Prof. Pere Roca i Cabarrocas, is an Electrical Engineer from the “Universitat Politécnica de Barcelona”. In 1984 he moved to Paris, where he received his PhD from University Paris VII in 1988. After a post-doc position in Princeton University he joined the Laboratory of Physics of Interfaces and Thin Films at Ecole Polytechnique where he holds a position as a CNRS director of research and as a professor. From 2012 to 2020 he was the director of LPICM and of the French PV Federation. He is currently the scientific director of IPVF. He has thirty years of experience in the field of plasma deposition of silicon based thin films for large area electronic applications. His topics cover the study of RF discharges for the deposition of amorphous, polymorphous and microcrystalline silicon thin films. He has used in-situ diagnostic techniques such as UV-visible ellipsometry, Kelvin probe and time resolved microwave conductivity to understand the growth of these materials and apply them to the production of devices such as solar cells, thin film transistors, particle detectors, sensors, etc. More recently he has been applying silicon nanocrystals synthesized in the plasma as building blocks for the epitaxial growth of silicon thin films and Si/Ge quantum wells. On the other hand, he has extended the plasma processes to the growth of vertical silicon nanowires for third generation solar cells and of horizontal ones for planar electronic applications. He was the recipient of the Médaille Blondel in 2004, of the Innovation Award at Ecole polytechnique in 2009 and the Silver medal from CNRS in 2011. Since 2016 he is invited professor at Nara Institute of Technology and scientific director of IPVF since 2019. He has over 520 papers, holds 38 patents and has supervised 56 PhD students.

Plasma Enhanced Chemical Vapor Deposition: From the basics of Plasma Physics to Thin Film Deposition and Epitaxial Growth 



Pere Roca i Cabarrocas


In this tutorial I will address the basics of plasma processes used for the deposition of thin films. We will start with the reactions taking place in the gas phase, which are responsible for a wide variety of film growth precursors: radicals, ions, electrons, photons, and clusters. The charge and reactivity of these species determines their interaction with the substrate and the “growing surface”, where cross-linking reactions activated by the substrate temperature determine the structure and opto-electronic properties of the films. We will see that the growing surface can extend over few tens of nanometers, due to the impact of energetic ions and the in-diffusion of atomic hydrogen. Moreover, the nature of the substrate: conductive, insulating, reactive, etc. has also a strong impact on the growth process and resulting film properties; this is particularly true in the case of using low melting temperature materials which can catalyze the growth of nanostructures. Finally we will discuss how the richness and complexity of the plasma and surface processes allows to produce a wide variety of materials, ranging from hydrogenated amorphous silicon (a-Si:H); nano- and micro-crystalline silicon, polymorphous, epitaxial growth and nanowires.


Tutorial Speaker


Pere Roca i Cabarrocas

LPICM-CNRS, Ecole polytechnique, Institut Polytechnique de Paris, France

Tutorial (11:20-12:20, 23rd Aug, Zhongda Lecture Hall (中大报告厅))



LPICM-CNRS, Ecole polytechnique, Institut Polytechnique de Paris, France


Route de Saclay, 91128 Palaiseau, Cedex






Tutorial: Pere Roca i Cabarrocas