Factors Affecting the Quality of CVD Deposited Films
Deposition temperature in CVD technology, total flow and total pressure of mixed gas entering the reaction chamber, partial pressure of each gas phase component in the mixed gas and their relative proportions, deposition time, nature, shape of the substrate and in the reaction chamber The location and so on are all factors that affect the quality of the CVD deposited film, and these factors are both related to each other and affect each other.
The following briefly introduces the effect of deposition temperature on film quality:
Different deposition temperatures not only make the deposition rate of the film different, but also in the same reaction system at different temperatures, the deposited film can be single crystal, polycrystalline or amorphous, and it is even difficult to deposit. For example, using H2 as the carrier gas, and using the mixed gas of SH4 and HCL as 1:1 as the reactive gas, the relationship between the deposition temperature, growth rate and deposition layer structure on a silicon single crystal substrate, because the lower the deposition temperature, the lower the deposition temperature. The more difficult it is for the Si atoms generated by the reaction to diffuse and migrate on the surface of the substrate, they will not be arranged on the normal lattice points in time, which will cause a large number of defects. In other words, the higher the temperature, the higher the growth rate, the higher the deposition rate, the higher the growth rate, and the higher the deposition rate, and the crystal arrangement of the film gradually changes from disorder to regularity.