Two combinatorial approaches for rapid automated screening of electrochemical activity of modified electrode surfaces are described. One approach enables simultaneous comparison of electrochemical current by fluorescence associated with pH changes that accompany consumption or production of protons at the electrode surface during a redox process. However, this method cannot distinguish small differences in current at differently modified electrodes. A second approach relies on computer-automated, serial measurement of electrochemical current at each electrode of a 64-electrode array immersed in a single electrochemical cell. Unlike the fluorescent screen, the second method is capable of distinguishing small differences in current at differently modified electrodes, as demonstrated here for gold electrode surfaces covered with organosulfur monolayers of different chain lengths. The improved precision of the computer-automated direct electrochemical method enables examination of active zones that have been first identified by less precise parallel fluorescent screening methods. The direct electrochemical measurement method can easily be extended to a variety of electrode materials, including fuel cell electrocatalysts and redox storage materials. A complete description of the methodology, hardware and computer program for automated measurement is provided.

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We report a novel approach to enable the fabrication of dielectric isolated FinFETs on bulk substrates by bottom oxidation through STI (BOTS). BOTS FinFET transistors are manufactured with 42nm fin pitch and 80nm contacted gate pitch. Competitive device performances are achieved with effective drive currents of I eff (N/P) = 621/453 μA/μm at I off = 10 nA/µm at V DD = 0.8 V. The BOTS process results in a sloped fin profile at the fin bottom (fin tail). By extending the gate vertically into the fin tail region, the parasitic short-channel effects due to this fin tail have been successfully suppressed. We further demonstrate the extension of the BOTS process to the fabrication of strained SiGe FinFETs and nanowires, providing a path for future CMOS technologies. IntroductionFinFET has become a viable technology for 22nm node and beyond [1][2][3][4]. Bulk FinFET [1-3] requires punchthrough stop (PTS) doping below the fin channel to suppress short-channel effects (Fig. 1a). This PTS results in undesirable device variability. Dielectric-isolated FinFET (DI-FinFET) eliminates the need of PTS doping, and thus avoids its adverse impact (Fig. 1b). Using SOI substrates is the most straightforward way to fabricate DI-FinFETs. However, bulk substrates can offer some integration and device design flexibility. To combine the advantages of SOI FinFETs and the flexibility to use bulk substrates, motivation exists to fabricate SOI-like FinFETs on bulk substrates. This has indeed been demonstrated in the original FinFET work [5] by thermal oxidation of fin bottom. Nevertheless, this early approach has a major manufacturing issue -fins tend to tilt due to oxidation induced stress. In this paper we report a novel DI-FinFET approach, Bottom Oxidation Through STI (BOTS), to solve critical manufacturing and device issues of DI-finFET. The extendibility of BOTS to future CMOS technologies is also demonstrated. Bottom Oxidation Through STI (BOTS) Process FlowThe BOTS process flow for fabricating SOI fins on bulk substrates is depicted in Fig. 2. SOI fins are formed by converting the bottom portion of bulk fins into a buried oxide layer (BOX) through thermal oxidation. A novel feature of BOTS is the use of STI oxide for two purposes. First, STI surrounding fins acts as a mechanical anchor to hold the fins straight during oxidation. Second, STI regions are filled with permeable oxide, allowing oxidation species to diffuse through STI to oxidize the fin bottom. The top portions of the fins are covered by nitride spacers and nitride caps and they become SOI fins after oxidation. Vertically standing SOI fins with a pitch of 42nm are achieved by BOTS (Fig. 3). In contrast, conventional oxidation without STI [5] results in tilted fins (Fig. 4). Excessive oxidation stress may generate defects in SOI fins. To minimize oxidation stress, the bottom portions of fins are further recessed and intentionally narrowed prior to oxidation. As a result, only a small amount of oxidation is needed to laterally oxidize the narrow fin bottom from both sides (F...