Radical-Enhanced Deposition and Etching of Thin Films without Plasma: Dream and Reality

Description

Manufacturing of semiconductor devices relies on deposition and etching of thin dielectric, semiconductor and metallic films of various functionalities. A reduced processing temperature additionally extends application areas, allowing manufacturing of devices on (or made of) thermally-unstable materials such as e.g. glass and plastic. A plasma is often used to partially substitute thermal energy by the energy of electrons and ions generated: plasma produces reactive radicals caused by electron-impact collisions. However, two main limitations make the use of plasma less attractive: damage to the wafer under treatment and numerous (tens, hundreds) chemical reactions. As a result, the wafer surface is exposed to a mixed flux of ions, radicals, atoms, and UV photons. This makes the composition and structure of the exposed area hard to predict and control.
This work explores alternative techniques to generate radicals without plasma. We choose processes where dissociation of a certain precursor to form radicals can be achieved by (a) collisions with a hot tungsten wire heated up to a temperature in the range of 1600-2000 oC, and (b) an expanding supersonic jet of molecules. We use in situ real-time spectroscopic ellipsometry in combination with ex-situ techniques, to characterize thin-film deposition and/or etching processes. In this presentation, the concept will be explained and discussed; several examples of the radical-enhanced processes, enabled by utilizing a hot wire instead of using a plasma, will be given. The examples include etching of tellurium (Te) as well as chemical vapour deposition (CVD) and atomic layer deposition (ALD) of tungsten (W) films.

Period	17 Nov 2015 → 20 Nov 2015
Event title	The 3rd International Conference on Advanced Electromaterials
Event type	Conference
Conference number	3
Location	Jeju, Korea, Democratic People's Republic ofShow on map
Degree of Recognition	International