Scientists investigate charge distribution inside single molecule

By Agam Shah

IBM researchers for the first time have succeeded in imaging how charge is distributed inside a single molecule, which is a fundamental research breakthrough as scientists try to miniaturise circuitry to the nanometer scale.

IBM is studying molecular structures when put on artificial surfaces so functional molecules in the future can be used as switches or transistors, said Fabian Mohn, an IBM researcher. IBM used advanced microscopy tools and techniques to image how charge is redistributed and arranged when chemical bonds are formed between atoms and molecules on surfaces.

The research breakthrough is a step ahead in understanding, controlling and tweaking molecular structures in electrical devices, Mohn said. For example, there may be a molecule with desirable properties to separate photons into positive and negative charges in each direction, which could help solar cells more effectively convert light to electricity.

The breakthrough is also a step forward in understanding the efficiency of a molecular structure as a switch, diode or transistor, said Michael Crommie, a professor of physics at the University of California and a faculty researcher at Lawrence Berkeley National Laboratory. He was not involved in the IBM research.

“Some people think it’s interesting to use molecules as building blocks for electrical devices,” Crommie said. “One of the troubles is to figure out how to put molecules, and to do what we want them to do, on surfaces. Many people are working on this.”

IBM’s technique is a diagnostic tool that allows researchers to better characterise small structures, Crommie said. Molecules are assemblies of atoms in particular configurations connected by chemical bonds, and behave differently depending on the environment. Electrons hold the atoms together and give molecules all of their properties.

There are infinite ways molecular systems can behave, and researchers want to be able to predict molecular behaviour on surfaces and tweak structures, Crommie said. For example, IBM’s tool could help researchers in Crommie’s lab create more effective graphene devices through modifications at an atomic level. Crommie wants to be able to modify the graphene by adding or removing charge, or see how graphene changes the behaviour of a molecule.

IBM has been conducting its own research on graphene, last year showing a graphene transistor that can execute 155 billion cycles per second, which was about 50 percent faster than previous experimental transistors shown by the company’s researchers. Electron flow is considered to be faster on graphene transistors than conventional transistors, which enables faster data transfers between chips.

However questions remain on whether molecules are feasible as building blocks for semiconductors. It’s also hard to predict the ultimate outcome of IBM’s breakthrough, and years of research and experimentation are required to figure out whether molecular structures perform rationally in a synthetic environment, Crommie said.

“This is fundamental research. It’s not like they are optimising a process that already exists. They are looking at new material combinations that are not being used in the industry. It’s not something that’s close to production,” Crommie said.

IBM’s Mohn said the next step could be to build on the technique further and to connect molecules, and also attach molecules to metal as they build nano-scale devices. The company’s ultimate goal is to advance the technology to build electronic devices, but only time will tell where the research goes.

“It’s like quantum computing. The idea is in principal it should be useful, but we are not there yet with direct applications,” Mohn said.

• New SSDs combine fast SATA III performance with power consumption as low as 10mW¹-enable feature-rich computing platforms with longer battery life
• SanDisk® SSD series’ U100 drive for ultra-thin notebooks offers SATA III performance and customized form factors
• SanDisk® iSSD™ integrated storage device series’ i100 drive is the world’s smallest, fastest 128 gigabyte (GB)² (SATA III) BGA-based SSD-ideal for slim, high-performance tablets and ultra-thin notebooks
• Sampling now with volume production scheduled for Q3 2011

Computex, Taiwan, May 31, 2011- SanDisk Corporation (NASDAQ: SNDK), a global leader in flash memory storage solutions, today introduced two new solid state drives (SSDs) for the mobile computing market. The U100 drive, successor to the popular SanDisk® P4 modular SSD series, delivers a flexible, cost-effective solution for ultra-thin notebooks. The SanDisk® iSSD™ integrated storage device series’ i100 drive is the world’s smallest, fastest 128 gigabyte (GB)² (SATA III) BGA (ball grid array) SSD and an ideal storage solution for slim, powerful tablets and ultra-thin notebooks.

The new SSDs utilize the high-performance SATA III interface to improve application loading times, web-browsing speeds, multimedia synchronization, file-transfer rates and overall system responsiveness. The drives employ a low-power architecture that reduces power consumption to as low as 10mW¹. This combination of high performance and low power allows OEMs to develop feature-rich products with longer battery life.

“Our deep involvement with key ecosystem stakeholders allows us to align our products with fast-moving market requirements,” said Rizwan Ahmed, director, SSD product marketing, SanDisk. “We develop low-power, high-performance SATA SSDs that optimally fit into a growing number of thin client devices.”

SanDisk® SSD Series’ U100 Drive for Ultra-Thin Notebooks
The U100 drive builds upon the successful SanDisk P4 modular SSD series, which enjoyed widespread adoption among ultra-thin notebooks and other mobile computing platforms. U100 supports an array of design needs and is available in a variety of form factors, including Half-Slim SATA SSD, mSATA, mSATA mini, 2.5″ cased, as well as customized modules.

The U100 drive delivers fast SATA III performance with up to 450 megabyte per second (MB/sec)3 sequential read and up to 340MB/sec sequential write speeds3. The drive’s low-power architecture allows OEMs to extend their products’ battery life while maintaining high performance. The drive is available in 8GB to 256GB capacities, and OEMs, attracted to the outstanding price/performance value proposition, are already successfully integrating the new SSD into their next-generation platforms.

SanDisk® iSSD™ for Tablets
The i100 drive is the smallest, fastest 128GB (SATA III) BGA-based SSD on the market and the newest product in the SanDisk iSSD integrated storage device series. The drive is available in 8GB to 128GB capacities, offering OEMs a flexible range of storage options. Measuring only 16mm x 20mm x 1.4mm (for up to 64GB) and 16mm x 20mm x 1.85mm (for 128GB), the drive allows OEMs to design sleek, high-performance tablets and ultra-thin notebooks.

The drive’s SATA performance achieves up to 450MB/sec3 sequential read and up to 160MB/sec sequential write speeds3. The i100 drive can improve sideloading rates, multitasking capabilities, real-time gaming experience and multimedia synchronization-all while extending battery life via its low-power architecture.

New SSDs Offer Additional Benefits

• Drives support Power Classes for flexible performance and power-budget control capabilities
• nCache™ Acceleration Technology provides fast random burst write performance for improved system responsiveness and multitasking functionality
• Based on a JEDEC-standard package for industry compliance

The i100 and U100 drives are sampling now with volume production scheduled for Q3 2011.

Phase-change memory offers 100 times the write performance of NAND flash

By Lucas Mearian | Computerworld US | Published: 10:11, 01 July 2011

IBM Thursday announced a breakthrough in computer memory technology, which may lead to the development of solid-state chips that can store as much data as NAND flash technology but with 100 times the performance and vastly greater lifespan.

Currently, NAND flash memory products, such as SSDs, have write rates as high as 2Gbit/sec .

IBM said it has produced phase-change memory (PCM) chips that can store two bits of data per cell without data corruption problems, something that has plagued PCM development from the start.

IBM’s phase-change memory chip uses circuitry that is 90 nanometers in width

Like NAND flash memory, which is used in solid state drives (SSDs) and is embedded in computers like Apple’s MacBook Air, PCM is nonvolatile — meaning it retains data after its power supply is shut down.

Unlike NAND flash, PCM memory does not require that existing data be marked for deletion prior to new data being written to it — a process known to as an erase-write cycle. Erase-write cycles slow NAND flash performance and, over time, wear it out, giving it a lifespan that ranges from 5,000 to 10,000 write cycles in consumer products and up to 100,000 cycles in enterprise-class products.

PCM can sustain up to 5 million write cycles, according to IBM.

“If you can write to flash 3,000 times, that will outlive most cell phones and MP3 players, but that’s certainly not good enough for the enterprise that does that in an hour,” said Christopher Sciacca, manager of communications for IBM Research in Zurich.

As organizations and consumers increasingly embrace cloud-computing models and services, ever more powerful and efficient, yet affordable storage technologies are needed, according to Haris Pozidis, manager of memory and probe technologies at IBM Research.

Pozidis said that for the past five months, teams of IBM scientists have been testing a multi-level cell (MLC) chip that’s capable of storing two and eventually three bits of data, indicating that it can achieve a level of reliability that is suitable for practical applications.

Besides applications for enterprises and in the cloud, PCM may also serve as an extension for DRAM .

While DRAM will continue to be used as the closest memory device to the CPU for the most active data, Pozidis said, PCM, with its greater capacity, can be used less frequently accessed data. “The PCM, which is much larger, acts as a repositor. If the data becomes hot again it will move back to the DRAM,” he said.

In another scenario, Pozidis said, the CPU can talk directly to the PCM, but it thinks its talking to the DRAM using a controller. “Again, the hot data speaks to DRAM and not so hot data speaks to the PCM,” he said.

DRAM is also expected to hit a technical wall in several years when it reaches lithography sizes of between 20-30 nanometers. One nanometer is roughly the size of four gold atoms.

A nascent technology, PCM is used today as a replacement for NOR, EEPROM, NVRAM memory that are currently manufactured by Micron Technology, Samsung, and South Korea’s Hynix Semiconductor.

Current technology is single-level cell (SLC) PCM, which only stores one bit per cell with limited capacity. For example, Samsung produces a 512Mbit PCM chip for its GT-E2550 GSM mobile phone. Micron’s Numonyx division makes a 128 Mbit PCM chip and isshipping product to several customers who use it in networking equipment, medical monitoring devices, and security cameras. .

Samsung’s PCM RAM chip

PCM uses electrical charges to change areas on a glassy material from crystalline to random or amorphous. The technique uses far less power than NAND flash to store data and it has data write rates up to 100 times faster because it does not first require existing data to be marked for deletion.

PCM leverages the resistance change that occurs in the material — an alloy of various elements — when it changes its phase from crystalline – featuring low resistance – to amorphous – featuring high resistance – to store data bits. In a PCM cell, where a phase-change material is deposited between a top and a bottom electrode, phase change can controllably be induced by applying voltage or current pulses of different strengths. These heat up the material, and when distinct temperature thresholds are reached cause the material to change from crystalline to amorphous or vice versa.

IBM scientists said they were able to address the bit error problem associated with MLC PCM memory by using an advanced modulation coding technique, which addresses the problem of short-term drift. Short-term drift is analogous to a problem in NAND flash memory where electrons leak through the thin walls of cells and create data read errors.

In NAND flash, the problem is addressed through the use of error correction code (ECC) in controller chips. But in PCM, data errors are not corrected, but avoided through the use of specialized code.

“With modulation codes you try to avoid the most probable errors. Modulation codes appear today in hard disk drives as well as optical drives such as Blu-ray discs,” Pozidis said. “We apply a voltage pulse based on the deviation from the desired level and then measure the resistance. If the desired level of resistance is not achieved, we apply another voltage pulse and measure again – until we achieve the exact level.”

IBM scientists achieved a worst-case write latency of about 10 microseconds, which represents a 100x performance increase over even the most advanced flash memory on the market today.

Pozidis said IBM is currently using PCM circuitry that is 90 nanometers in size, or about twice the width of today’s densest SLC PCM products. But that too will shrink over time.

IBM is not planning to produce consumer grade products out of PCM, Pozidis said. The main target for the technology is to license it to memory manufacturers, such as Toshiba and Samsung, and help them accelerate the production of the memory chips for enterprise applications.

Other researchers have been combining carbon nanotube technology with PCM to create chips that sip electricity and could extend the battery life of mobile devices to weeks.

Samsung announced that it has begun the mass production of a new 30nm-class 32GB memory module for green IT systems. This is the first time in the industry that mass production using 32GB modules and 30nm class chips has started. The 30nm modules use 4Gb DDR3 DRAM chips.

“With this module, Samsung has secured the highest level of product and solution competitiveness in the DRAM market for PC, server and mobile applications,” said Wanhoon Hong, executive vice president, memory sales & marketing, Samsung Electronics.

“We also plan to ship more energy-efficient 4Gb DDR3 DRAM based on 20nm-class* process technology in the second half of this year, which will significantly expand the rapidly growing market for green IT memory solutions. Moreover, we intend to keep delivering the greenest memory products with optimal performance for customers,” he added.
The new modules that Samsung is producing include 32GB RDIMM and 8GB SO-DIMM modules.

The RDIMM modules operate on 1.35V and can perform at up to 1866Mbps, which is 40% better than the 1333Mbps 40nm class modules operating at 1.5V. The new modules also consume 18% less power. The 8 GB SO-DIMM modules operate at up to 2133Mbps at 1.5V.

Samsung expects that almost 10% of its total DRAM shipments in 2012 will be 4Gb modules.

Shane McGlaun

Computer Memory, also known as RAM (Random Access Memory) is an integral part of your computer and plays an important role in the way your PC functions. In this guide, we will show you how you can test and identify bad memory modules on your PC.

If your PC is running on a single memory stick and emits endless beeps during boot-up, it is usually a sign of a completely damaged memory module. Identifying partially damaged RAM however can be difficult especially if your PC has multiple memory modules installed. But with a systematic approach and a series of memory tests, you can easily nail down the culprit memory module yourself!

Getting Started
Before proceeding further, let’s have a quick look at some of the most common symptoms of a bad memory module:

1. Computer freezes, crashes, or shows the Blue Screen of Death (BSOD) for no apparent reason.
2. Distorted graphics or interrupted media playback.
3. BSOD during software/operating system installations.
4. Computer crashes while you are playing games or running memory intensive applications such as Adobe® Photoshop®.

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