The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 26, 2001
Filed:
Nov. 23, 1999
Olivier Lefort, Valence, FR;
Isabelle Thomas, Valence, FR;
Sextant Avionique, Velizy Villacoublay, FR;
Abstract
A process for the production of microsensors machined in silicon, and in particular accelerometers for applications of assisting with navigation in aircraft, and pressure sensors. In order to improve the production of certain active parts of the sensor, and in particular of a beam forming a resonator, which needs to have well-controlled width and thickness characteristics, the following procedure is adopted. A beam having a thickness equal to the desired final thickness, and a width greater than the desired final width, is produced by micromachining the silicon on a first plate, the beam being covered on its upper face by a mask defining the desired final width. The plate is assembled with another plate. The two faces of the beam are oxidized in order to cover them with a thin protective layer. The thin protective layer on the upper face is removed, by vertical directional etching, without removing the mask already present. The silicon in the area exposed by the preceding operation is attacked by a vertical directional etch on the upper face, until the entire part of the beam not protected by the mask is eliminated, and the beam having the desired width is thus formed.