Molecular Dynamics Simulation and Verification of the Improvement of Getter Performance by Porous Scaffold

Getters play a vital role in maintaining the vacuum of MEMS devices. Currently, a common method to improve the performance of getters is to deposit getters on porous scaffolds with large specific surface areas. In order to verify the significant role of porous structure in improving getter performance, the molecular dynamics simulation software Lammps was used to simulate the adsorption behavior of thin film getters and getters with porous scaffolds. The simulation results show that the adsorption capacity of the getter with a porous scaffold is 2.69 times that of the thin film getter. A layer of Ti getter was deposited on the surface of silicon and porous nickel scaffolds using the magnetron sputtering method, and the adsorption capacity of both was tested using the thermogravimetric method. The results show that the adsorption amount of the getter with porous nickel scaffold (0.5961 mg) is 2.11 times that of the thin film getter (0.2829 mg). Gas adsorption tests were conducted on the two types of getters using the constant pressure method. The getter capacity of the Ti getter with porous nickel scaffold (2.16×10⁻³ Pa∙ml/cm²) is 3.2 times that of the thin film Ti getter (6.74×10⁻⁴ Pa∙ml/cm²).