AVS 49th International Symposium
    Plasma Science Thursday Sessions
       Session PS+TF-ThM

Paper PS+TF-ThM8
Plasma and In Situ Film Diagnostic Study of Amorphous and Microcrystalline Silicon Deposition

Thursday, November 7, 2002, 10:40 am, Room C-103

Session: Plasma Enhanced Deposition
Presenter: W.M.M. Kessels, Eindhoven University of Technology, The Netherlands
Authors: W.M.M. Kessels, Eindhoven University of Technology, The Netherlands
J.P.M. Hoefnagels, Eindhoven University of Technology, The Netherlands
Y. Barrell, Eindhoven University of Technology, The Netherlands
P.J. Van den Oever, Eindhoven University of Technology, The Netherlands
M.C.M. Van de Sanden, Eindhoven University of Technology, The Netherlands
Correspondent: Click to Email
Our comprehensive investigation of the film growth process of amorphous silicon (a-Si:H) from a remote H@sub 2@/SiH@sub 4@ plasma has recently also been extended to microcrystalline silicon (µc-Si:H). This material is of particular interest for applications in thin film solar cells and thin film transistors because of its higher stability. In this contribution we will compare the absolute densities of the different silane radicals, as determined from cavity ringdown spectroscopy, for the two plasma regimes yielding the two different materials. Moreover, the surface reaction probability of the silane radicals will be presented as obtained under real deposition conditions (e.g., as a function of substrate temperature) by time-resolved cavity ringdown experiments. >From this information, it is, for example, revealed that Si, SiH, and SiH@sub 3@ radicals have approximately an equal contribution to µc-Si:H growth, unlike a-Si:H film growth which is almost completely governed by SiH@sub 3@. Furthermore, we will present 'film depth-information' with respect to hydrogen bonding, hydrogen concentration, and other structural film properties as has been obtained by in situ monitoring of film growth by attenuated total reflection infrared spectroscopy and spectroscopic ellipsometry. This powerful combination of diagnostics applied to the well-characterized plasma conditions has revealed a rather homogeneous hydrogen distribution throughout the film (also for µc-Si:H) apart from an initial incubation phase corresponding to interface/surface layer formation. The interface thickness and surface roughness increase with increasing deposition rate but decrease with increasing substrate temperature. New insights into the film growth process of both materials will be discussed.