AVS 62nd International Symposium & Exhibition
    Plasma Science and Technology Friday Sessions
       Session PS+SS+TF-FrM

Invited Paper PS+SS+TF-FrM6
Potential Solutions for Atomic Precision Etching

Friday, October 23, 2015, 10:00 am, Room 210B

Session: Atomic Layer Etching (ALE) and Low-Damage Processes II
Presenter: Olivier Joubert, LTM-CNRS, France
Authors: O. Joubert, LTM-CNRS, France
E. Despiau-Pujo, LTM, France
G. Cunge, LTM - CEA/LETI, France
L. Vallier, Univ. Grenoble Alpes-CNRS-CEA/Minatec-LTM, France
J. Dubois, Univ. Grenoble Alpes-CNRS-CEA/Minatec-LTM, France
A. Tavernier, Univ. Grenoble Alpes-CNRS-CEA/Minatec-LTM, France
O. Luere, Applied Materials
S. Banna, Applied Materials
Y. Zhang, Applied Materials
Correspondent: Click to Email
The continuous downscaling of device dimensions and introduction of new transistor architectures such as FDSOI or FINFEts transistors is bringing up new challenges for plasma etching technologies. For the gate transistor for example, future technological nodes require patterning capabilities in a range of dimension going below 10 nm. Extremely thin layers (less than 1nm) of materials are now involved in the stacks of materials to pattern requiring in some cases an etch precision better than 1 nm. In other words, the etch selectivity and physical/ chemical damage induced by the plasma must be controlled in a way such as the plasma can stop in a layer of materials as thin as 1nm without damaging the underlayers or the substrate material. Such a precision in processes becomes difficult to reach with the state of the art plasma technologies.

In this presentation, we will describe two plasma technologies that could potentially reach that goal.

A new Technology is the so-called “Thin Layer Etching” technology. In the first step of the TLE technology, H2 or He Ions produced by a capacitive plasma induce modification of silicon based materials while in a second step the modified material is removed in an all dry NF3/NH3 remote plasma that form volatile products with the modified silicon based materials. Performance achieved by TLE for nitride spacer etching will be shown and compared to conventional ICP results.

Fast gas pulsing technology could also be a promising way to form ultra-thin reactive layer during plasma processing, allowing atomic precision etching to be achieved. This concept will be explained and discussed based on preliminary result of silicon etching in chlorine plasmas using atomistic simulation.