"A comparative analysis of Silicon Dioxide films deposited by ECR -PECVD, RF-PECVD and APCVD for low temperature polysilicon TFTs"

In this work, we compared structural and electrical properties of SiO2 films obtained using three different deposition techniques: electron cycoltron resonance-plasma enhanced chemical vapor deposition (ECR-PECVD), tetraethylorthosilicate-plasma enhanced chemical vapor deposition (TEOS-PECVD) and vapor deposited oxide-atmospheric pressure chemical vapor deposition (Vapox-APCVD). Fourier transform infrared spectroscopies (FTIR) were carried out on the as-deposited SiO2 films in order to evaluate the structural properties of the dielectrics. From the infrared absorption bands we also evaluated the evolution of hydrogen content evolution with time at a thermal annealing temperature of 450 °C. Electrical characterization was performed on MOS capacitors. In particular, we investigated the interface hydrogen-passivation mechanism at different annealing temperatures and for different annealing times. We also successfully applied the ECR and TEOS oxides as gate insulators on low-temperature polycrystalline silicon thin-film transistors (polysilicon TFTs).