Abstract:
A means for fabrication of solenoidal inductors interated in a semiconductor chip is provided. A solenoidal coil (50) is partially embedded in a deep well etched into the chip substrate (10). The non-embedded part (30) of the coil is fabricated as part of BEOL metallization layers (52). This allows for large cross-sectional area of the solenoid turns, tus reducing the turn-to-turn capacitive coupling. Because the solenoidal coils of this invention have a large diameter cross-section, the coil can be made with a large inductance value and yet occupy a small area of the chip. The farbication process includes etching of a deep cavity in the substrate after all the FEOL steps are completed; lining said cavity with a dielectric (14) followed by fabrication of the part of the coil (22) that will be embedded by deposition of a conductive material metal through a mask; deposition of dielectric (24 and 28) and planarization of the same by CMP. After planarization the fabrication of the remaining part (30) of the solenoidal coil is fabricated as part of the metallization in the BEOL (i.e. as line/vias of the BEOL). To further increase the cross section of the solenoidal coil, part of it may be built by electrodeposition through a mask on top of the BEOL layers.
Abstract:
A micro-electromechanical (MEM) RF switch provided with a deflectable membrane (60) activates a switch contact or plunger (40). The membrane incorporates interdigitated metal electrodes (70) which cause a stress gradient in the membrane when activated by way of a DC electric field. The stress gradient results in a predictable bending or displacement of the membrane (60), and is used to mechanically displace the switch contact (30). An RF gap area (25) located within the cavity (250) is totally segregated from the gaps (71) between the interdigitated metal electrodes (70). The membrane is electrostatically displaced in two opposing directions, thereby aiding to activate and deactivate the switch. The micro-electromechanical switch includes: a cavity (250); at least one conductive path (20) integral to a first surface bordering the cavity; a flexible membrane (60) parallel to the first surface bordering the cavity (250), the flexible membrane (60) having a plurality of actuating electrodes (70); and a plunger (40) attached to the flexible membrane (60) in a direction away from the actuating electrodes (70), the plunger (40) having a conductive surface that makes electric contact with the conductive paths, opening and closing the switch.
Abstract:
A micro-electromechanical switch (MEMS) having a deformable elastomeric element (1) which exhibits a large change in conductivity with a small amount of displacement. The deformable elastomeric element (1) is displaced by an electrostatic force that is applied laterally resulting in a small transverse displacement. The transversal displacement, in turn, pushes a metallic contact (7) against two conductive paths (5, 6), allowing passage of electrical signals. The elastomer (1) is provided on two opposing sids with embedded metallic elements (9, 10), such as impregnated metallic rods, metallic sheets, metallic particles, or conductive paste. Actuation electrodes (18, 8) are placed parallel to the conductive sides of the elastomer. A voltage applied between the conductive side of the elastomer and the respective actuation electrodes (18, 8) generate the electrostatic attractive force that compresses the elastomer (1), creating the transverse displacement that closes the MEMS. The elastomeric based MEMS extends the lifetime of the switch by extending fatigue life of the deformable switch elements.