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采用Auger电子分光镜(AES)检测由高剂量离子注入产生的硅上表面沾污层。纵向剖面分析证明当在注入机靶室的真空系统中用普通扩散泵油,Si~+或BF_2~+的高剂量注入导致～100A厚的碳质表面层。注入机剩余真空的碳氢化合物的物理吸附以及辐照感应聚合反应是形成这种沾污层的最大原因。在重注入硅中经常观察到这种沾污层可引起非均匀腐蚀特性和非欧姆接触结构。用有机溶剂清洗或过氧化物清洗溶液,在550℃下退火100分钟,并按势垒层剥除工艺估计阳极氧化及HF解吸作用。只发现HF解吸和阳极氧化对完全清除聚合层有效。实质上,用过氟化聚醚油替换靶室真空系统中的普通扩散泵油清除沾污。最近几年,在制造双极晶体管,FET源和漏区以及在其它各种应用中,对用高剂量离子注入工艺的要求日益增长。然而,已知离子束感应吸附的碳氢化合物聚合,导致在离子注入的样品(1.2)上形成碳化表面沾污层。注入机的剩余真空是碳氢分子的主要来源。沾污层的厚度随剂量的增加而增长,所以,重注入Si呈现出可注意到的沾污问题,反冲碳可产生结构上损伤浅P—n结的反相电流,并在注入退火后形成硅碳化物。为了更好的了解这种沾污问题并阐明解决方法,使用Auger电子分光镜(AES)检查在各种注入条件下制备的高剂量注入的硅表面层。估计了各种表面层的剥离技术,也分析了注入机真空系统中的注入温度效应和扩散泵油的种类。最后,估计化学腐蚀和欧姆按触结构对表面沾污的效应。
The Auger electron beamsplitter (AES) was used to examine the silicon on top surface contaminated layer produced by high dose ion implantation. Longitudinal profile analysis demonstrated that high-dose Si + or BF 2 + implantation resulted in a ~ 100 A thick carbonaceous surface layer when using common diffusion pump oil in a vacuum system injected into the target chamber. Physiological adsorption of hydrocarbons in the residual vacuum of the implanter and irradiation-induced polymerization are the major causes of this contamination layer. It is often observed that this contaminating layer is reinjected into the silicon causing non-uniform corrosion characteristics and non-ohmic contact structures. The solution was washed with an organic solvent or peroxide and annealed at 550 ° C for 100 minutes. The anodization and HF desorption were evaluated according to the barrier stripping process. Only HF desorption and anodic oxidation were found to be effective at completely removing the polymeric layer. In essence, common fluorinated polyether oils are used to replace common diffusion pump oil in target chamber vacuum systems to remove contaminants. In recent years, there has been an increasing demand for high-dose ion implantation processes in the manufacture of bipolar transistors, FET sources and drain regions, and in various other applications. However, it is known that the ion beam-induced adsorption of hydrocarbons causes the formation of a carbonized surface stain on the ion-implanted sample (1.2). The remaining vacuum at the implanter is the main source of hydrocarbon molecules. The thickness of the contaminated layer increases with dose, so re-implanting Si presents noticeable contamination problems, and recoil carbon can produce an inverse current that structurally damages the shallow P-n junction and, after implantation annealing Silicon carbide is formed. To better understand this staining problem and to clarify the solution, a high-dose implanted silicon surface layer prepared under various implantation conditions was examined using an Auger electron beamsplitter (AES). The debonding techniques for various surface layers were estimated, as well as the injection temperature effect and the type of diffusion pump oil in the vacuum system of the implanter. Finally, the effects of chemical corrosion and ohmic contact structures on surface contamination are estimated.