The exceptional advantages of channeling implantation into 4H-SiC to make abrupt deep profiles

We investigated the channeling implantation of dopant ions into 4H-SiC in detail. The advantages of channeling implantation were clarified by both experimental and Monte Carlo simulation. Extremely abrupt deep profile with box-like can be formed by channeling implantation of Al and P ions. In the case of B and N ions, retrograde-like profile can be obtained by channeling implantation. The unique dopant profile can be realized by channeling implantation. Both vertical and lateral straggling becomes small by using channeling implantation for Al ions. This technique should contribute to improve the device performance such as gate pitch scaling and low specific on-resistance.

Bottom-up nanoscale patterning and selective deposition on silicon nanowires

We demonstrate a bottom-up process for programming the deposition of coaxial thin films aligned to the underlying dopant profile of semiconductor nanowires. Our process synergistically combines three distinct methods – vapor-liquid-solid (VLS) nanowire growth, selective coaxial lithography via etching of surfaces (SCALES), and area-selective atomic layer deposition (AS-ALD) – into a cohesive whole. Here, we study ZrO2 on Si nanowires as a model system. Si nanowires are first grown with an axially modulated n-Si/i-Si dopant profile. SCALES then yields coaxial poly(methyl methacrylate) (PMMA) masks on the n-Si regions. Subsequent AS-ALD of ZrO2 occurs on the exposed i-Si regions and not on those masked by PMMA. We show the spatial relationship between nanowire dopant profile, PMMA masks, and ZrO2 films, confirming the programmability of the process. The nanoscale resolution of our process coupled with the plethora of available AS-ALD chemistries promises a range of future opportunities to generate structurally complex nanoscale materials and electronic devices using entirely bottom-up methods.