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低压CVD氮化硅薄膜的沉积速率和表面形貌 总被引:7,自引:0,他引:7
以三氯硅烷(TCS)和氨气分别作为低压化学气相沉积(LPCVD)氮化硅薄膜(SiNx)的硅源和氮源,以高纯氮气为载气,在热壁型管式反应炉中,借助椭圆偏振仪和原子力显微镜,系统考察了工作总压力、反应温度、气体原料组成等工艺因素对SiNx薄膜沉积速率和表面形貌的影响.结果表明:随着工作压力的增大,SiNx薄膜的沉积速率逐渐增加,并产生一个峰值.随着原料气中NH3/TCS流量比值的增大,SiNx薄膜的沉积速率逐渐增加,随后逐步稳定.随着反应温度的升高,沉积速率逐渐增加,在830℃附近达到最大,随着反应温度的进一步升高,由于反应物的热分解反应迅速加剧,使得SiNx薄膜的沉积速率急剧降低.在730-830℃的温度范围内,沉积SiNx薄膜的反应表观活化能约为171kJ/mol.在适当的工艺条件下,制备的SiNx薄膜均匀、平整.较低的薄膜沉积速率有助于提高薄膜的均匀性,降低薄膜的表面粗糙度. 相似文献
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综述了材料经过表面纳米化处理后其表层纳米结构热稳定性的国内外研究现状.包括研究表层纳米结构热稳定性的一些常用的方法、影响表层纳米结构的热稳定性的主要因素(主要是影响晶粒长大的因素)及机理. 相似文献
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在利用高分辨电子显微术研究 Si_3N_4结构过程中,有了新的发现。这些发现包括纳米级裂纹、超结构、纳米畴和辐射损伤等。纳米级裂纹是晶粒中纳米大小的裂纹,它可能是导致穿晶断裂的裂纹。超结构可能影响Si_3N_4晶粒的力学性能,我们在研究中发现了三种超结构。纳米畴是晶粒中一种新的结构缺陷,在研究中我们发现了两种这类畴。也研究了辐射损伤,发现 α-Si_3N_4比β-Si_3N_4更易于受到辐射损伤,这说明β-Si_3N_4比α-Si_3N_4结构更稳定。还仔细地研究了 Si_3N_4陶瓷的晶界,结果指出,晶界工程对于改善 Si_3N_4陶瓷的力学性能是强有力的手段。 相似文献
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本文评述了氮化硅及其复合材料的蠕变行为;讨论了材料加工工艺,添加剂和增强组元对蠕变速率的影响,以及蠕变机理和蠕变寿命预测方法。 相似文献
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M. C. Chu S. Sato Y. Kobayashi K. Ando 《Fatigue & Fracture of Engineering Materials & Structures》1997,20(6):829-838
Abstract— Microstructure and mechanical properties of HP (Hot Pressed), HP/GP (Gas Pressed), and HP/HIP (Hot Isostatic Pressed)—Si3 N4 are studied using scanning electron microscopy, bending tests and the indentation fracture method. The grain diameter distribution is analyzed to clarify the relationship between microstructure and mechanical properties; and also the bending strength and fracture toughness. It is shown that bending strength increases with decreasing grain diameter. The results also show that a Hall—Petch type of relationship is obtained between grain diameter and fracture strength. The fracture toughness shows a linear relationship with , where σF = bending strength, β= a proportionality factor and d a = average grain diameter, and is closely related to the aspect ratio of Si3 N4 grains. It is concluded, from the morphological analysis, that a microstructure composed of Si3 N4 grains, with both a small grain diameter and a large aspect ratio, is effective in improving both the fracture strength and fracture toughness. 相似文献
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利用简易合金靶材在Si(100)和SiO2基底上磁控溅射制备了Cu(1.42%Ti)薄膜。研究了少量钛对Cu/Si(100)和Cu/SiO2薄膜体系在573-773 K退火前后的微观组织结构以及界面反应的影响。X射线衍射分析表明,溅射态Cu(Ti)薄膜均呈现Cu(111)和Cu(200)衍射峰,而钛显著增强铜薄膜的(111)织构。对于退火态的Cu(Ti)/Si薄膜体系,由于少量钛在薄膜/基底界面处的存在,起到净化界面作用,促使Cu3Si的形成,从而降低了薄膜体系的热稳定性。但对于Cu(Ti)/SiO2薄膜体系,在773 K退火后,仍然呈现出良好的热稳定性。薄膜截面的结构形貌以及界面处俄歇谱的分析结果都充分证实了上述结果。 相似文献
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M. Okane Y. Mutoh Y. Kishi S. Suzuki 《Fatigue & Fracture of Engineering Materials & Structures》1996,19(12):1493-1504
A cyclic fretting fatigue test machine was constructed. The piezoelectric bimorphs were used as actuators for cyclic loading and fretting motion at the resonance frequency of the system. Fretting fatigue tests under static and cyclic loading conditions were carried out using HIP-sintered silicon nitride. From the experimental results, it was found that fretting fatigue strengths under the two test conditions were identical and hence the effect of cyclic loading on fretting fatigue strength of silicon nitride was almost negligible. A fretting crack initiated in a very early stage of the fatigue life at the position of the maximum frictional stress in the contact area. Fretting fatigue life prediction based on fracture mechanics was also carried out. The predicted lives were in good agreement with the experimental results. 相似文献
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采用化学滴定、X 射线衍射(XRD) 及径向分布函数(RDF) 等方法, 测定了BN 纤维中残余B2O3 含量与氮化温度的关系, 研究了氮化过程中BN 纤维的结构演变规律。分析表明: 经1100℃氮化后,BN 纤维以乱层结构为主, 同时存在少量类六方相(Hexagonal-BN ) 和菱方相(O rthorhombic-BN ) ; 随高温处理温度的升高, 纤维结构逐渐向菱方相结构转变, 经1900℃高温处理后,BN 纤维的结构主要为菱方相。 相似文献