Silicon oxide has been grown by rapid thermal processing. The growth rate, in the range of very thin films (<10 nm), has been studied as a function of the oxidation temperature. Combined films composed by conventional thermal silicon oxide growth over SiO2 passivation layer deposited by rapid thermal processing onto Si(1 0 0) substrates have been used as gate oxide of p-channel metal-oxide semiconductor (p-MOS) transistors of dynamic random access memory (DRAM). The effect of rapid thermal annealing treatments on these films has also been experimented. Improvements in the electrical performances of transistors have been observed.