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Hi.
My name is Bill Dusch, and I'm a member of the Graduate
Student Association.
Our next professor is Dr. Jerzy Ruzyllo, distinguished
professor of electrical engineering.
Dr. Ruzyllo's research activities are in the area of
manufacturing methods and devices for semiconductor,
micro and nano electronics, as well as the processing and
characterization of electronic and photonic materials.
He is also creator and the author of the semiconductor
portal, semi1source.com.
We're very excited to have him here today.
Please give a round of applause for Dr. Ruzyllo.
Thanks for having me.
I would like to talk, switch gears, I'll be talking about
types of different nanotechnology, although what
sorts of growth with, talking to us about this also,
nanotechnology related, et cetera, this bio-technology.
So there's a very close correlation between what I'll
be talking about today and bio-nanotechnology.
My outline is very simple minded.
I'll be talking about nanotechnology and then the
semiconductor, and then semiconductor nanotechnology.
So there's not much into it.
First, I would like to remind you what nano stands for.
Nano is a prefix, and it means [INAUDIBLE] multiplier in the
metric system, and it basically follows centimeter,
millimeter, micrometer, and 10 to the minus ninths meter,
which is one billionths of the meter.
How does it translate to the physical object which we are
interacting with?
For instance, we associate certain things with being thin
or being very small, and how it really relates to
micrometers.
Paper, for instance, very thin paper is
100,000 nanometers thick.
Human hair.
If you have that, it's 50,000 nanometers thick.
Very fine sand grain, 50,000.
Dust particles.
Thousands of hundreds of nanometers.
Even the poppy seed is 500,000 nanometers as well.
Now in the bio world, nanometers are very common.
Although, if you notice, most of the building blocks that we
are made out of are mostly micrometers, right?
So we are built in micro-scale rather than nano-scale.
That's something I think is very interesting, because we
are convening in the nano-scale and into the
micrometers world.
Anyway, to make a long story short, fist thing you want to
remember from this is that atoms in size varies depending
on the element.
Can be as small as 0.1 nanometers in the case of
small hydrogen atoms.
0.5 nanometers in the case of fairly large cesium atom.
But we are talking nanometers.
So whenever we are referring to our manipulation of the
nanometer five, nanometer lever, we are talking
manipulation.
At the truly, truly, atomic level.
If you look at, for instance, neurons, what we think about
neurons now, Professor Rolls was referring to their lengths
being one meter or more.
But in terms of diameter, we are talking nanometers.
Although high nanometers.
You look at the virus, 20 nanometers.
The red blood cell, thousands of nanometers.
Bacteria, also thousands of nanometers.
Now, how about what we are doing at the nano level?
Well, we are pretty good at manipulating matter at a truly
very low nanometer regime.
We can create nano wires and shove maybe 30, 40, 50
nanometers in the regime.
We are building quantum well laser diodes which contain
layers that are one nanometer thick.
We are synthesizing carbon nanotubes which are 1.2
nanometers in diameter.
We are creating crystalline dots which are maybe 10
nanometers in diameter.
Those are individual atoms.
And we have full control over how many atoms we
put in the dot line.
So we gain capabilities to manipulate matter at a truly,
truly atomic level.
This would be a state of a transistor, that you have
billions of those in every microchip in your lab.
And we are talking geometries in the range of 22 nanomaters
in the gate lengths, thicknesses of materials, 1
nanometer, 6 nanometers.
So we are really fully into a nanometer regime with
technology that we have available for us.
I would like to distinguish between nanoscience and
nanotechnology.
Nanoscience as kind of my definition is exploring at the
nanoscale fundamental phenomena in the world
surrounding us.
Nanotechnology is what it is.
It's basically manipulation of matter at the nano scale
aiming at accomplishment of a specific goal.
There's a significant difference between these two,
because nanoscience existed 200, 300 years ago.
Our colleagues, physicists back in the 19th century, they
were predicting theoretically physical phenomena at the
atomic and molecular level.
Except they didn't have tools to do something about it.
And now we have developed tools and we move them to the
stage which we can refer to as nanotechnology.
We have learned how to manipulate matter at the
nanometer level.
So how did we come to this?
What was the driving force behind all this?
Well, the answer is really fairly simple.
It's all based on semiconductors and
improvements.
If you are kind of working on for the last 50 years since
the invention of transistors.
Semiconductors are solids which are sitting in between
insulators and conductors in terms of electrical
conductivity.
But unlike insulators and conductors, we can control
conductivity of semiconductors with a very broad range.
So copper being metal being conducted will always be a
very good conductor.
There's no way we can make it into the insulator.
And vice versa, you take [? gravel ?] or glass, you'll
never make it into a conducting material.
You take silicon or germanium, you can change conductivity
over orders and orders of magnitude.
So this is really very a important, distinguishing
feature of semiconductors.
Also, in the case of semiconductors, electrical
conductivity depends on the electric field, on light and
temperature, magnetic and so on.
They're unlike any other solids.
So they're very special solids.
Actually in nature, there are very few of them.
We can find semiconductors in this part of
the periodic table.
Most of, I mean, elemental semiconductors are located in
the fourth group.
And most important of all them is of course
silicon, as you may know.
All other semiconductors that we use combine elements from
the third and fifth group of the periodic table and second
and sixth are man made, are synthetic semiconductors.
[INAUDIBLE]
phosphate, and so on.
Are all man made semiconductors.
Very, very useful.
This element is by far the most important, and that's
really-- if you wanted [INAUDIBLE]
the progress of technical civilization
over the last 15 years.
OK.
Semiconductors are everywhere.
There's not a single element with an on, off switch which
does not contain some kind of semiconductor element in the
diode or transistor.
You look at the gadgets you use every day, and they are
stuck with semiconductors.
Every part of its operation is based on the use of
semiconductor elements.
Again, that's just integrated circuits, diodes and
transistors, so on and so forth.
I mentioned transistors already several times in my
few minutes long presentation.
And really, a transistor is the technology drive.
The scaling of the transistor geometry can kind of get us to
where we are in terms of nanotechnology these days.
This is a schematic section of the transistor.
This is the SEN image of the transistor.
And there's one feature of the transistor which is called
gate lengths, which is defining the operation
transistor.
We tried to make it short and shorter and shorter and
shorter so that electrons from the source can really be
moving faster and faster and faster.
The shorter time means higher switching speed, meaning
higher performance, meaning superior computational
capabilities.
In our search for the improvement in nano
electronics, we went all the way from one micrometer long
gate in some 20 years ago, all the way down to 22 nanometer
long gate instead of the chips that you are using currently
in your laptops, smartphones, and so on.
This is a magnified picture of the part of the device that we
create those features in the fully controlled fashion.
We control the thickness of this [INAUDIBLE], the
electricals, and the fractured nanometer.
We have tools.
We have developed tools, we are fully in control of the
materials these days.
And this is an exemplification of what we can really do in
terms of materials engineering.
You improve transistors, you shorten the gate, you make it
work faster.
And then you take three billion of those, stuff it
into one chip, making it into what they, for instance, call
a 1.7 Intel chip.
You package it in the package, and then you enclose with the
Intel little top, and you put it into your laptop.
Suddenly now your games are running faster, and video is
streaming with no difficulties.
You access, you browse internet, the great
[INAUDIBLE] and with no delay whatsoever.
So that's basically what was driving technology.
That's what got us through to this nanotechnology regime.
I'd like to emphasize, there's no revolution in all this.
This is just out of the hard work and natural progress.
We were following certain things in microelectronics,
and then we came to nano electronics, and now we have
developed tools which allow us to also play the roles in our
colleagues' chemistry, biologists, biochemists, to
manipulate and observe matter and our world, that
[INAUDIBLE]
nanometers can.
I'm maybe too selfish in saying this, but I think this
is all because of our need to spend money.
Actually, our willingness to spend money on improved,
continuously improved gadgets, which was feeding funds back
into the Toshibas, IBMs of this world that in turn was
developing tools that we are now using to advance our
civilization, basically.
That's really the way it is.
OK now one thing which I would like to mention to some of you
who may not be immediately familiar, this is a slightly
different aspect of nanoscience, nanotechnology.
The message is very clear.
Physical properties material depends on the dimension.
What you see in terms of physical properties in the
case of bulk material, in the material where electrons can
roam freely and are not interacting with each other
will be very different in the case of the same,
exactly same material.
It measures in silicon.
Bulk silicon, a wafer, or piece of silicon.
Physical properties of this silicon, this form will be
very different from silicon that was squeezed from one
dimension into one atomic layer thick feature such as,
for instance, quantum well or ultra thin film.
Physical properties can [INAUDIBLE]
remain unchanged completely.
Physical properties of silicon in the form are very different
than they are in the form of bulk material.
We continue the process, reduce geometry of material
along the x-axis.
And if we make it into the nanotube or nanowire, physical
properties of silicon in this form are very different than
in this form, in this form.
And we didn't change chemical properties of the material.
The same silicon.
Same silicon bonded to other silicons
using covalent bonding.
No difference, yet physical properties of this silicon and
this are very different.
And we continue the process, as you can see.
We end up with the zero dimensional feature, which is
known as quantum dot.
Which features yet different physical properties, offering
us tremendous opportunities in building novel, innovative
devices, and a device for all sorts of applications.
So I input in this slide just for the one and only purpose
to make sure that we are really aware of the fact that
things happen in a different way as the
geometry of solids change.
It goes through the center threshold.
Up to a certain geometry, there is no change in the
material physical properties.
Everything that is going on is described by the laws of
conventional, classic physics.
When you go beyond a certain stage, and electrons are no
longer roaming freely, they start to interact with each
other, whether in the two-dimensional electron gas,
or within the nano dot, they [INAUDIBLE].
Physical properties of material are completely
different, and are completely controlled by a
different set of rules.
We are just entering the world of quantum physics.
Classical physics is no longer able to describe this
phenomenon.
So that's the message I would like to convey.
Now, in terms of what we are doing in terms of research at
Penn State in the part of molecule engineering, but this
message covers a number of other departments and colleges
in Penn State.
For instance, in our case, we are [INAUDIBLE]
working in next generation transistors for our
[? logic ?] microchips.
This is following the Moore's Law.
The same thing we were discussing earlier.
Smaller, smaller, smaller.
Maybe 10 nanometer gate as opposed to 22.
Maybe 7 nanometer gates, and our electronics
will work even better.
In my case, I'm working on nanocrystalline quantum dots,
which were synthesized using carbon cell.
Again, there are very, very nanometer scale devices you
can [INAUDIBLE].
And we use them to build this place of the [INAUDIBLE] in
diodes that we are fabricating using quantum dots.
And we are also using quantum dots to print barcodes which
are undetectable unless you know how to detect them.
So they are very suitable in counterfeiting, printing and
labelling applications.
And there is a significant amount of work done in
semiconductor nanotechnology around campus in the new
Millennium Science Complex.
Basically most of it is being done on the material side, as
opposed to life science side.
This is concerned with one way or another with semiconductor
nanotechnology.
So I would like to end that with the quick comment that
semiconductors are very useful.
It's really cool stuff.
You should think about it, or you should exchange geometry
material, and then suddenly you end up with completely
different material for all practical purposes.
Although chemically, it's still the same material.
OK, thanks.
Thank you very much.