Surface Smoothing at the Atomic Scale

Abstracts

Bias-Pulsed Atomic Layer Etching of Wide Bandgap Semiconductors
Julian Michaels, University of Illinois

Plasma Atomic Layer Etching (ALE) offers unparalleled precision when etching semiconductor material because it removes single atomic layers in each controlled etch cycle; however, the regular purging of reagent gases substantially slows its etch rate, limiting the widespread applicability of ALE processing. Bias-Pulsed Atomic Layer Etching (BP-ALE) offers the same level of atomic precision as conventional ALE at approximately ten times the speed. It eliminates the purging steps in a cycle and instead relies solely on pulsing the plasma DC bias. BP-ALE has been applied to a variety of wide bandgap semiconductors and has been shown to smooth the etched surface significantly through atomic force microscopy. This talk overviews BP-ALE, highlighting its differences to ALE, and seeks to predict the future materials for which it is compatible.

Using atomic layer deposition and etching for surface smoothing in 3D
Nicholas Chittock, Eindhoven University of Technology

As nanoelectronics pushes towards ever smaller technology nodes, control of surfaces and interfaces becomes increasingly important. One way to control the surface quality is to implement atomic layer deposition (ALD) and etching (ALE), where smoothing has been observed experimentally. However, the mechanism which drives smoothing was not understood for both ALD and ALE. In this talk we will discuss a model developed to predict the rate of smoothing for ALD and ALE of Al₂O₃, showing good agreement with experimental data and elucidating the mechanism by which smoothing occurs. By studying surface smoothing from ALD and ALE interesting avenues for combined processing became apparent, which enabled smoother films than can be achieved by either technique individually.