SiO2 films can be made by thermal oxidation and CVD. Which of the following statements is correct?
A、The process temperature for depositing SiO2 by CVD is lower than that used for thermal oxidation.
B、Both CVD deposition and oxidation growth of SiO2 films need to consume Si on wafer surfaces.
C、The density of SiO2 films deposited by CVD is relatively low.
D、Both the SiO2 layers deposited by CVD and grown by thermal oxidation are amorphous films.