Selective Deposition of Multiple Sensing Materials on Si Nanobelt Devices through Plasma-Enhanced Chemical Vapor Deposition and Device-Localized Joule Heating

This paper describes a novel method, using device-localized Joule heating (JH) in a plasma enhanced atomic layer deposition (PEALD) system, for the selective deposition of platinum (Pt) and zinc oxide (ZnO) in the n^- regions of n⁺/n^-/n⁺ polysilicon nanobelts (SNBs). COMSOL simulations were adopted to estimate device temperature distribution. However, during ALD process, the resistance of SNB device decreased gradually and reached to minima after 20 min JH. As a result, thermal decomposition of precursors occurred during PEALD process. Selective deposition in the n^- region was dominated by CVD instead of ALD. Selective deposition of Pt and ZnO films has been achieved and characterized using atomic force microscopy, scanning electron microscopy, and transmission electron microscopy.