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Multi-chamber PECVD cluster system

English title Multi-chamber PECVD cluster system
Applicant Ballif Christophe
Number 133832
Funding scheme R'EQUIP
Research institution Institut de microtechnique EPFL - STI - IMT
Institution of higher education EPF Lausanne - EPFL
Main discipline Material Sciences
Start/End 01.08.2011 - 30.04.2013
Approved amount 300'000.00
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All Disciplines (2)

Material Sciences
Microelectronics. Optoelectronics

Keywords (3)

PE-CVD; Mulit-chamber Deposition System; Thin Film Silicon

Lay Summary (English)

Lay summary

Thin film silicon layers deposited out of a plasma phase can find a wide variety of application;they can be used for low cost solar cells, high efficiency crystalline solar cell, as well as base material for the thin film transistors in displays of mobile devices, computer monitors and TV screens. Within this project, a deposition platform for thin film silicon is purchased and installed at the Photovoltaics and Thin Film Electronics Laboratory at the EPFL (IMT Neuchâtel), but the system will be made available to other research groups at EPFL. The requested system comprises a cluster of 3 deposition chambers with gas showerheads and a central loading unit with a load-lock allowing multiple sample charging, offering thereby a maximum of versatility. In the starting configuration, the system is equipped with dedicated chambers for the deposition of amorphous and micro-crystalline silicon as well as mixed phase nano-crystalline silicon oxides, as well as other Si based alloys. Besides solar and macro-electronic applications, the system will also be used for optical applications like multilayer stacks and waveguides as well as MEMS and sensors.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


Back-Contacted Silicon Heterojunction Solar Cells: Optical-Loss Analysis and Mitigation
Paviet-Salomon Bertrand, Tomasi Andrea, Descoeudres Antoine, Barraud Loris, Nicolay Sylvain, Despeisse Matthieu, Wolf Stefaan De, Ballif Christophe (2015), Back-Contacted Silicon Heterojunction Solar Cells: Optical-Loss Analysis and Mitigation, in IEEE Journal of Photovoltaics, 5(5), 1293-1303.
Silicon Heterojunction Solar Cells With Copper-Plated Grid Electrodes: Status and Comparison With Silver Thick-Film Techniques
Geissbuhler Jonas, Wolf Stefaan De, Faes Antonin, Badel Nicolas, Jeangros Quentin, Tomasi Andrea, Barraud Loris, Descoeudres Antoine, Despeisse Matthieu, Ballif Christophe (2014), Silicon Heterojunction Solar Cells With Copper-Plated Grid Electrodes: Status and Comparison With Silver Thick-Film Techniques, in IEEE Journal of Photovoltaics, 4(4), 1055-1062.


Group / person Country
Types of collaboration
NREL United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Helmholtz Zentrum Berlin Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Ecole Polytechnique Paris France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
EPFL-CMI Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Uni Delft Netherlands (Europe)
- in-depth/constructive exchanges on approaches, methods or results
AIST Japan (Asia)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
42nd IEEE Photovoltaic Specialist Conference (PVSC), 2015 Talk given at a conference Advances in crystalline silicon heterojunction research and opportunities for low manufacturing costs 14.06.2015 New Orleans, United States of America Ballif Christophe;

Associated projects

Number Title Start Funding scheme
125177 Interface texturing for light trapping in solar cells 01.10.2009 Project funding
149588 Nanocrystalline silicon oxide for solar cells and light emission 01.05.2014 Project funding
139135 Multi-chamber multi-source sputtering cluster system 01.10.2012 R'EQUIP
126926 Vertically integrated amorphous silicon sensors for particle detection 01.05.2010 Project funding
134506 Wiring quantum dots - phase separation inducing new functionality 01.08.2011 Project funding


We propose the acquisition of a new state-of-the art cluster PECVD (plasma enhanced chemical vapor deposition system). The system design should allow a maximum reproducibil-ity, versatility, wide parameter space to explore new plasma chemistry, and avoid all issues linked to contaminants especially critical in the case of semiconductor devices. It will allow the synthesis of “classical” and novel materials, essential disordered semiconductors (a-Si, nc-Si), mixed phase insulating/conductive materials (e.g. a-SiOx/nc-Si and variation thereof, ), dielec-tric layers (e.g. SiOxNyCz) and mechanical layers. These layers should find a wide variety of application, such as high/low bandgap absorber in solar cells, as optical layers/stacks or wave guides in MOEMS and MEMS, as well as protective or insulating layers in a variety of devices and sensors. The system acquisition is supported by several research groups of EPFL and by the CMI, as it extends its processing capabilities.We focus first on layers for photovoltaic application, the core of the activities at the Photovol-taics and Thin Film Electronics Laboratory in Neuchâtel (PV-Lab). The PV-Lab has a worldwide reputation of introducing novel procedures and innovative ideas for thin film silicon photovol-taics. Several concepts that are found in current state of the art for high efficiency devices have been developed in the lab, among those are the use of high plasma excitation frequencies (VHF regime), microcrystalline silicon as absorber material, thin film silicon tandem cells, intermedi-ate reflector layers, textured ZnO transparent conductors, etc. Today thin film silicon is a well established material for the production of photovoltaic modules on an industrial scale; the total production volume reached close to 750 MW in 2009. Continu-ing progress in a field that reached a certain level of maturity requires a reproducible and reli-able technology base on all levels, but especially so in research and development. With a depo-sition system that is capable of delivering this reliability by a high level of automatisation and process control, researchers will be able to concentrate on the development of novel ideas and novel materials rather than meticulously keeping track of experimental parameters. The main use of the requested system will be devoted to the development of thin film silicon solar cells on glass and on flexible substrates. This later aspect clearly differentiates the work from more common applications based on rigid glass substrates. Beside their obvious advan-tages for building integration, flexible solar modules also have huge cost saving potentials dur-ing fabrication, transport and deployment. In order to fully exploit the advantages of flexible substrates, the PV-Lab abandoned temperature resistant, but costly polyimide or steel sub-strates in favour of low cost plastics like poly-ethylene. The PV-Lab could recently demonstrate stabilized efficiencies close to 10% on such flexible low cost substrates. The modular design of the system will be employed to deposit a variety of materials without the risk of cross-contamination. For solar cell applications, these considerations are mostly con-cerned with dopants like boron and phosphorous that must be avoided in the undoped ab-sorber layers because there they act as impurities. In a more general sense the need for sepa-ration of growth processes extends also to the use of elements that widen or shrink the band-gap like carbon or germanium, or to oxygen and nitrogen that may be required for the growth of diffusion barriers against moisture. They may be required in one part of the cell, but must be avoided in another; this is only possible with a multi-chamber design. Through its specifica-tion, the system should in particular allow the fabrication of standard and novel absorber ma-terials (especially low and high gap materials with reduced metastablity), to a better control of the interfaces in semiconductor devices. It has the potential to lead to breakthrough in the field of thin film PV.Finally, in the last part of the proposal, we’ll show other specific applications of the PECVD cluster linked to application for microchanel plates detectors, electrodes in nanowire solar cells, ultra-pure rare earth doped oxides and multilayers waveguides.The equipement shall be used within several running FNS project, but also in numerous other publically funded projects (e.g. by EU, by SFOE,…)