Transducer structure employing vertically walled diaphragms with quasi rectangular active areas
AssigneeKulite Semiconductor Products, Inc.
InventorsJoseph R. Mallon, Anthony D. Kurtz
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Abstract
There is disclosed a rectangular diaphragm employing a quasi rectangular active area. The diaphragm as configured has an aspect ratio which is the length to width ratio of greater than 3:1. The active area of the diaphragm, which is the area which most readily deflects upon application of a force to the diaphragm, is formed by an anisotropic etching technique to provide steep vertical sidewalls. The diaphragm structure thus described exhibits as a response to an applied force or pressure, a maximum longitudinal stress and a minimum transverse stress and can accommodate piezoresistive elements located within the active area of the diaphragm.
Claims6
A diaphragm for a pressure transducer for use with piezoresistors comprising:
- a rectangular planar monocrystalline semiconductor member having a predetermined crystallographic orientation of (110), having located on a major surface thereof a cavity of a parallelogram configuration defining an active diaphragm area with said cavity characterized in having steep sloped vertical walls formed by an anisotropic etching with the said walls aligned to the <111>
- plane of said monocrystalline semiconductor member, whereby said diaphragm exhibits a maximum response in only the longitudinal stress mode suitable for the use of piezoresistive elements operating in the longitudinal peizoresistive mode.
Dependencies are inferred from the claim text.