Supplementary Information Experimental Section Hybrid Nanoparticle Synthesis The hafnium nanoparticles surface-modified with methacrylic acid (MAA, Sigma Aldrich, 99%), trans 2, 3-dimethylacrylic acid (DMA, Sigma Aldrich, 98%), and benzoic acid (BA, Sigma Aldrich, 99.5%) were prepared by the modified sol-gel method. All reagents were used as received with no further purification. Hafnium isopropoxide (Aldrich, 99.9%) was used as the primary Hf source and was dissolved into the corresponding acid. A fixed amount of tetrahydrofuran (THF, Fisher Scientific, 99.9%) was added to dissolve DMA and BA, at 65 C through slow addition of water. The product was precipitated with the addition of water after the solution was aged and stirred for 21 h. The precipitation was then washed with water and acetone for several times and the final powder was obtained after drying at 60 C overnight. Particle Size Measurement and Photo-patterning Evaluation The schematic of experimental setup for particle size investigation is shown in Figure S1. Nanoparticles with different ligands were pressed into films on the bottom of a wash-glass using a quartz slide. The nanoparticle films were then irradiated with 254 nm UV lamp (390 µw/cm 2 for 254 nm wavelength) for different durations to reach the same dosage needed for the patterning and then dispersed into propylene glycol monomethyl ether acetate (PGMEA, Sigma-Aldrich, 99.5%). Dynamic light scattering (DLS, Malvern Zetasizer Nano) was used to measure the hydrodynamic diameter of the nanoparticles dispersed in the solvent. Three measurements were 1
recorded for each sample. The photopatterning evaluation of hybrid nanoparticle photoresists was conducted using the following steps: a fixed amount of as-prepared nanoparticles was dissolved into PGMEA solvent; the solution, after filtration with a 0.2 µm syringe filter to remove possible aggregates or dust, was spin-coated on the top of 4 inch silicon wafer (N type, WRS Materials) at 2000 rpm for 60 seconds. The spin-coated film (film thickness 100 nm for DUV exposure and 40 nm for EUV exposure, respectively) was then baked at 110 C for 1 min to remove any excess solvent before UV exposure. DUV patterning (wavelength 254 nm) with the dosage of 150 mj/cm 2 was performed with ABM mask aligner through a quartz mask at Cornell Nanoscale Science & Technology Facility (CNF). High resolution EUV patterning (wavelength 13.4 nm) was carried out at the Berkeley Microfield Exposure Tool (BMET) at Lawrence Berkeley National Lab (LBNL). 4- methyl-2-pentanol (Sigma Aldrich, 98%) was used as the developer. Materials Characterization Scanning electron microscope (SEM, Zeiss LEO 1550 FE-SEM) and optical microscope were used to evaluate the patterning formation after UV exposure. The film dissolution rate was evaluated with a Quartz Crystal Microbalance (QCM). The surface composition of nanoparticles was analyzed with attenuated total reflectance-fourier transformation infrared (ATR-FTIR) on a Nicolet iz10 spectrometer, followed by analysis through the Omnic Software. Raman spectroscopy was performed on an Invia Raman spectrometer (Reinshaw) at 488 nm. Chemical bonding information was obtained by X-ray photoelectron spectroscopy (XPS, 2
SSX-100, Surface Science Instrument) with Al Kα 1/2 x-ray source (x-ray energy: 1486.6 ev) and 180-degree hemispherical analyzer. Thermogravimetric analysis and differential thermal analysis (TG-DTA, Seiko Instruments TD/DTA 6200) was used to monitor the change in organic content of the nanoparticles before and after exposure under N 2 from 25 C to 580 C at the heating rate of 10 C/min. UV-vis spectra were obtained on a Molecular Devices SpectraMax M2 from 200 nm to 700 nm. 3
Figure S1. Experimental Setup of Particle Size Investigation. 4
Figure S2. Optical image of DUV line-space patterning with HfMAA (no photoactive compound was added). The dosage for patterning is 150 mj/cm 2. 5
Figure S3. Particle size distribution as detected by DLS of 10 mg HfMAA hybrid nanoparticles dissolved in 5 ml PGMEA solution : (a) initial and (b) 10-days later. 6
Figure S4. Optical image of HfMAA nanoparticles dissolved in the organic solution after UV exposure for different durations. 7
Figure S5. DLS investigation of different hybrid nanoparticles after heating at 150 C for 1 h. 8