Design of Low Noise pH-ISFET Microsensors and Integrated Suspended Inductors

with Increased Quality Factor Q

Author: PALAN B.

Advisor: COURTOIS B.

Coadvisor: TORKI K.

Thèse de Doctorat INPG, Spécialité Microélectronique

Defense: 01/03/2002

ISBN: 2-913329-81-0

Pages: 186

Abstract:

The main effort of the first part of this thesis is concentrated on the pH-ISFET development in a low-cost, unmodified 0.6um CMOS technology (AMS). The research includes feasibility study, design, fabrication, and full pH characterization. One of the main aspects in the sensor's reliability is the ISFET encapsulation. Several of novel designed ISFET structures are functional and show promising results. Noise contribution of commercial ISFETs, as well as of our new designed pH-sensors, is studied and measured. At the end of the first part, two designed ISFET sensor interfaces are presented. The aim of the second part of this thesis is the investigation of high-Q planar spiral inductors for RF analogue applications in biomedical microsystems. Our research present studies, calculations and design of on-chip micromachined spiral inductors developed in 0.8um CMOS technology (AMS). Proposed innovative design architecture maximizes quality factor Q. Suspended inductors can be placed vertically above the substrate, thus, parasitic substrate effects are considerably reduced. Designed passive inductors have values from 1nH to 7nH. The Q-factor greater than ten is estimated from calculations, and it is experimentally verified by S-parameter measurements.

Identifiers: microsystems, microsystems for safety critical applications