Depositions and Etching chambers: low pressure plasma-enhanced processes
Reactive cathodic sputtering (PVD)
(mise à jour 10 octobre 2022)
Magnetron sputtering (DC, RF, HiPIMS)
Cluster of two deposition chambers dedicated to sulphides (Room RC012)
Contact : Marie-Paule Besland, Pierre-Yves Jouan
The cluster is made up of two chambers linked together by an introduction airlock, an airlock equipped with a transfer rod which allows the samples to be loaded into one of the chambers.
Reactor 1: deposition chamber dedicated to GaV4S8 deposition
This reactor is equipped with a 1.3'' (3.25 cm diameter) magnetron source, located on the side of the chamber (a central flange allows the installation of a 2nd cathode of 2'' diameter (5 cm)). The chamber is supplied by two gas lines: one classical allowing to work in pure Ar or reactive plasma with O2 or N2, the other is an H2S gas supply line for deposition of sulfur materials. The H2S line is equipped with the necessary safety devices: ventilated storage cabinet, connection with an N2 safety line, commissioning switch, emergency stop, effluent filtration column and H2S detector.
This reactor is used in Ar/H2S reactive plasma with a GaV4S8 target for the controlled deposition of stoichiometric and crystallized GaV4S8 after ex-situ annealing under a controlled atmosphere.
GaV4S8 belongs to the " Mott insulator" materials family and is studied at IMN for memory applications and neuromorphic systems.
The GaV4S8 target was made from powder synthesized in the laboratory and then transformed into a target by Spark Plasma Sintering (SPS on the PNF2 platform in Toulouse).
Reactor 2: deposition chamber dedicated to CIGSe(S) and sulfur materials
This home-designed deposition chamber has been installed in the framework of a CIFRE PhD thesis (Romain Meunier; 2012-2016) funded by CROSSLUX company. The chamber is equipped with a 2” (5 cm) diameter magnetron cathode and connected to a main gas line (Ar, O2, N2) and to a secured H2S line. It has been used in pure Ar plasma and Ar/H2S plasma to produce CIG(Se,S) thin films (1.5 to 2 µm) from a single commercial CIGSe target of different chemical composition in Selenium (Se).
The system is also equipped with safety devices: secured valve for H2S supply, H2Se detector in the room (control at the end of deposit when opening the chamber). The samples are loaded through a quick-opening porthole while the chamber is to atmospheric pressure with flowing Nitrogen (N2).
After optimization of the deposition parameters, CIGSe and CIG(S,Se) thin layers were obtained after a post-deposition ex-situ annealing under neutral flux (Ar or N2) between 500 and 650°C.
Plasma Enhanced Chemical Vapour Deposition (PECVD)
ICP (PECVD) reactor for inductively coupled plasma - plasma enhanced chemical vapour deposition with 3 organo-metallic injection lines + 1 liquid solution injection line (DLI)
Contact : Agnès Granier
IMN's PECVD thin film deposition reactor is equipped with an inductively coupled radio frequency (13.56 MHz) plasma source (ICP source) that operates at low pressure (1-10 10-3mbar). This plasma diffuses into a deposition chamber equipped with a substrate holder (13 cm in diameter) that can be polarised by radio frequency and a Woolam M2000 spectroscopic ellipsometer that allows, virtually undisturbed, the growth of the thin film to be monitored in situ in real-time thin film growth from 470 simultaneously recorded optical wavelengths (245-1000 nm spectral range). This PECVD reactor is also equipped with 3 organometallic vapour injection systems (allowing the simultaneous and controlled injection of organometallics of different vapour pressures) and a liquid solution injection system. Plasma diagnostics can also be added to identify neutral and charged reactive species in the plasma and provide insight into plasma-surface interactions.
Organometallic vapour injection systems for
- titanium isopropoxide (TIPT): Nanosource, Omicron Technologies
- hexamethyldisiloxane (HMDSO): Minisource, Omicron Technologies
- tungsten pentaethoxide: bubbler with carrier gas in a temperature controlled oven, Omicron Technologies
Injection of colloidal solutions
- Kemstream direct liquid injector (DLI), injection control unit (ICU) and Vapsoft injection control software to drive the pulsed injection sequence
Plasma diagnostics
- Optical emission spectrometers: Jobin Yvon HR460 (180-850 nm), Maya Pro2000, Ocean Insight (235-475 nm)
- Electron and ion densities and plasma potential: Langmuir Impedans Octiv Suite | 350kHz-240MHz | QC
- Neutral and ionic species analysis: mass spectrometry: Hiden EQP 300
This PECVD reactor allows to study the growth of thin films under perfectly controlled plasma conditions (ion flux and energy) by implementing in situ and real time characterisation of the thin film by ellipsometry and of the plasma by optical emission spectroscopy (determination of the active species flux). Furthermore, the RF power (typically 400 W) can be applied to the plasma in pulsed mode (from 1 Hz to 10 kHz) which allows to reduce the deposition temperature and for example to obtain TiO2 in anatase form at a temperature lower than 80°C.
By injecting oxygen into the ICP plasma, it is thus possible to deposit customisable thin oxide layers ranging from one oxide (SiO2, TiO2.... ) to an amorphous mixed oxide (TixSi1-xO2) or metal-substituted anatase (TiO2:W5+/6+) to a SiO2:TiO2 nanocomposite obtained by injecting a colloidal solution of TiO2 nanoparticles into an O2/HMDSO (hexamethyldisiloxane) plasma. Pulsed injection of the solution via the DLI allows control of the rate of nanoparticles dispersed in the host matrix.
Magnetron sputtering (DC, RF, HiPIMS)
Cluster of 2 chambers dedicated for nitrides/oxides/oxynitrides and pure metals
1 cluster with sas and 2 chambers : 1 PVD chamber with 4 cathodes (3’’) + RF polarisable and heatable (max 800°C) sample holder + 1 PECVD/PVD (ICP + 3 cathodes)
Contact : Pierre-Yves Jouan
The laboratory has a Cluster (Figure 1) equipped with 2 deposition chambers (referenced PC1 and PC2) used for the deposition of thin films by magnetron sputtering.
These two deposition chambers are equipped with a load lock chamber for rapid introduction of samples into the reactor under high vacuum. The residual pressure before deposition of less than 5x10-5 Pa. The equipment has 4 gas lines: Ar, N2 , NH3 and O2 for the synthesis of thin films of pure metal, oxides, nitrides, oxynitrides ... Working pressure as well as gas flow can be controlled independently.
The transfer of samples from the SAS to PC1 or 2 is done manually using a magnetic linear motion drive (Figure 2).
The PC1 deposition chamber is equipped with an ICP source and 2 magnetron cathodes (targets 3 inches in diameter) in a co-focal position (Figure 3). This configuration allows the simultaneous sputtering of the two targets (co-sputtering). Magnetron cathodes are powered by DC or radio-frequency (DC or RF Magnetron) voltage generators.
The substrate holder is rotatable, heating and RF biasable.
The PC2 deposition chamber is equipped with 3 magnetron cathodes 3 inches in diameter (Figure 4) powered by DC, RF or HiPIMS Magnetron (Figure 5) generators. The substrate holder is heatable and biasable in DC or RF.
Figure 5
Reactive sputtering reactor with airlock and three 4'' magnetron cathodes (AV02)
La Chantrerie site, Polytech
Contact : Jérémy Barbé
Description:
The AV02 reactive sputtering reactor at IMN has three 4" (100 mm) cathodes in co-focal configuration, located under the substrate holder. All the cathodes are equipped with a magnetron which allows to increase the target sputtering rate and the thin film growth rate. The target-cathode distance can be varied (range 12-18 cm) for each cathode. The cathodes can be used simultaneously for co-sputtering with two RF generators (13.56 MHz) with a maximum power of 1000 W and a DC generator that can be connected to each cathode independently. The substrate holder can accommodate samples of 150 mm (6'') diameter and can be biased by a RF generator. The substrate holder manipulator has two movements: a vertical translation movement for the transfer/positioning of the substrate and a rotation movement which allows to realize homogeneous films in thickness. The reactor is fed by three gas lines: Argon (Ar) line (flowmeter 1-100 sccm) and two reactive gas lines (O2 and N2 with flowmeters in the range 0-10 sccm and 0-5 sccm, respectively) allowing the realization of oxidized and nitrided materials in non-equilibrium condition. The pumping system and the airlock allow to maintain a residual vacuum of 10-7 - 10-8 mbar in the deposition chamber. Plasma diagnostic techniques can be implemented on the system thanks to the different openings and portholes positioned on both sides of the main chamber.
Research topics:
The reactor was commissioned in the framework of a Technological Research Team (ERT) and two CIFRE doctoral theses with the company MHS Electronics (2007-2010) and the laboratory IREENA (now IETR).
Initially equipped with two ceramic targets TiTaO (Ti0.6Ta0.4O) and BST (Ba0.2Sr0.8TiO3) and a metallic target of Titanium (Ti), the objective of the ERT was the development of two materials (TiTaO and TiON) with high capacitances and resistances for CMOS technologies:
Current research includes the development of thin film materials based on VNxOy (vanadium oxynitride) or TiNx (titanium nitride) for micro-supercapacitors. These materials are synthesized by using vanadium and titanium targets in the presence of reactive gas. The control of the deposition parameters (gas flow rates, pressure, power, substrate bias...) allows the synthesis of new capacitive or pseudocapacitive electrode materials with improved microstructural (density, crystallinity) and electrochemical properties for energy storage devices such as micro-supercapacitors. Unlike other processes (electrodeposition), reactive sputtering allows to elaborate materials out of thermodynamic equilibrium, and to study precisely the role of composition (multications, oxynitrides) and oxidation states on electrical energy storage properties.
In a more general way, this reactor is used to deepen the knowledge of reactive plasmas, in particular to characterize the different deposition regimes (metallic, contaminated) as a function of the partial pressure of the reactive gas, and the impact on the morphology and the structural properties of the deposited layers.
IMN mutualized cathodic sputtering reactors
Contact : Pierre-Yves Tessier
The laboratory has two Alliance Concept AC450 reactors (in co-focal and planar configurations) used for the deposition of thin films by magnetron sputtering. The deposited thin films are typically between a few nanometres and a micrometre thick.
Both reactors are equipped with a sample load lock chamber for rapid introduction of samples into the reactor under high vacuum with a residual pressure before deposition of less than 5x10-5 Pa.
AC450 reactor in co-focal configuration:
This reactor has a manual load lock chamber (Figure 1). In the upper part of the deposition chamber, 2 magnetron cathodes are positioned for 3-inch diameter targets (Figure 2). The axes of the 2 magnetron cathodes aim at the substrate holder which is located in the lower part of the chamber.This configuration is used to achieve simultaneous sputtering of the two targets (co-sputtering). The magnetron cathodes are powered by DC magnetron generators.
The substrate holder can accommodate substrates up to 100 mm in diameter (Figure 3). It is rotatable, heatable up to 800 °C and RF-biased.
The equipment has three gas lines: Ar, N2 and O2 for the deposition of pure metal, oxide, nitride and oxynitride films. Discharge pressure and gas flows can be controlled independently.
A third 2" diameter magnetron cathode in a vertical position, used with an offset substrate arm, is used for the deposition of precious metals (e.g. Au, Pt).
AC450 reactor in planar configuration:
The system consists of an automatic transfer chamber and a deposition chamber (Figure 4). In the upper part, 4 magnetron cathodes are positioned vertically on which the targets to be sputtered can be fixed (diameter 2 inches).
Cathodes 1 and 2 are RF-biased, a type of polarisation that should be reserved for the deposition of electrically insulating materials.
Cathodes 3 and 4 are DC biased, a mode suitable for the deposition of metals and conductive materials.
The 4-inch diameter substrate holder is located in the lower part of the machine on an arm which can be position under either target. The substrate holder is RF-biased.
Two substrate holder stations are possible:
- Standard N1 station without heating
- N2 station for heating up to 800°C (water cooling).
The equipment has 3 gas lines: Ar, N2 and O2 for the film deposition of pure metal, oxides, nitrides and oxynitrides. Discharge pressure and gas flows can be controlled independently.
Plasma etching : 3 reactors including a mutualized one
Contact : Aurélie Girard, Christophe Cardinaud
“Alcatel" etching reactor
Fluorinated plasmas, alkane-hydrogen mixture or liquid organic precursors, with the possibility of adding O2, N2 and Ar
This reactor is so called in relation to its plasma source. It is an inductively coupled source with a cylindrical geometry consisting of an alumina tube surrounded by a circular "half Nagoya III" antenna. This source is powered by a 13.56 MHz RF generator, with a maximum power of 1500 W. The substrate holder, located in the diffusion chamber beneath the plasma source, receives 4" diameter wafers and is equipped with a mechanical clamping ring. Its temperature is controlled by a thermostat (-40 / +60°C), He injection on the back side of the wafer ensures heat transfer. The substrate holder can be RF biased (13.56 MHz – 600 W max).
The vessel is equipped with several ports allowing plasma diagnosis by means of optical emission or absorption spectrometry (200 – 1000 nm), mass spectrometry (0.3 – 300 amu) and electrostatic probes. A multi-wavelength (412 – 730 nm) UV-visible ellipsometer allows real-time monitoring of the process; with direct access to etching kinetics in the case of transparent thin films (Figure 1). This reactor is coupled to a surface analysis chamber (SPECS) by a vacuum transfer system (Figure 2).
Equipped with ten gas lines, this reactor is dedicated to plasma etching processes operated in fluorinated (SF6, fluorocarbon) gases, alkane-hydrogen mixtures or liquid organic precursors in mixtures with O2, N2 and Ar.
Figure 1- “Alcatel" plasma etching reactor : in front monochromator for optical spectroscopy (emission and absorption).
Figure 2 - Scheme of sample transfert under Ultra High Vacuum between Alcatel chamber and surface analysis chamber SPECS
“Nextral” plasma etching reactor: pure Cl2 or mixed with H2, Ar, or N2
This is a Nextral NE810 commercial reactor that we have modified. The original microwave plasma excitation system has been replaced by an inductively coupled RF excitation (13.56 MHz – 600 W max) by means of a single-turn circular antenna around the quartz tube. The substrate holder is RF biased (13.56 MHz – 300 W max). The sample holder accepts samples up to 4" in diameter.
Plasma diagnostics by electrostatic probes and optical emission spectrometry can be installed on this reactor.
This reactor is dedicated to studies and etching processes in chlorinated plasma: pure Cl2 or mixed with H2, Ar, or N2.
“Nextral” reactor
“Optimist” plasma chamber, sample holder -180°/+1100°C
This plasma reactor is part of a set called "Optimist Platform". This platform is a shared tool of the CNRS network of Cold Plasmas (history and detailed presentation, see Optimist Platform) open to the plasma community. The source is an RF powered planar inductive source (13.56 MHz - 500 W max). The sample holder is temperature controlled (-180°C / +1100°C) by a circulation of liquid nitrogen coupled with a heating system. The sample size is 10*10 mm2. The reactor is connected under ultra-vacuum to the "SPECS" surface analysis assembly (Figure 1), with direct transfer of the sample holder (Figure 2). This assembly, which is unique in France, allows the study of the physical and chemical mechanisms involved in material and surface treatment processes in a controlled atmosphere (gas or plasma) or under vacuum over a very wide range of temperatures; sample transfer and analysis is possible at any temperature between -180°C and +100°C.
Plasma diagnostics by optical emission spectrometry (200 - 1000 nm), mass spectrometry (0.3 - 300 amu) and electrostatic probes can be installed on the reactor.
Four gas lines are available, among those from the "Alcatel" reactor. A fifth line dedicated to SiF4 was added in 2020 for studies in cryogenic etching of silicon-based compounds.
Figure 1 : « Optimist » reactor and « SPECS »
surface analysis system
Figure 2 : « Optimist » platform sketch coupling plasma treatment and surface analysis.