| 1. |
- Aine, Mattias, et al.
(författare)
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Molecular analyses of triple-negative breast cancer in the young and elderly
- 2021
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Ingår i: Breast cancer research : BCR. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Breast cancer in young adults has been implicated with a worse outcome. Analyses of genomic traits associated with age have been heterogenous, likely because of an incomplete accounting for underlying molecular subtypes. We aimed to resolve whether triple-negative breast cancer (TNBC) in younger versus older patients represent similar or different molecular diseases in the context of genetic and transcriptional subtypes and immune cell infiltration.PATIENTS AND METHODS: In total, 237 patients from a reported population-based south Swedish TNBC cohort profiled by RNA sequencing and whole-genome sequencing (WGS) were included. Patients were binned in 10-year intervals. Complimentary PD-L1 and CD20 immunohistochemistry and estimation of tumor-infiltrating lymphocytes (TILs) were performed. Cases were analyzed for differences in patient outcome, genomic, transcriptional, and immune landscape features versus age at diagnosis. Additionally, 560 public WGS breast cancer profiles were used for validation.RESULTS: Median age at diagnosis was 62 years (range 26-91). Age was not associated with invasive disease-free survival or overall survival after adjuvant chemotherapy. Among the BRCA1-deficient cases (82/237), 90% were diagnosed before the age of 70 and were predominantly of the basal-like subtype. In the full TNBC cohort, reported associations of patient age with changes in Ki67 expression, PIK3CA mutations, and a luminal androgen receptor subtype were confirmed. Within DNA repair deficiency or gene expression defined molecular subgroups, age-related alterations in, e.g., overall gene expression, immune cell marker gene expression, genetic mutational and rearrangement signatures, amount of copy number alterations, and tumor mutational burden did, however, not appear distinct. Similar non-significant associations for genetic alterations with age were obtained for other breast cancer subgroups in public WGS data. Consistent with age-related immunosenescence, TIL counts decreased linearly with patient age across different genetic TNBC subtypes.CONCLUSIONS: Age-related alterations in TNBC, as well as breast cancer in general, need to be viewed in the context of underlying genomic phenotypes. Based on this notion, age at diagnosis alone does not appear to provide an additional layer of biological complexity above that of proposed genetic and transcriptional phenotypes of TNBC. Consequently, treatment decisions should be less influenced by age and more driven by tumor biology.
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| 2. |
- Athle, Robin, et al.
(författare)
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Effects of TiN Top Electrode Texturing on Ferroelectricity in Hf1-xZrxO2
- 2021
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Ingår i: ACS applied materials & interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:9, s. 11089-11095
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Tidskriftsartikel (refereegranskat)abstract
- Ferroelectric memories based on hafnium oxide are an attractive alternative to conventional memory technologies due to their scalability and energy efficiency. However, there are still many open questions regarding the optimal material stack and processing conditions for reliable device performance. Here, we report on the impact of the sputtering process conditions of the commonly used TiN top electrode on the ferroelectric properties of Hf1-xZrxO2. By manipulating the deposition pressure and chemistry, we control the preferential orientation of the TiN grains between (111) and (002). We observe that (111) textured TiN is superior to (002) texturing for achieving high remanent polarization (Pr). Furthermore, we find that additional nitrogen supply during TiN deposition leads to >5× greater endurance, possibly by limiting the scavenging of oxygen from the Hf1-xZrxO2 film. These results help explain the large Pr variation reported in the literature for Hf1-xZrxO2/TiN and highlights the necessity of tuning the top electrode of the ferroelectric stack for successful device implementation.
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| 3. |
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| 4. |
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| 5. |
- Glodzik, Dominik, et al.
(författare)
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Comprehensive molecular comparison of BRCA1 hypermethylated and BRCA1 mutated triple negative breast cancers
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Homologous recombination deficiency (HRD) is a defining characteristic in BRCA-deficient breast tumors caused by genetic or epigenetic alterations in key pathway genes. We investigated the frequency of BRCA1 promoter hypermethylation in 237 triple-negative breast cancers (TNBCs) from a population-based study using reported whole genome and RNA sequencing data, complemented with analyses of genetic, epigenetic, transcriptomic and immune infiltration phenotypes. We demonstrate that BRCA1 promoter hypermethylation is twice as frequent as BRCA1 pathogenic variants in early-stage TNBC and that hypermethylated and mutated cases have similarly improved prognosis after adjuvant chemotherapy. BRCA1 hypermethylation confers an HRD, immune cell type, genome-wide DNA methylation, and transcriptional phenotype similar to TNBC tumors with BRCA1-inactivating variants, and it can be observed in matched peripheral blood of patients with tumor hypermethylation. Hypermethylation may be an early event in tumor development that progress along a common pathway with BRCA1-mutated disease, representing a promising DNA-based biomarker for early-stage TNBC.
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| 6. |
- Lindelöw, Fredrik, et al.
(författare)
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III-V nanowire MOSFETs with novel self-limiting Λ-ridge spacers for RF applications
- 2020
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 35:6
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Tidskriftsartikel (refereegranskat)abstract
- We present a semi self-aligned processing scheme for III-V nanowire transistors with novel semiconductor spacers in the shape of Λ-ridges, utilising the effect of slow growth rate on {111}B facets. The addition of spacers relaxes the constraint on the perfect alignment of gate to contact areas to enable low overlap capacitances. The spacers give a field-plate effect that also helps reduce off-state and output conductance while increasing breakdown voltage. Microwave compatible devices with L g = 32 nm showing f T = 75 GHz and f max = 100 GHz are realized with the process, demonstrating matched performance to spacer-less devices but with relaxed scaling requirements.
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| 7. |
- Mamidala, Saketh, Ram, et al.
(författare)
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Low-Power Resistive Memory Integrated on III-V Vertical Nanowire MOSFETs on Silicon
- 2020
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 41:9, s. 1432-1435
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Tidskriftsartikel (refereegranskat)abstract
- III-V vertical nanowire MOSFETs (VNW-FETs) have the potential to extend Moore’s law owing to their excellent material properties. To integrate highly scaled memory cells coupled with high performance selectors at minimal memory cell area, it is attractive to integrate low-power resistive random access memory (RRAM) cells directly on to III-V VNW-FETs. In this work, we report the experimental demonstration of successful RRAM integration with III-V VNW-FETs. The combined use of VNW-FET drain metal electrode and the RRAM bottom electrode reduces the process complexity and maintains material compatibility. The vertical nanowire geometry allows the RRAM cell area to be aggressively scaled down to 0.01 μm2 enabling realization of dense memory (1T1R) cross-point arrays on silicon.
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| 8. |
- Menon, Heera, et al.
(författare)
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Improved quality of InSb-on-insulator microstructures by flash annealing into melt
- 2021
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 32:16
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Tidskriftsartikel (refereegranskat)abstract
- Monolithic integration of III-V semiconductors with Silicon technology has instigated a wide range of new possibilities in the semiconductor industry, such as combination of digital circuits with optical sensing and high-frequency communication. A promising CMOS compatible integration process is rapid melt growth (RMG) that can yield high quality single crystalline material at low cost. This paper represents the study on ultra-thin InSb-on-insulator microstructures integrated on a Si platform by a RMG-like process. We utilize flash lamp annealing (FLA) to melt and recrystallize the InSb material for an ultra-short duration (milliseconds), to reduce the thermal budget necessary for integration with Si technology. We compare the result from FLA to regular rapid thermal annealing (seconds). Recrystallized InSb was characterized using electron back scatter diffraction which indicate a transition from nanocrystalline structure to a crystal structure with grain sizes exceeding 1 μm after the process. We further see a 100× improvement in electrical resistivity by FLA annealed sample when compared to the as-deposited InSb with an average Hall mobility of 3100 cm2 V−1 s−1 making this a promising step towards realizing monolithic mid-infrared detectors and quantum devices based on InSb.
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| 9. |
- Olausson, Patrik, et al.
(författare)
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Optimization of Near-Surface Quantum Well Processing
- 2021
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Ingår i: Physica Status Solidi (A) Applications and Materials Science. - : Wiley. - 1862-6300. ; 218:7
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Tidskriftsartikel (refereegranskat)abstract
- Herein, an optimized process flow of near-surface quantum well metal–oxide–semiconductor field-effect transistors (MOSFETs) based on planar layers of metalorganic vapor-phase epitaxy (MOVPE) grown InxGa1−xAs is presented. It is found that by an optimized pre-growth cleaning and post-metal anneal, the quality of the MOS structure can be greatly enhanced. This optimization is a first step toward realization of a scalable platform for topological qubits based on a well-defined network of lateral InxGa1−xAs nanowires grown by selective area growth.
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| 10. |
- Persson, Anton E. O., et al.
(författare)
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A method for estimating defects in ferroelectric thin film MOSCAPs
- 2020
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 117:24
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Tidskriftsartikel (refereegranskat)abstract
- We propose a capacitance measurement scheme that enables quantitative characterization of ferroelectric thin films integrated onsemiconductors. The film defect density is estimated by measurements of the CV hysteresis and frequency dispersion, whereas importantdevice parameters such as memory window and endurance can be extracted by a unidirectional CV method. The simple measurementscheme and the usage of metal-oxide-semiconductor capacitors rather than MOSFETs make the proposed methods suitable for the futureoptimization of ferroelectric field effect transistor and negative capacitance field effect transistor gate stacks. Specifically, we present data forthe narrow bandgap semiconductor InAs and show that low temperature characterization is critical to reduce the influence of the minoritycarrier response; however, the methods should be transferrable to room temperature for semiconductors with a wider bandgap. Our resultsclearly indicate that the defect density of the HfxZr1xO2 (HZO) films increases at the crystallization temperature, but the increase is modestand remains independent of the annealing temperature at even more elevated temperatures. It is also shown that the shrinkage of thememory window caused by field cycling is not accompanied by an increase in defect density.
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