MEMS (Micro Electro Mechanical System) probe manufacturing method for improving electrical performance by utilizing ion implantation

Abstract

The invention belongs to the technical field of MEMS probes, and particularly relates to an MEMS probe manufacturing method for improving electrical performance by ion implantation, which comprises the following steps: firstly, manufacturing a silver target copper alloy probe base material, and implanting rhodium ions into the tip part of a probe to form a required doping layer; the rhodium metal is injected into the silver target copper alloy base material, so that the electrical performance of the probe is remarkably improved, and the probe is outstanding in application scenes with high requirements; the injected rhodium metal obviously enhances the wear resistance of the probe tip and prolongs the service life of the probe; the rhodium metal has excellent oxidation resistance, so that the probe can still keep good performance in high-temperature and severe environments.

Description

Technical Field

[0001] The present invention relates to the technical field of MEMS probes, and in particular to a method for manufacturing a MEMS probe that utilizes ion implantation to improve electrical performance. Background Art

[0002] With the rapid development of AI technology and high-performance computing, high-power, high-transmission-rate chips are widely used in data centers, supercomputers, and other fields. The performance test of these chips places extremely high demands on probes, which need to meet the three main requirements of high precision, high current, and high-speed data transmission. Although the probes made by traditional probe manufacturing methods such as chemical etching and mechanical polishing can meet basic requirements, they have limitations in precisely controlling the shape and performance of the probe tip. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for manufacturing a MEMS probe using ion implantation to improve electrical performance.

[0004] To this end, the technical solution of the present invention is: a method for manufacturing a MEMS probe using ion implantation to improve electrical performance, comprising the following steps: S1, prepare silicon wafer substrate and perform pretreatment; S2, depositing a TiNi seed layer on a silicon substrate; S3, developing a probe pattern on the TiNi seed layer by photolithography; S4, performing probe electroplating; S5, perform CMP to grind the top of the probe flat; S6, performing photolithography development on the probe to expose the probe tip; S7. Perform ion implantation on the needle tip: S7.1. Design implantation parameters: determine ion type, dose, energy and implantation angle; S7.2, implanting the selected ions into the probe tip portion to form a desired doping layer; S8, debonding and peeling off the probe; S9, annealing the probe tip to activate the doping atoms and repair lattice damage; S10, processing the probe tip into a desired shape and size.

[0005] On the basis of the above scheme and as a preferred scheme of the above scheme: the implanted ion type is rhodium ion, the dose is 1×10^15 cm^-2, the energy is 50 keV~60 keV, and the implantation angle is 0°.

[0006] On the basis of the above scheme and as a preferred scheme of the above scheme: the total length of the probe is 6.5 mm, and the length of the needle tip part is 450 μm.

[0007] On the basis of the above scheme and as a preferred scheme of the above scheme: in step S4, the electroplating solution is a silver target copper alloy.

[0008] On the basis of the above solution and as a preferred solution of the above solution: in step S10, the probe tip portion is processed by chemical etching or mechanical polishing method.

[0009] Compared with the prior art, the present invention has the following beneficial effects: Injecting rhodium metal onto the silver target copper alloy substrate significantly improves the electrical performance of the probe, enabling it to perform well in demanding application scenarios and become a key component of advanced microelectronics testing systems.

[0010] The injected rhodium metal significantly enhances the wear resistance of the probe tip and extends the service life of the probe; rhodium metal has excellent anti-oxidation properties, allowing the probe to maintain good performance under high temperature and harsh environments.

[0011] The injected rhodium metal improves the conductivity of the probe, improves the current resistance of the probe, ensures the reliability of high current and high-speed data transmission, and supports the testing requirements of high-power chips at the kilowatt level.

[0012] Through ion implantation technology, the overall performance of the probe is more stable, the resistance of the probe tip itself is reduced, and the contact impedance is reduced from the original 2Ω to about 0.5Ω. Due to the high-energy ion implantation, the 450-micron tip of the probe can maintain a high degree of performance consistency, reducing performance fluctuations and test errors caused by tip loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a preparation flow chart of the present invention; Figure 2 The test result diagram of the current carrying capacity of the probe, the orange curve is the test result of the probe after ion implantation, and the blue curve is the test result of the probe before ion implantation; Figure 3 This is the test result diagram of the probe contact impedance. The orange curve is the test result of the probe after ion implantation, and the blue curve is the test result of the probe before ion implantation.

[0014] Marked in the figure are: silicon wafer substrate 1, TiNi seed layer 2, probe pattern 3, probe 4, and needle tip part 41. DETAILED DESCRIPTION

[0015] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present invention.

[0016] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the definition of "first" and "second" features can explicitly or implicitly include one or more of the features. In the description of the present invention, "several" and "a number" mean two or more, unless otherwise clearly and specifically defined.

[0017] Example 1 The method for manufacturing a MEMS probe using ion implantation to improve electrical performance described in this embodiment includes the following steps: S1, preparing a silicon wafer substrate 1 and performing pretreatment; The silicon wafer needs to be chemically cleaned (such as acetone, isopropyl alcohol ultrasonic cleaning) to remove organic pollutants, then rinsed with deionized water and blown dry with nitrogen, and finally baked on a 150°C hot plate for 5 minutes to completely dry.

[0018] S2, depositing a TiNi seed layer 2 on a silicon substrate; The titanium-nickel (TiNi) seed layer is deposited on the silicon substrate using magnetron sputtering technology. Titanium (Ti) acts as an adhesion layer to enhance the adhesion between the seed layer and silicon, and nickel (Ni) acts as a conductive layer to promote the growth of subsequent electroplated metal.

[0019] S3, developing a probe pattern 3 on the TiNi seed layer by photolithography; Spin-coat a negative photoresist (such as AZ NLof 2070) with a thickness of 7 μm, and transfer the mask pattern to the photoresist using a UV lithography machine (wavelength 365 nm). After exposure, a developer (such as AZ 726 MIF) dissolves the unexposed area to expose the probe pattern area of ​​the TiNi seed layer.

[0020] S4, performing probe electroplating; A silver target copper alloy electroplating solution was selected, and the metal deposition rate was controlled by adjusting the current density (2–10 mA / cm²) and the electroplating time (30–120 seconds) to form the probe body. The total length of the probe was 6.5 mm, and the length of the usable needle tip was 450 μm.

[0021] S5, performing CMP to grind the top of the probe 4 flat; Use aluminum oxide or silicon dioxide slurry with a polyurethane polishing pad at 50–100 rpm to polish the surface. Monitor the surface roughness or thickness changes in real time to ensure that only the metal layer in the probe structure area is retained.

[0022] S6, performing photolithography development on the probe to expose the probe tip portion 41; Negative photoresist is spin-coated and the mask pattern is transferred to the photoresist through a UV lithography machine. After exposure, the developer dissolves the unexposed area, exposing the tip of the probe.

[0023] S7. Perform ion implantation on the needle tip: S7.1. Design the injection parameters: select rhodium ions, the dose is 1 × 10^15 cm^-2, the energy is 50 keV, the injection angle is 0°, and the injection area is the tip of the probe.

[0024] S7.2. Implant selected rhodium ions into the tip portion of the probe to form the desired doping layer.

[0025] S8, debonding, peeling off the probe 4; Use wet stripping (acetone immersion + ultrasound assistance) or dry plasma ashing (O2 plasma) to completely remove residual photoresist; Use a mixed acid solution (such as HF:HNO3=1:10) to etch the TiNi seed layer that is not covered by the electroplated metal, and finally only the probe structure is retained.

[0026] S9, annealing the probe tip to activate the doping atoms and repair lattice damage; S10. Processing the probe tip into a desired shape and size by chemical etching, mechanical polishing, etc.

[0027] After the above-mentioned process, the wear resistance, oxidation resistance, conductivity and stability of the probe are significantly improved. The test results show that the contact resistance is reduced and the performance is stable.

[0028] Example 2 The remaining processes of this embodiment are the same as those of embodiment 1, except that: The implantation ion process parameters are: rhodium ions are selected, the dose is 1 × 10^15 cm^-2, the energy is 60 keV, the implantation angle is 0°, and the implantation area is the tip of the probe.

[0029] Compared with Example 1, the wear resistance and conductivity of the probe in this embodiment are further improved, but the contact resistance is slightly increased, and the overall performance is still better than that of the traditional probe.

[0030] The MEMS probe manufactured in Example 1 was subjected to performance tests, including current carrying capacity (CCC ISMI), maximum allowable current (CCC MAC), contact resistance (Contact Resistance) and life time test (Life Time Test).

[0031] The goal of the probe current carrying capacity test method is to test the maximum carrying capacity of the probe when current is applied once, and to evaluate the limit performance of the probe in a high current environment. The test steps are as follows: A1. Sample preparation: Select the probe sample and ensure that the probe surface is clean and free of contamination.

[0032] A2. Initial measurement: Under standard overdrive conditions, measure the initial spring force of the probe to establish a baseline.

[0033] A3. Current application: Apply current starting at 75% of the maximum current carrying value estimated by the probe supplier, in increments of 25 mA each time for 2 minutes, with a 10 second cool down after each application.

[0034] A4. Elastic force monitoring: Measure the elastic force of the probe after each current is applied. When the elastic force drops by 20% compared to the initial value, record this current as the maximum carrying current value of the probe.

[0035] Contact Resistance Test Method Objective: To measure the resistance between the probe and the test point and evaluate its conductivity and stability. The test steps are as follows: B1. Test equipment: Use a contact resistance tester and apply a constant current.

[0036] B2. Sample preparation: Install the probe on the test bench and ensure stable contact between the probe and the test point.

[0037] B3. Measurement process: Apply standard current (such as 1 mA) and record the contact resistance value of the probe. Measure multiple times to evaluate the fluctuation range of the contact resistance.

[0038] B4. Result analysis: Calculate the average and standard deviation of the contact resistance to ensure that the contact resistance of the probe is within the target value (such as 0.5Ω).

[0039] Life Time Test Method Objective: To verify the durability and performance stability of the probe under long-term repeated use. The test steps are as follows: C1. Test conditions: Set the number of times the probe contacts under standard overdrive conditions (e.g. 2 million Touch Downs).

[0040] C2. Test process: Simulate the real test environment and use automated equipment to perform cyclic contact tests on the probes. Measure the probe's contact resistance, elastic force and other performance parameters at regular intervals (e.g. 500,000 times).

[0041] C3. Failure judgment: When the elastic force of the probe drops by more than 20% or the contact resistance exceeds the target value, the probe life is judged to have ended.

[0042] C4. Data recording: record the performance change trend of the probe during the test process to analyze the factors affecting the life span.

[0043] The present invention significantly improves the electrical performance of the probe by injecting rhodium metal into the silver target copper alloy substrate, making it perform well in high-demand application scenarios. By optimizing the process parameters, the performance of the probe can be further improved to meet the needs of different application scenarios.

[0044] The specific optimization points are as follows: Wear resistance: The injected rhodium metal significantly enhances the wear resistance of the probe, prolongs the service life of the probe, reduces the frequency requirement of probe cleaning by 50%, and increases the service life from the traditional 800,000 touch downs to 2 million touch downs.

[0045] Oxidation resistance: Rhodium metal has excellent oxidation resistance, which enables the probe to maintain good performance in high temperature and harsh environment.

[0046] Conductivity: Figure 2 As shown in the figure, the current carrying capacity of the probe before and after ion injection is tested, where the orange curve is the test result of the probe after ion injection, and the blue curve is the test result of the probe before ion injection. According to the data in the chart, the injected rhodium metal improves the conductivity of the probe and the current carrying capacity of the probe. On the cylindrical MEMS probe based on 60um*60um, the current carrying capacity is increased from the original 1200mA to 1800mA, ensuring the reliability of high current and high-speed data transmission, and supporting the test requirements of high-power chips at the kilowatt level.

[0047] Stability: As Figure 3As shown in the figure, the contact resistance of the probe before and after ion implantation is tested, where orange is the test result of the probe after ion implantation, and blue is the test result of the probe before ion implantation. According to the data in the chart, before ion implantation, the average contact resistance of the probe is stable at about 2Ω, and after ion implantation, the average contact resistance of the probe is stable within the range of 0.5Ω.

[0048] Through ion implantation technology, the overall performance of the probe is more stable, the resistance of the probe tip itself is reduced, and the contact impedance is reduced from the original 2Ω to about 0.5Ω. Due to the high-energy ion implantation, the 450-micron tip of the probe can maintain a high degree of performance consistency, reducing performance fluctuations and test errors caused by tip loss.

[0049] These improvements enable the probe to perform well in demanding application scenarios such as AI chips, making it a key component of advanced microelectronics test systems.

[0050] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for manufacturing a MEMS probe using ion implantation to improve electrical performance, characterized in that: The following steps are involved: S1, prepare silicon wafer substrate and perform pretreatment; S2, depositing a TiNi seed layer on a silicon substrate; S3, developing a probe pattern on the TiNi seed layer by photolithography; S4, performing probe electroplating; S5, perform CMP to grind the top of the probe flat; S6, performing photolithography development on the probe to expose the probe tip; S7. Perform ion implantation on the needle tip: S7.

1. Design implantation parameters: determine ion type, dose, energy and implantation angle; S7.2, implanting the selected ions into the probe tip portion to form a desired doping layer; S8, debonding and peeling off the probe; S9, annealing the probe tip to activate the doping atoms and repair lattice damage; S10, processing the probe tip into a desired shape and size.

2. A method for manufacturing a MEMS probe using ion implantation to improve electrical performance as claimed in claim 1, characterized in that: The implanted ion type is rhodium ion, the dose is 1×10^15 cm^-2, the energy is 50 keV~60 keV, and the implantation angle is 0°.

3. A method for manufacturing a MEMS probe using ion implantation to improve electrical performance as claimed in claim 2, characterized in that: The total length of the probe is 6.5 mm, and the length of the needle tip is 450 μm.

4. The method for manufacturing a MEMS probe using ion implantation to improve electrical performance as claimed in claim 1, characterized in that: In step S4, the electroplating solution is a silver target copper alloy.

5. The method for manufacturing a MEMS probe using ion implantation to improve electrical performance as claimed in claim 1, characterized in that: In step S10, the probe tip portion is processed by chemical etching or mechanical polishing.

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