Traitements et re-utilisation des slurries dans l’industrie microelectronique

National audienceno abstrac

Réutilisation d’un slurry dans l’industrie microélectronique

National audienceno abstrac

Effects of mixed oxidizers and additives on the removal rate of tungsten film on wafer: Preliminary study to optimize Tungsten-CMP process

International audienceno abstrac

Recycling a slurry for reuse in chemical mechanical planarization of tungsten wafer: effect of chemical adjustments and comparison between static and dynamic experiments

International audienceRecycling abrasive slurry that has been used in chemical mechanical polishing (CMP) is one of the options for reducing the cost of manufacturing microchip processors. We use ultrafiltration which is a method of choice to recycle silica (SiO2)-based slurry. Taking into account that the chemical composition of abrasive slurry plays an important role in tungsten CMP (W-CMP), chemical adjustments have to be made so that the concentrated after used slurry can be reused. In this study, we investigate the effects of chemical additives (iron catalyst, oxalic acid as complexing agent and surfactants as stabilizers) in slurry that has been retreated by ultrafiltration. Experiments are conducted both under static and dynamic conditions and results are compared to better understand the effect of chemical adjustments on the main performances of W-CMP. An optimal chemical adjustment is proposed through a design of experiments evaluation to obtain a concentrated after used and chemically adjust slurry comparable to the operational point of use slurry

Treatment and slurry reuse in microelectronic industry

International audienceno abstrac

Treatment and slurry reuse in microelectronic industry: case of silicium CMP

International audienceno abstrac

Reused of Slurry By Membrane Processes for Microelectronic Industry

International audienc

Retreatment of silicon slurry by membrane processes

International audienceThe purpose of the present study is to develop a process to regenerate the polish liquid used in Chemical and Mechanical Polishing (CMP), called "slurry", and more specifically Silicon CMP slurry. Physico-chemical analyses show a considerable dilution of slurry through washing waters used in polishing. Thus, this effluent has been characterised for a better identification of the deviations from the slurry of reference (Point Of Use). Hence, the principle is to regenerate this effluent by membrane processes. The ultrafiltration results obtained at laboratory scale have led to the development of an industrial prototype. An optimal utilisation of this treatment allows completing a two-step process: the reconcentration by ultrafiltration and a chemical adjustment by addition of concentrated slurry. A stable behaviour of the slurry at the different steps of the process has been observed. Polishing results are similar with retreated and POU slurries. Furthermore, the functioning at industrial scale permits to maintain the performances obtained on the laboratory pilot

Static dissolution rate of tungsten film versus chemical adjustments of a reused slurry for chemical mechanical polishing

International audienceTungsten is widely used as deposited layer for the multi-level interconnection structures of wafers. The chemical composition of abrasive slurry plays an important role in chemical mechanical polishing (CMP) process. Removal of tungsten is driven by complex oxidation mechanisms between slurry components. The slurry for tungsten CMP generally contains oxidizer, iron catalyst, complexing agents and stabilizers in a pH adjusted solution of abrasive particles. Interaction between iron complex and H2O2 in the slurry is the main factor governing the chemical mode of material removal, oxidation potencies and kinetics. In this study, we investigate the effects of chemical additives in silica (SiO2)-based slurry on the removal rate of the tungsten film. Experiments were carried out in static batch as a preliminary study to understand and optimize chemical mechanisms in CMP-Tungsten process. Experiment designs were conducted to understand the influence of the chemical additives on the main performances of W-CMP. Used slurry, concentrated and retreated with chemical adjustments, is compared to the original slurry as a reference