Lithographically Defined Cross-Linkable Top Coats for Nanomanufacturing with High-χ Block Copolymers

The directed self-assembly (DSA) of block copolymers (BCPs) is a powerful method for the manufacture of high-resolution features. Critical issues remain to be addressed for successful implementation of DSA, such as dewetting and controlled orientation of BCP domains through physicochemical manipulations at the BCP interfaces, and the spatial positioning and registration of the BCP features. Here, we introduce novel top-coat (TC) materials designed to undergo cross-linking reactions triggered by thermal or photoactivation processes. The cross-linked TC layer with adjusted composition induces a mechanical confinement of the BCP layer, suppressing its dewetting while promoting perpendicular orientation of BCP domains. The selection of areas of interest with perpendicular features is performed directly on the patternable TC layer via a lithography step and leverages attractive integration pathways for the generation of locally controlled BCP patterns and nanostructured BCP multilayers

Dépôt d'oxyde de silicium par procédé plasma hors équilibre à basse pression et à pression atmosphérique sur de l'acier : application aux propriétés anticorrosion

The aim of this study was the development of two surface treatment processes for the improvement of the corrosion resistance of steel (HLE S235). Silicon oxide films (SiOxCy) were deposited on steel substrates by plasma enhanced chemical vapor deposition (PECVD) at low pressure as well as at atmospheric pressure. Hexamethydisiloxane (HMDSO), which is an organosilicon, was the precursor. These films show very good protection and adhesion properties to steel. Gas and liquid permeability performances of coatings deposited by plasma (PECVD) are very strongly linked to their chemical composition (presence of carbon, absence of silanol) and structure (thickness, density, free volume?). These directly depend on the conditions of polymerisation process. That means it depends on the plasma parameters such pressure, power, monomer mass flow, time of treatment? Analysis about deposit morphology and its composition were necessary to characterize the deposits. We were able to obtain thick, continuous, smooth, not very porous layers, containing some carbon. The efficiency of the deposition processes of silicon oxide was validated by the study of corrosion protection properties of films by voltamperometry and electrochemical impedance spectroscopy in an aerated NaCl 0,5 M solution. For optimal conditions of treatment, in low pressure as well as in atmospheric pressure, the corrosion protection were much improved and remained constant for long immersion times (Rp stabilized after 25 h). Low pressure oxygen pretreatment allowed to increase the adhesion of the coatings to the substrate and thus the corrosion protection for the films realized at low pressure and at atmospheric pressure. The polarization resistances thus obtained reached the value of 191 kOhm.cm² and 550 kOhm.cm², respectively (untreated steel: 1,2 kOhm.cm ²).L'objectif de ce travail a été la mise au point de deux procédés de traitement de surface par voie plasma destinés à l'amélioration des propriétés de résistance à la corrosion d'un acier (HLE S235). Des films d'oxyde de silicium (SiOxCy) ont été déposés sur des substrats d'acier par PECVD (Plasma Enhanced Chemical Vapor Deposition) à basse pression et à pression atmosphérique. L'héxaméthyldisiloxane (HMDSO), qui est un organosilicié, a été utilisé comme précurseur. Ces films affichent de très prometteuses propriétés anticorrosion et d'adhésion. Les performances de perméabilité aux gaz et aux liquides des couches déposées par plasma (PECVD) sont très fortement liées à leur composition chimique (présence de carbone, absence de silanol) et à leur structure (épaisseur, densité, volume libre etc...). Celles-ci dépendent des conditions du procédé de polymérisation, c'est à dire des paramètres du plasma tels que la pression, la puissance, le débit d'oxygène, le débit de monomère, le temps de traitement? Les analyses concernant la morphologie du dépôt ainsi que sa composition ont été nécessaires afin de caractériser les dépôts. Nous avons pu obtenir des couches épaisses, continues, lisses, peu poreuses, contenant du carbone. L'efficacité des procédés de dépôts de films d'oxyde de silicium a été validée par l'étude des propriétés de protection contre la corrosion des films par voltampérométrie et par impédancemétrie en milieu NaCl 0,5 M aéré. Pour des conditions optimales de traitement, aussi bien à basse pression qu'à pression atmosphérique, les propriétés anticorrosion ont été nettement améliorées et persistent pour des temps d'immersion importants (Rp stabilisée après 25 h). Un pré-traitement à l'oxygène à basse pression a permis d'augmenter l'adhérence des couches au substrat et donc la protection contre la corrosion pour les dépôts réalisés à basse pression et à pression atmosphérique. Les résistances de polarisation ainsi obtenues ont atteint une valeur de 191 kOhm.cm² et 550 kOhm.cm², respectivement (acier non traité : 1,2 kOhm.cm²)

Influence of the carrier wafer during GaN etching in Cl2 plasma

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Influence of the carrier wafer during GaN etching in Cl2 plasma

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Aspect ratio impact of etched silicon wafers on ion energy distribution in plasma etching

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Cycling of implantation step and remote plasma process step for nitride spacer etching applications.

International audienceThe etching of silicon nitride spacers is one of the most challenging steps of transistor fabrication. It requires anisotropy to preserve the sidewalls and a high etch selectivity over the underlying substrate to achieve a high surface quality. Recently, an interesting approach using a two step-process was proposed for the etching of silicon nitride spacers with high anisotropy and minimal induced damage [1]. The first step uses an H2 implantation to selectively modify the horizontal SiN surfaces over the vertical ones, while the second step selectively removes the modified layer either via HF exposure or via a remote plasma (RP). This paper explores a new route to implement those two steps in a cycling process achieved in the same plasma reactor chamber. The reactor has the capability to produce both a capacitive plasma discharge (CCP) for the implantation step and a remote discharge for the removal step. This study demonstrates that the remote plasma process, whose etching mechanisms are driven by reactive neutrals, is highly sensitive to the material surface state and consequently an incubation time exists before the etching starts when exposed to neutrals. The modifications induced by the first implantation step shortens the incubation time offering a process window with infinite etch selectivity between horizontal implanted and vertical non-implanted surfaces. Based on this understanding a two-step cycling process was developed and applied successfully to the etching of Si3N4 spacer patterns for imager applications

Etching of Silicon and Silicon Oxide in a Pulsed Inductively Coupled Plasma with Chlorine

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Improvement of sidewall roughness of sub-micron silicon-on-insulator waveguides for low-loss on-chip links

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CYCLING OF IMPLANTATION STEP AND REMOTE PLASMA PROCESS STEP FOR NITRIDE SPACER ETCHING APPLICATIONS.

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Aspect ratio impact of etched silicon wafers on ion energy distribution in plasma etching

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