With the continuous demand for higher performance of computer chips and memories, device patterns and structures are becoming smaller and more complicated. Hard mask processes have been implemented in various steps in the devise manufacturing, and requirements for those materials are versatile. In this paper, novel organometal materials are presented as a new class of spin on solution in order to support the hard mask process. Type of metals, formulation scheme and processing conditions were carefully designed to meet the fundamental requirements as a spin on solution, and their characteristic properties were investigated in comparison to other conventional films such as spin on carbons (SOC), organic bottom anti-reflective coatings (oBARC) and inorganic films formed by chemical vapor deposition (CVD). Several advantages were identified with these SOMHM materials over other films which include 1) better thermal stability than SOC once fully cured, 2) reworkable with industry standard wet chemistry such as SC-1 where conventional Si-BARC is difficult to remove, 3) a wide range of optical constants to suppress reflection for photoresist imaging, 4) high etch resistance and 5) better gap filling property. Curing conditions showed a significant impact on the performance of SOMHM films, and X-ray photoelectron spectroscopy (XPS) was utilized to elucidate the trends. With SOMHM film as a BARC, photolithographic imaging was demonstrated under ArF immersion conditions with 40nm linewidth patterning.
Directed self-assembly (DSA) of block copolymers (BCPs) is a promising technology for advanced patterning at future
technology nodes, but significant hurdles remain for commercial implementation. The most widely studied material for
DSA is poly(styrene-<i>block</i>-methyl methacrylate) (PS-PMMA), but this material has a relatively weak segregation
strength that has limited its utility to patterns above 24 nm pitch. This paper reports on some of Dow's efforts to develop
new materials capable of extending DSA to smaller pitch by development of new BCP copolymer materials with
stronger segregation strength. Some preliminary efforts are reported on new substrate treatments that stabilize
perpendicular orientations in a high-χ block copolymer that also incorporate an etch-resistant block to facilitate
patterning at small dimensions. In addition, development of new block copolymer materials that have a χ-parameter that
is large enough to drive defect reduction and but not so high that it precludes thermal annealing are also presented. DSA
of these new materials is demonstrated using thermal annealing processes at pitch ranging from 40 to 16 nm, and etch
capability is also demonstrated on a material with 18 nm pitch. These technologies hold promise for the extension of
DSA to sub 24 nm pitch.
Block copolymers have been proposed for self-assembled nanolithography because they can spontaneously form
well-ordered nanoscale periodic patterns of lines or dots in a rapid, low-cost process. By templating the selfassembly,
patterns of increasing complexity can be generated, for example arrays of lines with bends or
junctions. This offers the possibility of using a sparse template, written by electron-beam lithography or other
means, to organize a dense array of nanoscale features. Pattern transfer is simplified if one block is etch resistant
and one easily removable, and in this work we use a diblock copolymer or a triblock terpolymer with one Sicontaining
block such as polydimethylsiloxane or polyferrocenylsilane, and one or two organic blocks such as
polystyrene or polyisoprene. Removal of the organic block(s) with an oxygen plasma leaves a pattern of Sicontaining
material which can be used as an etch mask for subsequent pattern transfer to make metallization lines
or magnetic nanostructures with feature sizes below 10 nm and periodicity below 20 nm.