公开(公告)号：DE69726718T2

公开(公告)日：2004-10-07

申请号：DE69726718

申请日：1997-07-31

Applicant: ST MICROELECTRONICS SRL

Inventor： FERRARI PAOLO ,  VIGNA BENEDETTO ,  MONTANINI PIETRO ,  FERRERA MARCO

IPC: G01P9/04 ,  B81B3/00 ,  G01C19/56 ,  G01P15/08 ,  G01P15/125 ,  H01L21/762 ,  H01L21/764 ,  H01L41/08

Abstract: To increase the sensitivity of the sensor, the movable mass (40) forming the seismic mass is formed starting from the epitaxial layer (13) and is covered by a weighting region of tungsten (26c) which has high density. To manufacture it, buried conductive regions (2) are formed in the substrate (1); then, at the same time, a sacrificial region is formed in the zone where the movable mass is to be formed and oxide insulating regions (9a-9d) are formed on the buried conductive regions (2) so as to cover them partially; the epitaxial layer (13) is then grown, using a nucleus region; a tungsten layer (26) is deposited and defined and, using a silicon carbide layer (31) as mask, the suspended structure (40) is defined; finally the sacrificial region is removed, forming an air gap (38).