Cirrus Logic Inc.

Mark Hesketh

Tsjerk Hans Hoekstra

John Laurence Pennock

James Thomas Deas

Jean Pierre Lasseuguette

This application relates to an integrated circuit die () comprising a MEMS transducer structure () integrated with associated electronic circuitry (). The electronic circuitry comprises a plurality of transistors and associated interconnections and is formed in a first area () of the die from a first plurality () of layers, e.g. formed by CMOS metal () and dielectric () layers and possibly doped areas () of substrate (). The MEMS transducer structure is formed in a second area () of the die and is formed, at least partly, from a second plurality () of layers which are separate to the first plurality of layers. At least one filter circuit () is formed from said second plurality of layers overlying the plurality of transistors of the electronic circuitry (). The second plurality of layers comprise at least a first metal layer () which is patterned to form a first electrode of the MEMS transducer and at least a resistor, capacitor electrode or inductor element () of the filter circuit.

Integrated MEMS transducer and circuitry

This application relates to MEMS devices, especially MEMS capacitive transducers and to processes for forming such MEMS transducer that provide increased robustness and resilience to acoustic shock. The application describes a MEMS transducer having a flexible membrane () supported relative to a first surface of a substrate () which has one or more cavities therein, e.g. to provide an acoustic volume. A stop structure () is positioned so as to be contactable by the membrane when deflected so as to limit the amount of deflection of the membrane. The stop structure defines one or more openings to the one or more substrate cavities and comprises at least one narrow support element () within or between said one or more openings. The stop structure thus limits the amount of membrane deflection, thus reducing the stress experienced at the edges and prevents the membrane from contacting a sharp edge of a substrate cavity. As the stop structure comprises narrow support elements any performance impact on the transducer is limited.

Growing community of inventors

Edinburgh, United Kingdom

Mark Hesketh