Low Temperature Fabrication of Diamond Films by CVD Method with Laser Induced Surface Reaction

激光诱导表面反应 CVD 法低温制备金刚石薄膜

• 批准号: 13450291
• 负责人: MITSUDA Yoshitaka
• 金额: $ 9.66万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450291/
• 关键词: diamond films; vapor growth; hydrogen atom; laser induced surface reaction; Nd : YAG laser; surface adsorption; laser induced desorption; low temperature fabrication; Nd : YAGレーザー

The novel apparatus was designed and manufactured for thermal desorption and laser induced desorption. This apparatus has 4 kinds of inlet window through which laser beam can irradiate onto the sample (incident angle : 0-60o), XYZθ sample stage (detection angle : 0-80o), time-of-flight and/or quadrupole mass spectrometer, and sample heating system up to 1400oC. The dosing system, by which the sample surface can be modified, is the thermal cracking system through hot W tube which was replaced as a part of gas introduction tube, since the gas molecule can be dissociated on the inner wall of hot W tube. Therefore, we can choose either method to control the sample surface termination, using the thermal dissociation of molecules on hot sample surface or atomic flux generated in thermal cracking system.Using this apparatus both for thermal desorption and for laser induced desorption, the dangling bonds on the sample surface was terminated by the thermal dissociation of deuterium on 1300K sam … More ple. Then, the thermal desorption spectrum of deuterium molecules was detected from the D-terminated surface. The termination structure of sample surface after dosing was confirmed by the result of thermal desorption spectra.On basis of the results and speculation of thermal desorption measurement, laser induced desorption spectrum was detected using Nd : YAG pulse laser (fundamental - 4th harmonic wave). H2 desorption of H-terminated, CO and CO2 from O-terminated diamond crystal tried to be measured. After the sample was heated up to 200℃ to desorb physiabsorbed H2O and/or CO, a variety of lased wavelength and energy density of laser pulses were irradiated onto the sample. In case of the fundamental, 2nd, and 3rd harmonic wave, we could not detect any desorption spectra. Although we could detect desorption spectra in case of the 4th harmonic wave, it was not due to the desorption by the laser induced reaction at the surface bond, but due to the thermal desorption by the sample heating as a result of the absorption of laser pulse at the defects in diamond crystals. Less

设计并制作了热脱附和激光诱导脱附装置。该仪器具有4种入射窗口，激光束可通过该窗口照射到样品上（入射角：0- 60 o），XYZθ样品台（检测角：0- 80 o），飞行时间和/或四极质谱仪，以及高达1400 oC的样品加热系统。由于气体分子在热钨管内壁上解离，因此，将热钨管作为气体导入管的一部分，采用热钨管热裂解加药系统对样品表面进行改性。因此，我们可以选择利用热样品表面分子的热解离或热裂解系统中产生的原子流来控制样品表面的终止，利用该装置同时进行热脱附和激光诱导脱附，在1300 K样品上通过氘的热解离来终止样品表面的悬挂键。 ...更多信息 请。然后，氘分子的热脱附光谱从D-终止表面被检测到。根据热脱附测量结果和推测，采用Nd：YAG脉冲激光（基波-4次谐波）探测了样品表面的激光诱导脱附谱。尝试测量了H-端金刚石晶体的H_2脱附、O-端金刚石晶体的CO脱附和CO_2脱附。将样品加热至200℃，解吸物理吸附的H2O和/或CO后，对样品照射多种激光波长和能量密度的激光脉冲。在基波、二次谐波和三次谐波的情况下，我们不能检测到任何解吸光谱。虽然在四次谐波的情况下我们可以检测到脱附光谱，但这不是由于表面键处的激光诱导反应的脱附，而是由于由于激光脉冲在金刚石晶体中的缺陷处的吸收导致的样品加热的热脱附。少