# US 2014/0197502 A1 · Comb MEMS Device and Method of Making a Comb MEMS Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197502 A1 - Document ID: US20140197502A1 - Status: Published application - Kind: A1 - Application number: 13/743,306 - Filed: 2013-01-16 - Published: 2014-07-17 - Earliest claimed: 2013-01-16 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Alfons Dehe - Web page: https://patentgrep.com/patent/US20140197502A1 ## CPC - B81B 3/0005: {Anti-stiction coatings} - B81B 3/001: {Structures having a reduced contact area, e.g. with bumps or with a textured surface} - B81C 1/0015: {Cantilevers (switches using MEMS H01H1/0036; electrostatic relays using micromechanics H01H59/0009; microelectro-mechanical resonators H03H9/02244)} - B81C 1/00968: {Methods for breaking the stiction bond} - B81B 2201/0257: Microphones or microspeakers - B81B 2203/0136: Comb structures - B81C 2201/112: Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts - H04R 19/02: Loudspeakers (H04R19/01 takes precedence) - B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00) - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A MEMS device and a method to manufacture a MEMS device are disclosed. An embodiment includes forming trenches in a first main surface of a substrate, forming conductive fingers by forming a conductive material in the trenches and forming an opening from a second main surface of the substrate thereby exposing the conductive fingers, the second main surface opposite the first main surface. ## Claims ### Claim 1 A method for making a MEMS device, the method comprising: forming trenches in a first main surface of a substrate; forming conductive fingers by forming a conductive material in the trenches; and forming an opening from a second main surface of the substrate thereby exposing the conductive fingers, the second main surface opposite to the first main surface. ### Claim 2 (depends on 1) The method according to claim 1, further comprising forming an anti-sticking coating over the conductive fingers. ### Claim 3 (depends on 2) The method according to claim 2, wherein the anti-sticking coating comprises hexamethyldisilazane (HDMS) or a self-assembling monolayer (SAM) based on octadecyltrichlorosilance (OTS) or perflourodecyltrichlorosilance (FDTS). ### Claim 4 (depends on 2) The method according to claim 2, wherein the anti-sticking coating comprises a hydrophobic monolayer. ### Claim 5 (depends on 1) The method according to claim 1, further comprising forming structures in sidewalls of the trenches. ### Claim 6 (depends on 5) The method according to claim 5, wherein each trench comprises a first structure in a first sidewall and a second structure in a second sidewall. ### Claim 7 (depends on 5) The method according to claim 5, wherein only every other trench comprises structures in the sidewalls. ### Claim 8 (depends on 1) The method according to claim 1, further comprising forming an insulating layer on a bottom and sidewall surfaces of the trenches before forming the conductive fingers. ### Claim 9 (depends on 8) The method according to claim 8, wherein forming the opening from the second main surface comprises: performing a first etch process to remove a portion of the substrate; and performing a second etch process to remove the insulating layer around the conductive fingers, the first etch process being different than the second etch process. ### Claim 10 (depends on 1) The method according to claim 1, wherein forming the conductive fingers comprises forming polysilicon in the trenches. ### Claim 11 (depends on 10) The method according to claim 10, wherein forming the conductive fingers further comprises forming a dielectric material in the trenches. ### Claim 12 (depends on 11) The method according to claim 11, wherein forming the polysilicon and the dielectric material comprises forming a sandwich structure. ### Claim 13 (depends on 11) The method according to claim 11, wherein forming the dielectric material comprises forming silicon nitride. ### Claim 14 (depends on 10) The method according to claim 10, wherein forming polysilicon in the trenches comprises forming in-situ doped polysilicon in the trenches. ### Claim 15 (depends on 1) The method according to claim 1, wherein forming the conductive fingers comprises forming a metallic material in the trenches. ### Claim 16 (depends on 1) The method according to claim 1, wherein forming the conductive fingers comprises forming a metallic material and a dielectric material in the trenches. ### Claim 17 (depends on 16) The method according to claim 16, wherein forming the metallic material and the dielectric material comprises forming a sandwich structure. ### Claim 18 (depends on 1) The method according to claim 1, further comprising forming pads and a passivation layer on the first main surface of the substrate. ### Claim at position 19 19-34. (canceled) ### Claim 35 A method of forming a MEMS device, the method comprising: forming a stator comprising a first set of fingers; forming a movable element comprising a second set of fingers, wherein the first set of fingers and the second set of fingers are interdigitated; and forming an anti-sticking mechanism between the first set of fingers and the second set of fingers. ### Claim 36 (depends on 35) The method according to claim 35, wherein the second set of fingers is formed only on a first side of the movable element. ### Claim 37 (depends on 35) The method according to claim 35, wherein the second set of fingers is formed only on a first side and a second side of the movable element. ### Claim 38 (depends on 35) The method according to claim 35, wherein the second set of fingers is formed on all sides of the movable element or along a perimeter of the movable element. ### Claim 39 (depends on 35) The method according to claim 35, wherein the first set of fingers and the second set of fingers comprise conductive fingers. ### Claim 40 (depends on 39) The method according to claim 39, wherein the conductive fingers comprise polysilicon fingers. ### Claim 41 (depends on 39) The method according to claim 39, wherein the conductive fingers comprise metallic fingers. ### Claim 42 (depends on 35) The method according to claim 35, wherein forming the movable element comprises forming a cantilever. ### Claim 43 (depends on 35) The method according to claim 35, wherein forming the anti-sticking mechanism comprises forming an anti-sticking coating. ### Claim 44 (depends on 35) The method according to claim 35, wherein the anti-sticking coating comprises a hexamethyldisilazane (HDMS) or a self-assembling monolayer (SAM) based on octadecyltrichlorosilance (OTS) or perflourodecyltrichlorosilance (FDTS). ### Claim 45 (depends on 35) The method according to claim 35, wherein forming the anti-sticking mechanism comprises forming an anti-sticking structure, the anti-sticking structure protruding out from at least one of the first set of fingers and the second set of fingers.