Mems device with reduced stress in the membrane and manufacturing method
AssigneeWolfson Microelectronics plc
InventorsRichard Ian Laming, Colin Robert Jenkins, Anthony Bernard Traynor
Life of this patent
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Abstract
A MEMS device comprises a membrane layer and a back-plate layer formed over the membrane layer. The membrane layer comprises an outer portion and an inner portion raised relative to the outer portion and a sidewall for connecting the inner portion and the outer portion. The sidewall is non-orthogonal to the outer portion.
Claims44
A micro-electrical-mechanical system (MEMS) device comprising:
- a membrane layer;
- a back-plate layer formed over the membrane layer;
- wherein the membrane layer comprises:
- an outer portion;
- an inner portion raised relative to the outer portion;
- and
- a sidewall for connecting the inner portion and the outer portion;
- wherein the sidewall is non-orthogonal to the outer portion.
A method of fabricating a micro-electrical-mechanical system (MEMS) device having a membrane layer, the membrane layer having an inner portion and an outer portion, the method comprising the steps of:
- depositing a sacrificial layer;
- shaping the sacrificial layer to leave a portion of sacrificial material to define the inner portion of the membrane layer, wherein the edges of the portion of sacrificial material are sloped;
- and
- depositing the membrane layer over the portion of sacrificial material.
A method of fabricating a micro-electrical-mechanical system (MEMS) device having a back-plate layer, the back-plate layer having an upper portion and a lower portion, the method comprising the steps of:
- depositing a sacrificial layer;
- shaping the sacrificial layer to leave a portion of sacrificial material, wherein the edges of the portion of sacrificial material are sloped;
- and
- depositing the back-plate layer.
A micro-electrical-mechanical system (MEMS) device comprising:
- a membrane layer;
- a back-plate layer formed over the membrane, the back-plate layer comprising an inner portion and an outer portion, and a sidewall connecting the outer portion and the inner portion;
- wherein the inner portion of the back-plate layer is spaced apart from the membrane layer, and wherein the membrane layer is connected to at least the sidewall of the back-plate layer.
A method of fabricating a micro-electrical-mechanical system (MEMS) device, the method comprising the steps of:
- forming a membrane layer having an inner portion and an outer portion, with a sidewall connecting the inner portion and the outer portion;
- depositing a sacrificial layer over the inner portion of the membrane layer;
- and
- depositing the back-plate layer over the sacrificial layer, and the sidewall and outer portion of the membrane layer.
Dependencies are inferred from the claim text.