St atistical p roperties of Plasm a Enhance d Chemic al Vapor Deposition na noparticles

Chemical Vapor Deposition (CVD) proce ss is an imp ortant method to fabricate uniform layer with low-porosity, high-purity, high-performance and local deposition. The process is often used to produce n anothin fil ms and nan oparticles. I t will be very useful an d practical if we could produce na noparticles with the desired size. A number of forms of CVD`s are in wide use an d are frequently referenced in the literatures. These processes differ in the means by which chemical reactions ar e initiated (e.g., activation process) and process conditio ns. In semiconductor te chnology three methods are us ed for th e deposition of layers on semiconductor wafers[۱,۲]:۱ -APCVD. Atmospheric Pressure Chemical V apor Deposition requires rather high tempera tures.۲-LPC VD.low Pressure Chemical Vapo r Deposition. ۳-PECVD. Plasma Enhanced Chemical Vapor Deposition. Th e necessary energy for the chemical reaction is not introduced by he ating the whole reaction chamber b ut just by h eated gas or plasma. The properties of the coated layers can be better i nfluenced w ith PECVD than in simple thermal deposition technique, b ecause more process parameters can be varied.Fractal dimension (FD) is a u seful feature for texture segmentation, shape c lassification , and graphic analysis in many fields. The bo x-counting approach is one of the frequently used techniques to estimate the FD of an ima ge. Fractal g eometry pr ovides a mathematical model for m any comple x objects found in nature [۳–۵], such as coastlines, mountains, and clouds.

کلیدواژه ها:

Chem ical Vapor Deposition ، Statistical properties ، F ractal dimension ، nanoparticles