Abstract: A gas-sensing semiconductor device 1? is fabricated on a silicon substrate 2? having a thin silicon dioxide insulating layer 3? in which a resistive heater 6 made of doped single crystal silicon formed simultaneously with source and drain regions of CMOS circuitry is embedded. The device 1? includes a sensing area provided with a gas-sensitive layer 9? separated from the heater 6? by an insulating layer 4?. As one of the final fabrication steps, the substrate 2? is back-etched so as to form a thin membrane in the sensing area. The heater 6? has a generally circular-shaped structure surrounding a heat spreading plate 16?, and consists of two sets 20?, 21? of meandering resistors having arcuate portions nested within one another and interconnected in labyrinthine form.

Abstract: A gas-sensing semiconductor device 1? is fabricated on a silicon substrate 2? having a thin silicon dioxide insulating layer 3? in which a resistive heater 6 made of doped single crystal silicon formed simultaneously with source and drain regions of CMOS circuitry is embedded. The device 1? includes a sensing area provided with a gas-sensitive layer 9? separated from the heater 6? by an insulating layer 4?. As one of the final fabrication steps, the substrate 2? is back-etched so as to form a thin membrane in the sensing area. The heater 6? has a generally circular-shaped structure surrounding a heat spreading plate 16?, and consists of two sets 20?, 21? of meandering resistors having arcuate portions nested within one another and interconnected in labyrinthine form.

Abstract: A gas-sensing semiconductor device is fabricated on a silicon substrate having a thin silicon oxide insulating layer in which a resistive heater made of a CMOS compatible high temperature metal is embedded. The high temperature metal is tungsten. The device includes at least one sensing area provided with a gas-sensitive layer separated from the heater by an insulating layer. As one of the final fabrication steps, the substrate is back-etched so as to form a thin membrane in the sensing area. Except for the back-etch and the gas-sensitive layer formation, that are carried out post-CMOS, all other layers, including the tungsten resistive heater, are made using a CMOS process employing tungsten metallisation. The device can be monolithically integrated with the drive, control and transducing circuitry using low cost CMOS processing. The heater, the insulating layer and other layers are made within the CMOS sequence and they do not require extra masks or processing.

Abstract: A method for the degradation of lignocellulosic material by applying to the material an enzyme composition which is a mixture comprising at least a cellulase, xylanase and ligninase, and optionally other enzymes, such as a protease, lipase, urease, uricase, and/or pectinase, to solubilise or decompose the material at least partially. The method may be used for removing a biological deposit from a surface or location on or in which it is undesirably deposited. Typical deposits include human or animal faeces, bird droppings, and leaves. The cellulase, xylanase and ligninase component may be obtained as a mixture by cultivating a White Rot fungus, preferably using cattle dung, or a liquid extract, as an inducer.