Highly Selective Directional Atomic Layer Etching of Silicon (original) (raw)
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Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2017
Atomic layer etching has emerged as a viable approach to address the challenges associated with continuous or quasicontinuous plasma processes. To this end, the authors previously reported the quasiatomic layer etching of silicon nitride via sequential exposure to hydrogen and fluorinated plasma. The underlying premise was the surface modification via implantation of hydrogen ions into silicon nitride resulting in an anisotropic etch. In this paper, the authors will demonstrate that a similar enhancement in reactivity of silicon nitride can also be attained via diffusion of hydrogen atoms into silicon nitride with the resultant etch being isotropic. These results confirm the realization of self-limiting etch of silicon nitride with tunable directionality. Selectivity to oxide is >100 and damage to underlying silicon can be minimized by optimizing the flux of atomic fluorine during the exposure to fluorinated plasma. Thus, hydrogen plasma step controls the directionality while flu...
Selective Atomic Layer Deposition and Etching of Oxides
2018
First chapter provides the background on today’s worldwide developments in the field of selective atomic layer processing involving material deposition and etching. These techniques hold great potential in mitigating the process complexity and development costs currently faced by the semiconductor industry. In order to fully exploit the potential of these techniques in modern (three-dimensional) device fabrication, knowledge regarding challenges in state-of-the-art nanomanufacturing is a prerequisite. In this chapter an outline of selective atomic layer processing techniques is given to provide a bird’s eye perspective of nanomanufacturing and to guide the reader in comprehending the prospects of atomic layer processing. It is important to note that the results of this dissertation are not solely aimed at specific applications in semiconductor manufacturing but more at investigating atomic layer processing techniques. The main objective was to develop area-selective deposition as we...