Abstract: A method for fabricating an electrostatic microswitch has the steps of depositing a silicon nitride layer over a silicon substrate with an opening therethrough to expose the planned sacrificial layer region; oxidation to form a silicon dioxide sacrificial layer; phosphorus ion implantation into the sacrificial layer; forming a phosphorus-doped polysilicon microbeam of the microswitch and its electrode contacts; lateral etching all of the silicon dioxide sacrificial layer in buffered hydrofluoric acid to form an air gap between the microbeam and the substrate; rinsing the structure in DI water, and then in methanol; and drying the structure by a warm nitrogen flow.

Abstract: A magnetic-field sensor has an array of split-drain transistors connected in parallel, each having a first, a second, and a third drain electrode, and a negative reference current generating transistor. A biasing circuit is utilized to bias the split-drain transistors in the saturated state, and to actuate the negative reference current generating transistor to generate a negative reference current. A first, a second, and a third current mirror are all controlled by a reference voltage. The second current mirror is coupled to the second drain electrode of each of the split-drain transistors to keep the reference voltage at a reference level. The first current mirror is coupled to the first drain electrode of each of the split-drain transistors to generate a first sensed current, and the third current mirror is coupled to the third drain electrode of each of the split-drain transistors to generate a second sensed current.