Random Telegraph Noise in 3D NAND Flash Memories.

In this paper, we review the phenomenology of random telegraph noise (RTN) in 3D NAND Flash arrays. The main features of such arrays resulting from their mainstream integration scheme are first discussed, pointing out the relevant role played by the polycrystalline nature of the string silicon channels on current transport. Starting from that, experimental data for RTN in 3D arrays are presented and explained via theoretical and simulation models.

Bipolar switching in chalcogenide phase change memory.

Phase change materials based on chalcogenides are key enabling technologies for optical storage, such as rewritable CD and DVD, and recently also electrical nonvolatile memory, named phase change memory (PCM). In a PCM, the amorphous or crystalline phase affects the material band structure, hence the device resistance. Although phase transformation is extremely fast and repeatable, the amorphous phase suffers structural relaxation and crystallization at relatively low temperatures, which may affect the temperature stability of PCM state.

Enabling universal memory by overcoming the contradictory speed and stability nature of phase-change materials.

The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition.

A multi-channel low-power system-on-chip for single-unit recording and narrowband wireless transmission of neural signal.

This paper reports a multi-channel neural recording system-on-chip (SoC) with digital data compression and wireless telemetry. The circuit consists of a 16 amplifiers, an analog time division multiplexer, an 8-bit SAR AD converter, a digital signal processor (DSP) and a wireless narrowband 400-MHz binary FSK transmitter. Even though only 16 amplifiers are present in our current die version, the whole system is designed to work with 64 channels demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels.

Silicon nanocrystal memories: a status update.

In the last decade, the silicon nanocrystal memory technology has received widespread interests from the scientific community working in the field of non-volatile solid-state memories, considering it as a feasible candidate for the post-Flash scenario. The immunity to stress-induced leakage current and the reduction of parasitic floating-gate capacitive couplings make the nanocrystal technology very attractive, especially when considering the CMOS compatible process flow. However, many open issues still exist for its development, first of all concerning its scaling perspectives.

Single-photon detection beyond 1 µm: performance of commercially available InGaAs/lnP detectors.

Commercially available InGaAs/lnP avalanche photodiodes, designed for optical receivers and range finders, can be operated biased above the breakdown voltage, achieving single-photon sensitivity. We describe in detail how to select the device for photon-counting applications among commercial samples. Because of the high dark-counting rate the detector must be cooled to below 100 K and operated in a gated mode.

Avalanche photodiodes and quenching circuits for single-photon detection.

Avalanche photodiodes, which operate above the breakdown voltage in Geiger mode connected with avalanche-quenching circuits, can be used to detect single photons and are therefore called singlephoton avalanche diodes SPAD's. Circuit configurations suitable for this operation mode are critically analyzed and their relative merits in photon counting and timing applications are assessed. Simple passive-quenching circuits (PQC's), which are useful for SPAD device testing and selection, have fairly limited application.

Time-resolved photoluminescence measurements of InGaAs/ InP multiple-quantum-well structures at 1.3-µm wavelengths by use of germanium single-photon avalanche photodiodes.

A commercially available germanium avalanche photodiode operating in the single-photon-counting mode has been used to perform time-resolved photoluminescence measurements on InGaAs/lnP multiple-quantum-well structures. Photoluminescence in the spectral region of 1.3-1.

Counting, timing, and tracking with a single-photon germanium detector.

We report the performance of a germanium quad-cell, composed of four avalanche photodiodes operated in the photon-counting regime, biased above the breakdown voltage. Each pixel detects a single photon in the wavelength range 1-1.5 microm with ~10% quantum efficiency and measures the photon arrival time with a time resolution of 100 ps.

Single-photon detection beyond 1 µm: performance of commercially available germanium photodiodes.

Germanium avalanche photodiodes (APD's) working biased above the breakdown voltage detect single optical photons in the near-infrared wavelength range. We give guidelines for the selection of devices suitable for photon-counting applications among the commercial samples, and we discuss in detail how the devices should be operated to achieve the best performance, both in terms of noise-equivalent power (NEP) and the timing-equivalent bandwidth. We introduce the driving electronics and we show that, in the measurements of fast optical signals, the adoption of single-photon techniques is very favorable, notwithstanding that presently available photodiodes are not designed for this purpose.

Nanosecond single-photon timing with InGaAs/InP photodiodes.

We demonstrate that separate absorption and multiplication InGaAs/InP avalanche photodiodes can work biased above the breakdown voltage and detect the arrival time of single photons with 1-ns resolution and a noise-equivalent power of 1 x 10(-14) W/Hz((1/2)) at 150 K. We investigated the performance of various samples, cooling the detectors from different temperatures down to 50 K. These devices are suitable for the detection of short optical pulses in the near-infrared range up to a 1.

Subnanosecond single-photon timing with commercially available germanium photodiodes.

We demonstrate that commercially available germanium avalanche photodiodes can achieve single-photon sensitivity and subnanosecond time resolution at 77 K. Experiments show that carrier trapping phenomena give the main contribution to the detector noise. Therefore technological efforts will be welcome to overcome the present limitations that are due to the material quality.

High-accuracy picosecond characterization of gain-switched laser diodes.

A unique combination of the time-correlated photon-counting technique and single-photon avalanche diode detectors gives an accurate characterization of gain-switched semiconductor lasers with picosecond resolution. The high sensitivity and the clean shape of the time response reveal even small features (reflections and relaxation oscillations), making a true optimization of the laser-diode operation possible. The technique outperforms the standard characterization with ultrafast p-i-n photodiodes and a sampling oscilloscope.