(Invited) Selective Area Growth of Deactivating Polymers
2019; Institute of Physics; Volume: MA2019-02; Issue: 24 Linguagem: Inglês
10.1149/ma2019-02/24/1137
ISSN2152-8365
Autores Tópico(s)Advanced Polymer Synthesis and Characterization
ResumoAs the semiconductor community continues scaling, area selective atomic layer deposition (ASD) offers the potential to relax down-stream processing steps by enabling self-aligned processes (e.g. self-aligned via). ASD can be achieved under a variety of conditions and, with the use of organic inhibiting materials, exhibit some of the highest levels of selectivity. However, the organic materials exploited are generally relegated to small molecules and may require multiple cycles of etch-back processes followed by renewal of the surface protection coating. The chemical composition of polymeric materials offers significant potential to broaden the number and film compositions that can be selectively deposited as they draw from such a vast number of chemical functionalities that can be exploited to tailor surface properties [1,2]. There are two approaches to exploiting polymers for ASD, (i) grafting to a substrate with polymer brushes or (ii) growing polymers from a surface. Grafting polymer brushes, with materials shown to inhibit ALD film growth and functionalized with metal binding ligands, exhibited poor selectivity to surfaces and resulted in high defectivity on patterned surfaces where polymer particles were observed on both a metal and dielectric. Growing polymers from a substrate is an attractive strategy, though difficult to realize experimentally. Using a facile synthetic route, a surface binding monomer was engineered that maintained high activity for surface polymerizations and which selectively adheres to a nanoscale metal features, in a field of dielectric material. The resulting surface afforded the ability to produce polymers in an area selective manner and chemically engineer the surface, as desired. The resulting surface polymers were both thermal and chemically stable under ALD conditions and highly selective at guiding the ALD of several films including TiO 2 and ZnO for extended periods of time that allow the growth of film thicknesses greater than 48nm, relevant in a number of device applications. This method was also found to be scalable where initial experiments were carried out on laboratory scale experiments and could be scaled to a full 300mm wafer. Furthermore, the mechanism of inhibition was shown where ALD films inhibition is the result of precursor solubility in the polymer film. This unique strategy of growing polymers in an area selective manner and the inhibiting mechanism, present a set of design rules for engineering surfaces to direct the formation of inorganic films. References: [1] J. Vac. Sci. Technol. A, 2019 , 37(2), 020923-1. [2] ACS Appl. Mater. Interfaces , 2018 , 10(44), 38630. Figure 1
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