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P型金刚石薄膜具有压阻效应,是最近五六年才发现的新现象。利用压阻效应,可望将金刚石膜制成高灵敏度的新一类压阻传感器材料和压力微传感器,从而拓宽金刚石膜在电子学领域的应用范围。 对金刚石膜的压阻因子进行了测量,结果表明,P型定向生长的多晶金刚石膜室温压阻因子可达100O以上;金刚石薄膜的压阻效应比硅和金属显著得多;多晶金刚石膜的压阻效应不如单晶金刚石膜。金刚石膜具有显著的压阻效应,其理论原因和机制问题到目前一直不太清楚,本研究工作对此进行了系统和深入的研究。在能带结构和形变势理论的基础上,首次结合价带分裂模型和M-S多晶模型,分别推导出P型单晶和多晶金刚石膜压阻因子的近似计算公式。分析结果认为,金刚石薄膜的压阻效应是应力诱导价带分裂造成的。轻、重空穴有效质量之间的巨大差异,是导致P型金刚石具有显著压阻效应的主要原因之一。P型多晶材料的压阻效应,是应力诱导价带分裂和晶界散射联合作用的结果,晶界有阻碍电阻随应变发生改变的作用。从而,第一次从理论上阐明了导致P型多晶材料压阻效应不如同种的P型单晶材料的原因。 对负偏压热灯丝CVD系统下,金刚石膜核化过程进行了研究,结果认为.负偏压对金刚石膜核化的增强是离子对衬底的轰击与发射电子激发的等离子体联合作用于衬?
P-type diamond film has a piezoresistive effect, which is only a new phenomenon discovered in the last five or six years. Using the piezoresistive effect, it is expected that the diamond film can be made into a new type of piezoresistive sensor material and a pressure micrometer sensor with high sensitivity, thus broadening the application range of the diamond film in the field of electronics. The piezoresistive factors of diamond films were measured. The results show that the piezoresistive effect of P-type oriented polycrystalline diamond films is above 100O at room temperature. The piezoresistive effect of diamond films is much more than that of silicon and metals. The polycrystalline diamond films The piezoresistive effect than single crystal diamond film. Diamond film has a significant piezoresistive effect, the theoretical causes and mechanism of the problem has been less clear, the research work carried out a systematic and in-depth study. Based on the theory of energy band structure and deformation potential, the approximate formula for calculating the piezoresistive factors of P-type and polycrystalline diamond films is deduced for the first time by combining the valence band split model and M-S polycrystalline model. The analysis shows that the piezoresistive effect of diamond film is caused by stress-induced valence band splitting. The large difference between the effective masses of light and heavy holes is one of the major causes of the significant piezoresistive effect of P-type diamond. The piezoresistive effect of P-type polycrystalline material is the result of the combination of stress-induced valence band splitting and grain boundary scattering. The grain boundary has the effect of preventing the resistance from changing with strain. Thus, for the first time, the reason why P-type polycrystalline materials have less piezoresistive effect than P-type single-crystal materials has been theoretically elucidated. Under the negative bias hot filament CVD system, the diamond nucleation process was studied, the results show that the negative bias on the diamond nucleation enhancement is the ion bombardment of the substrate and the emission of electronically excited plasma in conjunction with the liner ?