Sensitivity is one of the key performance indicators of gas sensors

and controlling the microfractal characteristics of semiconductor thin films is one of the methods to improve sensor sensitivity.In this paper

the fractal dimension is introduced to characterize the microstructure and gassensitive properties of SnO

2

thin films.The effects of annealing temperature and annealing time on the fractal characteristics and sensitivity of SnO

2

thin films are studied.The results of fractal analysis and experiments using ethanol as the target gas show that the gas sensor with an annealing temperature of 500℃ and an annealing time of 3h has the highest fractal dimension

of 18365 and the maximum sensitivity to ethanol of 0.08580.The study shows that the fractal dimension can characterize the gassensitive properties of the thin film

and the film with optimal fractal dimension and sensitivity can be obtained by changing the preparation parameters to regulate the fractal characteristics of SnO

2

thin films.