A method for manufacturing a MEMS probe with a high aspect ratio

Abstract

The present invention discloses a method for manufacturing a MEMS probe with a high aspect ratio, which comprises selecting porous anodized aluminum as a substrate material; performing photolithography on the substrate, coating photoresist and performing pattern development; performing etching in the nanopores of the substrate; performing electroplating in the etched grooves, stacking multiple layers of metal; performing CMP treatment on the top metal layer; removing the substrate to obtain a MEMS probe. The present invention etches the nanopores of the porous anodized aluminum into an electroplating mold, which can achieve a higher aspect ratio and a stronger mechanical structure, so that the MEMS probe can maintain its structural stability when a large needle pressure is applied, is not easy to deform or break, and ensures the accuracy and reliability of the test process.

Description

Technical Field

[0001] The invention relates to the technical field of MEMS probes, and in particular to a method for manufacturing a MEMS probe with a high aspect ratio. Background Art

[0002] MEMS probe (Micro-Electro-Mechanical Systems probe) is a miniature probe manufactured using micro-electro-mechanical system technology. The diameter of the MEMS probe is between 45 and 100um, and it has a complex mechanical structure with multiple layers of different metals stacked. At the same time, in order to achieve better flow resistance, the higher the number of internal stacking layers of the MEMS probe, the better the performance.

[0003] The traditional MEMS probe manufacturing process is generally processed by photolithography, electroplating, chemical mechanical polishing and other processes similar to the manufacturing of semiconductor chips. The general steps are:

[0004] A1. Sputtering a metal seed layer on a silicon substrate to facilitate subsequent photolithography;

[0005] A2, applying photoresist, and using light with a probe shape to perform exposure and development;

[0006] A3, using organic solvent to remove the photolithography part;

[0007] A4. Use an alloy-containing plating solution for electroplating;

[0008] A5. So far, the first layer of metal is completed;

[0009] A6. Since the flatness of electroplating is not high, a chemical mechanical polishing (CMP) process is required to thin the surface pattern of the electroplated probe to a flatness within 1um;

[0010] A7. The metal exposed after thinning can be used as the seed layer for the next electroplating and then electroplated again;

[0011] A8. Repeat the above steps 3-10 times to form MEMS probes with different stacking effects.

[0012] The traditional MEMS probe process is relatively complicated, requiring metal sputtering, photolithography, electroplating, chemical mechanical grinding and polishing operations layer by layer. The bonding force between layers is poor, the thickness of the photoresist is limited, and the thickness of a single layer of photoresist is limited to less than 30 microns. As a result, the manufacturing accuracy of traditional MEMS probes is relatively low, and probes with a high aspect ratio cannot be prepared, which cannot meet the increasingly high testing needs. Summary of the invention

[0013] In order to solve the above problems, the present invention provides a method for manufacturing a MEMS probe with a high aspect ratio, which can achieve higher aspect ratio processing, thereby making the processing accuracy of the probe higher and realizing more probe beam arm designs.

[0014] To this end, the technical solution of the present invention is: a method for manufacturing a MEMS probe with a high aspect ratio, comprising the following steps:

[0015] S1, select porous anodized aluminum as the substrate material;

[0016] S2, performing photolithography on the substrate, coating photoresist and performing pattern development;

[0017] S3, etching in the nanopores of the substrate;

[0018] S4, electroplating is performed in the etched grooves to stack multiple layers of metal;

[0019] S5, performing CMP treatment on the top metal layer;

[0020] S6. Remove the substrate to obtain the MEMS probe.

[0021] On the basis of the above scheme and as a preferred scheme of the above scheme: in step S1, the method for preparing the substrate is as follows:

[0022] S1.1, prepare an aluminum substrate;

[0023] S1.2, generating a porous anodized aluminum layer on an aluminum substrate by an anodizing process;

[0024] S1.3. Separate the generated porous anodized aluminum layer from the aluminum substrate to obtain a porous anodized aluminum substrate.

[0025] On the basis of the above scheme and as a preferred scheme of the above scheme: in the step S3, after etching, the nanochannels on the substrate form an electroplating mold, and the depth ratio of the electroplating mold is x:30, and the value of x is 0~1 and is not 0.

[0026] On the basis of the above scheme and as a preferred scheme of the above scheme: in the step S4, the electroplated metal includes gold and nickel target alloy.

[0027] On the basis of the above scheme and as a preferred scheme of the above scheme: in the step S6, the finished product of step S5 is immersed in HF / H2O2 solution for etching to remove the porous anodized aluminum substrate.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention etches nanopores of porous anodized aluminum into an electroplating mold, which can achieve a higher aspect ratio and a stronger mechanical structure, so that the MEMS probe can maintain its structural stability when a large needle pressure is applied, and is not easy to deform or break, thereby ensuring the accuracy and reliability of the test process.

[0030] The present invention can make the structure of the MEMS probe more compact and firm, reduce the resistance and heat generated when current passes through, and significantly improve the current carrying capacity of the probe.

[0031] When the present invention electroplates multiple layers of metal in the nano-channel, no CMP treatment is required between the layers, and only the top metal layer needs to be CMP treated, which greatly simplifies the difficulty of manufacturing the MEMS probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The schematic diagram of the manufacturing process of the present invention includes: ① photolithography, ② etching, ③ electroplating, ④ CMP, and ⑤ substrate removal;

[0033] Figure 2 It is a schematic diagram of the manufacturing process of the substrate of the present invention, wherein: a. anodization, b. separation;

[0034] Figure 3 It is a schematic diagram of the wet etching process of the present invention;

[0035] Figure 4 It is a flowchart of the present invention.

[0036] Marked in the figure are: substrate 1, nanochannel 11, electroplating mold 12, photoresist 2, MEMS probe 3, and aluminum substrate 4. DETAILED DESCRIPTION

[0037] 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.

[0038] 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.

[0039] See also Figure 1~Figure 4 The method for manufacturing a MEMS probe with a high aspect ratio described in this embodiment includes the following steps:

[0040] S1, select porous anodized aluminum as the substrate material;

[0041] The preparation method of the substrate is as follows:

[0042] S1.1, aluminum substrate 4: select aluminum substrate 4 as the initial material;

[0043] S1.2, anodizing: generating a porous anodized aluminum oxide (AAO) layer on the aluminum substrate 4 by an anodizing process;

[0044] S1.3. Separation: Separating the generated porous anodic aluminum oxide (AAO) layer from the aluminum substrate to obtain a porous anodic aluminum oxide (AAO) substrate 1.

[0045] S2. Photolithography: Photolithography is performed on the AAO substrate 1, photoresist 2 is coated and pattern development is performed.

[0046] S3, wet etching: pour etching liquid into the nano-channel 11 of the AAO substrate 1, and evenly distribute the etching liquid on the vertical straight wall from top to bottom to perform wet etching; after wet etching, the nano-channel on the substrate is etched into an electroplating mold 12, and the depth ratio of the electroplating mold is 1:30.

[0047] S4, electroplating: In the electroplating mold 12 etched in step S3, multiple metals are electroplated using high-precision electroplating control technology to achieve multi-layer metal stacking. The electroplating materials mainly include gold and nickel target alloy.

[0048] S5. Chemical Mechanical Polishing (CMP): CMP the top metal layer to ensure a smooth surface.

[0049] S6, removing the AAO substrate; after completing all electroplating and CMP treatments, immersing the finished product in a HF / H2O2 solution for etching to remove the porous anodized aluminum substrate 1 and obtain the final MEMS probe 3.

[0050] This embodiment can achieve a high aspect ratio of 1:30, the thickness of a single-layer mold can reach 150 microns, and a narrow spacing of less than 5 microns can be achieved, thereby making the processing accuracy of the probe higher and realizing more probe beam arm designs.

[0051] The performance indicators of MEMS probes are as follows:

[0052] Current Carrying Capacity (CCC) is a measure of the maximum current that a MEMS probe can withstand during operation. The MEMS probe manufactured in this embodiment has a significantly improved aspect ratio and structural strength, and the structure of the MEMS probe is more compact and solid, which reduces the resistance and heat generated when current passes through, and significantly improves the current carrying capacity of the probe, thereby maintaining stability and reliability under high current conditions.

[0053] Pin force is the pressure applied by the MEMS probe during contact and testing. The MEMS probe manufactured in this embodiment has higher mechanical strength and rigidity, and can maintain its structural stability when a large pin force is applied, and is not easy to deform or break, thereby ensuring the accuracy and reliability of the test process.

[0054] 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 with a high aspect ratio, characterized in that: The following steps are involved: S1, select porous anodized aluminum as the substrate material; S2, performing photolithography on the substrate, coating photoresist and performing pattern development; S3, etching in the nanopores of the substrate; after etching, the nanopores on the substrate form an electroplating mold, the depth ratio of the electroplating mold is x:30, and the value of x is 0 to 1 and is not 0; S4, electroplating is performed in the etched grooves to stack multiple layers of metal; S5, performing CMP treatment on the top metal layer; S6. Remove the substrate to obtain the MEMS probe.

2. The method for manufacturing a MEMS probe with a high aspect ratio as claimed in claim 1, characterized in that: In step S1, the substrate is prepared as follows: S1.1, prepare an aluminum substrate; S1.2, generating a porous anodized aluminum layer on an aluminum substrate by an anodizing process; S1.

3. Separate the generated porous anodized aluminum layer from the aluminum substrate to obtain a porous anodized aluminum substrate.

3. The method for manufacturing a MEMS probe with a high aspect ratio as claimed in claim 1, characterized in that: In step S4, the electroplated metal includes gold and nickel target alloy.

4. The method for manufacturing a MEMS probe with a high aspect ratio as claimed in claim 1, characterized in that: In the step S6, the finished product of step S5 is immersed in a HF / H2O2 solution for etching to remove the porous anodized aluminum substrate.

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