ULTRAMINIATURE SILICON CAPACITIVE PRESSURE-SENSING ELEMENTS OBTAINED BY SILICON FUSION BONDING

We present a technology to fabricate ultraminiature capacitive-type se nsing elements for use in blood-pressure measurements, each of them ha ving a side dimension of only 130 mu m The devices, which are made in an array configuration, are fabricated using the silicon fusion-bondin g technique and self-aligned boron ion implantation. The process is si mple, requiring only three mask levels, and has high yield. Throughout the paper we compare the fabrication process as well as the measureme nt results of the array configuration with single membranes having the same measurement range. Measurement results are presented for both st atic and dynamic pressure conditions. (C) 1998 Elsevier Science S.A. A ll rights reserved.