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金刚石膜与天然金刚石类似,具有许多优异的特性,可广泛用于机械、光学和电子等领域.目前已用各种CVD技术制备出了可供实际应用的金刚石膜.这些技术遇到的一个主要问题是怎样提高成核密度和质量.特别是在异质衬底材料(如Si)上如何控制核化密度和貌相,从而达到异质外延生长金刚石膜.为了实现这一目的人们采取了各种方法和措施,如在沉积膜前对Si衬底进行划痕或在金刚石粉末溶液中进行超声波处理;用化学腐蚀或沉积非晶碳过渡层等.最近研究发现,对衬底加负偏压可大大提高成核密度.在微波等离子体CVD法中对衬底加负偏压后,在不经任何处理的抛光Si片上金刚石成核密度达10~(10)cm~(-2).并且利用此方法已成功地在Si衬底上实现了异质外延或织构生长金刚石膜.然而至今对热灯丝CVD法沉积金刚石膜中加负偏压增强成核密度研究的还不多.本文对热灯丝CVD负偏压法增强成核问题进行了实验研究,并对其结果进行了讨论.热灯丝CVD法沉积金刚石膜装置同文献[3]中的一样,衬底材料是Si(100),首先对硅衬底分别在丙酮和乙醇中分别进行超声处理,然后在50%HF溶液中腐蚀2min,去除天然氧化硅,接着用去离子水冲洗数次,最后用甲醇超声处理烘干后放入反应室中抽真空以备实验.沉积条件为衬底温度850℃,灯丝温度2000～2400℃,甲烷浓度(CH
Similar to natural diamond, diamond film has many excellent properties and can be widely used in mechanical, optical and electronic fields, etc. Currently, various CVD techniques have been used to prepare practical diamond films. One of the main problems encountered by these techniques The problem is how to improve the nucleation density and quality, especially how to control the nucleation density and appearance in heterogeneous substrate materials such as Si, so as to achieve the heteroepitaxial growth of diamond film.In order to achieve this purpose, Methods and measures such as scratching the Si substrate prior to film deposition or sonication in a diamond powder solution, chemically etching or depositing an amorphous carbon transition layer, etc. Recent studies have found that negative biasing the substrate can Greatly increasing the nucleation density.The diamond nucleation density was 10 ~ (10) cm ~ (-2) on the polished Si without any treatment after the substrate was negatively biased in the microwave plasma CVD method, This method has been successfully carried out on the Si substrate heteroepitaxial or textured growth of diamond film However, so far, hot filament CVD deposition of diamond film negative bias to enhance the nucleation density is not much research on the heat Filament CVD negative Bias method to enhance the nucleation problems were studied experimentally and the results were discussed.The hot filament CVD deposition of diamond film device with the literature [3], the substrate material is Si (100), the first silicon liner Respectively, respectively, in acetone and ethanol were sonicated, and then 50% HF solution corrosion 2min, remove the natural silicon oxide, followed by rinsed with deionized water several times, and finally with methanol ultrasound drying into the reaction chamber pumping Vacuum for the experiment deposition conditions were substrate temperature 850 ℃, filament temperature 2000 ~ 2400 ℃, methane concentration (CH