Sunday, January 31, 2010

Advances in magnetic tape data density

Via ElectroIQ: "IBM, Fujifilm tweak BaFe particles for record magnetic tape data density"
In work with Japan's Fujifilm, the researchers recorded data on a prototype tape at a density of 29.5 billion bits/in2, about 39× the areal data density of today's industry-standard magnetic tapes.

Tuesday, January 26, 2010

Sony on Wireless Power Feeding Technologies

Via Tech-on, a look at Sony's recent developments in wireless power transmission.
The system can transmit 60W electricity to a device located about 50-80cm away by using magnetic resonance. The efficiency of electric power transmission between the transmission and reception devices is 80%. When the rectifier circuit of the power supply device is included, the transmission efficiency is 60%.

Thursday, January 21, 2010

IEEEXplore watch: More on Feb 2010's IEEE TED

So this issue is turning out quite good, with two papers on mixed-signal performance of high-voltage drain-extended MOS devices and another on process variation effects on emerging technologies. The link to the issue is here.

IEEEXplore watch: Quantified Temperature Effect in a CMOS Image Sensor

Another paper from the February 2010 issue of IEEE TED on image sensors: "Quantified Temperature Effect in a CMOS Image Sensor".
To quantify the influence of temperature, the maximum depth of an affected region was defined as DAR. The experimental results revealed that the DAR index increased with either an increase in power consumption or a space reduction between the resistor and the pixel array. The DAR index not only characterized affected regions in the experiment but also provided a valuable reference regarding temperature protection for future imager designs.

IEEEXplore watch: Measurement of High Sensitivity and Low Crosstalk of Zero-Space Microlens for 2.8- microns-Pitch Active Pixel Sensor

From the February 2010 IEEE Transactions on Electron Devices: "Measurement of High Sensitivity and Low Crosstalk of Zero-Space Microlens for 2.8-um-Pitch Active Pixel Sensor"
This paper presents the sensitivity analysis of both normal microlenses and zero-space microlenses based on the wafer test data from the Teradyne IP750, which is a special wafer test platform for CMOS sensors. The results of the statistical data of the wafer test show that the sensitivity of the zero-space microlenses has been improved by about 73.6% on the red pixel (69.6% on the green pixel and 76.3% on the blue pixel) compared with that of the normal microlenses.

Wednesday, January 20, 2010

Paper watch: Carbon Nanotubes as MIR detector

From Applied Physics Letters: "Carbon nanotube-Si diode as a detector of mid-infrared illumination".
We report a room temperature mid-infrared photodetector based on a carbon nanotube-silicon heterojunction nanostructure. The observed mid-infrared band (8–12 ยตm) in the photocurrent spectrum is consistent with the estimated band gap energy of semiconducting multiwall nanotubes (15 to 30 nm diameter). The fast response time (16 ms) and small temperature change (~10−8 K) upon infrared light suggest that the photocurrent response is not due to bolometric effect. We determined that the primary mechanism of the photocurrent in this spectral range is associated with photon absorption of semiconducting multiwalled carbon nanotubes followed by charge separation at the interface, their transport, and collection at the external electrodes

More on advanced memory technologies and materials

From EETimes: Superlattices enable small, fast, low-power RRAM.
RRAMs are being proposed as the non-volatile memory of choice for the 22-nanometer process technology node on the International Technology Roadmap for Semiconductors, below which traditional flash memory bit cells are not expected to scale well.

IEEEXplore watch: top 100 articles from Dec. 2009

IEEE Top 100 Documents Accessed: Dec 2009.

Tuesday, January 19, 2010

Towards NEMS

Semiconductor International reports on work at the Argonne National Lab in the US which tries to harness the Casimir effect: "Scientists to Conquer Casimir Effect, Enable NEMS".

The researchers' goal is to do the most precise characterization of this force to learn exactly how material properties influence its function, which is important in trying to eliminate it. The Argonne group received a grant from the Defense Advanced Research Projects Agency (DARPA) to try to design mechanisms to control it. The Casimir Effect produces an attractive force. If it were possible to make it repulsive, it might be used to actuate NEMS devices. "This is an attractive option, because then you could use quantum mechanics to move nanoscale objects," Lopez said. "Perhaps it can be the energy source to move these tiny devices."


A decade ago, the Casimir Effect was an academic curiosity. Today, it is a technological problem, because if NEMS devices are to be used for thousands of applications, it becomes necessary to control the quantum forces that come into play at those scales. Quantum mechanics is quickly becoming quantum engineering.

Monday, January 18, 2010

Curved photodetector array

From Applied Physics Letters: "Paraboloid electronic eye cameras using deformable arrays of photodetectors in hexagonal mesh layouts":
We report on a type of digital camera that uses a hexagonal array of silicon photodetectors on a substrate whose surface has parabolic curvature. This elliptical paraboloid shape closely matches the image surface formed by a simple, planoconvex lens. The hexagonal arrangement provides high area coverage with an approximately circular peripheral view. Details of the design strategies and underlying features of the mechanics and optics are described. Full imaging with these parabolic cameras and comparison to planar layouts reveals improved uniformity of illumination and focus across a wide field of view

Imaging beyond the difraction limit

Small Times summarizes this recent Applied Physics Letter: "Peering into the nano world with a nanolens".
"This is the best superlens realized so far, and is a significant development in the field of high-resolution optical imaging," said Srinivas Sridhar, prof. and chair of physics at Northeastern, in a statement.

Sridhar claims the group already has capabilities for large-scale production of the nanolenses, and wants to begin manufacturing "in the near future," he added. End applications include biomedical imaging and lithography techniques. The work is funded by the National Science Foundation and the US Air Force.

Sunday, January 17, 2010

Engineering history: on the development o the planar process

Another nice post by David Manners: What Motivated Hoerni To Develop The Planar Process.
[...] The demonstration device he made was completely flat withoutr the elevated structures of the mesa transistor. When he demo-ed the transistor in March 1959, Hoerni showed its robustness by spitting on it. [...]

Power-line networking update from CES

Brian Dipert lists some thoughts on power-line networking.

Analog test

Nice overview of the importance of analog testing in current systems, from EDN.

The future?

Recent articles/papers to take into account for the future of electronics:
  • Nano-engineering for ever decreasing device sizes (link to the Nature Nanotechnology Letter):
  • "Self-assembled structures are often too small and affordable lithographic patterns are too large," said Albert Hung, lead author of the Nature Nanotechnology paper and a post doc working in Cha's lab. "But rationally designed synthetic DNA nanostructures allow us to access length scales between 5 and 100 nanometers and bridge the two systems.

  • At IEEEXplore, recent developments in memristor fabrication from the 2009 Semiconductor Device Research Symposium.

Thursday, January 14, 2010

Wednesday, January 13, 2010

Tutorial on MRAM memory

At Low Power Design, a tutorial on MRAM memories: "MRAM—The Future of Non-Volatile Memory?"

Wednesday, January 6, 2010

Lunar laser ranging

An article at SPIE reviewing forty years of lunar laser ranging.
Some calculations using this data, such as the distance between the earth and moon, are straightforward. The average distance from the centers of the earth and the moon is 238,897 miles (384,467 km) -- measured with a precision equivalent to determining the distance between Los Angeles and New York to 1/100 of an inch. The speed of rotation of the earth and moon, as well as their axial and orbital variations, can also be determined.

Novel organic sensor concepts

An article at SPIE by a researcher from the University of Graz on organic sensor developments.

The road to 15nm CMOS

A nice overview of the challenges faced by ever shrinking CMOS technologies at Semiconductor International: "CMOS transitions to 22 and 15 nm".

Monday, January 4, 2010

Towards a germanium-based CMOS technology

From Semiconductor International: "MIRAI Advances Ge Transistor Prototype"

The prototype is produced on a bulk germanium material, but later the transistor will be fabricated with a Ge-on-Si substrate. In the early days of the semiconductor industry, germanium was replaced by silicon partly because germanium lacked a stable native oxide, a challenge now being resolved by the introduction of high-k dielectrics. Also, the early germanium transistors could not withstand high-temperature operations because of the lower energy bandgap, which is being resolved in part by the use of strain techniques.

The attraction of germanium is its higher mobility of 4000-5500 cm2/Vsec, depending on the amount of strain, which is almost triple the electron mobility of silicon. According to a calculation by MIRAI engineers, the electron mobility increases as the energy bandgap decreases, which allows strain to impact the germanium bandgap.