Fluorine-Silicon Interactions and Competitive Etching Pathways

该计划旨在研究氟与硅表面的相互作用，蚀刻所带来的修饰，以及材料去除背后的原子尺度相互作用。氟硅（100）系统是一个理想的模型系统，因为可以解决具有广泛重要性的问题，即当暴露于反应物时，理想表面如何形成“腐蚀层”，以及多层蚀刻如何与逐层蚀刻竞争。原子分辨率扫描隧道显微镜将用于研究氟的化学吸附和氟-氟排斥相互作用。已经设计了一些研究，以确定导致二氟化硅解吸的事件的原子顺序，以及与去氟化硅逐层蚀刻相比较的影响。其他研究则侧重于腐蚀层四氟化硅的形成、表面氟硅基结构的成核，以及从这些无序层中移除材料的结构后果。这些关于硅的氟蚀刻的研究与基于硅和其他半导体的现代技术有关。例如，在7000亿美元的微电子工业中，1997年生产的大部分1018晶体管都是用化学蚀刻的方法雕刻成单片硅片的。这些结构的形状、位置和注册表以亚微米精度控制。该项目侧重于负责这种蚀刻的潜在化学和物理过程。为了实现未来电路的进一步小型化，需要更深入的见解。＊＊＊

9803177 Weaver The proposed program aims to investigate the interactions of fluorine with silicon surfaces, the modifications that are brought about by etching, and the atomic-scale interactions that underlie material removal. The fluorine-silicon (100) system is an ideal model system because problems can be addressed that are of broad importance, namely how ideal surfaces develop "corrosive layers" when exposed to reactants and how multilayer etching competes with layer-by- layer etching. Atomic-resolution scanning tunneling microscopy would be used to investigate fluorine chemisorption and fluorine-fluorine repulsive interactions in the adlayer. Studies have been designed that would determine the atomic sequency of events leading to silicon difloride desorption and the implications vis-a-vis layer-by- layer etching with silicon defluoride. Others would focus on corrosive-layer silicon tetrafluoride eteching, the nucleation of fluorosilyl structures on the surface, and the strucural consequences of material removal from these disordered layers. %%% These studies of fluorine etching of silicon are pertinent to modern technologies based on silicon and other semiconductors. In the $700b microelectronics industry, for example, the majority of the 1018 transistors produced in 1997 were carved into monolithic pieces of silicon using themethods of chemical etching. The shapes, positions, and registry of these structures are controlled with sub-micron accuracy. This project focuses on the underlying chemical and physical processes responsible for this etching. Deeper insights are needed to achieve dfurther miniaturization for tomorrow's circuitry. ***