TW574499B - Method of thin-film strain measurement and the measurement structure of the same - Google Patents

Description

574499 11647twf.doc / 006 (ii) Description of the invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method and a structure for measuring the strain of a thin film, and in particular to a method for measuring the strain of a thin film in a surface microfabrication process or Method of thermal expansion coefficient and its measurement structure. In the prior art, the surface microfabrication process has a higher flexibility in the manufacture of three-dimensional components than the body microfabrication process. Therefore, it has gradually become one of the popular MEMS processing technologies in recent years. In the past, there have been many microfabrication using surfaces. Micro-system components produced by technology, such as optical scanning systems, micro-motors, micro-actuators and other components, can be combined to form a micro-electro-mechanical system after integrating these components. However, the entire micro-electro-mechanical system must have good performance. In addition to integrating each component, another more important factor is how to control the performance of each component to achieve the predetermined design goal. We know that the performance of the component will differ from the design goal. Most of the reasons come from process errors and uncertainty of the mechanical properties of the thin film. Therefore, to fully control the performance of the component, the first task is to be able to accurately grasp the mechanical properties of the thin film material. These mechanical properties include Young's coefficient of the film, residual stress and so on. The residual β stress of the film is an important indicator for adjusting process parameters and improving yield. There are two known types of residual stress measurement in films, one of which is a "coplanar residual strain gauge" with a micro-scale ruler structure as the detection structure. Because the residual strain of general thin film materials is about 10-4, and the in-plane deformation detection technology is mostly measured directly through microscopic observation, the resolution is only about 0.1 microns, so purely by the micromechanical structure due to 5 574499 11647twf.doc / 006 Release the strain generated by the residual strain to detect the residual strain of the film under test. The size of the micromechanical structure must be at least greater than 1 cm. This is lack of economic benefits in actual detection, so the micro-scale ruler structure is used. Equivalent to the planar detection technology to detect the residual stress of the thin film ', it is necessary to use the link mechanism to enlarge the displacement of the micro-detection beam. The residual strain of the film to be tested is detected. However, at present, there is no literature suggesting a thin film measurement structure or method that can be practically applied to a surface-type microfabrication process. ^ Another theory for measuring the residual strain of a thin film is the so-called "out-plane residual strain gauge", which uses a micro-detection structure to convert the residual stress of the film to be measured into the out-plane displacement of the micromechanical structure. Measure the deformation of this out-of-plane plane, and in accordance with the geometric dimensions of the micro-detection structure, infer the residual strain 値 of the film to be measured. Because the current measurement resolution of the out-of-plane deformation is much higher than the resolution of the in-plane displacement, the resolution ratio of the out-of-plane residual strain gauge to detect the residual strain of the film to be measured is much higher than that of the same plane. , So it can easily reach a detection resolution of 10-6 or more. However, 'the previous literature rarely used a planar detection mechanism to detect the residual stress of the thin film in the surface microfabrication process. The reason should be that the use of the planar detection mechanism often requires excellent structural fixed boundaries. Type _ = Cheng Zhongyi to make a good fixed boundary requires a good boundary design. The idea is far from being reached in the industry. _The purpose of the present invention is to provide a method for measuring the strain of a thin film and a skid, which can be applied to the surface microfabrication process to accurately measure the residual strain of the thin film to facilitate the adjustment of process parameters and improve the product. Yield. 6 574499 11647twf.doc / 006 Another object of the present invention is to propose a new coplanar residual strain gauge structure, which can accurately measure the residual strain of the film. If the film is heat treated, its thermal expansion coefficient can also be measured. It is still another object of the present invention to provide a new type of planar residual strain gauge structure, which can accurately measure the residual strain and gradient distribution of residual strain of the film. If the film is heat-treated, its thermal expansion coefficient and thermal expansion gradient distribution can also be measured. Another object of the present invention is to provide a method and a structure for measuring the strain of a thin film, which can be applied to a surface microfabrication process, while forming a coplanar residual strain gauge and a planar residual strain gauge on a substrate, respectively. Measure the film strain to obtain more accurate film residual strain and film strain gradient distribution. If the film is heat-treated, its thermal expansion coefficient and thermal expansion gradient distribution can also be measured. According to the above and other objectives, the present invention provides a method for measuring strain of a thin film, which is suitable for measuring strain of a thin film. The method for measuring strain of a thin film includes firstly providing a substrate and forming a sacrificial layer on the surface of the substrate. Then, a thin film is formed on the surface of the sacrificial layer, and the thin film has at least one plane strain gauge pattern and one plane strain gauge pattern. The coplanar strain gauge pattern includes: an index beam, one end of which further has a first vernier ruler, and the other β end has a balance block; a second vernier ruler corresponds to the first vernier ruler, and Extend a first boundary film and dispose it from the first vernier gauge; two curved detection beams are arranged on two sides of the index beam, one end of the curved detection beam has a second boundary film, and the other end is arc-shaped The ground extends toward the two sides of the indicator beam, and is connected to the indicator beam at a position of approximately the center of gravity of the indicator beam, and forms a force couple. The plane strain gauge pattern includes: a bridge-shaped 11647twf.doc / 006 beam, each of which has a third boundary film at each end; a plurality of structural beams extending from the side of the bridge-shaped beam and parallel to the bridge-shaped beam. Then, a part of the sacrificial layer is removed, and only at least the first boundary film, the second boundary film, and the third boundary film are covered to form a covering material layer supporting film, and the indicator beam, the arc detection beam, and the bridge shape are formed. Beams and structural beams are suspended. Measure the reading of the first vernier scale and the deformation of the center point of the bridge beam's buckling to measure the strain of the film, and measure the radius of curvature of the structural beam to obtain the gradient strain of the film. After the above film is heat-treated, the thermal expansion coefficient and thermal expansion gradient distribution of the film can be measured by the above-mentioned in-plane strain gauge and out-of-plane strain gauge. After the above process, the in-plane strain gauge structure of the present invention can be manufactured, which is constructed on a substrate, and includes a sacrificial layer disposed on the surface of the substrate and having a first support pattern and two second support patterns. A film is disposed on the surface of the sacrificial layer. The film has a plane strain gauge pattern, including: an index beam, one end of which has a first vernier scale and the other end has a balance block; a second vernier scale corresponds to A first vernier ruler, and extending a first boundary film, which is misaligned with the first vernier ruler, wherein the first boundary film covers the first supporting pattern; two curved detection beams are respectively disposed on two sides of the index beam, One end of the two-arc detection beam has a second boundary film, while the other end of the two-arc detection beam extends toward the two sides of the indicator beam in an arc shape, and is connected to the indicator beam at the position of approximately the center of gravity of the indicator beam, and A force couple is formed, wherein the two second boundary films respectively cover the second and second supporting patterns, and the index beam and the arc detection beam are suspended on the substrate. The cover layers are respectively disposed on the first boundary film and the second and second boundary films. 574499 11647twf.doc / 006 The plane strain gauge of the present invention can also be achieved by the above process, and its structure is constructed on the substrate, including a sacrificial layer disposed on the surface of the substrate, and the sacrificial layer has two supporting patterns. The film is disposed on the surface of the sacrificial layer and has a plane strain gauge pattern. The plane strain gauge pattern includes: a bridge beam with a boundary film at each end thereof and two boundary films covering the two support patterns respectively. A plurality of structural beams extending from the side of the bridge beam and parallel to the bridge beam, wherein the bridge beam and the structure beam are suspended on the base material. The above-mentioned thin film strain gauge structure can be applied to-surface micro-machined micro-electro-mechanical workpieces, in which the thin film is simultaneously formed-^ micro-electro-mechanical workpiece portion, together with a planar strain gauge portion and / or a planar strain gauge portion . # With the coplanar strain gauge part and the out-of-plane strain gauge part, the strain number or thermal expansion number of the film can be read, and the out-of-plane strain gauge part can read out the strain gradient or thermal expansion gradient of the film. With the above-mentioned thin film strain measurement method and structure, the present invention can measure the corresponding residual strain 値 and / or the residual strain gradient distribution of a thin film-machined micro-electro-mechanical workpiece when the film is formed, thereby monitoring the manufacturing process. And adjust process parameters to improve yield. In addition, the thermal expansion coefficient and thermal expansion gradient distribution of the heat-treated film can also be measured. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail in conjunction with the accompanying drawings as follows: Embodiments = the first step in the present invention The design of two new micro-vernier scale strain gauges-straight-arm and arc-arm micro-vernier scale strain gauges are proposed. Finally, the two types of 9 574499 11647twf.doc / 006 are combined with the advantages of the new micro-mirror scale as a side gauge. The high-resolution, high-resolution arc-arm micro-vernier scale strain gauge was verified by the common process of MUMPs provided by American Cronos to verify the feasibility of this strain gauge. [Example 1] Straight-arm type micro vernier strain gauge

Please refer to Figure 1, which shows a schematic diagram of the design of a straight-arm micro vernier strain gauge. The design of the straight-arm micro-measuring scale strain gauge 100 is to use a pair of cantilever structural beams (length LA) as the detection beams 102 and 104 to sense the residual strain of the film and convert it into the deformation variables of the detection beams 102 and 104. The detection beams 102 and 104 are connected to the center disc 106 with an extension beam 110 (length LB), and then the shape of the detection beams 102 and 104 is enlarged by the center disc 106 (radius R) and the index beam 108 (length Lc). Finally, the deformation of the index beam 108 is read out by a micro-scale ruler, and then the geometrical dimensions of the index beam 108 and the detection beams 102 and 104 are matched with this deformation variable, and the residual strain 値 of the film to be measured is calculated through calculation. Because the residual strain is generally about the negative 4th power of 10, the micro-scale ruler rotation angle caused by the residual strain of the film will be much less than 1 degree. Therefore, the entire system can be regarded as a small-angle rotation system. After simple geometric calculations, , The relationship between the rotational displacement and the residual strain can be simplified as:

_ {R ^ LB) ^ y (R + Lc) La where ε is the residual strain of the film, R is the radius of the disc, and y is the lateral displacement of the vernier. And the conversion rate of the strain-displacement amount of the entire micro-swivel scale strain gauge. Therefore, if you want to increase the conversion magnification, you can increase la, LC 値, or shrink 10 574499 11647twf.doc / 006 small LB and disk radius R, but reduce Although the disk radius R can increase the magnification, it may increase the rotation angle and increase the error 値. [Embodiment 2] Strain gauge of arc-arm type micro vernier scale Please refer to FIG. 2 for the schematic diagram of the strain gauge of arc-arm type micro vernier scale. The arc-arm type micro-scale ruler strain gauge 200 uses a pair of arc-shaped cantilever detection beams 202 and 204 with a radius of R and an opening angle of 0 to sense the residual strain of the film, and then through the link mechanism and the index beam 206 (length L), the detection beam The strains of 202 and 204 are converted into rotational displacements and amplified, and then the amplified rotational displacements are also read out by the micro vernier, and the geometric dimensions of the indicator beam 206 are also matched, and the residual strain of the film to be measured is obtained after calculation. value. If the rotation of the micro-scale is also regarded as a small-angle rotation, the relationship between the rotational displacement and the residual strain can be simplified by geometric calculation as follows:

9L Among them, ε is the residual strain of the thin film, so when the length of the index beam and the angle of the beam are detected, the amount of residual strain can be calculated by measuring the rotational displacement y of the micro vernier. And the strain-displacement conversion rate of this arc-arm type micro vernier scale gauge is: ’

M = 0L It can be found from the formula that the strain-displacement conversion rate is only related to the opening angle and the length of the index beam. Therefore, the conversion rate of the displacement can be increased by increasing the opening angle of the arc detection beam and the length of the index cantilever beam. . In terms of the feasibility evaluation of the above two micro-vernier scale strain gauges, the present invention uses a finite element method to analyze the relationship between the micro-vernier scale rotation displacement and the film residue 574499 11647twf.doc / 006 strain, and the results show that these two micro-verniers The ruler strain gauge has extremely high linearity performance in the elastic detection range (small angle rotation). Figure 3 is a finite element analysis model of a straight-arm micro vernier strain gauge. Because the effect of the bending moment of the structure is considered, the solid 73 element with rotational degrees of freedom is selected as the analysis element. Figure 4 shows the relationship between the rotational displacement and the residual strain of the straight-arm micro vernier scale. 'The length of the detection beam LA is 100 microns, and the equivalent length of the index beam (R + LC) is 450 microns.' The equivalent length (R + LB) of the arm is 75 microns. The analysis results show that the strain-displacement conversion rate is very linear. Figure 5 shows the finite element analysis model of the arc-arm micro vernier with an opening angle of π / 6. Figure 6 shows the simulation results of the finite element method for the rotational displacement and residual strain of the arc-arm micro vernier. Its conversion rate is also very good linearity with the straight-arm micro vernier scale, and the radius of the arc detection beam used in the analysis is 150 microns, and the length L of the index cantilever beam is 450 microns. From the comparison of the results in Figures 3, 4 and 5 and 6, it is found that the arc-arm micro-scale slider can get better strain under the same area occupation rate because the area occupied by the arc-arm micro-scale slider is small. -Conversion rate of displacement. In addition, comparing the simulation results of the finite element method with the theory, it is found that the error between the analytical solution of the straight-arm micro-scale and the finite element method is about 4.76%, while the error of the arc-arm micro-scale is 9.46%. In addition, the measurement resolution of the micro-travel ruler is mainly affected by two factors, namely the strain-displacement conversion rate and the resolution of the vernier scale. Among them, the resolution of the vernier ruler is limited by the resolution of the process line width, and the conversion rate of the strain-displacement amount is determined by the structural geometry. The minimum line width of the MUMPs shared process provided by American Cronos is 2 micron ’, so without special design of the 12 574499 11647twf.doc / 006 vernier ruler, the resolution of the vernier ruler is limited to 2 micron. Therefore, when the geometric size of the straight-arm micro vernier scale proposed by the present invention is the limit size allowed by the general process (gp 1 ^ and Lc are both 500 microns, LB is 5 microns, and the disk radius R is 10 microns) , Together with the resolution of the upstream scale gauge is 2 microns, the strain measurement resolution of the straight-arm microscale can be calculated to be 1.2x 10-4; but if the process technology (especially in the test piece suspension process) allows, When the length of the detection beam LA and the index beam Lc in this paper can be increased to 1 (00 μm), the resolution of the strain measurement of the entire micro vernier scale can be increased to 3x 10-5. A resolution of 1 micron, so that the resolution can be further improved to 1.5 x 10-5. Assuming that the film to be tested is a polycrystalline sand material commonly used in general surface manufacturing processes (Young's coefficient is 150 GPa), the resolution of the stress measurement of the straight-arm micro vernier scale is about 2.25 MPa. However, if the film to be tested is two When the oxidation-shaped 7 material (Young's coefficient is 70 GPa), the resolution of the stress measurement is reduced to 1.05 MPa. ’For the strain measurement resolution of the arc-arm type micro vernier scale. Assuming the length of the index rubber is 1000 microns, and the opening angle of the arc arm is 90 degrees, and the resolution of the vernier scale M is also 1 micron, the strain measurement resolution of the arc arm type micro vernier scale can reach 6.3χ 10- 4. Compared with the straight-arm type micro vernier scale, its resolution is far worse than that of the straight-arm type micro vernier scale. The strain solution is only 15 × 10_5. Although the arc-arm type micro vernier scale takes up a small area, the straight-arm type; ί The resolution resolution of the Scatter gauge is relatively high, so each has its own advantages and disadvantages. If I can combine the advantages of the two, a more practical micro-scale gauge can be obtained. Therefore, after combining the advantages of the two, the present invention proposes a new one: a new high-resolution arc-arm type micro vernier scale strain gauge. 13 574499 11647tvvf.doc / 006 [Example 3] High-resolution arc-arm micro vernier strain gauge I found that the reason why arc-arm micro vernier cannot be as straight as a micro-arm vernier, has a high resolution of about 10-5 The reason is that in its measurement mechanism, the force-applying arm of the two structural beams to the index beam is also the radius of the circular arc arm, and the radius, opening angle and arc length are dependent on each other. Therefore, after mathematical calculation, The amplification effect of the arm will be eliminated. Therefore, it is necessary to avoid such situations when designing micro-gauge rulers. Under such considerations, the use of a straight-arm micro-scale is a better choice, but the high area of the straight-arm micro-scale is occupied. Rate is the main factor limiting its application. However, if you can capture the advantages of the arc-arm micro vernier plus the advantages of the straight-arm micro vernier, you can get a thin film residual stress test key that considers both measurement resolution and applicability. In view of this, the present invention replaces the detection beam of the straight-arm micro-measuring scale with the design method of the arc detection beam of the arc-arm micro-measuring scale. In addition, by doing “misalignment design” for the vernier ruler part, the new micro-measuring scale can be further developed. The detection resolution of the strain gauge has been increased to ~ 10-6 or more, becoming a "high-resolution arc-arm type micro vernier strain gauge." Please refer to FIG. 7, which shows a high-resolution arc-arm type micro vernier scale strain gauge of the present invention. The arc-arm type micro vernier scale strain gauge 300 of this embodiment is constructed in a microfabricated micro-electro-mechanical workpiece and is formed on a substrate. The thin film forms a micro-electro-mechanical workpiece part and a flat-type strain gauge part at the same time, that is, the arc-arm type micro vernier scale strain gauge in this embodiment. The thin-film arc-arm micro vernier strain gauge section includes an index beam 306 with an index length of LA. One end of the index beam 306 has a first vernier gauge 310, and the other end has a balance block 308. The second vernier ruler 312 corresponds to the first vernier ruler 310, and extends a first boundary film 314, 14 574499 11647twf.doc / 006 and is arranged in a misalignment with the first vernier ruler 310. Two curved detection beams 302 and 304 are respectively disposed on two sides of the index beam 306. One end of the two curved detection beams 302 and 304 has a second boundary film 316 and 318, and the other end of the two curved detection beams 302 and 304 are respectively. The arc extends toward the two sides of the index beam 306 and is connected to the index beam 306 at a position about the center of gravity of the index beam 306, and a force couple is formed by a misaligned design. The strain of the arc detection beams 302, 304 causes a rotation displacement of the index beam 306 in the form of a force couple. The first boundary film 314, the second boundary film 316, and 318 are respectively connected to the substrate through a sacrificial layer. The sacrificial layer forms a support pattern at this position. In order to strengthen the fixed effect of the boundary of the arc-shaped detection beams 302 and 304, a film may be covered with a cover layer corresponding to the sacrificial layer position. The manufacturing process of the above structure includes: first providing a substrate and forming a sacrificial layer on the surface of the substrate. A thin film is formed on the surface of the sacrificial layer, and the thin film has at least one plane strain gauge pattern. Among them, the in-plane strain gauge pattern includes an index beam with a first vernier ruler at one end and a balance block at the other end; the second vernier ruler corresponds to the first vernier ruler and extends a first boundary film, It is misaligned with the first vernier gauge; two curved detection beams are arranged on the two sides of the index beam, one end of the two curved detection beams has a second boundary film, and the other end of the two curved detection beams is arced. It extends toward the two sides of the ® indicator beam, and is connected to the indicator beam at a position about the center of gravity of the indicator beam, forming a force couple. Then, a part of the sacrificial layer is removed, and only at least a portion covered by the first boundary film and the second boundary film is left to form a covering material layer supporting film, and the indicator beam and the arc detection beam are suspended. After forming the structure of the arc-arm type micro vernier strain gauge, the reading of the first vernier gauge corresponding to the second vernier gauge can be measured to obtain the strain of the film. 15 574499 11647twf.doc / 006

Similarly, the rotation of the micro vernier scale is regarded as a small angle rotation. After structural geometric calculation, this high-resolution arc arm micro vernier scale gauge can be obtained. The relationship between the rotational displacement and the residual strain can be expressed as: c: yLB

dRLA Among them, 0 is the opening angle of the arc detection beam, R is the radius of the arc detection beam, LA and LB are the length of the index beam and the arm, respectively, and the conversion rate of the strain-displacement of the micro-gage scale gauge is:

LB As mentioned above, in addition to the measurement resolution of the micro-gauge ruler gauge, it is not limited to the measurement mechanism and structure size, but there is another important factor-the resolution of the vernier scale. In the design of general vernier rulers, the idea of "alignment" is used. Therefore, the resolution of vernier rulers is completely determined by the resolution of the photomask making machine. However, in the application of micro-electromechanical products, the 1 micron The mask resolution is already a relatively high resolution, but under such a vernier ruler resolution, the strain resolution of the micro vernier scale is only about ~ 10-5, so a higher measurement resolution is being pursued In consideration of this, a new design rule of the vernier ruler is bound to be necessary, so the present invention also proposes a new design of the vernier ruler. Please refer to FIG. 8 for a schematic diagram of a new type of vernier ruler. As shown in the figure, with the “misalignment” design of the vernier rulers, the resolution of the vernier caliper can be increased to 0.1 micron, that is, the measurement resolution of the micro vernier ruler can be increased to ~ 10-6. In addition to the advantages of the new vernier ruler design, it can not only improve the measurement resolution, but also make the entire micro-vernier strain gauge use area larger than that of the traditional "alignment" vernier ruler under the same measurement resolution The designed micro-gage ruler strain gauge is an order of magnitude smaller, and this advantage 16 574499 11647tvvf.doc / 006 will make the micro-gage scale gauge from a higher commercial application. In addition to detecting the residual uniform stress of the film, the residual gradient stress of the film is also one of the items that can be detected by the "coplanar residual strain gauge" proposed in this paper. The detection method only needs to directly indicate the curvature radius 梁 of the beam, and then the residual gradient stress of the film to be measured can be obtained through the following relationship.

Among them, y is the distance from the neutral axis of the index beam, and P is the radius of curvature of the index beam. Therefore, as long as the radius of curvature of the index beam is measured with a known thickness and Young's coefficient of the film, the residual film can be detected. Gradient stress. In order to verify the feasibility of applying the high-resolution micro vernier strain gauge to the detection of the residual strain of the thin film in the surface microfabrication process, the present invention also uses the MUMPs common process provided by the American company Cronos as an example. Residual strain of the two layers of the polycrystalline silicon structure layer to verify the feasibility of this detection technology. Among them, the radius of the arc-shaped detection beam is 100 micrometers and the opening angle is 90 degrees. The length of the index beam is distributed from 200 micrometers to 1000 micrometers, increasing by every 100 micrometers, and the length of the forcing arm is set to 5 micrometers. In addition, in the connection part between the arc detection beam and the index beam, in theory, this connection point should show complete point contact. However, the so-called point contact is difficult to implement in practice, so the only way to minimize this contact point is The area has reduced detection errors. However, reducing the area of the contact point indiscriminately will lead to a decrease in the yield of the process. Therefore, after considering both the process stability and the detection error, the present invention designs the width of the contact point to 3 micrometers. After actual verification, This width can make the yield rate of micro-slider strain gauges reach 100%. In addition, although the impact of the flexible boundary of the test beam on the residual stress released by the test beam at 17 574499 11647twf.doc / 006 is not particularly significant, based on the consideration of reducing the detection error, the present invention is designed to design a curved test beam In the case of a boundary, a stacked structure layer is still used to cover the boundary to improve the strength of the boundary, that is, the end of the arc detection beam is connected to the substrate by a sacrificial layer, and a cover layer is covered thereon. Finally, in the aspect of measuring the deformation of the test piece, the present invention uses a tool microscope STM-6 manufactured by Nissho Olympus to observe and measure the displacement of the index beam. The high-resolution micro-slider scale gauge proposed by the present invention can achieve a high resolution of more than 10-6 after the structural design, and further verify its feasibility through the β MUMPs shared process. Therefore, this "coplanar residual strain gauge" can not only be used as a process test key to detect the residual strain of the film, but also can be combined with another "out-plane residual strain gauge" proposed below in the present invention to mutually verify and improve the detection. The accuracy then forms a test key group. [Embodiment 4] A plane residual strain gauge As described above, the present invention has proposed a high-resolution coplanar residual strain gauge, and successfully verified and explored its feasibility. Next, we will introduce another # "out-plane residual strain gauge" which can be used as a key for residual strain test in surface microfabrication. The so-called "out-plane residual strain gauge" is to use a micro-detection structure to convert the residual strain of the film to be measured into the out-plane displacement of the micromechanical structure. The geometric dimensions of the structure are used to infer the residual strain 値 of the film under test. Because the current measurement resolution of the out-of-plane deformation is much higher than the resolution of the in-plane displacement, the "out-of-plane residual strain gauge" is used to detect the change in the resolution of the residual strain of the film to be measured. 18 574499 11647twf.doc / 006 It is much higher than the same plane type, so it can easily reach a detection resolution of 10-6 or more. As mentioned earlier, it is rare to use a planar inspection mechanism to detect the residual stress of a thin film in a microfabrication process. The main reason is that the use of a planar inspection mechanism often requires excellent structural fixed boundaries. In order to make a good fixed boundary in the molding process, good boundary design thinking is required. According to the above embodiments, the present invention proposes a type of solution, which proves that an excellent fixed boundary can be obtained by covering the boundary with a stacked structure layer. Therefore, the present invention facilitates the use of this enhanced boundary to design a "plane "Residual Strain Gauge" for detecting the residual strain of thin films in surface microfabrication processes. # According to the post-buckling behavior of micro-bridge beams proposed by W. Fang in 1994, after the micro-bridge beams have buckling behavior, the deformation of the center point of the bridge structure and the uniform distribution of the film The response will have the following relationship:

Among them, 6jmax is the central deformation of the micro-bridge beam, ε is the residual uniform strain of the film, and L, I, and A are the length, moment of inertia, and cross-sectional area of the micro-bridge beam, respectively. After finishing, the relationship between the residual uniform strain of the thin film and the center deformation of the micro-bridge beam is as follows: where t is the thickness of the film to be measured, assuming that the length and thickness of the micro-bridge beam are known. In this case, the residual uniform strain of the film to be measured can be obtained by measuring the deformation of the center point of the micro-bridge beam after the buckling due to the release of the residual strain, and substituting it into the above formula. For the residual gradient strain detection of the film under test 19 574499 11647twf.doc / 006, a quarter of the length of the micro-bridge beam can be derived from a suspended structural beam parallel to the micro-bridge beam and measured. The curvature radius of this structural beam is substituted into the expression of the residual gradient stress in the previous embodiment, and the residual gradient strain can be detected. As for the reason why the derived suspended structural beam is placed at a quarter of the micro-bridge beam, the reason is that when the micro-bridge beam has a buckling behavior, its strain energy at the quarter length is the smallest, so Placing the structural beam that detects gradient strain here has the least effect on the post-buckling behavior of the micro-bridge beam. In addition, with regard to the measurement resolution analysis of the residual strain gauge of the micro-bridge beam, the micro-bridge beam converts the residual strain of the film into the out-of-plane deformation. The interferometer RST-500 has an out-of-plane measurement resolution of more than Inm. If you use a micro-bridge with a length of 500 microns to detect the residual strain of the film, you can get an ultra-high resolution of 4.93 × 10-9. Easily meet the detection resolution requirements above I0-6. To use the micro-bridge structure to detect the residual strain of the film on the surface microfabrication process, there are three important points to consider, namely the fixed boundary, the residual strain and the critical buckling length. First of all, the boundary design part of the hypothesis of a fixed boundary can meet this requirement with the previously proposed boundary layer of the stacked structure layer, so there is no question in this respect. But for the second part, because only compressive strain can cause the micro-bridge beam to buckle, the micro-bridge beam can only be used to detect the residual compressive strain. Therefore, there are still many applications for micro-bridge structures. The last and third point is the most important design factor. 'Because of the buckling behavior for the bridge, in addition to the residual compressive strain of 20 574499 11647twf.doc / 006, this compressive strain must be greater than that of the micro-bridge beam. The buckling behavior only occurs when the critical buckling strain is critical, and the critical buckling strain of the micro-bridge beam can be expressed by the following formula: π2ί2 Therefore, the length of the micro-bridge beam must be adjusted appropriately according to the residual strain of the film to be measured. After the above formulas are sorted, the relationship between the length of the micro-bridge beam and the boundary between the buckling boundary and the residual strain can be obtained. Therefore, assuming that the residual strain of the film to be measured is lx 10-4 and the thickness is 2 micrometers The critical buckling length of the micro-bridge beam is 458 microns, so the length of the micro-bridge beam must be greater than 458 microns to detect the residual compressive strain of the film to be measured. Based on the above analysis results, when the present invention uses the MUMPs common process to verify the feasibility of the residual strain gauge of the micro-bridge beam, the structure design of the present invention is to use a micro-bridge-like probe in addition to the use of stacked structure layers to cover the boundary design at fixed boundaries. The length is distributed from 250 microns to 500 microns, increasing in length per 50 microns. In addition, in the design of the gradient strain detection structural beam, 'the length is designed to 100 micrometers according to experience, and the part connected to the micro-bridge beam' φ takes into account the impact on the micro-bridge beam, so The width is designed to be 2 microns. Please refer to Figure 9 for a schematic diagram of the residual strain gauge of the micro-bridge beam. The micro-bridge beam residual strain gauge 400 is constructed in a micro-machined micro-machined electrical workpiece and is formed on a substrate. The thin film is formed with a magneto-electromechanical workpiece portion and an in-plane strain gauge portion, that is, the residual strain gauge of the micro-bridge beam of this embodiment. The plane strain gauge pattern of the film includes: a bridge beam 402, and two ends of the bridge beam 402 have a boundary film 21 574499 11647twf.doc / 006 406; a plurality of structural beams 404 extend from the side of the bridge beam 402 And parallel to the bridge beam 402. The boundary film 406 uses a stacked structure layer, that is, the film at the end of the bridge beam is connected to the substrate through a sacrificial layer. The sacrificial layer forms a support pattern at the position, and the film is covered with a cover layer to strengthen the bridge. Boundary strength of the beam. The manufacturing method of the above structure includes providing a substrate and forming a sacrificial layer on the surface of the substrate. A film is formed on the surface of the sacrificial layer. The film has at least one out-of-plane strain gauge pattern, and the out-of-plane strain gauge pattern includes: a bridge beam with a boundary film at each end thereof; a plurality of structural beams from the sides of the bridge beam Extend and parallel to the bridge beam. Then, a part of the sacrificial layer is removed, and only the part covered by the boundary film is left to form a covering material layer to support the film, and the bridge beam and the structural beam are suspended. At this point, the production of the plane strain gauge is completed, and the strain at the center point of the buckling of the bridge beam is measured to obtain a thin strain variable, and the curvature radius of the structural beam is measured to obtain the gradient strain of the #film. The central deformation of the micro-bridge beam is measured using a three-dimensional optical interferometer. With regard to the analysis of the measurement inaccuracy of the residual strain gauge of the micro-bridge beam, during the detection process, only the length, thickness and center point deformation of the micro-bridge beam were independent variables. Therefore, the measurement resolution of the three-dimensional interferometer is 20 φ nm, and the measurement accuracy of the tool microscope is 3 micrometers. If a micro-bridge beam residual strain gauge with a length of 500 micrometers is used, the structure thickness is 2 micrometers, and the center The point deformation is 1 micron, and the thickness inaccuracy is based on Cronos' measurement inaccuracy results and its 値 is 12%, so the overall detection inaccuracy is about 4.8%. Residual strain gauge detection surface of micro-bridge beam using out-of-plane detection mechanism 22 574499 11647twf.doc / 006 The thin film residual strain in the microfabrication process has not only a very high detection resolution, but also with a good fixed boundary design, It can also get good measurement accuracy in the surface process. Although the micro-bridge beam residual strain gauge can only be used to detect the residual compressive strain, it does not completely limit its applicability. Combined with other residual strain detection mechanisms in this paper, a more accurate film residual strain test group can be formed. The residual strain gauge structure of the thin film proposed in the above four embodiments can be used to measure and monitor the residual strain or strain gradient distribution of the thin film during film formation, and can also be used as a thermal expansion strain gauge to measure The strain of the thin film after heat treatment, so as to obtain the thermal expansion coefficient or thermal expansion gradient of the thin film. To sum up, the present invention has at least the following advantages: 1. The method and structure for measuring the strain of the thin film of the present invention can be applied to the surface microfabrication process to accurately measure the residual strain of the thin film to facilitate the process parameters Adjustment to improve product yield. 2. The new coplanar residual strain gauge structure of the present invention can accurately measure the residual strain of the film. If the film is heat treated, its thermal expansion coefficient can also be measured. 3. The new type of planar residual strain gauge structure of the present invention can accurately measure the residual strain and strain gradient distribution of the film. If the film is subjected to heat treatment, its thermal expansion coefficient and thermal expansion gradient distribution can also be measured. 4. The method and structure for measuring the strain of the thin film of the present invention can be applied to the surface microfabrication process, and at the same time, a coplanar residual strain gauge and a flat residual strain gauge are formed on the substrate to measure the thin film strain, In order to obtain a more accurate film residual strain and gradient distribution of residual strain, if the film is heat-treated at 23 574499 11647tvvf.doc / 006, its thermal expansion coefficient and thermal expansion gradient distribution can also be measured. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application. Brief description of the drawing Figure 1 shows a schematic diagram of the design of a straight-arm micro-vernier strain gauge. Figure 2 shows a schematic diagram of an arc-arm type micro vernier strain gauge. Figure 3 shows a finite element analysis model of a straight-arm micro-vernier strain gauge. Figure 4 shows the relationship between the rotational displacement and the residual strain of the edge gauge of the straight-arm micro vernier. Figure 5 shows the finite element analysis model of the arc-arm type micro vernier with an opening angle of 7Γ / 6. Figure 6 shows the simulation results of the finite element method for the rotational displacement and residual strain of the arc-arm type micro vernier scale. FIG. 7 shows the strain of the high-resolution arc-arm type micro vernier of the present invention. FIG. 8 shows a schematic diagram of a new type of vernier gauge. Figure 9 shows a schematic diagram of the residual strain gauge of the micro-bridge beam. Description of graphical symbols = 100: Straight-arm type micro vernier strain gauge 102, 104: Detection beam 106 · • Center disc 24 574499 11647twf.doc / 006 108, 206, 306: Index beam 110: Extension beam 200: Arc-arm type micro Vernier Strain Gauges 202, 204: Arc Cantilever Inspection Beam 300: Arc Arm Micro Vernier Strain Gauge 302, 304: Arc Inspection Beam 308: Balance Block 310: First Vernier Ruler. 312: Second Vernier Ruler 314 : First boundary film 316, 318: second boundary film 400: micro-bridge beam residual strain gauge 402: bridge beam 404 :, structural beam 406 ·· boundary film 25

Claims (1)

574499 11647twf.doc / 006 The scope of patent application: 1. A method for measuring the strain of a thin film, which is applied to a microfabricated microelectromechanical workpiece of a surface type, which is constructed on a substrate. And there is at least one thin film layer, and the method for measuring the strain of the thin film includes: forming the thin film layer on the substrate, the thin film layer having a micro-electromechanical workpiece part and at least one residual strain gauge part; and measuring the residual strain gauge The geometrical dimensions and deformation variables of the film are used to derive the residual strain of the film and the gradient of the residual strain distribution. 2. The method for measuring the strain of a thin film as described in item 1 of the scope of the patent application, wherein the residual strain gauge includes a coplanar strain gauge, and the coplanar strain gauge includes at least two curved detection beams and an index beam. The arc detection beam is configured correspondingly, and its ends are connected to the index beam at the same time to form a force couple, so that the index beam rotates due to the strain of the two arc detection beams. By measuring the rotational displacement of the index beam, The residual strain 値 of the film is derived, and the gradient of the residual strain distribution of the film is derived by measuring the radius of curvature of the deformation of the index beam. 3. The method for measuring the strain of a thin film as described in item 2 of the scope of the patent application, wherein the index beam is further equipped with a ruler device at the end, which can read the rotation displacement of the index ® beam. 4. The method for measuring the strain of a thin film as described in item 2 of the scope of the patent application, wherein one end of the two-arc detection beam away from the index beam is connected to the substrate through a support material supporting film. 5. The method for measuring the strain of a thin film as described in item 4 of the scope of the patent application, wherein the surface of the film corresponding to the position of the supporting material layer supporting the film further has a cover layer of 26 574499 11647twf.doc / 006. 6. The method for measuring the strain of a thin film as described in item 1 of the scope of the patent application, wherein the residual strain gauge includes a plane-type strain gauge, and the plane-type strain gauge includes a bridge beam, and the bridge beam is measured by The amount of deformation displacement to derive the residual strain 値 of the film. 7. The method for measuring the strain of a thin film as described in item 6 of the scope of patent application, wherein the displacement of the bridge beam is measured by a three-dimensional optical interferometer. 8. The method for measuring the strain of a thin film as described in item 6 of the scope of the patent application, wherein the out-of-plane strain gauge further includes a plurality of structural beams arranged on the side of the bridge beam, and by measuring the radius of curvature of the structural beam, To derive the thin film # gradient of residual strain distribution. 9. The method for measuring strain of a thin film as described in item 8 of the scope of patent application, wherein the curvature radii of the structural beams are measured by a three-dimensional optical interferometer. 10. The method for measuring the strain of a thin film as described in item 6 of the scope of the patent application, wherein the two ends of the bridge beam are respectively connected to the substrate through a supporting material layer supporting film. 11. The method for measuring the strain of a film as described in item 10 of the scope of the patent application, wherein the surface of the film corresponding to the position of the supporting material layer supporting the film has a cover layer. 12. —A method for measuring the thermal expansion property of a thin film, which is applied to a microfabricated micro-electromechanical workpiece of a surface type. The microfabricated microelectromechanical workpiece of the surface type is constructed on a substrate and has at least a thin film layer. A method for thermal expansion properties of a thin film includes: forming the thin film layer on the substrate, the thin film layer having a MEMS 27 574499 11647twf.doc / 006 workpiece portion and at least one thermal expansion strain gauge portion; performing a heat treatment on the thin film layer; and The geometric size and deformation of the thermal expansion strain gauge were measured to derive the thermal expansion coefficient and thermal expansion distribution gradient of the film. 13. The method for measuring the thermal expansion properties of a thin film as described in item 12 of the scope of the patent application, wherein the thermal expansion strain gauge includes a coplanar strain gauge, and the coplanar strain gauge includes at least two curved detection beams and an index beam, and the two The arc detection beam is configured correspondingly, and its ends are simultaneously connected to the index beam to form a force couple, so that the index beam rotates due to the strain of the two arc detection beams. By measuring the rotation displacement of the index beam, The thermal expansion coefficient of the film is derived, and the thermal expansion gradient of the film is derived by measuring the curvature radius of the beam deformation of the index. 14. The method for measuring the thermal expansion properties of a thin film as described in item 13 of the scope of the patent application, wherein the end of the index beam is further equipped with a ruler device, and the rotational displacement of the index beam can be read. 15. The method for measuring the thermal expansion property of a thin film as described in item 13 of the scope of the patent application, wherein one end of the two-arc detection beam away from the index beam is connected to the substrate through a covering material support film. 16. The method for measuring the thermal expansion property of a film as described in item 15 of the scope of the patent application, wherein the film surface corresponding to the position where the coating material layer supports the film further has a covering layer. 17. The method for measuring the thermal expansion properties of a thin film as described in item 12 of the scope of the patent application, wherein the thermal expansion strain gauge includes a plane-type strain gauge, and the plane-type strain gauge includes a bridge-shaped beam. The amount of displacement of the beam deformation to derive the thermal expansion coefficient of the film. 28 574499 11647tvvf.doc / 006 18. The method for measuring the thermal expansion property of a thin film as described in item 17 of the scope of patent application, wherein the displacement of the bridge beam is measured by a three-dimensional optical interferometer. 19. The method for measuring the thermal expansion properties of a thin film as described in item 17 of the scope of the patent application, wherein the out-of-plane strain gauge further includes a plurality of structural beams arranged on the side of the bridge beam, and by measuring the radius of curvature of the structural beam To derive the thermal expansion gradient of the film. 20. The method for measuring the thermal expansion properties of a thin film as described in item 19 of the scope of the patent application, wherein the radius of curvature of the structural beams is measured by a three-dimensional optical interferometer. # 21. The method for measuring the thermal expansion property of a thin film as described in item 17 of the scope of patent application, wherein the two ends of the bridge beam are respectively connected to the substrate through a covering material supporting film. 22. The method for measuring the thermal expansion property of a film as described in item 21 of the scope of the patent application, wherein the film surface corresponding to the position where the cover material layer supports the film further has a covering layer. 23. —A thin-film measurement structure applied to a microfabricated micro-electro-mechanical workpiece, the thin-film measurement structure includes:-a substrate; and _ a thin film disposed on the substrate, at least one micro-electro-mechanical workpiece Part, the plane strain gauge part, and the plane strain gauge part can read the strain number of the film, the strain distribution gradient, the thermal expansion coefficient or the thermal expansion gradient. 24. The thin film measurement structure described in item 23 of the scope of patent application, wherein the coplanar strain gauge part includes at least a two-arc detection beam and an index 29 574499 11647twf.doc / 006 beam, the two-arc detection beam Corresponding configuration, and the index beams are connected to the index beam at the same time to form a force couple, so that the index beam rotates due to the strain of the two arc detection beams. 25. The thin film measurement structure described in item 24 of the scope of patent application, wherein a ruler device is further arranged at the end of the indicator beam, and the rotation angle of the indicator beam can be read. 26. The thin film measurement structure according to item 24 of the scope of the patent application, wherein one end of the two-arc detection beam away from the index beam is connected to the substrate through a support material supporting film. 27. The thin film measuring structure described in item 26 of the scope of patent application, wherein the surface of the film corresponding to the position of the supporting material layer supporting the film further has a covering layer. 28. A thin-film measurement structure applied to a microfabricated micro-electro-mechanical workpiece, the thin-film measurement structure includes: a substrate; and a thin film disposed on the substrate and having at least one micro-electro-mechanical workpiece portion A plane-type strain gauge part can read out the strain number 値, strain gradient, thermal expansion coefficient, or thermal expansion gradient of the film. 29. The thin film measurement structure described in item 28 of the scope of patent application, wherein the out-of-plane strain gauge part further includes a bridge beam. 30. The thin film measurement structure described in item 29 of the scope of the patent application, wherein the out-of-plane strain gauge part further includes a plurality of structural beams arranged on the side of the bridge beam. 31. According to the thin film measurement structure described in item 29 of the scope of patent application, the two ends of the bridge beam in 30 574499 11647twf.doc / 006 are connected to the substrate through a covering material supporting film respectively. 32. The thin film measurement structure described in item 31 of the scope of patent application, wherein the surface of the thin film corresponding to the position where the cover material layer supports the thin film further has a covering layer. 33. A thin-film measurement structure applied to a microfabricated micro-electro-mechanical workpiece, the thin-film measurement structure includes: a substrate; and a thin film disposed on the substrate with at least one micro-electro-mechanical workpiece portion With the plane-type strain gauge part and a plane-type strain gauge part, the co-planar-type strain gauge part and the plane-type strain gauge part can read the strain number 値, strain gradient, thermal expansion coefficient or The thermal expansion gradient, and the out-of-plane strain gauge section can read the strain gradient or thermal expansion gradient of the film. 34. The thin film measurement structure as described in item 33 of the scope of patent application, wherein the in-plane strain gauge part includes at least two curved detection beams and an index beam, and the two curved detection beams are configured correspondingly, and the ends are respectively At the same time, the index beam is connected to form a force couple, so that the index beam rotates due to the strain of the two arc-shaped detection beam. · 35. The thin film measurement structure described in item 34 of the scope of patent application, in which the index beam is further equipped with a ruler device at the end, which can read the rotation angle of the index beam. 36. The thin-film measurement structure according to item 34 of the scope of the patent application, wherein one end of the two-arc detection beam away from the index beam is connected to the substrate through a covering material layer supporting film, respectively. 31 574499 11647twf.doc / 006 37. The thin film measurement structure described in item 36 of the scope of the patent application, wherein the surface of the film corresponding to the position of the supporting material layer supporting the film further has a covering layer. 38. The thin film measurement structure described in item 33 of the patent application scope, wherein the out-of-plane strain gauge part further includes a bridge beam. 39. The thin film measurement structure described in item 38 of the scope of the patent application, wherein the out-of-plane strain gauge part further includes a plurality of structural beams arranged on the side of the bridge beam. 40. The thin film measurement structure according to item 38 of the scope of the patent application, wherein the two ends of the bridge beam are connected to the substrate through a support material layer supporting film, respectively. 41. The thin film measurement structure described in item 40 of the scope of patent application, wherein the surface of the film corresponding to the position where the cover material layer supports the film further has a covering layer. 42. A method for measuring strain of a thin film, which is suitable for measuring strain of a thin film. The method for measuring strain of a thin film includes: providing a substrate; forming a sacrificial layer on the surface of the substrate; forming the thin film on the sacrificial On the surface of the layer, the film has at least one plane strain gauge pattern and one plane strain gauge pattern, wherein the coplanar strain gauge pattern includes = an index beam, and one end of the index beam further has a first vernier scale, and The other end has a balance block; a second vernier ruler, which corresponds to the first vernier ruler, extends a first boundary film, and is misaligned with the first vernier ruler; 32 574499 11647twf.doc / 006 2 The arc-shaped detection beams are respectively disposed on two sides of the index beam. One end of the two-curved detection beams each has a second boundary film, and the other ends of the two arc-shaped detection beams are arc-shaped toward the index beams. The two sides extend and are connected to the indicator beam at a position of approximately the center of gravity of the indicator beam and form a force couple, wherein the out-of-plane strain gauge pattern includes: a bridge beam, the bridge beam Each end has a third boundary film; a plurality of structural beams extending from the side of the bridge beam and parallel to the bridge beam; · · removing part of the sacrificial layer, leaving only at least the first boundary film, the · The second boundary films and the portions covered by the third boundary films form a covering material layer supporting film, and make the indicator beams, the arc detection beams, the bridge beams and the structural beams suspended; And measure the first vernier ruler corresponding to the reading of the second vernier ruler and the deformation of the bridge beam's buckling center point to obtain the strain of the film, and measure the radius of curvature of the structural beam to obtain Gradient strain of the film. 43. The method for measuring strain of a thin film according to item 42 of the scope of patent application, wherein after forming the thin film, it further comprises forming a cover layer to cover the second boundary films and the third boundary films, respectively. φ 44. The method for measuring the strain of a thin film as described in item 42 of the scope of the patent application, wherein the method of measuring the deformation of the center point of the bridge beam's buckling and the method of measuring the radius of curvature of the structural quantity are three times. The element interferometer performs the measurement. 45. A method for measuring the thermal expansion coefficient of a thin film, which includes: providing a substrate; 33 574499 11647tvvf.doc / 006 forming a sacrificial layer on the surface of the substrate; forming a thin film on the sacrificial layer On the surface of the layer, the film has at least one plane strain gauge pattern and one plane strain gauge pattern, wherein the coplanar strain gauge pattern includes: an index beam, one end of which has a first vernier ruler, and The other end has a balance block; a second vernier ruler, corresponding to the first vernier ruler, and extending a first boundary film, and being misaligned with the first vernier ruler; two curved detection beams, each configured On the two sides of the indicator beam, one end of the two-arc detection beam has a second boundary film, and the other end of the two-arc® detection beam extends in an arc shape toward the two sides of the indicator beam, and The position of the center of gravity of the indicator beam is connected to the indicator beam, and a force couple is formed, where the out-of-plane strain gauge pattern includes = a bridge beam, and two ends of the bridge beam are respectively provided with A third boundary film; a plurality of structural beams extending from the side of the bridge beam and parallel to the bridge beam; removing part of the sacrificial layer, leaving only at least the first boundary film, the second boundary films and The parts covered by the third boundary films form a cladding material supporting film, and make the indicator beams, the arc detection beams, the bridge beams and the structural beams suspend; Heat treatment; and measuring the first vernier ruler ’s reading corresponding to the second vernier ruler and the deformation of the bridge beam ’s buckling center point to obtain the thermal expansion coefficient of the film, and measuring the curvature radius of the structural beam, A thermal expansion of 34 574499 11647twf.doc / 006 gradient was obtained to obtain the film. 46. The method for measuring the thermal expansion coefficient of a thin film as described in item 45 of the scope of patent application, wherein after forming the thin film, it further comprises forming a cover layer to cover the second boundary films and the third boundary films, respectively. 47. The method for measuring the coefficient of thermal expansion of a thin film as described in item 45 of the scope of the patent application, wherein the method of measuring the deformation amount of the buckling center point of the bridge beam and the radius of curvature of the structural beam are three times. The element interferometer performs the measurement. 8. A method for measuring the strain of a thin film, which is suitable for measuring the strain of a thin film. The method for measuring the strain of a thin film includes: providing a substrate; forming a sacrificial layer on the surface of the substrate; forming the thin film on On the surface of the sacrificial layer, the film has at least one plane strain gauge pattern, wherein the coplanar strain gauge pattern includes: an index beam, one end of which has a first vernier scale, and the other end has a balance A second vernier ruler, corresponding to the first vernier ruler, and extending a first boundary film, which is misaligned with the first vernier ruler; two curved detection beams, which are respectively disposed on the index beam On both sides, one end of the β-arc detection beam has a second boundary film, and the other end of the two-arc detection beam extends arc-shaped toward the two sides of the indicator beam, and is approximately the same as that of the indicator beam. The position of the center of gravity is connected to the index beam, and a force couple is formed; removing a part of the sacrificial layer, leaving only at least the portion covered by the first boundary film and the second boundary films to form a cladding The material layer supports the thin 35 574499 11647tvvf.doc / 006 film, and makes the indicator beam and the arc detection beams suspended; and the reading of the first vernier ruler corresponding to the reading of the second vernier ruler to obtain the film strain. 49. The method for measuring strain of a thin film according to item 48 of the scope of the patent application, wherein after forming the thin film, it further comprises forming a cover layer to cover the second boundary films, respectively. 50. A method for measuring strain of a thin film, which is suitable for measuring strain of a thin film. The method for measuring strain of a thin film includes: providing a substrate; forming a sacrificial layer on the surface of the substrate; forming the thin film on the sacrificial On the surface of the layer, the film has at least one out-of-plane strain gauge pattern, wherein the out-of-plane strain gauge pattern includes: a bridge beam, and two ends of the bridge beam each have a boundary film; a plurality of structural beams from the bridge The side of the beam extends and is parallel to the bridge beam; removing part of the sacrificial layer, leaving only at least the parts covered by the boundary films, forming a covering material layer to support the film, and making the bridge beams and the bridges The structural beam is suspended; and the deformation of the bridge beam's buckling center point is measured to obtain the strain of the film, and the curvature radius of the structural beam is measured to obtain the gradient strain of the film. 51. The method for measuring strain of a thin film as described in item 50 of the scope of patent application, wherein after forming the thin film, it further includes forming a cover layer to cover the boundary films, respectively. 52. The method for measuring the strain of a thin film as described in item 50 of the scope of the patent application 36 574499 11647twf.doc / 006 method, wherein the deformation of the center point of buckling of the bridge beam and the curvature of the structural beam are measured The method of radius is measured by a three-dimensional interferometer. 53. A method for measuring the thermal expansion coefficient of a thin film, the method for measuring the thermal expansion coefficient of a thin film includes: providing a substrate; forming a sacrificial layer on the surface of the substrate; forming a thin film on the surface of the sacrificial layer, the film being at least There is a coplanar strain gauge pattern, wherein the coplanar strain gauge pattern includes: an index beam, one end of the index beam further has a first vernier ruler, and the other end has a balance block; a second vernier ruler, Corresponds to the first vernier ruler, and extends a first boundary film, and is misaligned with the first vernier ruler; two curved detection beams are respectively disposed on two sides of the index beam, and the two curved detection beams One end has a second boundary film, and the other end of the two arc-shaped detection beams respectively extends toward two sides of the indicator beam in an arc shape, and is connected to the indicator beam at a position of approximately the center of gravity of the indicator beam, and forms A force couple; removing a part of the sacrificial layer, leaving only at least a portion covered by the first boundary film and the second boundary films to form a supporting material layer supporting film, and The indicators have the plurality of arc-shaped beam and detection beam suspended; the film is a heat treatment; and a measuring gauge for the first vernier readings should be the second vernier gauge to obtain a thermal expansion coefficient of the film. 54. The method for measuring the thermal expansion coefficient of a thin film as described in item 53 of the scope of patent application, wherein after forming the thin film, it further includes forming a covering layer, divided into 37 574499 11647twf.doc / 006 and covering the second boundary films. . 55. A method for measuring the thermal expansion coefficient of a thin film, the method for measuring the thermal expansion coefficient of a thin film includes: providing a substrate; forming a sacrificial layer on the surface of the substrate; forming a thin film on the surface of the sacrificial layer, the film being at least The utility model has a plane strain gauge pattern, wherein the plane strain gauge pattern comprises: a bridge beam, each of which has a boundary film at two ends; a plurality of structural beams extending from the side of the bridge beam, and Parallel to the bridge beam; removing part of the sacrificial layer, leaving only at least the portions covered by the boundary films to form a covering material layer supporting film, and making the bridge beam and the structural beams suspend; Performing a heat treatment; and measuring the deformation of the bridge beam's buckling center point to obtain the thermal expansion coefficient of the film, and measuring the curvature radius of the structural beam to obtain the thermal expansion gradient of the film. 56. The method for measuring the thermal expansion coefficient of a thin film as described in item 55 of the scope of patent application, wherein after forming the thin film, it further comprises forming a cover layer to cover the boundary films, respectively. 57. The method for measuring the thermal expansion coefficient of a thin film as described in item 55 of the scope of the patent application, wherein the method of measuring the deformation of the center point of the bridge beam's buckling and the method of measuring the radius of curvature of the structural beam are performed three times. The element interferometer performs the measurement. 5 8. A thin film in-plane strain gauge structure suitable for 38 574499 11647twf.doc / 006 variable measurement and thermal expansion coefficient measurement of a film. The thin film in-plane strain gauge structure includes: a substrate; A sacrificial layer is disposed on the surface of the substrate, the sacrificial layer has a first support pattern and two second support patterns; the film is disposed on the surface of the sacrificial layer, and the film has at least one plane strain gauge pattern, wherein the same plane The strain gauge pattern includes: an index beam, one end of which has a first vernier ruler, and the other end has a balance block; a second vernier ruler, corresponding to the first vernier ruler, and extending # Extend a first boundary film and arrange it in a misalignment with the first vernier gauge, wherein the first boundary film covers the first support pattern; two curved detection beams are respectively arranged on two sides of the index beam, and the two arcs One end of the shape detection beam has a second boundary film, and the other end of the two arc detection beams respectively extend toward the two sides of the indicator beam in an arc shape, and is approximately the same as that of the indicator beam. The position of the center of gravity is connected to the index beam and forms a force couple, wherein the two second boundary films respectively cover the two second support patterns, and the index beam and the arc detection beams are suspended on the substrate; and The cover layers are respectively disposed on the first boundary film and the two second-side β-boundary films. 59. A thin-film strain gauge structure suitable for measuring the strain of a thin film and measuring the thermal expansion coefficient of the thin film. The thin-film strain gauge structure includes a substrate; a sacrificial layer is disposed on the surface of the substrate. The sacrificial layer has two supporting cases as shown in Figure 39 574499 11647twf.doc / 006; and the film is disposed on the surface of the sacrificial layer, the film has at least one out-of-plane strain gauge pattern, wherein the out-of-plane strain gauge pattern includes: a bridge Two beams on each end of the bridge beam, the two boundary membranes covering the two supporting patterns respectively; a plurality of structural beams extending from the side of the bridge beam and parallel to the bridge beam , Wherein the bridge beam and the structural beams are suspended on the substrate. 60. The thin-film out-of-plane strain gauge structure described in item 59 of the scope of patent application, further comprising a cover layer disposed on the two boundary films, respectively.