The surface micromachining process of Robert Bosch GmbH has been used to fabricate a novel type of magnetic-field sensor. The Lorentz force, caused by the interaction of a current and an external magnetic field in a suspended surface micromachined conducting beam, laterally displaces the suspended structure. The displacement of the structure is converted into a capacitance change by comb-electrodes, which form a differential capacitor. An appropriate electronic circuitry measures the magnetic field by quantifying the displacement of the conducting beam. In order to increase sensitivity to magnetic fields, the magnitude of the deflection is increased by resonant operation in a vacuum ambient. The sensor obtains its vacuum environment by encapsulation with a new wafer bonding process. Prototype sensors with resonant frequencies in the range around 1300 Hz show Q-factors above 30. With these samples, relative magnetic sensitivities of 900 000 (V/A/spl middot/T) with a detection limit in the sub /spl mu/T-range are reported.
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机译：Robert Bosch GmbH的表面微加工工艺已用于制造新型的磁场传感器。由电流和外部磁场在悬浮表面微加工的传导束中的相互作用引起的洛伦兹力使悬浮结构横向移位。通过梳状电极将结构的位移转换为电容变化，从而形成差分电容器。适当的电子电路通过量化传导束的位移来测量磁场。为了增加对磁场的敏感性，通过在真空环境中的共振操作来增加偏转的幅度。该传感器通过采用新的晶圆键合工艺进行封装来获得其真空环境。共振频率在1300 Hz附近的原型传感器显示Q因子超过30。使用这些样本，相对磁敏度为900 000（V / A / spl middot / T），检测极限在sub / spl mu / T以内-范围被报告。
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