Sealed force sensor with etch stop layer

A microelectromechanical system (MEMS) force sensor, comprising:

• a sensor die configured to receive an applied force, the sensor die comprising a first substrate and a second substrate, wherein a cavity is formed in the first substrate, and wherein at least a portion of the second substrate defines a deformable membrane;
• an etch stop layer arranged between the first substrate and the second substrate;
• a sensing element arranged on a surface of the second substrate, wherein the sensing element is configured to convert a strain on the surface of a membrane substrate to an analog electrical signal that is proportional to the strain;
• wherein the etch stop layer is configured for precise thickness control of the deformable membrane of the membrane substrate;
• wherein an etch rate of the etch stop layer is different than an etch rate of the first substrate;
• and
• wherein an etch rate ratio between the etch rate of the first substrate and the etch rate of the etch stop layer is between 50 and 150.