MEMS integrated pressure sensor devices having isotropic cavitites and methods of forming same

A device comprising:

• a membrane of a first micro-electromechanical (MEMS) device;
• a first sealed cavity over and aligned with the membrane, wherein a first surface of the membrane is exposed to a first pressure level of the first sealed cavity;
• a first substrate comprising a second cavity under and aligned with the membrane, wherein the second cavity comprises:
• a first portion extending partially into the first substrate, wherein a material of the first substrate is disposed under the first portion of the second cavity;
• and
• a second portion connected to the first portion, wherein the second portion extends lower than the first portion to extend through the first substrate and expose a second surface of the membrane to an ambient pressure level;
• a first MEMS structure disposed in the first sealed cavity;
• and
• a second MEMS structure adjacent the first MEMS structure and disposed in a third sealed cavity, at least a portion of the third sealed cavity is disposed in the first substrate, and wherein the third sealed cavity comprises an upper portion and a lower portion wider than the upper portion.

A device comprising:

• a micro-electromechanical (MEMS) portion comprising:
• a membrane of a first MEMS device;
• and
• a first MEMS structure higher than the membrane, wherein the first MEMS structure is part of a second MEMS device;
• a first substrate bonded to the MEMS portion, wherein a first surface of the membrane is exposed to ambient pressure by a first cavity extending through the first substrate;
• and
• a second substrate bonded to the MEMS portion, wherein the second substrate and the MEMS portion define a second cavity and a third cavity, and wherein:
• a second surface of the membrane is exposed to a sealed pressure level of the second cavity;
• and
• the first MEMS structure is disposed in the third cavity.