蒸发工艺是在真空中将金属加热至挥发温度,而使金属粒子淀积在半导体基片或其它材料上以得到这种金属的薄层。由于蒸发室中真空度较高(10~(-5)托以上),所以金属粒子在漫长的行进过程中不会氧化。为了简化计算忽略不计重力的影响,则可认为金属粒子由蒸发源是均匀的向四周散射的。如果蒸发源是点源,那么距以蒸发源为园心,以源与片 Evaporation processes heat a metal to a volatile temperature in a vacuum, depositing metal particles on a semiconductor substrate or other material to provide a thin layer of such metal. Due to the higher vacuum in the evaporation chamber (above 10 -5 Torr), the metal particles do not oxidize during long travels. In order to simplify the calculation and neglect the effect of gravity, it can be considered that the metal particles are uniformly scattered around the evaporation source. If the evaporation source is a point source, then away from the evaporation source for the center, with the source and film