Author's Latest Posts


The Other Side Of H1-B Visas


There is a lot of discussion these days about “Hire American.” But what does that actually mean in practice? I’m at the Materials Research Society Spring Meeting this week, where one of the presentations was by a scientist who works at the TEL Technology Center, America, in Albany, NY. It’s the largest Tokyo Electron research center outside of Japan. It’s affiliated with the SUNY P... » read more

Will Self-Heating Stop FinFETs


New transistor designs and new materials don’t appear out of thin air. Their adoption always is driven by the limitations of the incumbent technology. Silicon germanium and other compound semiconductors are interesting because they promise superior carrier mobility relative to silicon. [getkc id="185" kc_name="FinFET"] transistor designs help minimize short channel effects, a critical limi... » read more

TFETs And/Or MOSFETs For Low-Power Design


As discussed in Reducing Subthreshold Swing With TFETs, papers at December’s IEEE Electron Device Meeting examined a variety of potential designs for tunneling transistors (TFETs). That focus continued at the recent CS International Conference. In particular, Nadine Collaert discussed IMEC’s work on InGaAs homo-junction devices. Many compound semiconductor devices depend on heterojunctio... » read more

TFETs Cut Sub-Threshold Swing


One of the main obstacles to continued transistor scaling is power consumption. As gate length decreases, the sub-threshold swing (SS) — the gate voltage required to change the drain current by one order of magnitude — increases. As Qin Zhang, Wei Zhao, and Alan Seabaugh of Notre Dame explained in 2006, SS faces a theoretical minimum of 60 mV/decade at room temperature in conventional MO... » read more

Progress In Flexible Electronics


Flexible electronics have been proposed for a wide variety of applications, from pulse and activity monitoring to electrolyte balance measurements. That makes generalizations difficult, but most proposed devices involve some combination of [getkc id="187" kc_name="sensors"], a power source, onboard data storage and analysis electronics, and some form of communications for configuration and data... » read more

Managing Parasitics For Transistor Performance


The basic equations describing transistor behavior rely on parameters like channel doping, the capacitance of the gate oxide, and the resistance between the source and drain and the channel. And for most of the IC industry's history, these have been sufficient. “Parasitic” or “external” resistances and capacitances from structures outside the transistor have been small enough to discoun... » read more

More Reactive, Less Warming


As mentioned in Part 4 of Semiconductor Engineering's series on fab sustainability, molecular fluorine is one alternative to PFCs or NF3 for CVD chamber cleaning in the integrated circuit and flat panel display industries. It has a number of advantages relative to NF3: an unstable, highly reactive molecule, F2 breaks down easily and has no global warming potential.  When NF3 is used, atomic... » read more

More Than Just Carbon Dioxide


As discussed in Part Two of this series, lifecycle analyses of greenhouse gas emissions consider both direct and indirect sources. Indirect CO2 emissions, attributed to electricity and other forms of energy purchased by the fab, are the semiconductor industry’s single largest environmental impact. Of those emissions, a large fraction are attributable to plasma-based etch and deposition steps,... » read more

Sustainability Saves Water, Too


After energy (discussed in Part 2 of this series), water is the largest fab input and the largest contributor to fab waste. Yet tools for analyzing a fab’s water footprint are generally less mature than tools for analyzing emissions of CO2 and other greenhouse gases. In part, this may be because water consumption is primarily a local issue, while greenhouse gas emissions are a global c... » read more

The Limits Of The Lifecycle


In the first article in my series on sustainability, I cited one estimate that attributed most of the electricity consumed by an integrated circuit to manufacturing, not use. Other analyses, however, come to exactly the opposite conclusion, with above 90% of lifetime energy consumption accounted for by the use phase. How can that be? The glib answer is that industry efforts to build more eff... » read more

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