A new method for improving piezoresistive response of thin (less than 1 µm) cantilevers with Argon implantation is described. Argon implantation is used to damage the atomic structure of one side of the cantilever. Test cantilevers have a thickness of less than 500 nm while the length and width are 60 µm and 30 µm respectively. For a total implanted dose of 35×10¹⁵ ions/cm² maximum displacement, the sensitivity obtained is 8.24×10^-7 [1/Å] which is 82% of the theoretical maximum. Force sensitivity is found to be 3.5×10^-3 [1/µN].

References :
Murat Gel, Isao Shimoyama, “Sub-Micron Thick High Sensitive Piezoresistive Cantilevers by Boron Etch Stop and Argon Implantation,” 16th IEEE International Micro Electro Mechanical Systems Conference (MEMS '03), pp. 494-497, Kyoto, Japan, Jan. 19-23, 2003. [Proceedings]

Murat Gel, Isao Shimoyama, “Force Sensing Sub-Micrometer Thick Cantilevers with Ultra-Thin Piezoresistors by Rapid Thermal Diffusion,” Journal of Micromechanics and Microengineering, vol. 14, no. 3, pp. 423-428, 2004. [Paper]