The growth characteristics of thin film switches are influenced by sedimentary conditions, the main factors are deposition rate, substrate temperature, atomic incidence direction, substrate surface state and vacuum degree.
For different types of metals, the influence of deposition rate is different, because the transfer rate of the metal atoms deposited on the substrate is related to the properties and surface conditions of the metal. Even the same metals, in different process conditions, the deposition rate of the film structure of the impact is not entirely consistent. Generally speaking, the deposition rate affects the grain size and the uniformity of grain distribution and defects in the membrane layer.
In the case of low deposition rate, the metal atoms migrate on the substrate longer, easy to reach the adsorption point position, or by the other adsorption point on the location of the small island captured by the formation of coarse grains, making the structure of the thin film, pet thin film switch is not dense.
At the same time, since the deposition atoms arrive at the substrate, the subsequent atoms have not arrived in time, thus exposed to the longer time, susceptible to residual gas molecules or the deposition of impurities in the process of contamination, and the emergence of various defects.
Therefore, the deposition rate is high. High deposition rate can make thin film grains small, dense structure, but because of the nucleus of a lot of condensation at the same time, the energy nucleus is higher than the state of energy, so the film switch has a relatively large internal stress, but also more defects.