Abstract
This paper develops the technologies of mechanical characterization of CMOS-MEMS devices, and presents a robust algorithm for extracting mechanical properties, such as Young’s modulus, and mean stress, through the external electrical circuit behavior of the micro test-key. An approximate analytical solution for the pull-in voltage of bridge-type test-key subjected to electrostatic load and initial stress is derived based on Euler’s beam model and the minimum energy method. Then one can use the aforesaid closed form solution of the pull-in voltage to extract the Young’s modulus and mean stress of the test structures. The test cases include the test-key fabricated by a TSMC 0.18 μm standard CMOS process, and the experimental results refer to Osterberg’s work on the pull-in voltage of single crystal silicone microbridges. The extracted material properties calculated by the present algorithm are valid. Besides, this paper also analyzes the robustness of this algorithm regarding the dimension effects of test-keys. This mechanical properties extracting method is expected to be applicable to the wafer-level testing in micro-device manufacture and compatible with the wafer-level testing in IC industry since the test process is non-destructive.
Highlights
Due to the excellent development of the complementary metal oxide semiconductor (CMOS)technology, many micro-electromechanical systems (MEMS) devices such as comb-fingers [1], micro-mirrors [2], and resonators [3], the so-called CMOS-MEMS, can be fabricated by standardCMOS processes
Characterization of the mechanical properties of CMOS-MEMS devices is important since their performance depends on the constitutive properties of the thin film made by the CMOS process
Cases but with a large standard deviation for small ΔL cases in two kinds of common structural materials, such as the material made by the TSMC 0.18 μm standard CMOS process, and mono-crystalline silicon in (100) and (110) orientations
Summary
Technology, many micro-electromechanical systems (MEMS) devices such as comb-fingers [1], micro-mirrors [2], and resonators [3], the so-called CMOS-MEMS, can be fabricated by standard. Apart from the electrical testing of circuits, the MEMS-side still requires the mechanical testing of micro-sensing or -actuating components. There is no standard mechanical testing method for CMOS-MEMS devices. Characterization of the mechanical properties of CMOS-MEMS devices is important since their performance depends on the constitutive properties of the thin film made by the CMOS process. It is known that the properties of thin films are different from those of bulk materials, depending on the fabrication process. Large residual stress may induce failure of the micro-devices and circuits. The material properties, such as Young’s modulus and residual stress, should be controlled as early as possible to ensure the repeatability for each device
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
