Evaluation of platinum as a structural thin film material for RF-MEMS devices Export

@article{Ekkels:2009, abstract = {Surface micromachined metal armatures are commonly used for MEMS applications of which RF-MEMS is the most well known. In most cases metals with a high conductivity, such as aluminum or gold, are used. These metals often have a low melting point and therefore have a low thermal stability and show plastic deformation of the structures at relatively low temperatures (\<200 degC). High melting point metals, such as platinum, are expected to show plastic deformation only at higher temperatures which makes them interesting for use as a structural layer in RF-MEMS devices. In this paper, we present a technology to realize suspended platinum structures by means of surface micromachining. An improved lift-off process allows patterning 1 um Pt films on a polyimide sacrificial layer. A comparison of the characteristics and armature resonance frequencies between RF-MEMS switches with Pt armatures and AlCu0.5\% alloy armatures reveals an increased thermal stability for the former up to at least 250 degC. This enables zero-level packaging of switches at relative high temperatures without affecting their performances. The lower conductivity of Pt compared to AlCu0.5\% does not lead to a significant increase in RF losses. Implementing AlN as a dielectric material, the Pt-based capacitive shunt switches reported in this paper showed lifetimes in excess of 5x107 cycles under standard testing conditions.}, author = {Ekkels, P. and Rottenberg, X. and Puers, R. and Tilmans, H. A. C.}, citeulike-article-id = {4636685}, citeulike-linkout-0 = {http://dx.doi.org/10.1088/0960-1317/19/6/065010}, doi = {10.1088/0960-1317/19/6/065010}, journal = {Journal of Micromechanics and Microengineering}, keywords = {materials, mems, mems-switch, rf-mems}, number = {6}, pages = {065010+}, posted-at = {2009-05-26 17:03:46}, priority = {2}, title = {Evaluation of platinum as a structural thin film material for RF-MEMS devices}, url = {http://dx.doi.org/10.1088/0960-1317/19/6/065010}, volume = {19}, year = {2009} }

TY - JOUR ID - Ekkels:2009 L3 - citeulike-article-id:4636685 N2 - Surface micromachined metal armatures are commonly used for MEMS applications of which RF-MEMS is the most well known. In most cases metals with a high conductivity, such as aluminum or gold, are used. These metals often have a low melting point and therefore have a low thermal stability and show plastic deformation of the structures at relatively low temperatures (<200 degC). High melting point metals, such as platinum, are expected to show plastic deformation only at higher temperatures which makes them interesting for use as a structural layer in RF-MEMS devices. In this paper, we present a technology to realize suspended platinum structures by means of surface micromachining. An improved lift-off process allows patterning 1 um Pt films on a polyimide sacrificial layer. A comparison of the characteristics and armature resonance frequencies between RF-MEMS switches with Pt armatures and AlCu0.5% alloy armatures reveals an increased thermal stability for the former up to at least 250 degC. This enables zero-level packaging of switches at relative high temperatures without affecting their performances. The lower conductivity of Pt compared to AlCu0.5% does not lead to a significant increase in RF losses. Implementing AlN as a dielectric material, the Pt-based capacitive shunt switches reported in this paper showed lifetimes in excess of 5x107 cycles under standard testing conditions. IS - 6 JF - Journal of Micromechanics and Microengineering TI - Evaluation of platinum as a structural thin film material for RF-MEMS devices VL - 19 SP - 065010 KW - materials KW - mems KW - mems-switch KW - rf-mems AU - Ekkels, P AU - Rottenberg, X AU - Puers, R AU - Tilmans, HAC PY - 2009/// UR - http://dx.doi.org/10.1088/0960-1317/19/6/065010 ER -