A micromachined angled Hall magnetic field sensor using novel in-cavity patterning

This paper will present a novel technique used in the fabrication of a three-dimensional magnetic field vector sensor based on an angled Hall plate structure. This new sensor design relies on simultaneously detecting all magnetic field vector components using Hall plates that are imbedded into the silicon ⟨111⟩ sidewalls of a bulk micromachined cavity. A shadow mask technique was developed for the in-cavity patterning necessary for doping and metalization. This mask is made from standard thin film layers deposited onto a previously ion-etched silicon surface. Therefore, the patterned layers also served as the etch mask to expose the silicon for anisotropic etching. This paper will concentrate on how an angled Hall device (AHD) can be fabricated using this technique