Intel's FinFETs are less fin and more triangle
May 21, 2012 // Peter Clarke
Reverse engineering and analysis consultancy Chipworks Inc., has posted microscope cross-sections of parts of the 22-nm Ivy Bridge processor from Intel that has revealed that the FinFETs, which Intel calls tri-gate transistors, are in fact trapezoidal, almost triangular, in cross-section.
The ICs were 64-bit, four-core Xeon E3-1230 CPUs intended for the server market, which Chipworks (Ottawa, Ontario) said it obtained in Hong Kong, China.
The triangular section is markedly different to the idealized rectangular section that Intel had shown previously in 2011. However, it is not clear whether the non-vertical sides to the fins are a non-critical manufacturing artifact or are deliberately engineered by Intel and have a critical impact on electron mobility or yield.
Gold Standard Simulations Ltd., (Glasgow, Scotland), a spin-off from the University of Glasgow led by Professor Ase Asenov as CEO, responded by saying on its website: "There is a lot of speculation about the possible advantages and disadvantages of the trapezoidal, or almost triangular, shaped 'bulk' FinFET." GSS has performed a simulation analysis of the FinFET using its statistical 3-D TCAD simulator called Garand.
GSS's simulation was used to explore the dependence of threshold voltage on gate length for the trapezoidal Intel transistor and an equivalent rectangular-fin transistor. "Clearly the rectangular fin has better short channel effects. Still, the million-dollar question is if the almost-triangular shape is on-purpose design, or is this what bulk FinFET technology can achieve in terms of the fin etching?"
The comparisons between dimensionally comparable rectangular and trapezoidal FinFETs are not markedly different but as GSS had no knowledge of doping profiles it assumed a lightly doped channel. At the same time GSS acknowledged that there is a high doping concentration stopper below the fin in the shallow trench isolation (STI) region. "Clearly FinFETs are more complicated devices in terms of understanding and visualization compared to the old bulk MOSFETs," GSS concluded.
Dick James' blog at Chipworks
GSS' discussion of trapezoidal FinFET All news
Opening up the IoT data flood gates
November 21, 2014
Only a few days after their LoRa long range communication demo at electronica, IBM and Semtech are making the LoRa MAC protocol ...
Polarizing filter reduces energy drain from smartphone displays
From warm to cool white: colour-temperature tunable LEDs
System provides high-volume solution for flexible OLED displays
Isabellenhütte diversifies channels, clientele
SiRFusion enables accurate indoor location without new infrastructure
November 20, 2014
Indoor location has been a challenge to smartphone app developers and many ideas have been presented from Bluetooth beacons ...
EnOcean eyes the consumer market
Can Fool's gold reduce the cost of solar cells?
Nature constants: How variable are they really?
- Halogen-free options and increased performance for terminal blocks
- Wireless Power User Guide
- Secure is the New Smart
- 5 Best Practices for Designing Flexible Test Stations
InterviewFreescale CEO: 'IoT isn't just buzz'
Coming after the solid third quarter results that produced higher operating margins and improving cash flow, Freescale Semiconductor's CEO Gregg Lowe had every reason to be chipper and lively when EE Times ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, Cherry is giving away five of its Energy Harvesting Evaluation kits, worth over 266 Euros each, for EETimes Europe's readers to win. Cherry's energy harvesting technology benefit mostly applications where a complex wire assembly and/or batteries would be inappropriate.
The required RF-energy is created by the mechanical actuation of the switch and the data is transmitted...MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.