An Improved Model of Thin Film Growth.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
A VAX-11785 computer was used to simulate the two dimensional growth of thin films produced by vapor deposition. In this model molecules and impurities were represented by three different sized disks. In order to simulate varying deposition conditions and evaporants, several variable parameters were introduced. Among these parameters were the variation of the deposition angle about some main angle, the mobility of the disks upon collision, the ability to introduce impurities into the microstructure, the simulation of multilayered coatings and the ability to introduce imperfections into the substrate. The results obtained by this model show that disks can be used to simulate some of the main features exhibited by vapor deposited films. Among these features are the formation of columns and their compliance with the tangent rule, and the dissappearance of this structure in the case of large disk mobility. Another feature found to be exhibited in the modeled films is that under certain conditions impurities and substrate imperfections can produce large voids andor nodules. Other characteristics found in the simulated films include pores which could allow water absorption, and increased packing density for films produced with angle variations along with a moderate amount of disk mobility.
- Physical Chemistry
- Computer Programming and Software