# US 8,783,107 B2 · Resonant inertial microsensor with variable thickness produced by surface engineering > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,107 B2 - Document ID: US8783107B2 - Status: Granted - Kind: B2 - Application number: 11/724,795 - Filed: 2007-03-15 - Published: 2007-09-27 - Granted: 2014-07-22 - Earliest claimed: 2006-03-27 - Assignees: Commissariat a l'Energie Atomique - Applicants: Philippe Robert; Laurent Duraffour - Inventors: Philippe Robert; Laurent Duraffour - Web page: https://patentgrep.com/patent/US8783107B2 ## CPC - G01P 15/097: by vibratory elements - G01C 19/574: the devices having two sensing masses in anti-phase motion - G01C 19/5755: the devices having a single sensing mass - G01C 19/5769: Manufacturing; Mounting; Housings - G01P 15/0802: {Details} - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## Abstract The invention relates to a surface-type MEMS resonant sensor, comprising a resonator (4) with excitation in a plane, which sensor comprises: a first, so-called thick area (2), having a first thickness (E1), forming a seismic mass; and a second, thin area (4), having a second thickness (E2), lower than the first, for detection. ## Claims ### Claim 1 A MEMS resonant sensor comprising: a first area fabricated in a substrate using micromachining technology, the first area having a first thickness, wherein the first area forms at least one seismic mass movable in a plane parallel to a substrate surface, and said first area being comprised of a first upper surface and a first lower surface, both extending parallel to said substrate surface; a second area fabricated in the substrate using micromachining technology, the second area having a second thickness, wherein the second thickness is less than half the first thickness, and wherein the second area forms a resonator, said resonator comprising a second upper surface and a second lower surface, the second upper surface and the second lower surface both extending parallel to said substrate surface, said resonator configured for capacitive excitation, said resonator being for detecting a movement of said seismic mass in said plane parallel to said substrate; and a hinge fabricated in the substrate using micromachining technology, the hinge to maintain the at least one seismic mass in a plane parallel to the substrate surface, said hinge comprising a third upper surface and a third lower surface, the third upper surface and the third lower surface both extending parallel to said substrate surface, the hinge and the resonator being anchored at one end to a same surface of said seismic mass, said same surface being perpendicular to said substrate surface, and at another end to said substrate, said first upper surface, said second upper surface and said third upper surface being in a same common plane parallel to said substrate surface, or said first lower surface, said second lower surface and said third lower surface being in a same common plane parallel to said substrate surface. ### Claim 2 (depends on 1) Sensor according to claim 1, wherein the sensor is an accelerometer, and wherein the first area has a surface S smaller than 0.1 mm2. ### Claim 3 (depends on 1) Sensor according to one of claim 1, wherein the first and second areas are formed in the superficial semiconductor layer of a SOI substrate. ### Claim 4 (depends on 1) Sensor according to claim 1, wherein the hinge comprises a third area fabricated in the substrate. ### Claim 5 (depends on 4) Sensor according to claim 4, wherein the third area has a thickness between that of the first area and that of the second area. ### Claim 6 (depends on 4) Sensor according to claim 4, wherein the third area has a thickness equal to that of the first area. ### Claim 7 (depends on 4) Sensor according to claim 4, wherein the third area has a thickness equal to that of the second area. ### Claim 8 (depends on 1) Sensor according to claim 1, further comprising mechanical stops to limit the movement of the seismic mass. ### Claim 9 (depends on 1) Sensor according to claim 1, further comprising means for digital filtering and/or digital processing of a signal for detection of the excitation. ### Claim 10 (depends on 1) A surface detection device comprising a first MEMS resonant sensor according to claim 1 and a second MEMS resonant sensor according to claim 1.