PROCESS FOR MANUFACTURING A MICRO-ELECTRO-MECHANICAL DEVICE, IN PARTICULAR A MOVEMENT SENSOR WITH CAPACITIVE CONTROL/DETECTION, AND MEMS DEVICE

Process for manufacturing a MEMS device (30), wherein a first structural layer (41) of a first thickness is formed on a substrate (31); first trenches (58) are formed through the first structural layer (41); masking regions (60') separated by first openings (62) are formed on the first structural layer; a second structural layer (42) of a second thickness is formed on the first structural layer (41) in direct contact with the first structural layer (41) at the first openings (62) and forms here, together with the first structural layer, thick structural regions (64) having a third thickness equal to the sum of the first and the second thicknesses; a plurality of second trenches (67) are formed through the second structural layer (42), over the masking regions (60'); and third trenches (68) are formed through the first and the second structural layers (41, 42) by removing selective portions of the thick structural regions (64) .