What is MEMS Technology?

What is MEMS ? What is MEMS ? Micro Electro Mechanical Systems – micro scale dimensions (1mm = 1000 microns) – electrical and mechanical features – systems (features combined to perform a function) MEMS fabrication techniques – Originally used IC (computer chip) fabrication techniques and materials – More MEMS-specific fabrication techniques and materials are now in use MEMS is an enabling technology –Smaller device size –Batch processing for low cost, uniform production –Distributed device placement –More precise sensing 4000 die per 6 inch wafer

Why is MEMS useful? Sensors and Actuators - two classes of MEMS – Sensors - measure the environment  SMALL => interfere less with the environment it is measuring  SMALL => redundancy, batch fabricated, … – Actuators - perform work on the environment  SMALL => small motion but very precise  SMALL => can be placed in small spaces

How are MEMS made? Surface Micromachining - additive process (2-D) –Create device by adding materials on top of a wafer –Easily mixed with IC fabrication techniques –Limited to film thickness less than 4 microns (human hair microns, IC gate ~ 0.15 microns) –Typically used for high volume, low precision, low cost devices Bulk Micromachining - subtractive process (3-D) –Create device by etching material out of a wafer –Distinct processes and materials from IC fabrication –Flexible for design of diverse device features sizes –Advantageous for high precision sensors/actuators