INVESTIGATION OF BORON AND NITROGEN ION BEAM IMPLANTATION IN GOLD THIN FILMS FOR OHMIC MEMS SWITCH CONTACT IMPROVEMENT

Brice Arrazat (1) , Karim Inal (2) , Patrice Gergaud (3)

1 PS2-ENSMSE - Département Packaging et Supports Souples
2 CEMEF - Centre de Mise en Forme des Matériaux
3 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

Contact material and more precisely surface properties are a major issue for RF MEMS ohmic switch reliability. Shallow ion implantation of boron and nitrogen on gold thin film is investigated to increase surface hardness with a limited impact on Electrical Contact Resistance (ECR). The implantation energies were chosen to place the concentration peak of the implanted species at a depth of 100 nm. A microstructural analysis shows that the hardness increases with boron concentration due to a solid solution hardening mechanism, whereas in case of nitrogen, for concentration above 1%, the nitrogen precipitates into a nitride phase correlated to a hardness decrease. The ECR is measured using a Nanoindenter XP which experimental setup reproduces MEMS ohmic switch contact (from 100 μN to 1 mN applied loads under 1 mA). A notable result is obtained with a boron dose of 7.37 x 1016 ions/cm² at 90 keV into gold thin film: 50% hardness increase and 2.6 times higher ECR than pure gold.

Mots clés: Ohmic MEMS switch; Lifetime; Electrical contact resistance

Domaines: Matériaux et structures en mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]

Brice Arrazat, Karim Inal, Patrice Gergaud. INVESTIGATION OF BORON AND NITROGEN ION BEAM IMPLANTATION IN GOLD THIN FILMS FOR OHMIC MEMS SWITCH CONTACT IMPROVEMENT. Tansducers and Eurosensors XXVII, Jun 2013, Barcelona, Spain. ⟨emse-00840099⟩