抄録
Semiconductive TiO2 thin films were deposited by RF magnetron sputtering.
These films were then characterized to evaluate their NO gas sensitivity.
The results are as follows;
1. TiO2 thin films deposited at a power of 700W, substrate temperature 750°C and gas pressure 1.1∼4.1Pa are all n-type semiconductive ones.
2. The specific resistivity of films deposited at gas pressures of 5.3∼10.6Pa decreased markedly compared to those deposited at 1.1∼4.0Pa.
This was found to be caused by the increase in carrier concentration as a result of the large number of oxygen defects in the films.
3. The NO gas sensitivity of films deposited at 2.7∼4.0Pa was the highest of all films, and these showed a resistivity change ratio of about 20∼24% at 200°C.
This high sensitivity is attributed to the decrease in the grain size of the crystal column of films.
