[17a-B1-1~7] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

9:30 AM - 9:45 AM JST(12:30 AM - 12:45 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[17a-B1-3] Suppression of Proof-Mass Geometry on Warpage in Highly Sensitive Gold Single-Axis MEMS Accelerometers

〇(B)Chihaya Mukaide¹, Devi Srujana Tenneti¹, Kisuke Miyado¹, Torauto Yamada¹, Katsuyuki Machida¹, Tomoyuki Kurioka¹, Tso-Fu Mark Chang¹, Masato Sone¹, Yoshihiro Miyake¹, Hiroyuki Ito¹ (1.TokyoTech.)

Keywords:

MEMS accelerometer,high sensitivity,Au proof-mass

This paper describes a method for suppressing proof-mass warpage with a high-sensitivity Au proof-mass single-axis MEMS accelerometer. We have been developing highly sensitive gold single-axis MEMS accelerometers for micro-g (1.0g=9.8m/s²) level sensing, which means that the Brownian noise must be less than 1μg/√Hz. On the other hand, there is a problem with warping in the proof-mass during 300℃ annealing. In this paper, we focus on the shape and the thickness of the proof-mass as methods to suppress the warpage and propose an octagonal proof-mass as a new shape. From the FEA simulation results, it is revealed that adopting an octagonal proof-mass can suppress warpage better than increasing the thickness of the proof-mass. Based on this, we fabricate an octagonal gold proof-mass single-axis accelerometer. It is confirmed that the warpage is suppressed, and a Brownian noise of 0.179μg/√Hz is obtained. In conclusion, the octagonal proof-mass will be useful for the design of highly sensitive gold single-axis MEMS accelerometers.