System for stretching test of nano-film and manufacturing method of system
By designing a nanofilm tensile testing system, in-situ online tensile testing is performed on silicon wafers using a probe loading structure and photolithography etching process. This solves the problem of inaccurate evaluation of thin film mechanical properties during chip manufacturing, and realizes a true reflection of the mechanical response of thin films and device reliability assessment.
Patent Information
- Application Number
- CN202511110575.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-08
- Publication Date
- 2026-02-13
AI Technical Summary
Existing technologies make it difficult to directly load nanofilms during chip manufacturing, resulting in inaccurate mechanical performance assessments and an inability to truly reflect the state of the film in the device and the impact of the process.
A nanofilm tensile testing system is designed, including a tensile testing machine on a wafer and a probe station. The system enables in-situ online tensile testing of nanofilms directly on a silicon wafer. Tensile force is applied using a probe loading structure and an elastic beam, and uniaxial tensile testing of the film is achieved by combining photolithography, etching, and anodic bonding processes.
This invention enables in-situ online tensile testing of nanofilms directly on silicon wafers, accurately reflecting the mechanical response characteristics of the films, simplifying the loading process, reducing human error, and providing a theoretical basis for device design optimization and reliability assessment.
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Figure CN121521604A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of micro-electro-mechanical system (MEMS) processing technology, and discloses an online detection system for nano-film tensile test and a manufacturing method thereof. BACKGROUND
[0002] The film structure is a key component in the MEMS device, and the mechanical properties thereof directly affect the performance and reliability of the device. The common film material is usually formed on the substrate through various deposition processes. However, in the actual chip manufacturing process, the differences in process parameters, deposition methods and substrate materials will significantly affect the microstructure characteristics of the film, including composition, grain size, film thickness uniformity, surface roughness, porosity, defect density and crystal cluster form. These micro differences will cause significant fluctuations in the mechanical properties of the film, thereby affecting the consistency and reliability evaluation of the device.
[0003] At present, there are studies on the mechanical properties of the film, however, most of such studies are based on samples prepared independently from the chip manufacturing process, and the film forming environment and the film structure in the actual device are essentially different. Especially in the actual manufacturing process, the film is often closely combined with the substrate, and it is difficult to directly load, and needs to use complex stripping and positioning processes, which is easy to introduce artificial errors, and cannot truly reflect the film forming state and process influence in the device manufacturing process.
[0004] Therefore, a test method for in-situ online tensile test of nano-film on a silicon wafer is needed to truly reflect the mechanical response characteristics of the deposited film in the device manufacturing process. Based on the method, the mechanical behavior and failure mechanism of the nano-film under in-situ loading conditions can be further studied, and theoretical basis and experimental support are provided for the design optimization and reliability evaluation of the device. SUMMARY
[0005] In view of the above technical problems, the present application provides an online detection system for nano-film tensile test and a manufacturing method thereof, which uses the system to test the tensile fracture strength of the nano-film.
[0006] The present application specifically adopts the following technical solutions to solve the above technical problems.
[0007] A system for nano-film tensile test, characterized in that it comprises a tensile sheet tester and a probe station for applying driving force to the tensile sheet tester; the tensile sheet tester comprises a main frame, a probe loading structure connected to the main frame, a force transmission rod, a plurality of elastic beams, two deformation variable scales, two pointers, a plurality of suspension folding beams and a plurality of anchor points; the probe loading structure is used for receiving probe loading of the probe station; the two deformation variable scales are located on the two sides of the force transmission rod; the two pointers are used for marking the scales of the two deformation variable scales respectively; each suspension folding beam is symmetrically distributed on the two sides of the main frame, one end of each suspension folding beam is connected to the main frame, and the other end of each suspension folding beam is fixedly connected to one anchor point; the plurality of elastic beams are symmetrically distributed on the two sides of the force transmission rod; one end of the force transmission rod is connected to the main frame, and the other end of the force transmission rod is connected to one end of a nano-film sample, and the other end of the nano-film sample is fixedly connected to one anchor point; the main frame comprises a limiting shaft located between the two anchor points and used for limiting axial stretching of the main frame.
[0008] Further, the main frame, the probe loading structure, the force transmission rod, the elastic beams, the deformation variable scales, the pointers, and the suspension folding beams are movable structures.
[0009] Further, the number of the elastic beams is preferably eight.
[0010] Further, the number of the suspension folding beams is preferably four, and correspondingly, the number of the anchor points is seven.
[0011] Further, the probe loading structure has a U-shaped loading port.
[0012] A manufacturing method of a system for nano-film tensile test, comprising manufacturing a tensile sheet tester and a probe station, wherein the step of manufacturing the tensile sheet tester comprises:
[0013] forming each anchor point on the front surface of a silicon wafer by using photolithography and etching;
[0014] forming a metal nano-film sample on the front surface of the silicon wafer by magnetron sputtering of metal nano-film and then patterning the metal nano-film by photolithography and wet etching;
[0015] forming a shallow groove on a glass sheet by using photolithography and wet etching, and then forming a foot-proof metal electrode on the glass sheet by PVD and peeling;
[0016] anodically bonding the silicon wafer and the glass sheet processed through the above steps;
[0017] thinning the silicon wafer by wet etching;
[0018] depositing a metal mask on the upper surface of the silicon wafer by PVD;
[0019] Forming movable suspended structure by deep reactive ion etching;
[0020] Removing metal mask by oxygen ion bombardment and wet etching.
[0021] Further, the metal nanofilm is an aluminum nanofilm.
[0022] Further, the metal mask is an aluminum mask.
[0023] A manufacturing method of a system for nanofilm tensile test, comprising manufacturing a tensile on-chip tester and manufacturing a probe station, wherein the step of manufacturing the tensile on-chip tester comprises:
[0024] Forming each anchor point on the front surface of the silicon wafer by photolithography and etching;
[0025] Preparing a SiO2 film on the front surface of the silicon wafer, and patterning the SiO2 film by photolithography and wet etching, the reserved SiO2 film being used for protecting the anchor point in the subsequent process;
[0026] Preparing an AlN film on the front surface of the silicon wafer, and patterning the AlN film by photolithography and wet etching, to form an AlN film sample;
[0027] Forming a shallow groove on the glass wafer by photolithography and wet etching, and then forming a foot-proof metal electrode on the glass wafer by PVD and stripping;
[0028] Anodically bonding the silicon wafer and the glass wafer;
[0029] Thinning the silicon wafer by wet etching;
[0030] Releasing the movable structure and the AlN film sample by dry deep etching of the silicon wafer.
[0031] Compared with the prior art, the present application has the following beneficial effects:
[0032] The present application provides a system for nano-film tensile test and a manufacturing method thereof, which can realize in-situ online tensile test of nano-film directly on a silicon wafer, and can truly reflect mechanical response characteristics of a deposited film in a device manufacturing process. The present application is suitable for uniaxial tensile test of a film, and is used for extracting uniaxial tensile fracture strength of the film. By designing a probe loading point and a parallel elastic beam, a tensile force can be directly applied to the film, and the structure is simple and the layout occupies a small area. By designing a limiting block, the present application can apply uniaxial tensile force in the axial loading direction, so that the loading direction is not easy to deviate from the axial direction. The present application does not need to use external precision instruments to clamp and fasten the nano-film sample, and realizes release of the suspended film. By using the present application, mechanical behavior and failure mechanism of the nano-film under in-situ loading conditions can be further researched, and theoretical basis and experimental support can be provided for design optimization and reliability evaluation of a device. BRIEF DESCRIPTION OF DRAWINGS
[0033] Figure 1 is a structural schematic diagram of a tensile on-wafer tester in the embodiment 1 of the present application. In the figure: 10-main frame, 10A-limiting shaft, 11-probe loading structure, 12-anchor point, 13-suspended folded beam, 14-deformation scale, 15-needle, 16-elastic beam, 17-force transmission rod, 18-nano-film sample.
[0034] Figures 2A-2H is a manufacturing flow chart of a tensile on-wafer tester in the embodiment 2 of the present application. In the figure: 21-silicon wafer, 22-anchor point, 23-nano-film sample, 24-anti-footing metal, 25-glass wafer, 26-movable structure.
[0035] Figures 3A-3K is a manufacturing flow chart of an AlN nano-film tensile on-wafer tester in the embodiment 3 of the present application. In the figure: 31-silicon wafer, 32-anchor point, 33-SiO2, 34-AlN, 35-AlN film sample, 36-glass wafer, 37-anti-footing metal, 38-movable structure. DETAILED DESCRIPTION
[0036] In order to make the technical scheme of the present application more obvious and easy to understand, the embodiments are described in detail as follows in combination with the drawings.
[0037] Embodiment 1. A system for nano-film tensile test
[0038] The present embodiment discloses a system for nano-film tensile test, which comprises a tensile on-wafer tester and a probe station for applying a load force to the tensile on-wafer tester. As shown in Figure 1As shown, the tensile testing machine includes a main frame 10, a probe loading structure 11, seven anchor points 12, four suspended folding beams 13, two deformation scales 14, two pointers 15, eight elastic beams 16, and a force transmission rod 17. The probe loading structure 11 is used to receive the probe loading from the probe stage. The probe loading structure 11 has a U-shaped loading port to ensure the accuracy of the loading position and the direction of the loading force. Of the seven anchor points 12, four anchor points are connected to the four suspended folding beams 13, the fifth anchor point is connected to the nanofilm sample 18, and the sixth and seventh anchor points (… Figure 1 The two anchor points on the left are limiting blocks. The left side of the main frame 10 includes a limiting shaft 10A, located between the sixth and seventh anchor points, used to limit axial tension, ensuring that the testing machine is a movable on-plate structure. Two pointers 15 are used to mark the scales of the two deformation scales 14. The force transmission rods 17 are connected in the middle of the eight elastic beams 16, and the elastic beams 16 have a certain degree of elasticity.
[0039] Example 2. Tensile testing of aluminum nanofilms
[0040] This embodiment uses the system for tensile testing of nanofilms from Example 1 to perform tensile testing on aluminum nanofilms. Figures 2A-2H As shown, the glass substrate 25 and the movable structure 26 are connected by anchor points 22 to form the tensile testing machine on the sheet. The movable structure 26 is the rest of the part in Embodiment 1 except for the anchor points.
[0041] In this embodiment, the manufacturing process of the tensile testing machine for the system used for tensile testing of nanofilms is as follows: Figures 2A-2H As shown, the manufacturing process is based on the bonding deep etching release standard process, and the main steps include:
[0042] (1) As Figure 2A As shown, silicon wafer 21 is an N-type single crystal silicon wafer with a thickness of 400±10μm and a resistivity of 0.001~0.003Ω·cm. Then, silicon wafer 21 is etched using the DRIE dry etching method with an etching depth of 4μm to form all anchor points 22.
[0043] (2) Figure 2B As shown, aluminum nanofilms are sputtered under the step (anchor point 22) and patterned using photolithography and wet etching to form aluminum nanofilm sample 23;
[0044] (3) Figure 2C As shown, the glass substrate 25 is made of BF33 with a thickness of 500 μm. The glass substrate 25 is etched using photolithography and BHF wet etching, with an etching depth of [insert depth here]. Then Ti / Pt / Au were sputtered sequentially, with thicknesses of respectively The photoresist on the glass substrate and the Ti / Pt / Au on the photoresist are stripped to form anti-footing metal 24, ensuring the quality of the etching process;
[0045] (4) Figure 2D As shown, silicon wafer 21 and glass sheet 25 are anodicly bonded;
[0046] (5) Figure 2E As shown, silicon wafer 21 was thinned by wet etching with KOH solution, leaving a thickness of 60±4μm, and then potassium ions were removed by cleaning.
[0047] (6) Figure 2F As shown, Al is deposited on the upper surface of a silicon wafer using PVD as a mask for structure release;
[0048] (7) Figure 2G As shown, the movable structure 26 and the aluminum nanofilm sample are released by deep etching the silicon wafer 21 using the DRIE dry etching method, thus obtaining the entire tensile testing machine structure. The movable structure 26 includes... Figure 1 The components include a probe loading structure 11, a suspended folding beam 13, a deformation scale 14, a pointer 15, an elastic beam 16, and a force transmission rod 17.
[0049] (8) Figure 2H As shown, the Al mask is removed by oxygen ion bombardment and wet etching.
[0050] The tensile test pieces manufactured above were tested using a probe station on a testing machine. For example... Figure 1 As shown, a thrust is applied to the left at the U-shaped loading port of the probe loading structure 11 using the probe stage probe, thereby stretching the aluminum nanofilm sample 18 until the aluminum nanofilm sample 18 is observed to break through an optical microscope. The reading d of the deformation scale 14 at this time is recorded. The two ends of the nanofilm sample 18 are connected to the anchor point 12 and the force transmission rod 17, respectively. The tensile strength σ it experiences can be calculated using formula (1):
[0051]
[0052] Where E is the Young's modulus of single-crystal silicon, l is the length of the elastic beam, w is the width of the elastic beam, h is the thickness of the elastic beam, and A is the cross-sectional area of the thin film sample.
[0053] This embodiment can extract the internal stress of a thin film sample with a length of 600 μm and a width of 200 μm when it fractures under uniaxial tensile stress.
[0054] Example 3. Tensile testing of AlN nanofilms
[0055] This embodiment uses the system for tensile testing of nanofilms from Example 1 to perform tensile testing on AlN nanofilms. The manufacturing process of the tensile testing machine for the system used for tensile testing of nanofilms is as follows: Figures 3A-3K As shown, the manufacturing process is based on the bonding deep etching release standard process, and the main steps include:
[0056] (1) As Figure 3A As shown, silicon wafer 31 is an N-type single crystal silicon wafer with a thickness of 400±10μm and a resistivity of 0.001~0.003Ω·cm. Then, silicon wafer 31 is etched by DRIE dry etching to a thickness of 4μm to form all anchor points 32.
[0057] (2) Figure 3B As shown, a SiO2 thin film 33 with a thickness of 100 nm was formed by LPCVD;
[0058] (3) Figure 3C As shown, the SiO2 thin film 33 is patterned by photolithography and then wet etched with BHF solution. The remaining SiO2 thin film 33 is used to protect the anchor point 32 in subsequent processes.
[0059] (4) Figure 3D As shown, an AlN thin film 34 with a thickness of 500 nm was sputtered by PVD magnetron sputtering.
[0060] (5) Figure 3E As shown, the AlN thin film 34 was patterned by photolithography and then etched by wet etching with TMAH solution.
[0061] (6) Figure 3F As shown, the SiO2 thin film 33 was etched by wet etching with BHF solution to finally form the AlN thin film sample 35.
[0062] (7) Glass slide 36 is made of BF33 with a thickness of 500 μm. Photolithography and BHF wet etching are used to etch glass slide 36 to a depth of [insert depth here]. Then Ti / Pt / Au were sputtered sequentially, with thicknesses of respectively Peeling is performed to form anti-footing metal 37, ensuring the quality of the etching process;
[0063] (8) Figure 3I As shown, silicon wafer 31 and glass sheet 36 are anodicly bonded;
[0064] (9) such as Figure 3J As shown, silicon wafer 31 was thinned by wet etching with KOH solution, with an remaining thickness of 60±4μm;
[0065] (10) such as Figure 3KAs shown, the movable structure 38 and the AlN thin film sample 35 are released by deeply etching the silicon wafer 31 using the DRIE dry etching method, thus obtaining the entire tensile test machine structure.
[0066] In the above embodiment 1, there are eight elastic beams. In other embodiments, the number and size of the elastic beams can be adjusted according to the actual force measurement requirements.
[0067] In Embodiment 1 above, four suspension folding beams are used, which meets the suspension requirements. In other embodiments, the number of suspension folding beams can be adjusted according to actual needs. While meeting the requirements, the fewer the number of suspension folding beams, the better.
[0068] The application of the present invention has been described above through embodiments. However, it should be noted that the method of the present invention is also suitable for extracting the stress during uniaxial tensile fracture of thin films manufactured through other processing techniques. Those skilled in the art should understand that, without departing from the essence of this patent, while maintaining the feature of combining a tensile testing machine with a probe station for microelectronic process detection and analysis, certain changes and modifications can be made to the structure, and the manufacturing method is not limited to the manufacturing process in this embodiment. The scope of protection of the present invention should be determined by the claims.
Claims
1. A system for tensile testing of nanofilms, characterized in that, The tensile testing machine includes a tensile testing machine and a probe station for applying driving force to the tensile testing machine; the tensile testing machine includes a main frame, a probe loading structure connected to the main frame, a force transmission rod, multiple elastic beams, two deformation scales, two pointers, multiple suspension folding beams, and multiple anchor points; The probe loading structure is used to receive the probe loading from the probe station; two deformation scales are located on both sides of the force transmission rod; two pointers are used to mark the scales of the two deformation scales respectively; each suspended folding beam is symmetrically distributed on both sides of the main frame, one end of each suspended folding beam is connected to the main frame, and the other end of each suspended folding beam is fixedly connected to an anchor point; multiple elastic beams are symmetrically distributed on both sides of the force transmission rod; one end of the force transmission rod is connected to the main frame, and the other end of the force transmission rod is connected to one end of the nanofilm sample, and the other end of the nanofilm sample is fixedly connected to an anchor point; the main frame includes a limiting shaft, which is located between two anchor points and is used to limit the axial tension of the main frame.
2. The system according to claim 1, characterized in that, The main frame, probe loading structure, force transmission rod, elastic beam, deformation scale, pointer, and suspension folding beam are all movable structures.
3. The system according to claim 1, characterized in that, The number of elastic beams is eight.
4. The system according to claim 1, characterized in that, The number of suspended folding beams is four, and the number of anchor points is seven.
5. The system according to claim 1, characterized in that, The probe loading structure has a U-shaped loading port.
6. A method for manufacturing a system for tensile testing of nanofilms, characterized in that, This includes manufacturing a tensile testing machine and a probe station. The steps for manufacturing the tensile testing machine include: Anchor points are formed on the front side of the silicon wafer using photolithography and etching. Metal nanofilms are sputtered onto the front side of a silicon wafer, and then patterned using photolithography and wet etching to form a metal nanofilm sample. Shallow grooves are formed on a glass substrate using photolithography and wet etching, and then anti-footing metal electrodes are formed on the glass substrate using PVD and lift-off. Anodizing the silicon wafer and the glass sheet; Using wet etching to reduce the thickness of silicon wafers; A metal mask is deposited on the upper surface of a silicon wafer using PVD; Movable suspended structures are formed using deep reactive ion etching; The metal mask is removed by oxygen ion bombardment and wet corrosion.
7. The manufacturing method according to claim 6, characterized in that, The metal nanofilm is an aluminum nanofilm.
8. The manufacturing method according to claim 6, characterized in that, The metal mask is an aluminum mask.
9. A method for manufacturing a system for tensile testing of nanofilms, characterized in that, This includes manufacturing a tensile testing machine and a probe station. The steps for manufacturing the tensile testing machine include: Anchor points are formed on the front side of the silicon wafer using photolithography and etching. A SiO2 thin film is prepared on the front side of a silicon wafer, and the SiO2 thin film is patterned using photolithography and wet etching. The remaining SiO2 thin film is used to protect the anchor points in subsequent processes. An AlN thin film was prepared on the front side of a silicon wafer, and the AlN thin film was patterned using photolithography and wet etching to form an AlN thin film sample. Shallow grooves are formed on a glass substrate using photolithography and wet etching, and then anti-footing metal electrodes are formed on the glass substrate using PVD and lift-off. Anodizing the silicon wafer and the glass sheet; Using wet etching to reduce the thickness of silicon wafers; The movable structure and AlN thin film sample were released by dry etching of silicon wafer.