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Faster and Faster - Moore's Law Continues to Amaze

PCWorld

IBM Details World's Fastest Graphene Transistor

Joab Jackson, IDG News Service

Feb 5, 2010 12:20 pm

Thanks to a change in recipe, IBM has created a graphene-based processor that can execute 100 billion cycles per second (100GHz), almost four times the speed of previous experimental graphene chips.

With this research, IBM has also shown that graphene-based transistors can be produced by the wafer, which could pave the way for commercial-scale production of graphene chips, said Yu–Ming Lin, the IBM researcher who led the work.

If commercialized, such graphene processors could be the basis of superior signal processing componentry, improving the fidelity of audio and video recording, radar processing and medical imaging.

IBM conducted the work on behalf of the U.S. Defense Department's DARPA (Defense Advanced Research Projects Agency), under a program to develop high-performance RF (radio frequency) transistors. A write-up of the results has been published in the Feb. 5 issue of Science.

Graphene, a single-atom-thick honeycomb lattice of carbon atoms, can transport electrons more quickly than other semiconductors, a quality called electron mobility. "That makes graphene a promising material for high-speed or high-frequency electronic components," Lin said.

This prototype processor was created on a 2-inch wafer, though in principle it could be done on even larger wafers, which should bring the production costs down, Lin said. Graphene is produced by heating a silicon carbide wafer, allowing the silicon to evaporate.

Until now, the downside of graphene has been that it is very sensitive to the environment. During the fabrication process, an oxide layer is deposited over the graphene to form the gate insulator. Typically, this deposition degrades the graphene's electron mobility, due to defects in the oxide that scatter electrons in the graphene. The IBM researchers minimized the damage by separating the graphene from the oxide with a very thin polymer layer.

This new approach has been instrumental in allowing the researchers to almost quadruple the frequency of graphene chips. Last year, research teams from IBM and the Massachusetts Institute of Technology both demonstrated graphene processors capable of frequencies around 26GHz. By comparison, silicon-based transistors of the same gate length (240 nanometers) have only been able to scale up to a clock rate of 40Ghz or so.

It also sets the stage for commercial production. The research shows that "high-quality graphene can be produced on a wafer scale, and graphene transistors can be fabricated with those processes used in the semiconductor industries," Lin said.

Lin cautioned against thinking of graphene as a substitute for the silicon-based microprocessors used in today's computers, at least at anytime in the near future. One major roadblock is that graphene does not work easily with discrete electronic signals, he explained. Because graphene is a zero bandgap semiconductor, meaning there is no energy difference between its conductive and nonconductive states, transistors made of the semiconductor cannot be turned on and off. In contrast, silicon has a bandgap of one electron volt, making it good for processing discrete digital signals, Lin said.

Instead, graphene is better suited for making analog transistors, such as signal processors and amplifiers. Today, such circuitry is largely made from GaAs (gallium arsenide), though GaAs offers nowhere near the same electron mobility, Lin said.

February 5, 2010

IBM hits graphene transistor breakthrough
by Larry Dignan

IBM graphene transistor

IBM Research on Friday announced that it has demonstrated a radio-frequency graphene transistor with the highest frequency so far: 100GHz.

Graphene is a special form of graphite, consisting of a layer of carbon atoms packed in honeycomb lattice. In a nutshell, graphene is like "atomic scale chick wire." Graphene's properties could lead to faster transistors.

One-step graphene doping could enable complementary metal oxide graphene transistors

By Suzanne Deffree, Managing Editor, News -- Electronic News, 2/17/2010

Researchers at the Georgia Institute of Technology have claimed a one-step process that produces both n-type and p-type doping of large-area graphene surfaces and that could facilitate use of the material for future electronic devices.

The doping technique -- produced by applying a commercially available SOG (spin-on-glass) material to graphene and then exposing it to electron-beam radiation -- can also be used to increase conductivity in graphene nanoribbons used for interconnects, according to the university.

Both types of doping were created by varying the exposure time to the to e-beam radiation, the university said, explaining that higher levels of e-beam energy produced p-type areas, while lower levels produced n-type areas.

The technique was used to fabricate high-resolution p-n junctions. When properly passivated, the doping created by the SOG is expected to remain indefinitely in the graphene sheets studied by the researchers, Georgia Tech said.

"This is an enabling step toward making possible complementary metal oxide graphene transistors," said Raghunath Murali, a senior research engineer in Georgia Tech's Nanotechnology Research Center, in a statement.

In the doping process, Murali and graduate student Kevin Brenner began by removing flakes of graphene one to four layers thick from a block of graphite. Next, they placed the material onto a surface of oxidized silicon, then fabricated a four-point contact device. They then spun on films of HSQ (hydrogen silsesquoxane) and cured certain portions of the resulting thin film using e-beam radiation. According to Georgia Tech, the technique provides precise control over the amount of radiation and where it is applied to the graphene, with higher levels of energy corresponding to more cross-linking of the HSQ.

"We gave varying doses of electron-beam radiation and then studied how it influenced the properties of carriers in the graphene lattice," Murali said. "The e-beam gave us a fine range of control that could be valuable for fabricating nanoscale devices. We can use an electron beam with a diameter of four or five nanometers that allows very precise doping patterns."

Electronic measurements showed that a graphene p-n junction created by the new technique had large energy separations, indicating strong doping effects, he added.

Researchers elsewhere have demonstrated graphene doping using a variety of processes including soaking the material in various solutions and exposing it to a variety of gases. Georgia Tech said it believes its process is the first to provide both electron (n-type) and hole (p-type) doping from a single dopant material.

In the process, the doping is believed to introduce atoms of hydrogen and oxygen in the vicinity of the carbon lattice. The oxygen and hydrogen do not replace carbon atoms, but instead occupy locations atop the lattice structure, the university said.

In volume manufacturing, the e-beam radiation would likely be replaced by a conventional lithography process, Murali said. Varying the reflectance or transmission of the mask set would control the amount of radiation reaching the SOG, and that would determine whether n-type or p-type areas are created.

"Making everything in a single step would avoid some of the expensive lithography steps," he said. "Gray-scale lithography would allow fine control of doping across the entire surface of the wafer."

For doping bulk areas such as interconnects that do not require patterning, the researchers coat the area with HSQ and expose it to a plasma source. The technique can make the nanoribbons up to 10 times more conductive than untreated grapheme, Georgia Tech claimed.

However, the researchers noted that a better understanding of how the process works and whether other polymers might provide better results is needed.

"We need to have a better understanding of how to control this process because variability is one of the issues that must be controlled to make manufacturing feasible," Murali said. "We are trying to identify other polymers that may provide better control or stronger doping levels."

A paper describing the technique appeared February 10, in the journal Applied Physics Letters. The research was supported by the Semiconductor Research Corp and the Defense Advanced Research Projects Agency through the Interconnect Focus Center.

Family Trip to Israel

In just about a month, our family begins to assemble from Califoria, Utah, and Colorado, flying first to NYC and from there to Amman, Jordan, where we leave the Airport by bus almost immediately and travel to Petra for the first of many adventurous experiences together. Shirley and I are looking forward with great excitement to this trip with our children and their spouses - a trip to connect with our most basic spiritual roots, the geography, structures, and the story of the Bible, with particular emphasis on the life, death, and resurrection of the Savior. Then we travel to Egypt to compare the Holy Land with the land of Ancient Egypt, with its massive buildings, complex theology, and a people who formed one of the first powerful nation atates in the world, which lasted several thousand years. There is much to take in, to sort out, and to remember. It will be ownderful to return and fill in some of the gaps of our first tour. There is never enough time to see it all, but what we see is wonderful

Joseph Smith

I have the great blessing and privilege of teaching the Gospel Doctrine class in our ward. This year we review Church History and the Doctrine and Covenants. For the first time, I can use as reference for this class Richard Bushman's Joseph Smith, Rough Stone Rolling, and Volume I of Joseph Smith's Journals, books not available during the preceding cycle.

Richard Bushman has given me wonderful insight into Joseph Smith's life. He supports the contention of Michael Quinn that the generally accepted belief in magic among the more rustic population of New England helped both Joseph Smith, his family and the early adopter's of Mormonism believe Joseph's fantastical story of angels and golden plates and interpreters, including seer stones, initially used to find treasure and subsequently used in translation of the plates. But he points out repeatedly that Joseph Smith's own self image changed repeatedly during his life, and that in the summer of 1828, Joseph obtained a prophetic voice. Not just the gift of translation, but the ability to speak in the third person voice, the voice of God, with his first revelation a rebuke of his weakness in giving the 116 translated pages of the BM to Martin Harris and a similar rebuke to Martin Harris, himself. Joseph was poor and he depended on Martin's time and money to get the plates translated and the book published, and yet, speaking for God, he rebukes in the most forceful terms Martin for his failures in what is now Section 3 of the D&C. Remarkable! And just the first in a series of changes that took place, often year by year, in Joseph's realization of his gifts, powers, and prophetic mission. Like the description of the Savior, he grew, grace by grace, to his full stature - beyond what many could accept, always on the cutting edge, right through the King Follett discourse.

Happy New Year 2009

fMRI can now "read your thoughts." fMRI brain scan patterns have been identified for objects, emotions, and locations, including specific room locations and landmarks. The patterns are similar from person to person; similar enough that characteristic patterns identified by scanning 20 brains can be identified in a previously untested subject who remains mute but whose brain patterns show that the subject is familiar with, say, a crime scene or a terrorist training camp location. Large multinational corporations are now attempting to determine subjects' brain pattern responses to certain foods, clothing, shopping experiences or new tech gadgets. A woman in India was convicted of murder in part because fMRI showed that her brain "identified" the events surrounding the murder. Science fiction is becoming increasingly more like real life. The sophistication of this testing is improving rapidly; increasingly more complex patterns are identifiable. Scanning resolution doubles at least every 12-18 months (something analogous to Moore's Law applies here, too), and with it, smaller clusters of brain cell activity can be identified and categorized. The question is this: will the law allow scanning of an accused person in Europe and the U.S., like it now allows blood tests and genetic testing, or will it be regarded in the U.S. as an encroachment on the fifth amendment against self-incrimination? What do you think?

Home-made generation of electrical power

Students at M.I.T. recently demonstrated a thermal solar dish that can be built inexpensively, concentrate sunlight to an amazing level of intensity, and used in almost every country in the world to generate power inexpensively:

http://web.mit.edu/mitei/education/spotlights/solar-dish.html

http://raw-solar.com/technology.html

The idea is quite simple, the materials readily available, and the steam generated with the device can produce electrical power. We'll see if it works in the real world.

When Markets Collide

I have learned a lot during the two weeks reading "When Markets Collide," a book by Mohamed El-Erian, a bond specialist who focuses on developing countries and who, among other things, worked for a while managing Harvard University's endowment fund. The investment world has changed quite remarkably during the last decade. Among the best and brightest investment managers during that time have worked managing large, multi-billion dollar university endowment funds and have been remarkably successful. So successful, in fact, that they often move on after several years to establish private hedge funds which are much more remunerative. In fact, they usually earned more than anyone else employed by the universities whose funds they managed, but still far less than their subsequent income managing private funds, since their income while working for the universities was public knowledge, whereas their earnings managing private funds was not.

I learned about ETFs or exchange-traded funds, which have many forms but whose purpose is to offer securitization of almost any asset of value, such as a stock market index, a commodity (oil futures, for example), or a bundle of real estate mortgages of various qualities and duration. It is this last creation that was one of the instruments that got the big multinational and investment banks in this country into such big trouble. The sub-prime mortgages were packaged, securitized, and then bought and sold almost like stocks and bonds. When people began to realize that many of these pieces of paper were worthless, they became frightened and refused to put good money after bad. The flow of money slowed down and almost stopped. The country developed a liquidity crisis which required a government bailout in the case of Bear Stearns. Since then, the concern about liquidity has reoccured intermittently. But there is another form of ETF that increased in popularity: commodity ETFs. These commodity funds enabled a much larger group of people to speculate in commodity futures than before their development.

Since WWII, the common consensus has held that real estate, including residential real estate, was in a long-term or "secular" trend upward. Popular wisdom held that you were wise to buy as much home as possible because "they ain't makin' any more land" and steadily rising land and construction costs will always put a floor under today's price. There may be short-term fluctuations, but the long-term trend has always pointed up. And this wisdom has held true throughout the 50 years of my adult life, with a few exceptions, the last about 18 years ago. Until now. The current situation has engendered a lot of FUD (fear, uncertainty and doubt). The current decline in real estate has lasted a year and most believe that the worst is yet to come, with a round of new foreclosures about to hit the market. David, who has to tell builders and developers almost every day that the bank is about to foreclose on their property, that they are going to loose their real estate investment and may have to declare bankruptcy, can tell you that he is worried about the current trends in California and Utah. For the first time in a generation, people are concluding that their real estate investments may not be a sure thing. Many are feeling much poorer. Their home is no longer a big piggy bank. They can't take out a second anymore to pay for whatever. President Hinckley's advice to Church members 5-10 years ago to avoid indebtedness to fund lifestyle seems prescient (prophetic?) and sound.

Those who still have money to invest have turned from real estate to oil. ETFs in oil companies and oil futures have become very popular. The same kind of popular wisdom holds: "They ain't makin' any more oil," increasingly more people are using oil and increasing their consumption of it, and the price of oil points only in one direction: up. So buy oil futures or ETFs in petroleum and other hydrocarbons. It's a sure thing. Almost certainly, the expanded securitization of commodities, particularly petroleum, has had some effect on the price of oil and oil products. We can only hope that it is a bubble waiting to pop, but with both China and India growing at 8-10% a year and the per capita use of petroleum rising greater than that, don't count on a long-term downward trend in gas prices at the pump. At least not until some years after 2010.

I also learned about SWF or sovereign wealth funds. These have been created by the more prudent oil and gas rich countries. Norway created one of the earliest SWF. Kuwait, Abu Dhabi and Qatar three others. Saudi Arabia is a late comer to the SWF table. Almost all oil and gas rich countries have developed one or more SWF. China and South Korea also have SWFs. These state owned funds are giant, nationally-owned but privately run hedge funds. For many years, they were very conservative and invested mainly in U.S. Treasury notes and British debt instruments. More recently, however, they have shown a willingness to invest in a wide variety of financial instruments, concerned primarily about both security and return on investment.

The size of these funds is massive. China's fund is young, but the country has $1.5 trillon surplus, fully a third of which is invested in U.S. treasury notes. Another third is also invested conservatively in debt instruments. We have no greater friend; China makes and sells us cheap but good quality goods, buys little in return, and stashes the money away in the U.S. to fund our debt, keeping interest rates low. We use the liquidity to pay our lifestyle debt, which we tend to use the way others use earning.

The emergence of SWF and ETFs allow oil rich countries to invest their money in oil futures, which serve to keep the price of oil high, maybe even artificially so. So Kuwait, for example, sell their oil for $130/barrel, then takes the profits and invests item in oil future ETFs, making profits from their oil in two different stages. Great for them but not for us.

The book is packed with excellent explanations of the current economy and what is likely to happen to the world economy over the next 10 years. He offers general investment ideas but no specific recommendations. [No stock picks, but invest in scarce commodities over the long haul. Diversify at least half of you money out of the U.S. and Europe and into Asia, particularly China and India.

Freedom from the Grid

Here is an interesting idea offered up by Panasonic for commercial introduction in 2010, the same year plug-in hybrids will be introduced widely:

http://panasonic.co.jp/corp/news/official.data/data.dir/en080414-2/en080414-2.html

Where available, a home will have the option of generating its own electrical power. Natural gas will power a home-based 1KW fuel cell at a price 35% less than the average cost paid by an electric utility company (PG&E, for example) to create power from a gas turbine. The heat generated by the fuel cell can be used to heat water and provide heat for the home during cold months. Of course, grid power is still available at night for recharging a plug-in hybrid, when grid power is dirt cheap, but during peak power demands, this fuel cell will be attractive. Of course, these fuel cells will also prove attractive to folks who do not have ready access to grid power or who must pay generally high rates for electrical power vs. natural gas or propane. David has talked about buying a car powered by natural gas. Unfortunately, the price of natural gas is rising rapidly, now, just like petroleum. But for a few years, we can probably manage better with natural gas than petroleum-based fuels. We simply need to improve the fuel economy of our vehicles, move as rapidly as possible to electricity as the primary power for vehicles, and use cellulosic ethanol in addition to electrical power to fuel plug-in hybrid vehicles.

i'm obsessed by this subject! Peace and security depend on solving the world's energy problems.

Dad