Temperature-dependent coefficient of thermal expansion of silicon nitride films used in microelectromechanical systems
Materials Research Society Symposium - Proceedings
Microelectromechanical systems (MEMS) have potential application in high temperature environments such as in thermal processing of microelectronics. The MEMS designs require an accurate knowledge of the temperature dependent thermomechanical properties of the materials. Techniques used at room temperature often cannot be used for high-temperature property measurements. MEMS test structures have been developed in conjunction with a novel imaging apparatus designed to measure either the modulus of elasticity or thermal expansion coefficient of thin films at high temperatures. The MEMS test structure is the common bi-layered cantilever beam which undergoes thermally induced deflection at high temperatures. An individual cantilever beam on the order of 100 μm long can be viewed up to approximately 800°C. With image analysis, the curvature of the beam can be determined; and then the difference in coefficient of thermal expansion between the two layers can be determined using numerical modeling. The results of studying silicon nitride films on silicon oxide are presented for a range of temperatures.
Bargmann, M., Kumpel, A., Tada, H., Nieva, P., Zavracky, P., Miaoulis, I., & Wong, P. (2000). Temperature-dependent coefficient of thermal expansion of silicon nitride films used in microelectromechanical systems. Materials Research Society Symposium - Proceedings, 605, 235-240. Retrieved from https://docs.rwu.edu/seccm_fp/137