Manufacturing method for the miniaturization of silicon bulk-machined pressure sensors

Abstract

A method for manufacturing micro pressure sensors and the structure of the micro pressure sensor are disclosed. A bulk silicon wafer is provided to have an upper face formed thereon a desired circuit arrangement including a plurality of contact pads. The bulk silicon wafer defines a cutoff in an upper side portion thereof. A glass substrate is then provided to have an upper face defined therein a shallow cavity. The glass substrate has a plurality of contact pads formed on the upper face thereof. The bulk silicon wafer is bonded to the glass substrate in such a manner that the upper face of the bulk silicon wafer is attached to the upper face of the glass substrate and the plurality of contact pads on the bulk silicon wafer securely attach to the plurality of contact pads on the glass substrate. An etching process is undertaken to reduce the bulk silicon wafer down to a thin membrane. Finally the bulk silicon wafer is etched to expose the contact pads on said glass substrate. The size of the micro pressure sensor produced by the method can be miniaturized because the cavity is so shallow such that the side faces of the cavity are not significantly inclined with respect to the upper face of the glass substrate even though undercut in the side faces may be encountered due to the side etching effect whereby no chip area is wasted and the miniaturization of the silicon bulk-machined sensors is possible.

Dependencies are inferred from the claim text.