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Sunday, August 3, 2014

#299 Misuse of the term "semiconductors"

In business and financial communities the term "Semiconductors" is quite commonly used in reference to the industry concerned with development and manufacturing of advanced integrated circuit.


How misleading and inaccurate it is... I would have no problem with "semiconductor electronics", but to use the name of the entire class of materials in reference to only one type of products these materials are used to manufacture? How about optoelectronic devices including lasers and LEDs for lighting applications, photovoltaics, not to mention MEMS for instance?


Well, I don't get it. And I don't think this blog will change anything in this regard, but at least I expressed my opinion.

Posted by Jerzy Ruzyllo at 05:33 PM | Semiconductors | Link

Sunday, July 27, 2014

#298 Mist deposition

In blog #296 I mentioned other than spin-on physical liquid deposition methods including mist deposition. The idea behind mist deposition is to convert liquid precursor (for instance colloidal solution containing nanodots or viscous liquid such as  photoresist) into a very fine mist which is then carried by nitrogen to the deposition chamber where submicron droplets uniformly coalesce at room temperature and at atmospheric pressure on the wafer surface. The film is then subjected to thermal curing, just like a spin-coated material, and solidified.


Mist deposition has been proven useful in various thin-film formation applications including nanocrystalline quantum dot films, high-k dielectric films or photoresist.  


The method is particularly in the thickness regime below 100 nm where other PLD methods such as spin-on or microspray may not allow sufficient control over film thickness.

Posted by Jerzy Ruzyllo at 08:13 PM | Semiconductors | Link

Sunday, July 20, 2014

#297 An example of application

I was asked a question about thin film formation using colloidal solutions, flexible substrates and how it all may come together. Here is an example concerned with nanocrystalline quantum dot based LEDs on flexible substrate.


Posted by Jerzy Ruzyllo at 10:38 AM | Semiconductors | Link

Sunday, July 13, 2014

#296 Alternative PLD techniques

Following on comments in blog #293 let me point out that the technology of thin-film formation using liquid precursors expands rapidly in semiconductor device fabrication. It is no longer primarily photoresist deposition. Consider organic polymer semiconductors,  colloidal solutions containing nanodots, nanowires or nanotubes, low-k interlayer dielectrics, etc.


Responding to those emerging needs the arsenal of physical layer deposition techniques also grows well beyond the best established spin-on deposition. Printing, including ink-jet-like printing and nanoprinting, micro-spray and mist deposition (see next blog for more on this one) are finding their way into semiconductor manufacturing where a rigid, circular wafer is no longer the only type of the substrate (think very large area substrates, flexible sheets and ribbons substrates, roll-to-roll processing, etc.)


Posted by Jerzy Ruzyllo at 01:17 PM | Semiconductors | Link

Sunday, July 6, 2014

#295 July blogs

Due to the extensive travel, July blogs will be delayed, but stay tuned...

Posted by Jerzy Ruzyllo at 01:10 PM | Semiconductors | Link

Sunday, June 29, 2014

#294 Doubts about below 7 nm technology node

In relation to the blog # 291, I am taking note of the growing concerns regarding affordability of the gate length technology below 5 nm. See recent comments along the same lines.

Posted by Jerzy Ruzyllo at 04:00 PM | Semiconductors | Link

Sunday, June 22, 2014

#293 More on PLD

More on PLD because the pool of materials used in semiconductor technology to form thin-film using this deposition technique is growing. In general, process of physical liquid deposition forming thin-film involves application of the liquid precursor to the surface of the substrate followed by thermal curing causing vaporization of the solvent and solidification of the film. In the case of painting (see previous blog) liquid precursor (paint) would be applied using brush. Simple, right?


Well, PLD methods such as painting, brushing, screen-printing, etc. are too crude to be used in semiconductor device manufacturing where requirements regarding control over thickness and uniformity of the film are extremely stringent. The most common PLD process in semiconductor manufacturing is a process of spin-deposition of photoresist which initially in the form of a viscous liquid ends up on the surface of the wafer in the form of highly homogenous thin film.


More on the alternative PLD techniques later...

Posted by Jerzy Ruzyllo at 10:17 AM | Semiconductors | Link

Sunday, June 15, 2014

#292 Physical Liquid Deposition, PLD (think... painting!)

Thin film technology is a foundation of semiconductor manufacturing. In the process of thin film formation the source material (starting material) can be a gas (typical situation in the most of the Chemical Vapor Deposition or CVD processes), a solid (common in Physical Deposition Processes or PVD) or a liquid in which case the term Physical Liquid Deposition, or PLD, seems to adequately describe the nature of the process.


At the first glance the concept of Physical Liquid Deposition may not be all that obvious. In the case you don’t immediately see what PLD is all about think…. painting!


More on PLD next time

Posted by Jerzy Ruzyllo at 12:54 PM | Semiconductors | Link

Sunday, June 1, 2014

#291 "Concorde" and 5 nm technology node - what do they have in common?

You remember "Concorde", a supersonic passenger jetliner capable of moving passengers across the Atlantic in 3 hours of so? It was almost 2 times faster that any other passenger jet. How come then this engineering marvel was retired for good in 2003? Well, it was simply too expensive. In other words, gains resulting from the technological achievement did not justified a very high cost of its implementation.Besides, what if on a given day the time of door-to-door trip between offices in Manhattan and the City of London would be determined by the time of the taxi rides to and from the airports rather than by the time of the flight itself? In this context a supersonic speed of "Concorde" doesn't look so glamorous, right?


I have a feeling that the same will happen to 5 nm and below IC technology nodes. In other words, I venture to predict that 5 nm gate length technology will be never brought to fruition as a commercial, mass-manufactured  product for logic applications because of the cost of its implementation being significantly higher than the potential profit gains resulting from the improved transistor performance. Besides, what if overall circuit performance would be limited by the interconnect and package related delays and dissipated heat management problems and not by the performance of the ultra-short gate length transistor? In this context the fact that the gate of the transistor will be some 10 atoms long would look somewhat less exciting, right?


Well, I hope you see what I am trying to say. But just to make it clear, I fully understand how remote  the parallel between supersonic "Concord" and 5 nm integrated circuit technology node is. At the same time, however, I can not help but to take note of the fact that the times have come when outstanding, ground breaking, progress defining, ready to implement accomplishments of science and engineering are being  shelved because we are not willing to pay for them. To me, it looks like a somewhat new chapter in the history of our technical civilization.
Do you agree with me?

Posted by Jerzy Ruzyllo at 06:16 PM | Semiconductors | Link

Sunday, May 25, 2014

#290 Semiconductors - a truly global affair

Here is an observation coming from an old timer…


Semiconductor science and engineering has become a truly global affair. While it is obviously a status quo now, it was not the case in the past. There were times some 50 years ago when the vast majority of semiconductor related activities, whether in terms of academic research or industrial manufacturing, were taking place in the United States. That is not to say that the technically and scientifically meaningful developments with respect to semiconductor device fundamentals were not simultaneously taking place in Europe and Japan. For instance, important contributions to the development of transistor after World War II came from the Radar Research Establishment in Malvern, Great Britain while other key electronic and photonic device related innovations came at that time from Japan and Russia. Yet, when the 60’s and 70’s rolled in the overwhelming impact which the U.S. had on semiconductor science and engineering worldwide was evident.


Much has changed since those early years. Today, the vast majority of worldwide wafer processing capabilities are installed in Asia with Taiwan leading the field. China is bound to become a major player with wafer processing capabilities expected to double within the next few years while Samsung Electronics is projected (did it already happen?) to take over Intel as the largest semiconductor manufacturer in the world. In short, semiconductor production and R&D activities are gaining momentum all over the world including countries where semiconductor related industrial and educational initiatives are still a relative novelty.


All of those factors clearly illustrate a major paradigm shift in the distribution of semiconductor related activities across the world which took place over the last two decades or so.

Posted by Jerzy Ruzyllo at 08:36 PM | Semiconductors | Link

‹‹ ›› is the personal blog of Jerzy Ruzyllo. With over 35 years of experience in academic research and teaching in the area of semiconductor engineering (currently holding position of a Distinguished Professor of Electrical Engineering and Professor of Materials Science and Engineering at Penn State University), he has a unique perspective on the developments in this progress driving technical domain and enjoys blogging about it.

With over 2000 terms defined and explained, Semiconductor Glossary is the most complete reference in the field of semiconductors on the market today.

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