Using silane has some advantages over H2 High deposition rates have been achieved at low tem peratures( 1um/min at 210 C in a cold-wall reactor) High selectivity is maintained continuously Results in smoother films com pared to that of hydrogen reduction It is found that silane is required for the nucleation of w(from WF) on TiN. Therefor, W deposition is commonly carried out with initial use of WF and siHa followed by bulk growth of W from WF and H2
Using silane has some advantages over H2: • High deposition rates have been achieved at low temperatures(1μm/min at 210℃ in a cold-wall reactor) • High selectivity is maintained continuously • Results in smoother films compared to that of hydrogen reduction • It is found that silane is required for the nucleation of W (from WF6 ) on TiN. Therefor, W deposition is commonly carried out with initial use of WF6 and SiH4 followed by bulk growth of W from WF6 and H2
Disadvantages: Silicon incorporation in the film Reactor contamination through particle formation Poor step coverage Being expensive and difficult to handle
Disadvantages: • Silicon incorporation in the film • Reactor contamination through particle formation • Poor step coverage • Being expensive and difficult to handle
材料化学第课 第2章材料气相制备化学 23气相聚合
第2章 材料气相制备化学 2.3 气相聚合 材料化学 第课
什么是聚合? 聚合=聚合反应: 由低分子单体合成聚合物的反应。 n cha=ch iCH2-CH2,n 单体:能够形成结构单元的小分子所组成的化合 物,是合成聚合物的原料。 (CH2-CH2结构单元
什么是聚合？ • 聚合=聚合反应： 由低分子单体合成聚合物的反应。 n CH2=CH2 ( CH2 -CH2 )n 单体：能够形成结构单元的小分子所组成的化合 物，是合成聚合物的原料。 ( CH2 -CH2 ) 结构单元
什么是气相聚合? 聚合反应的分类 a按照单体和聚合物在组成和结构上变化分类:加 聚反应、缩聚反应、开环聚合、异构化聚合、氢 转移聚合、成环聚合 b按照聚合机理或动力学分类:连锁聚合(自由基 聚合、阴离子聚合、阳离子聚合)、逐步聚合 c按照反应原料体系组成和状态分类: 本体聚合、溶液聚合、悬浮聚合、乳液聚合
什么是气相聚合？ 聚合反应的分类 a 按照单体和聚合物在组成和结构上变化分类：加 聚反应、缩聚反应、开环聚合、异构化聚合、氢 转移聚合、成环聚合 b 按照聚合机理或动力学分类：连锁聚合（自由基 聚合、阴离子聚合、阳离子聚合）、逐步聚合 c 按照反应原料体系组成和状态分类： 本体聚合、溶液聚合、悬浮聚合、乳液聚合