What is the role of mean free path in thin film preparation?

The mean free path plays an important role in film preparation. Here are a few aspects of its role:

1.Gas diffusion: In thin film preparation processes such as chemical vapor deposition (CVD), gas molecules need to diffuse to the reaction surface in the reaction chamber.

The average free path determines the distance traveled by gas molecules in the gas. A shorter mean free path means a higher frequency of collisions between gas molecules and a faster diffusion rate.

2.Reaction rate: During vapor deposition, the reactant molecules need to undergo a chemical reaction on the reaction surface and form a thin film.

The mean free path can affect the distance and time for the reactant molecules to be transported to the surface. A shorter mean free path increases the chance of reactant molecules reacting with the surface, speeding up the reaction rate.

3.Mixing performance: The average free path can also affect the degree to which the gas is mixed. The shorter mean free path increases the frequency of collisions between gas molecules, thus facilitating the mixing between different gases, evenly distributed in the reaction chamber.

4.Gas transport: During the deposition process, gas molecules need to be transported from the ** source to the reaction chamber. The mean free path determines the frequency and distance of collisions between gas molecules during transport. A shorter mean free path can increase the transport rate of gas molecules.

Summary. Thin film: A thin layer of solid material formed by a single atom, ion, or atomic cluster incident on the surface of the substrate irregularly through surface attachment, migration, condensation, nucleation, nuclear growth and other processes.

Briefly describe the importance of mean free path in the preparation process of thin film materials, thin films: a thin layer of solid material formed by a single slag material, ionic beam lead, and atomic clusters irregularly entering the surface of the substrate, and forming through the processes of surface attachment, migration, condensation, nucleation, and nuclear growth.

The plane wave vector k (called the early vector of the Bloch wave foci, and the reduced Planck number multiplied by the hidden infinity product is the amount of grain crystals) represents the phase change of the radio wave function between the same cells, and the reciprocal lattice vector satisfies the correspondence relationship with the wave function, and the wave vector in the Dibuyuan region is generally considered. Given the wave vector potential field, the Schrödinger program is a series of solutions, called the electrical energy band, and the wave function is marked n differentiation. There are limited gaps at the boundaries of each single-value region of energy with energy k, which are called energy gaps.

The energy eigenstate ensemble structure of the Dibuyuan district. In the framework of the single-electric approximation, the macroscopic properties of the periodic potential field are calculated according to the band structure and the corresponding wave function.

What are the most suitable vacuum evaporation devices for the preparation of aluminum films, high-purity gold touches, and ceramic films? Please write down the reason for your choice.

The aluminized film vacuum evaporation device leakage type is to evaporate the metal under the condition of vacuum, and the evaporated metal forms a thin film on the surface of the substrate, and the plated metal can be gold, silver, copper, iron and zinc, etc., among which the most commonly used aluminum material can be used in the environment of vacuum searching, which can be used for the processing and production of new aluminized film with high efficiency and high quality. Because the height of the existing aluminized film vacuum evaporation device is relatively high, the ascending equipment needs to be placed separately in front of the fuselage, and it is inconvenient for the staff to operate the inside of the fuselage, and the ascending equipment occupies space, and the substrate of different sizes cannot be fixed in the inside of the fuselage, therefore, we propose an aluminized film vacuum evaporation device.