Phase Behavior Of Block Copolymers In Compressed Co2 And As Single Domain Layer Nanolithographic Etch Resists For Sub 10 Nm Pattern Transfer PDF Download

Block copolymer (BCP) self-assembly has found broad use in applications ranging from nanocomposites to nanolithography by exploiting the precise control of nanoscale order possible over macroscopic length scales. One application garnering significant attention for commercialization uses this nanoscale order to augment current photolithography patterning to achieve sub-20 nm features through directed self assembly (DSA). Extending current lithography to these smaller length scales is critical to enable cost-effective next-generation semiconductor devices, furthering technological progress and maintaining the pace of Moore's law. As with many of these applications, DSA utilizes BCPs starting from deeply metastable states. Detail of the initial phase segregation process, structure formation, and refinement are critical to device function, efficacy, and yield. However, understanding of this initial phase segregation from deeply metastable states, especially the temporal evolution, is currently lacking. This ignorance stems in part from both a difficulty in experimentally measuring the short time structural response of polymers, and on the computational difficulty in modeling large enough systems at high fidelity over molecular timescales. Furthermore, for DSA, the anneal must achieve a near perfectly aligned equilibrium structure. The timescale required, and thus the cost, to reach the fully aligned state is dependent upon kinetic pathways, especially past any potential trapped defect states. Laser spike annealing (LSA) can achieve high temperatures for short durations allowing investigation of potential process windows in the microsecond to millisecond time scales. In this work, a CO2 gas laser (120 W, wavelength=10600 nm) and a solid state diode laser (250 W, wavelength=980 nm), were used to achieve peak temperatures up to ~1000 degrees C on time scales from 0.05 ms to 10 ms. Additionally, high throughput experiments of the lateral gradient LSA (lgLSA) method were used to fully explore these time and temperature regimes. This has enabled exploration of a previously inaccessible temperature regime and the determination of kinetic parameters that potentially offers access to new processing regimes and resulting structures. For these short duration anneals, it is shown that the thermal stability of typical organic materials is extended by over 450 degrees C compared to hot plate limits. This stability was quantified using Arrhenius kinetics with activation enthalpies ranging between 0.6 and 1.2 eV. The activation energies appear to scale with the primary (backbone) bond formation energy and inversely with the bond polarity. This extended thermal stability was exploited to probe the self-assembly kinetics of cylinder forming poly(styrene-block-methyl methacrylate) (PS-b-PMMA, 54 kg/mol, fraction PS=0.67) by annealing at temperatures up to 550 degrees C for timescales from 0.25 ms to 10 ms with heating and cooling rates in excess of 10^6 K/s. Segregation kinetics were quantified by X-ray scattering (micro-GISAXS) and electron microscopy (SEM), resulting in kinetic phase maps that describe the phase segregation behavior. The onset of phase segregation and of disordering were found to be kinetically suppressed for times below 1 ms, exceeding the exp...