Method of manufacturing sensor

• US 5,616,523 A
• Filed: 04/02/1996
• Issued: 04/01/1997
• Est. Priority Date: 05/06/1993
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Laermer, Franz, Schilp, Andrea, Offenberg, Michael, Muenzel, Horst, Benz, Gerhard, Marek, Jiri, Bantien, Frank
• Primary Examiner(s): Bowers, Jr., Charles L.
• Assistant Examiner(s): Radomsky, Leon
• Application Number:
  US08/627,819
• Time in Patent Office: 364 Days
• Field of Search: 437/901, 437/927, 437/974, 437/921, 437/228, 148/DIG. 73, 148/DIG. 159, 73/718, 73/721, 73/724, 73/727, 73/777
• US Class Current: 438/50
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0817 for pivoting movement of the mass, e.g. in-plane pendulum
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends

Abstract

A method for manufacturing sensors from a multilayer plate with upper and lower monocrystalline silicon layers and an etching layer between them. The upper silicon layer is structured by the introduction of troughs therein extending down to the etching layer. Sensor structures, such as a bending beam that is used in an acceleration sensor, are created by etching the etching layer beneath a part of the silicon layer structured in this manner.

Claims

1. A method for manufacturing a sensor in a plate of monocrystalline silicon, comprising the steps of:

forming a multilayer plate in which an etching layer is arranged between an upper layer and a lower layer, the upper and lower layers being made of monocrystalline silicon and the etching layer being made of an insulating material selected from the group including silicon oxide, silicon nitride, and glass, wherein the step of forming the multilayer plate includes the steps of

joining two plates together, with at least one of the plates having, on a surface by which it is joined to the other plate, a layer of material the same as that of the etching layer, and

reducing the thickness of the upper silicon layer;

after forming the multilayer plate, forming a structure in the upper layer by introducing troughs that extend through the upper layer to the etching layers, wherein the structure includes

a bending member,

a mount attached to the bending member, and

at least two counterelectrodes; and

after forming the structure in the upper layer, removing a first portion of the etching layer by etching, a second portion of the etching layer remaining beneath the mount and the at least two counterelectrodes and anchoring the mount and the at least two counterelectrodes to the lower layer, the first portion of the etching layer being removed beneath the bending member, wherein the bending member is movable with respect to the mount in a direction parallel to a surface of the lower layer and between the at least two counterelectrodes in response to an acceleration only after the first portion of the etching layer is removed beneath the bending member, a distance between the bending member and the at least two counterelectrodes changing as a function of movement of the bending member.

2. The method according to claim 1, wherein the step of forming the structure in the upper layer includes the step of insulating parts of the upper layer from one another by introducing troughs and diffusion zones that extend through the upper layer to the etching layer.

3. The method according to claim 1, wherein the step of removing the etching layer beneath a part of the structure includes the step of applying an etching medium through the troughs to the etching layer beneath the part of the structure.

4. The method according to claim 1, wherein the step of removing the etching layer beneath a part of the structure includes the steps of:

introducing an etching opening into the lower silicon layer beneath the part of the structure; and

applying an etching medium to the etching layer through the etching opening.