Roadmap on ferroelectric hafnia- and zirconia-based materials and devices

Ferroelectric hafnium and zirconium oxides have undergone rapid scientific development over the last decade, pushing them to the forefront of ultralow-power electronic systems. Maximizing the potential application in memory devices or supercapacitors of these materials requires a combined effort by the scientific community to address technical limitations, which still hinder their application. Besides their favorable intrinsic material properties, HfO2–ZrO2 materials face challenges regarding their endurance, retention, wake-up effect, and high switching voltages. In this Roadmap, we intend to combine the expertise of chemistry, physics, material, and device engineers from leading experts in the ferroelectrics research community to set the direction of travel for these binary ferroelectric oxides. Here, we present a comprehensive overview of the current state of the art and offer readers an informed perspective of where this field is heading, what challenges need to be addressed, and possible applications and prospects for further development

Recurrent and multiple bladder tumors show conserved expression profiles

<p>Abstract</p> <p>Background</p> <p>Urothelial carcinomas originate from the epithelial cells of the inner lining of the bladder and may appear as single or as multiple synchronous tumors. Patients with urothelial carcinomas frequently show recurrences after treatment making follow-up necessary. The leading hypothesis explaining the origin of meta- and synchronous tumors assumes a monoclonal origin. However, the genetic relationship among consecutive tumors has been shown to be complex in as much as the genetic evolution does not adhere to the chronological appearance of the metachronous tumors. Consequently, genetically less evolved tumors may appear chronologically later than genetically related but more evolved tumors.</p> <p>Methods</p> <p>Forty-nine meta- or synchronous urothelial tumors from 22 patients were analyzed using expression profiling, conventional CGH, LOH, and mutation analyses.</p> <p>Results</p> <p>We show by CGH that partial chromosomal losses in the initial tumors may not be present in the recurring tumors, by LOH that different haplotypes may be lost and that detected regions of LOH may be smaller in recurring tumors, and that mutations present in the initial tumor may not be present in the recurring ones. In contrast we show that despite apparent genomic differences, the recurrent and multiple bladder tumors from the same patients display remarkably similar expression profiles.</p> <p>Conclusion</p> <p>Our findings show that even though the vast majority of the analyzed meta- and synchronous tumors from the same patients are not likely to have originated directly from the preceding tumor they still show remarkably similar expressions profiles. The presented data suggests that an expression profile is established early in tumor development and that this profile is stable and maintained in recurring tumors.</p

Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC

Record performance for junctionless transistors in InGaAs MOSFETs

We demonstrate junctionless tri-gate MOSFETs utilizing a single layer 7 nm thick In0.80Ga0.20As (ND ∼ 1×1019 cm-3) as both channel and contacts. Devices with source and drain metal separation of 32 nm and Lg of 25 nm exhibit SS = 76 mV/dec., both the highest reported gm = 1.6 mS/μα and Ion = 160 μA/μm (VDD = 0.5 V, IOFF = 100 nA/μm) for a junctionless transistor. We also examine the influence of the contact thickness, comparing double-layer junctionless devices with 37 nm thick contacts with single-layer 7 nm contact devices

Junctionless tri-gate InGaAs MOSFETs

We demonstrate and characterize junctionless tri-gate InGaAs MOSFETs, fabricated using a simplified process with gate lengths down to L g = 25 nm at a nanowire dimension of 7 - 16 nm2. These devices use a single 7-nm-thick In0.80Ga0.20As (N D = 1 - 1019 cm-3) layer as both channel and contacts. The devices show SSsat = 76 mV/dec, peak g m = 1.6 mSm and I ON = 160A/m (at I OFF = 100 nA/m and V DD = 0.5 V), the latter which is the highest reported value for a junctionless FET. We also show that device performance is mainly limited by high parasitic access resistance due to the narrow and thin contact layer

1/f Noise Sources in Dual-Gated Indium Arsenide Nanowire Transistors

1/f noise is studied in dual-gated InAs nanowire transistors consisting of an omega top gate with high-k atomic layer deposited dielectric and silicon dioxide to substrate back gate. Noise spectra at varying gate bias combinations are compared from devices with differing top-gate lengths to separate the noise contributions of the top-gated channel from the ungated access portion, including the metal-nanowire contacts. For a given device geometry, it is possible to bias the device into four different regimes where the resistance and the noise amplitude can each be independently dominated by either the channel or the access/contact regions. When the device is fully in the on state, the access/contact regions dominate both resistance and noise. When the device is operating near or below threshold, the channel dominates resistance and noise. For the lowest amount of overall 1/f noise, most of the nanowire should be covered by the top gate, minimizing the access region length

InSb heterostructure nanowires: MOVPE growth under extreme lattice mismatch

We demonstrate the growth of InSb-based nanowire heterostructures by metalorganic vapour phase epitaxy and use it to integrate InSb on extremely lattice-mismatched III-V nanowire templates made of InAs, InP, and GaAs. Influence of temperature, V/III ratio, and diameter are investigated in order to investigate the growth rate and morphology. The range of growth temperatures used for InSb nanowire growth is very similar to that used for planar growth due to the nature of the precursor decomposition. This makes optimization of growth parameters very important, and more difficult than for most other nanowire III-V materials. Analysis of the InSb nanowire epitaxial quality when grown on InAs, InP, and GaAs, along with InSb segment and particle compositions are reported. This successful direct integration of InSb nanowires, on nanowire templates with unprecedented strain levels show great promise for fabrication of vertical InSb devices