network with distributed parameter design and a signal conditioning circuit that integrates a low-noise amplifier and a programmable filter. The system control and monitoring unit is communicatively connected to the probe body structure, the contact interface enhancement module, and the signal transmission optimization module, and includes a high-precision four-wire Kelvin measurement circuit, a micro-force sensor, and an embedded signal processor.

2. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The palladium alloy material of the probe body structure is prepared by vacuum melting and rapid solidification process. The palladium alloy material has a volume resistivity of less than 2.5 micro ohm·cm and a Vickers hardness between 450 HV and 550 HV. Its microstructure is an equiaxed crystal structure with a grain size of no more than 5 micrometers.

3. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The probe body structure has a geometric shape including a multi-step cylindrical body and a polygonal conical tip formed by precision grinding. The diameter of the thinnest end of the body is configured to be 15 micrometers, 25 micrometers or 35 micrometers, and the apex angle of the polygonal conical tip is between 15 degrees and 30 degrees.

4. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The system control and monitoring unit also integrates a temperature compensation algorithm. This algorithm receives data from a temperature sensor located in the vicinity of the probe card and dynamically compensates and corrects the real-time measured contact resistance value based on the temperature coefficient of resistance of the probe material.

5. The high-sensitivity palladium-gold semiconductor test probe system according to claim 4, characterized in that, The temperature compensation algorithm is based on a linear model of metal resistance changing with temperature. The compensated contact resistance value is equal to the measured contact resistance value divided by 1 plus the resistance temperature coefficient multiplied by the difference between the current ambient temperature and the 25-degree Celsius reference temperature.

6. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The online evaluation process of contact resistance drift by the embedded signal processor includes: digitally filtering the acquired contact resistance sequence to eliminate random noise; calculating a moving average of 100 sampling points as a stable estimate of the current contact resistance; and generating a first-level warning signal for significant contact resistance drift when the relative change of the moving average relative to the historical baseline exceeds 5% and lasts for more than 10 sampling periods.

7. The high-sensitivity palladium-gold semiconductor test probe system according to claim 6, characterized in that, The online evaluation process of probe wear status by the embedded signal processor also includes: using the least squares method to linearly fit the most recent 1000 contact resistance data points to obtain the slope of the resistance change over time as the probe performance degradation rate; when the performance degradation rate is positive and its value exceeds 0.1 milliohms per hour for three consecutive calculation cycles, a secondary warning signal of probe wear acceleration is generated.

8. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The system is equipped with a sealed interface for connecting to an external gas source, and an inert gas protective environment is formed by continuously purging dry nitrogen or argon into the probe working area.

9. The high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The low-noise amplifier in the signal transmission optimization module adopts a junction field-effect transistor design and has an equivalent input noise voltage density of less than 1 nanovolt per root hertz.

10. A high-sensitivity palladium-gold semiconductor test probe system according to claim 1, characterized in that, The programmable filter in the signal transmission optimization module is a bandpass filter based on a switched capacitor architecture. Its passband range can be programmed between 1 GHz and 40 GHz by digital commands sent by the system control and monitoring unit.

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