1. A Single-Chip CMOS Micro-Hotplate Array for Hazardous-Gas Detection and Material Characterization Presentation by Hörður Mar Tómasson 16. October 2006

2. The principle of operation A sample of gas/material is exposed to a temperature sweep. The heat absorbtion of the material at the different temperatures is measured. The electrical resistance of a gas-sensitive film is measured.

4. The hotplate A heater ring of polysilicon Layers of silicon oxide/nitride provide thermal isolation from the chip bulk. Polysilicon temperature sensor in the centre Heated area diameter: 100 µm Electrical resistance of heater: 125 Ω. Power efficiency: 10.0°C/mW

5. Electrodes Structure of the electrodes that contact the sensitive layer or the sample: CMOS aluminium metallization Ti/W layer that blocks diffusion Platinum film

6. Temperature control 10 bit ADC for the temperature sensor PID controller 10 bit DAC DC amplifier drives the heater

8. The circuit Temperature control loops Chip bulk temperature measurement Resistance measurement of material Chip communication Logic for development of new controllers using an FPGA