We report on 2D photonic crystal InP membrane micro-lasers transferred onto a silicon wafer. Two types of lasers are investigated: microcavities and defect-free structures, exploiting either ...conventional defect modes, or DFB-like modes. Room temperature low threshold laser operation has been performed for low sized devices.
In this paper, for the first time, the reliability of HfO 2 -based RRAM devices integrated in an advanced 28nm CMOS 16kbit demonstrator is presented. The effect of the introduction of a thin Al 2 O 3 ...layer in TiN/Ti/HfO 2 /Al 2 O 3 /TiN is explored to improve the memory performances. Thanks to the in-depth electrical characterization of both HfO 2 and HfO 2 /Al 2 O 3 stacks at device level and in the 16×1kbit demonstrator the interest of the bilayer is put forward (endurance: 1 decade after 1M cycles and retention: 6 hours at 200°C). Finally, thanks to our 3D model based on calculation of the Conductive Filament resistance using trap assisted tunneling (TAT) the role of Al 2 O 3 as tunneling layer is highlighted.
We study in detail the impact of alloying HfO 2 with Al (Hf 1-x Al 2x O 2+x ) on the device characteristics through materials characterization, electrical measurements and atomistic simulation. ...Indeed, movements of individual oxygen atoms inside the dielectric are at the heart of RRAM operations. Therefore, we performed diffusion barrier calculations relative to the oxygen vacancy (VO) movement involved in R on data retention. Calculations are performed at the best level using ab initio techniques. Our study provides an insight on the improved R on stability of Hf 1-x Al 2x O 2+x RRAM, via a simple explanation based on its higher atomic density (atoms/cm 3 ) associated with shorter bond lengths between cations and anions in the presence of Al.
In this work, a comprehensive investigation of disturb in HfO 2 -Resistive Random Access Memories (RRAM) integrated in an advanced 65nm technology is presented. The effects of the oxide thickness and ...RESET conditions on disturb immunity of the High-Resistance-State (HRS) are explored. Constant Voltage Stress is applied on a large amount of samples at various temperatures. Data are collected and analyzed on a statistical basis. The SET dependence to the RESET conditions is investigated and correlated to the length of the induced depleted gap along the conductive filament. The conduction mechanism of the HRS is correlated to the failure/SET process of the RRAM device through a voltage acceleration model. It is shown that thicker dielectric oxide and stronger RESET conditions give rise to longer failure times.
In this work, we use ab initio simulations to explore neutral and charged Frenkel pair (FP) formation inside HfO 2 . FP plays a crucial role in the conductive filament (CF) formation. We explore two ...possible mechanisms for the FP formation, namely electron injection and electron detrapping. The existence of one of the two mechanisms or both depends on the nature of the metal electrodes and potential applied. The results show that at high voltage operation electron detrapping may occur which strongly degrades the HfO 2 dielectric layer. Contrary to electrodes with high work function (W f ) and non-reactive with oxygen, we show that oxygen active electrodes with low W f avoid electron detrapping, thus improving device variability and CF thermal stability.
In this paper, memory devices integrating a double layer of silicon nanocrystals (Si-ncs) as a trapping medium and a HfAlO-based control dielectrics are presented. We will show that the use of two ...stacked Si-nc layers significantly improves the memory window compared with the single Si-nc layer devices, without introducing anomalies on the charging dynamics. Then, we also evaluate the potential use of a hybrid Si-nc double-layer/SiN layer charge trapping stack. These devices show a good memory window in a Fowler-Nordheim (FN)/FN mode and a good retention (Formula Omitted 3 V after ten years) with small activation energy (0.35 eV up to 200 Formula Omitted), thus showing promise for future high-temperature memory applications. A model implying valence-band electron tunneling and a floating-gate-like approximation is used to explain the memory window improvement of the Si-nc double-layer memory devices.
In this work, we study the impact of Si and Al implantation on the current conduction mechanisms and operation of 1T-1R TiN/HfO 2 /Ti/TiN based ReRAM devices. The pre-forming current and forming ...voltage evolution clearly reveal different trends as a function of the implanted dose and species. We link our results to the microscopic structure of the material using a first principles approach.
This paper provides an overview of the temperature impact (up to 200 °C) on the electrical behavior of oxide-based RRAM, during forming, low-field resistance reading, SET/RESET, disturb, data ...retention and endurance. HfO 2 -RRAM devices (in a 1T1R configuration) integrated in an advanced 65 nm technology are studied for this aim. We show that forming operation is strongly activated in temperature (i.e. -0.5 V per hundred Celsius degree), being much less for SET and RESET voltages (i.e. <; -0.05 V per hundred Celsius degree); disturb of HRS at fixed voltage showed to be independent of temperature; endurance up to 3.10 6 cycles, with optimized set of stress parameters showed no significant variation; data retention at 150 °C up to 68 days showed stable programming window, after different initial programming algorithms.
We report here on the bonding of a thin InP(001) layer onto a Si host substrate via silicon dioxide, to be used as a substrate for heteroepitaxy. With this end in mind, these new InP/SiO/sub 2//Si ...substrates were compared to standard InP substrates through the growth by Solid Source Molecular Beam Epitaxy of (lattice-matched) InP thick layers and (-0.8% lattice-mismatched) InAs/sub 0.25/P/sub 0.75/ and In/sub 0.65/Ga/sub 0.35/As thick layers. The layers thus obtained were characterized by in-situ Reflection High-Energy Electron Diffraction (RHEED), and ex-situ Atomic Force Microscopy (AFM), double crystal x-ray diffraction (DXRD) and photoluminescence (PL). Finally, the quality of the InP/SiO/sub 2//InP heterostructure is assessed as a substrate for optoelectronics by the photoluminescence spectrum of a 60 /spl Aring/ thick InAs/sub 0.65/P/sub 0.35/ strained quantum well confined by 0.2 /spl mu/m thick InP barriers. We conclude that all the characteristics required for optoelectronic application are fulfilled.
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