Chemical Vapor Deposition Processes to Prepare Silicon Nitride Films from Organic Silicon Materials Containing Nitrogen

氮化硅和氮化碳硅薄膜具有耐磨性、化学惰性、透明性和绝缘性等吸引人的特性。采用催化化学气相沉积（Cat-CVD）技术，以SiH_4和NH_3为原料制备出器件级的氮化硅薄膜。可以涂覆有机材料，如有机发光二极管和用于包装的塑料薄膜。问题是SiH_4具有高爆炸性，需要替代材料。六甲基二氮杂烷（HMDS）是取代SiH_4的有吸引力的材料之一。本文主要研究了HMDS和三二甲氨基硅烷的Cat-CVD工艺。气相诊断采用三种质谱技术：电子冲击四极杆质谱、真空紫外光电离飞行时间质谱和离子附着四极杆质谱。结合这些质谱测量的结果，更多地揭示了Si-N键虽然比Si-C键更强，但它们是选择性断裂的。N原子的孤对电子可以与催化剂相互作用，选择性地破坏键。要使Si-C键断裂，必须存在位阻。添加HMDS后，NH_3的分解效率显著降低。说明HMDS污染了催化剂表面，阻碍了NH_3的分解。克服这一中毒问题的技术之一是远程Cat-CVD，在该技术中，NH_3或H_2在催化剂表面分解，产生的自由基被输送到下游，并引入有机硅化合物。为了探索这种远程Cat-CVD技术的可能性，在不锈钢腔壁上涂上SiO_2或Teflon。制备这种涂层时，h原子密度增加了一个数量级，表明远程Cat-CVD有机硅化合物是一种很有前途的制备固体薄膜的技术。少

Silicon nitride and silicon carbon nitride films have attractive properties, such as wear resistance, chemical inertness, transparency, and insulatability. Device quality silicon nitride films can be fabricated from SiH_4 and NH_3 by using a catalytic chemical vapor deposition (Cat-CVD) technique. It is possible to coat organic materials, such as organic light-emitting diodes and plastic films for packaging. The problem is that SiH_4 is highly explosive and alternative materials are expected. Hexamethyldisilazane (HMDS) is one of the attractive materials to replace SiH_4. In the present study, the Cat-CVD processes of HMDS and trisdimethylaminosilane were focused.Gas-phase diagnoses were performed by employing three kinds of mass spectrometric techniques: electron impact quadrupole mass spectrometry, vacuum-ultraviolet photoionization time-of-flight mass spectrometry, and ion attachment quadrupole mass spectrometry. Combining the results of these mass spectrometric measurements, it was … More revealed that Si-N bonds are broken selectively although they are stronger than Si-C bonds. The lone-paired electrons of N atoms may interact with the catalyzer to break the bonds selectively. A steric hindrance must be present to break Si-C bonds. It was also found that the decomposition efficiency of NH_3 decreases drastically by the addition of HMDS. This suggests that HMDS poisons the catalyzer surfaces and blocks the decomposition of NH_3. One of the techniques to overcome this poisoning problem is remote Cat-CVD in which NH_3 or H_2 is decomposed on catalyzer surfaces and the produced radicals are transported to down streams where organic silicon compounds are introduced. In order to explore the possibility of this remote Cat-CVD technique, the stainless-steel chamber walls were coated with SiO_2 or Teflon. An increase in H-atom density by one order of magnitude was observed when such coatings were made, showing that remote Cat-CVD of organic silicon compounds can be a promising technique to prepare thin solid films. Less