CAPACITIVE GAS SENSORS AND MANUFACTURING METHOD THEREOF
FIG6 is a schematic cross-sectional side view of the capacitive gas sensor depicted in FIG5, along the direction AA' 
As illustrated in FIG6, a dielectric-protective material 550 is applied on the surfaces of the interdigitated electrodes 510 and 520 that interface with the gas-sensitive dielectric material 540 for reducing the mechanical stress applied by two adjacent interdigitated electrodes, for e.g. electrodes 510a and 520b, on the gas-sensitive dielectric material 540 deposited in-between. However, the dielectric-protective material 550 may be formed so as to cover the interdigitated electrodes 510a-510c and 520a-520b only partially, for e.g. on the lateral surfaces of the electrodes which should exert more mechanical stress on the gas-sensitive dielectric material than the top surface.
schematic cross-sectional view
6
-
540
dielectric material
515
electrically conducting strip
530
substrate
525
respective conducting strip
510
electrodes electrode
520
electrodes electrode
550
dielectric-protective material
['1. A capacitive gas sensor, comprising: a first electrode (210; 310; 410; 510); a second electrode (220; 320; 420; 520); a gas-sensitive dielectric material (240; 340; 440; 540) arranged between the first and the second electrodes to form a gas sensitive capacitor, the gas-sensitive dielectric material (240; 340; 440; 540) having a permittivity that depends on an amount of gas compound absorbed from an environmental medium; and a dielectric-electrode interfacing material (250; 350; 450; 550) arranged at an interface between the gas-sensitive dielectric material (240; 340; 440; 540) and at least one of the first and second electrodes, the dielectric-electrode interfacing material (250; 350; 450; 550) being adapted to absorb thermally-induced dilatation of the at least one of the first and second electrodes for reducing the mechanical stress applied on the gas-sensitive dielectric material (240; 340; 440; 540).', '9. A capacitive gas sensor according to claim 8, wherein the capacitive gas sensor is integrated in a semiconductor circuit substrate (330), the second electrode (320) being arranged directly on the semiconductor circuit substrate (330), the first electrode (310) being connected to a patch in the semiconductor circuit substrate (330) through a via (360) that passes across the dielectric-electrode interfacing material (350) and the gas-sensitive dielectric material (340).']