MANHASSET, NY Research in semiconductor technology will be featured at the 55th International Electron Devices Meeting and two trends stand out: challenges for creating ever-decreasing feature sizes in next-generation processing nodes and integration of application-specific devices.
At the last two IEDMs, Intel has described an increasingly sophisticated quantum-well technology. This year, Intel researchers will describe InGaAs quantum-well field effect transistors (QWFETs) with an integrated composite high-k dielectric for reduced gate leakage.
Meanwhile, Purdue University researchers will describe a new damage-free dry/wet etching process with which they built the first InGaAs FinFETs. These had channel lengths down to 100 nm, widths down to 40 nm, and three gates (on the top and both sides) for better control of short-channel effects.
Researchers from South Korean research university KAIST will describe memory cells based on moveable fins, integrated with a totally CMOS logic process that also employs FinFETs, as independent gates. Data storage is accomplished via the mechanical position of the fins, which are either centered in their channels or are contacting the gate (via electrostatic forces). The physical positions represent binary digits 0 and 1.
On the application front, products that are made from organic materials can be printed using inkjet printers, as opposed to complex and costly mainstream fabrication processes.
At the IEDM, UC-Berkeley researchers will describe a wetting-based technique used to build self-aligned organic transistors and circuits with a minimum overlap of just 0.78m. Everything was inkjetted including the semiconducting layers, metallization and dielectrics. The researchers say the process is simple enough that inexpensive all-printed circuits may be realized in the near future.
For their part, Stanford University researchers used solar and MEMS technologies to build a self-powered, conformal retinal prosthetic. Electrode arrays are implanted in the retina and current is injected into underlying, still-functional neural cells. Electrical patterns corresponding to visual images can be created, which the brain can interpret as vision. The implanted electrodes are actually tiny silicon solar cells, three per pixel of vision.
A Goggle-mounted camera captures video, which is processed by a pocket computer. The resulting data is fed to a miniature projector, also Goggle-mounted. In turn, it projects images onto the solar cell, or photovoltaic, implant. (It does so at near-IR wavelengths to avoid conflict with visible light entering the eye.) When hit by the light, the photovoltaic cells inject current patterns corresponding to the projected images into neural tissue.
To achieve curvature, the implant was fabricated with a MEMS process that enables each pixel to move and rotate such that the entire array can conform to spherical surfaces with a radius of curvature as small as 5 mm. The photovoltaic electrodes produced enough current for neural stimulation.
The Emerging Technologies session will feature invited talks from leading experts on graphene nanoelectronics.
At the session, IBM will report on graphene FETs with cut-off frequencies as high as 50 GHz, the fastest ever. Their rather long gate length (350 nm) opens up the possibility that graphene one day may replace silicon for MOSFETs.
IEDM is being held December 7 - 9 in Baltimore this year.