This work addresses a major challenge in liquid-phase catalysis by enabling the synthesis of solvent dispersible "uncapped" metal nanoparticles (NPs) with enhanced density of accessible catalytic sites. We demonstrate that graphene oxide's (GO's) high density of accessible and bondable oxy-functional groups and the high steric hindrance from its micrometer-scale area covalently implant, stabilize, and support bare-surfaced gold nanoparticles (BSGNs) produced in situ by a unique microwave reduction process. Comparing the efficiency of catalytic reduction of p-nitroaniline ( p-NA) by BSGNs and similar sized surfactant-capped gold NPs showed that the uncapped surface on GO-supported NPs, (a) opens up 258% more active sites, and (b) enhances the catalytic reduction of p-NA by 10-100 fold. Further, BSGN implantation on GO, (a) amplifies the Raman signal of bare GO by ∼3 fold, and (b) increases the conductivity of native p-type GO by >10 fold via injection of 1.328 Â 10 12 electrons/cm 2 , consequently transforming it into an n-type semiconductor.
Electrical data from chromium-silicon-carbon (CrSiC) thin film resistors (tfr) consistently showed highly variable contact resistance (Rc) to the aluminum (Al) interconnect. Transmission electron microscopy data from CrSiC/Al interfaces exhibiting high Rc showed a conformal, amorphous layer sandwiched between the tfr and Al. Auger data from the tfr/Al interface showed this ‘crud’ layer to contain increased C, S, and SiOx. Auger data from CrSiC films on test wafers exposed to the process steps before Al deposition showed additional growth of the ‘crud’ layer after each photoresist (PR) operation. In addition, Rc variability was reduced on product wafers from split lots when 2x the normal PR strip time was used compared to the normal strip time. A Designed Experiment (DOE) to examine improving the removal of this ‘crud’ layer was run on product lots utilizing two factors: the standard strip and a two-step strip. Electrical results for both Rc and die yield were significantly improved using the two-step process. The variability of the Rc was also reduced.
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