Which of the following statements about thin films used in microelectronic devices is correct?

A、Films of the same material deposited by different deposition methods may have different properties.;

B、Most thin film layers used in ICs are fabricated by deposition.;

C、If chemical reactions are involved when a film is deposited on a substrate surface from a vapor phase, such a process is called chemical vapor deposition. ;

D、All vapor deposition processes operate at atmospheric pressure.