Nano-Crystalline Diamond Films with Pineapple-Like Morphology Grown by the DC Arcjet vapor Deposition Method

A nano-crystlline diamond film is grown by the dc arcjet chemical vapor deposition method. The film is characterized by scanning electron microscopy, high-resolution transmission electron microscopy （HRTEM）, x-ray diffraction （XRD） and Ftaman spectra, respectively. The nanocrystalline grains are averagely with 80hm in the size measured by XRD, and further proven by Raman and HRTEM. The observed novel morphology of the growth surface, pineapple-like morphology, is constructed by cubo-octahedral growth zones with a smooth faceted top surface and coarse side surfaces. The as-grown film possesses （100） dominant surface containing a little amorphous sp2 component, which is far different from the nano-crystalline film with the usual cauliflower-like morphology.     

Behaviour of Self-Standing CVD Diamond Film with Different Dominant Crystalline Surfaces in Thermal-Iron Plate Polishing

Self-standing CVD diamond films with different dominant crystalline surfaces are polished by the thermal-iron plate polishing method. The influence of the dominant crystalline surfaces on polishing etfficiency is investigated by measuring the removal rate and final roughness. The smallest rms roughness of 0.14 μm is measured with smallest removal rate in the films with the initial （220） dominant crystalline surface. Activation energy for the polishing is analysed by the Arrhenius relation. It is found that the values are 170kJ/mol, 222kJ/mol and 214kJ/mol for the film with three different dominant crystalline surfaces. Based on these values, the polishing cause is regarded as the graphitization-controlling process. In the experiment, we find that transformation of the dominant crystalline surfaces from （111） to （220） always appears in the polishing process when we polish the （111） dominant surface.     

直流电弧等离子体喷射化学气相沉积高质量金刚石膜残余应力分布的拉曼谱分析

不同工艺条件下在钼衬底(φ60mrn)上用100kW直流电弧等离子体喷射化学气相沉积设备进行金刚石膜的制备。金刚石膜用扫描电镜(SEM)、拉曼谱(激光激发波长为488m)和X射线衍射来表征。研究结果表明，在直流电弧等离子体喷射化学气相沉积金刚石膜的过程中，内应力大小从金刚石膜的中央到边缘是增加的，并且应力形式是压应力。这说明了在金刚石膜中存在明显的应力不均。甲烷浓度和衬底温度都影响金刚石膜中的内应力。随着甲烷浓度和衬底温度的提高，金刚石膜中的内应力呈增加的趋势。     

电子回旋共振等离子体特性及其对生长氮化镓晶膜的影响

为了解并优化在电子回旋共振等离子体辅助化学汽相沉积GaN晶膜的工艺研究中的等离子体特性,利用朗缪尔探针及法拉第筒系统地测量了离子密度(N_i)、等离子体势(V_p)、电子温度(T_e)及离子流强(J_i)等多个等离子体参量随微波功率(P_w)及沉膜室气压(p)变化的关系.给出了在P_w＝850W,p＝0.22Pa时,上述等离子体参量的轴向及径向分布.GaN晶膜的生长速率、电学及晶体学性能 关键词：     

用镀有钛过渡层的钼衬底制备无裂纹自支撑金刚石膜

为了解决金刚石膜脱膜开裂的问题,尝试了一种复合衬底,即镀有钛过渡层的钼衬底.利用直流等离子体喷射法在复合衬底上制备了不同厚度无裂纹的自支撑金刚石膜.用扫描电镜(SEM)、拉曼谱和X射线衍射表征金刚石膜的特征,并检测了其断裂强度.结果表明,用复合衬底制备的金刚石膜在950℃具有最小半高宽,在实验温度下所获得的金刚石自支撑膜的断裂强度均超过了500MPa.     

用有限元模拟的方法研究大面积自支撑金刚石膜沉积过程中的热应力

建立了没有过渡层和有过渡层的有限元模型,对大面积自支撑金刚石膜沉积过程中的热应力进行了研究.分别计算了在常用金属材料钼、钨、镍作衬底和用镀有钛过渡层的钼作衬底的情况下,膜/衬底间的热应力分布情况.模拟与实验的结果表明,在大面积自支撑金刚石膜沉积过程中,采用镀有钛过渡层的钼作衬底有利于热应力的释放,从而可能制备出高质量的大面积无裂纹金刚石膜.     

金刚石膜探测器研制

采用直流电弧等离子喷射(DC arc plasma jet)CVD(chemical vapour deposition)工艺制成的金刚石薄膜，研制成功MSM(metal-semiconductor-metal)型CVD金刚石脉冲辐射探测器.对制作的金刚石薄膜材料及探测器有关性能进行了测量，结果表明，采用Raman shift<4.5cm^-1的金刚石薄膜制成的探测器，可满足亚纳秒脉冲辐射探测的要求.由于其独特的物理性能，在制作成本合理的情况下，在脉冲辐射测量中可取代Si-PIN探测器. 关键词： CVD 金刚石薄膜 辐射探测器     

Growth of Structured Non—crystalline Boron—Oxygen—Nitrogen Films and Measurement of Their Electrical Properties

The boron-oxygen-nitrogen(BON) films have been grown on Si wafer by the low-frequency rf-plasma-enhanced metal-organic chemical vapour deposition method.The homogeneous film structure of completely amorphous BON is first fabricated on a low-temperature-made buffer at 500℃ with N2 plasma and is observed with a highresolution-electron microscope by the transmission-electron diffraction.The results show that the interfaces among substrate/buffer/film are clear and straight in the structured film.A heterogeneous film containing nano-sized crystalline particles is also grown by a routine growth procedure as a referential structure,The C-V characteristic is measured on both the amprphous and crystal-containing films by using the metal-oxidesemiconductor structure,The dielectric constants of the films are,therefore,deduced to be 5.9 and 10.5 for the amorphous and crystal-containing films,respectively,The C-V results also indicate that more trapped charges exist in the amorphous film.The binding energy of the B,O.and N atoms in the amprphous film is higher than that in the crystal-containing one,and the N-content in the latter is found to be higher than that in the former by x-ray photo-electron spectroscopy.The different electrical Property of the films is thought to originate from the energy state of the covalent electrons.     

直喷式直流电弧等离子化学气相沉积法金刚石单晶外延层制备研究

采用非循环直流喷射(直喷式)直流电弧等离子化学气相沉积法,在Ar/H2/CH4气氛下,成功制备了金刚石单晶外延层.试验采用的是3 mm×3 mm×1.2 mm的高温高压Ib型金刚石单晶衬底.研究了不同衬底温度和甲烷浓度对金刚石单晶外延层的形貌,速率和晶体质量的影响.采用光学显微镜,激光共聚焦表征了样品的形貌,利用千分尺测量其生长速率,利用Raman表征其晶体质量,采用OES诊断Ar/H2/CH4等离子气氛下C2、CH与Hβ的相对浓度.研究表明,温度和甲烷浓度对单晶刚石形貌和质量产生了明显的影响.在衬底为温度980℃,甲烷浓度在1.5;的条件下,生长速率达到了36 μm/h,并且晶体质量较好(半高宽仅为1.88 cm-1).同时发现生长参数对金刚石单晶外延层的生长模式有着显著地影响.     

金刚石的射频喷射等离子体化学气相沉积及其Ni-N掺杂的研究

对自行设计的RF喷射等离子体增强化学气相沉积系统(RF plasma jet CVD)进行了电子温度和电子密度的模拟计算分析.在优化的参数下进行了金刚石膜体的制备,并应用光发射谱技术(OES)在线分析了等离子体的成分.通过Raman、XRD和SEM分析了沉积样品的成分、晶体结构和形貌.通过在反应气体中加入NH3,并利用载气技术将含有Ni元素的金属有机物引入到沉积区,进行了Ni、N共掺杂沉积.利用XPS以及PL谱分析了掺杂样品的化学价键和光致发光特性,结果发现Ni-N价键的存在以及在800 nm附近的光发射峰.