Testing device for measuring thermal conductivity of conductor film

Abstract

The invention discloses a testing device for measuring the thermal conductivity of a conductor film, which comprises a plurality of anchor areas arranged on a substrate, and the anchor areas and a conductor film lead form a cantilever support structure to fix a conductor film strip. Two ends of the conductor film strip are respectively connected with a plurality of conductor film leads, and the lead pads are arranged on the anchor area to form a plurality of measuring electrodes. The heat dissipation beams which are uniformly distributed are additionally arranged above the conductor film strip to form an additional heat conduction structure, so that the temperature uniformity of the conductor film strip in the heating process is effectively improved, and the measurement precision of the heat conductivity is remarkably improved. The device can be manufactured by adopting processes such as surface micromachining of polycrystalline silicon and the like, is simple in structure and low in manufacturing cost, is compatible with an existing manufacturing process of a micro-electro-mechanical system, is suitable for carrying out on-line thermal conductivity testing on films such as polycrystalline silicon films and the like in a natural air convection environment, and meets the requirements of high-precision MEMS device process detection.

Description

Technical Field

[0001] The present invention relates to the field of microelectromechanical system (MEMS) manufacturing, and particularly to a test device for measuring the thermal conductivity of a conductor thin film, especially a test device for measuring the thermal conductivity of a conductor thin film with a simple structure, suitable for surface processing technology, and capable of achieving high-precision testing in a natural air environment. Background Art

[0002] As a key material in microelectromechanical system (MEMS) devices and integrated circuits, the thermal conductivity of polycrystalline silicon thin films directly affects the thermal stability and overall performance of the devices. In order to achieve precise control of the thermal behavior of the devices, it is urgent to accurately measure the thermal conductivity of polycrystalline silicon thin films. However, the thermal conductivity test structures adopted in the current existing technologies mostly rely on complex MEMS or CMOS-MEMS process flows, and usually need to achieve a suspended structure through post-processing technologies such as bulk silicon etching. This not only increases the manufacturing complexity and cost, but also has an adverse impact on the structural stability and the suppression of edge thermal effects. In addition, most of the existing test methods rely on a vacuum or low-pressure environment, and it is difficult to meet the on-line test requirements under normal pressure natural convection conditions.

[0003] In view of the above problems, there is an urgent need to provide a test device with a simple structure, strong manufacturing process compatibility, and capable of uniformly controlling the temperature field in a natural air environment, so as to improve the test accuracy of the thermal conductivity of the conductor thin film. For this reason, the present invention has been improved and designed on the basis of the traditional structure. By setting a temperature equalizing structure above the conductor thin film strip, the test error caused by uneven temperature distribution is effectively improved, and high-precision on-line testing of thermal conductivity suitable for surface processing technology is realized. Summary of the Invention

[0004] Object of the Invention: In order to solve the problems of complex thermal conductivity test structure, serious edge effect, and uneven temperature distribution in the prior art for the conductor thin film, the present invention provides a test device for measuring the thermal conductivity of a conductor thin film suitable for a microelectromechanical system. The device has a simple structure, strong manufacturing process compatibility, and can accurately measure the thermal conductivity of the thin film under natural air convection conditions.

[0005] To achieve the above-mentioned invention objectives, the technical solution adopted by the present invention is as follows: A test device for measuring the thermal conductivity of a conductor thin film, comprising a substrate, an oxide layer, an anchor region, conductor thin film leads, a conductor thin film strip, heat dissipation beams, and electrodes. An oxide layer is provided on the substrate, an anchor region is provided on the oxide layer, electrodes are provided on the anchor region, and multiple anchor regions are used to fix the conductor thin film leads. The conductor thin film leads form multiple cantilever beam structures and are respectively connected to the anchor regions and the conductor thin film strip. Multiple heat dissipation beams are provided on the conductor thin film strip, and the multiple heat dissipation beams are uniformly arranged along the direction of the conductor thin film strip. The heat dissipation beams are connected to the anchor regions and fixed on the substrate through the oxide layer to improve the temperature uniformity of the conductor thin film strip during the heating process.

[0006] As an improvement of the present invention, a thermal bridge structure is formed by thermally conductive connection between the conductor thin film strip, the heat dissipation beams, and the anchor regions, which is used for rapid heat conduction and temperature distribution equalization.

[0007] As an improvement of the present invention, the lengths of the conductor thin film leads are the same and symmetrically distributed on one side of the conductor thin film strip to ensure a uniform thermal field in the heating area.

[0008] To ensure a more uniform temperature distribution of the conductor thin film strip, the cross-sectional size of the heat dissipation beams is reduced, the number of heat dissipation beams is increased, and at the same time, the overall structure is ensured to have sufficient mechanical rigidity. Therefore, the heat dissipation beams are composed of multiple uniform thin heat dissipation beams and one thick heat dissipation beam; to reduce the heat dissipation effect brought by the conductor thin film leads at both ends of the conductor thin film strip, the cross-sectional size of the thick heat dissipation beam increases as it gets closer to the center position to compensate for the enhanced heat dissipation demand in the central region of the conductor thin film strip.

[0009] Beneficial effects: By introducing a temperature equalization structure above the conductor thin film strip, the present invention effectively improves the temperature gradient problem caused by uneven local heating in the traditional test structure, realizes uniform control of the temperature field of the conductor thin film strip, and thus significantly improves the accuracy and stability of the thermal conductivity test. Compared with the existing test methods that require a vacuum environment or complex support structures, the structure of the present invention is simple, the manufacturing process is highly compatible with the existing MEMS surface processing technology, avoids deep etching treatment of the silicon substrate, and can be directly applied to the on-line test during the device manufacturing process. At the same time, the test device can work in a natural air convection environment without additional airtight devices or thermal isolation treatment, and has higher practicality and promotion value. Description of the Drawings

[0010] Figure 1 is the structural schematic diagram of the present invention;

[0011] Figure 2 is Figure 1 the split structural schematic diagram;

[0012] Figure 3 is the side view of the present invention;

[0013] Figure 4 It is the temperature distribution curve with and without a heat dissipation beam. Specific implementation mode

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] Example: As Figures 1 - 3 shown is an improved test structure for measuring the thermal conductivity of a conductor thin film. The shown test structure includes a substrate 1, an oxide layer 2, an anchor region 3, a conductor thin film lead 4, a conductor thin film strip 5, a heat dissipation beam 6, and an electrode 7. An oxide layer 2 is provided on the substrate 1, an anchor region 3 is provided on the oxide layer 2, an electrode 7 is provided on the anchor region 3. A plurality of anchor regions 3 are used to fix the conductor thin film leads 4. The conductor thin film leads form a plurality of cantilever beam structures, which are respectively connected to the anchor region 3 and the conductor thin film strip 5. A plurality of heat dissipation beams 6 are provided on the conductor thin film strip 5. The plurality of heat dissipation beams 6 are uniformly arranged along the direction of the conductor thin film strip 5. The heat dissipation beam 6 is connected to the anchor region 3 and fixed on the substrate 1 through the oxide layer 2 to improve the temperature uniformity of the conductor thin film strip 5 during the heating process.

[0016] As Figure 4 shown is the temperature distribution curve with and without a heat dissipation beam. After adding the heat dissipation beam, the temperature distribution on the conductor thin film strip is more uniform, thereby significantly improving the accuracy of thermal conductivity measurement.

[0017] The above are only the preferred implementation modes of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A test device for measuring the thermal conductivity of a conductor thin film, characterized in that, It includes a substrate (1), an oxide layer (2), an anchor region (3), a conductor thin film lead (4), a conductor thin film strip (5), a heat dissipation beam (6) and an electrode (7). An oxide layer (2) is provided on the substrate (1), an anchor region (3) is provided on the oxide layer (2), and an electrode (7) is provided on the anchor region (3). A plurality of anchor regions (3) are used to fix the conductor thin film leads (4). The conductor thin film leads form a plurality of cantilever beam structures, which are respectively connected to the anchor regions (3) and the conductor thin film strip (5). A plurality of heat dissipation beams (6) are provided on the conductor thin film strip (5). The plurality of heat dissipation beams (6) are uniformly arranged along the direction of the conductor thin film strip (5). The heat dissipation beams (6) are connected to the anchor regions (3) and fixed on the substrate (1) through the oxide layer (2) to improve the temperature uniformity of the conductor thin film strip (5) during the heating process.

2. The test device for measuring the thermal conductivity of a conductor thin film according to claim 1, characterized in that: A thermal bridge structure is formed by thermal conduction connection between the conductor thin film strip (5), the heat dissipation beam (6) and the anchor region (3) for rapid heat conduction and temperature distribution equalization.

3. The test device for measuring the thermal conductivity of a thin conductor film according to claim 1, characterized in that: The heat dissipation beam (6) is composed of a plurality of uniform thin heat dissipation beams and one thick heat dissipation beam. The cross-sectional dimension of the thick heat dissipation beam increases as it gets closer to the center position, reducing the heat dissipation effect brought by the conductor thin film lead (4) at both ends of the conductor thin film strip (5) to compensate for the increased heat dissipation demand in the central region of the conductor thin film strip (5).

4. The test device for measuring the thermal conductivity of a conductor thin film according to claim 1, wherein: The lengths of the conductor thin film leads (4) are the same and they are symmetrically distributed on one side of the conductor thin film strip (5) to ensure a uniform thermal field in the heating region.

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