Methodology and system for wafer-level testing of mems pressure sensors

A method for testing a plurality of pressure sensors located on a first side of a substrate portion of a device wafer, each of said pressure sensors including a diaphragm and a cavity, said diaphragm being formed in at least one wall surrounding said cavity, and said method comprises:

• retaining said device wafer in a wafer chuck of a test system such that said device wafer is substantially parallel to an X-Y plane of said test system, wherein said device wafer chuck is coupled to a movable X-Y stage;
• indexing said X-Y stage to place one of said plurality of pressure sensors in proximity to a nozzle of said test system;
• moving at least one of said nozzle and said device wafer along a Z-axis substantially perpendicular to said X-Y plane to position said diaphragm of said one of said pressure sensors in proximity to said nozzle;
• sealing a cavity associated with said one of said pressure sensors;
• applying a pneumatic pressure stimulus from an outlet of said nozzle to said diaphragm via said cavity, said applying occurring following said sealing;
• and
• measuring a cavity pressure within said cavity in response to said applying said pneumatic pressure stimulus, said measuring occurring while a port into said cavity remains sealed.

A test system for testing pressure sensors on a device wafer, each of said pressure sensors including a diaphragm, and said test system comprising:

• a table for retaining said device wafer;
• a nozzle;
• an actuator for placing said nozzle and said diaphragm of one of said pressure sensors in proximity to one another;
• a fluid supply line in communication with said nozzle for providing a pneumatic pressure stimulus, said pneumatic pressure stimulus being applied to said diaphragm via an outlet of said nozzle;
• a pressure transducer for measuring a pressure within said fluid supply line in response to said pneumatic pressure stimulus, said pressure being indicative of a cavity pressure within a cavity associated with said one of said pressure sensors;
• and
• a controller configured to receive said pressure and ascertain functionality of said one of said pressure sensors in response to said pressure.