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Файл:Оптоэлектроника. Optoelectronics. Учебное пособие
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6. In terms of circuitry, a chip can (be) analog, digital, or mixed.
7. In analog chips, the signals are continuous, meaning they can (take) on
any value within a given range, and they use more traditional circuit elements
(resistors, capacitors and occasionally inductors).xs
8. The microchip manufacturing process involves hundreds of steps and
can (take up) to four months from design to mass production.
9. Modern chips can (have) up to 100 layers, which all need (align) on
top of each other with nanometer precision (called 'overlay').
10. If even the smallest speck of dust or other foreign materials ends up on
the wafer, it can ruin the microchip, so chipmakers are careful (keep) their
fabs clean.
21 Complete the blanks with verbs from the box. Mind the correct
form of the verb.
make create ensure define remove replicate reveal (x2)
print (x2) enable use wash Let’s
1. …………………………….. any chip, numerous processes play a role.
2. …………………………….. discuss six critical semiconductor manufacturing steps: deposition, photoresist, lithography, etch, ionization and
packaging.
3. Thin films of conducting, isolating or semiconducting materials –
depending on the type of structure being made – are deposited on the wafer
…………………………….. the first layer ………………………….. on it.
4. Light is projected onto the wafer through the 'reticle', which holds the
blueprint of the pattern …………………………….. .
5. As explained earlier, when light hits the resist, it causes a chemical
change that enables the pattern from the reticle ……………………………..
onto the resist layer.
6. The next step is …………………………….. the degraded resist
……………………………..the intended pattern.
7. During 'etch', the wafer is baked and developed, and some of the
resist is washed away …………………………….. a 3D pattern of open
channels.
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8. Advanced etch technology is enabling chipmakers …………………
………….. double, quadruple and spacer-based patterning ………………
…………….. to create the tiny features of the most modern chip designs.
9. Dry etching uses gases …………………………….. the exposed pattern on the wafer.
10. Wet etching uses chemical baths …………………………….. the wa-
fer.
11. So, it's important that etching is carefully controlled so as not to damage the underlying layers of a multilayer microchip structure or – if the etching is intended …………………………….. a cavity in the structure –
…………………………….. the depth of the cavity is exactly right.
22 Combine the two halves of the sentence.
1 Directing electrically charged
ions into the silicon crystal allows the flow of electricity
2 After the ions are implanted in
the layer, the remaining sections
of resist that were protecting areas
3 The entire process of creating a
silicon wafer with working
chips consists of thousands of
steps and
4 To get the chips out of the wa-
fer,
5 Some wafers e but one chip can contain billions of
6 This is a type of baseboard for
the microchip die that uses
metal foils
a can take more than three months
from design to production.
b it is sliced and diced with a diamond
saw into individual chips.
c can contain thousands of chips,
while others contain just a few
dozen.
d to be controlled and transistors – the
electronic switches that are the basic
building blocks of microchips – to
be created.
transistors.
f a 'heat spreader' is placed on top.
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7 And to close the lid, g that should not be modified are re-
moved.
8 The microchip is now ready h to direct the input and output signals
of a chip to other parts of a system.
9 It’s probably only about the size
of your thumb,
i to get to work as part of your
smartphone, TV, tablet or any other
electronic device.
GRAMMAR
23 Listen to the text Roy J. Glauber (Part 1).
24 Answer the questions.
1. Which achievements is Roy J. Glauber known for?
2. What prize was Roy J. Glauber awarded for his contributions to the
field of optics?
3. Which two fields does Mr Roy J. Glauber’s theory merge?
4. What field does the theory form the basis for the development?
5. What can you say about practicability of Mr Roy J. Glauber’s ideas?
25 Fill in the blanks with the word collocations.
quantum optics coherent light quantum physics incoherent light
light particles quantum computers quantum cryptography
Glauber’s prizewinning work centred on his development of a theory that
advanced the understanding of light by describing the behaviour of
………………..(1) (light quanta, or photons). Presented in the early 1960s,
the theory merged the field of optics with ……………….. (2) (which deals
with the behaviour of matter on the atomic and subatomic scales), and it
formed the basis for the development of a new field, ……………….... (3).
Glauber’s research helped clarify how light had both wavelike and particle-
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like characteristics and explained the fundamental differences between the
light emitted by hot objects, such as electric light bulbs, and the light emitted
by lasers. (Hot sources of light emit ……………….. (4), which consists of
many different frequencies and phases, whereas lasers emit …………….. (5),
light with a uniform frequency and phase.)
Practical applications of Glauber’s work included the development of
highly secure codes in the field known as……………….. (6). His research
also had a central role in efforts to develop a new generation of computers,
so-called ……………….. (7), which would be extraordinarily fast and powerful and use quantum mechanical phenomena to process data as qubits, or
quantum bits, of information.
26 Listen to the article Roy J. Glauber (Part 2). Complete the sentences
with the prepositions.
A traditional digital computer employs binary digits, or bits, that can be
…………………… (1) one of two states, represented as 0 and 1; thus, …….
…………….. (2) example, a 4-bit computer register can hold any one …….
…………….. (3) 16 (24) possible numbers. ………………… (4) contrast,
a quantum bit (qubit) exists …………………… (5) a wavelike superposition
……………….. (6) values from 0 to 1; thus, …………………. (7) example,
a 4-qubit computer register can hold 16 different numbers simultaneously.
………………. (8) theory, a quantum computer can therefore operate ………
…………… (9) a great many values ……………… (10) parallel, so that a
30-qubit quantum computer would be comparable ………………….. (11)
a digital computer capable ……………. (12) performing 10 trillion floatingpoint operations …………. (13) second (TFLOPS) ‒ comparable …………..
………. (14) the speed ……………… (15) the fastest supercomputers.
SUPPLEMENTARY READING
VOCABULARY
44
the ground state основное состояние (атома, молекулы);
основное состояние (квантовое)
conduction band зона электропроводности
valence band валентная зона; валентная область
a rectangular shape прямоугольная форма
arsenide ['a:sinaid] (As) арсенид (соединение мышьяка с металлом)
gallium (Ga) галлий
gallium arsenide Ga As
aluminum arsenide Al As
molecular beam epitaxy (MBE) молекулярно-лучевая эпитаксия;
молекулярная эпитаксия
epitaxy ['εpɪ tæksi] эпитаксия, процесс выращивания слоёв с
упорядоченной кристаллической структурой
an effusion cell эффузионная ячейка; эффузионный
элемент
27 Read the text.
What is a Quantum Well?
A quantum well is used to confine electrons at specific energy levels.
Quantum wells consist of an extremely thin semiconductor with a small band
gap, resting between material with a larger band gap. They are extremely
small, usually between 1 and 20 nanometers. They are most often used in
laser diodes and infrared imaging.
This well uses the properties of electron behavior and band gaps to work.
Band gaps are areas in an electron's orbital between the ground state, where
electrons rest normally, and the conduction band, higher energy orbitals electrons move to when they are excited. The gaps are barriers between the
ground state bands and conduction bands, which prevent the electrons from
45
reaching the conduction band without gaining more energy than they have in
their ground states. The larger the band gap, the more energy is necessary for
the electrons to jump this gap and reach the conduction band.
Once the electron reaches the conduction band, it releases its excess energy and falls back into its ground state. By placing a microscopically thin
semiconductor between material with band gaps too wide for electrons to
jump easily, scientists can force the electrons to remain in the two-dimensional area of the thin semiconductor. Trapping electrons in this manner allows for specific energy manipulation.
Since the electrons can only move in two directions, they can only produce the type of energy the scientist or manufacturer wishes. This energy is
also focused in an extremely narrow stream. Due to this focus quantum wells
create accurate lasers for optical devices. A well-known example of a quantum well is in the read lasers in compact disc (CD) players.
Quantum wells are named "wells" not only because of their behavior of
trapping electrons like a well would trap water, but also because of their appearance when graphed. When quantum wells are pictured on energy vs. position graphs, they look like deep valleys, or wells, often in a rectangular
shape. A quantum well is a type of potential well, meaning there is a potential
for a minimum, fixed amount of energy to be produced.
Grown, rather than created, a quantum well is usually made of material
like gallium arsenide surrounded by aluminum arsenide. Wells are grown,
most often, by a process called molecular beam epitaxy, which uses an effusion cell to shoot molecules of the substance at a base substance. This method
creates a single atomic layer of the well material with each firing of the cell.
28 Decide if these statements are true or false.
Correct the ones which are false.
1. Band gaps are areas in an electron's orbital between the ground state
and the conduction band.
2. Small band gaps of extremely thin semiconductor are most often used
in laser diodes and ultraviolet imaging.
3. The smaller the band gap, the less energy is necessary for the electrons
to jump the gap and reach the conduction band.
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4. As soon as the electron jumps onto the conduction band, it immediately
increases its excess energy.
5. The scientists find the electrons to remain in the two-dimensional area
of the thin semiconductor improbable when placing a microscopically thin
semiconductor between material with band gaps too wide for electrons to
jump easily.
6. The electrons freely transfer in the three-dimensional environment.
7. A quantum well is a kind of potential well, implying there are possibilities for both a minimum and a maximum, fixed amounts of energy to be
produced.
8. AlAs embraced by GaAs quite often produces a quantum well.
9. Molecular beam epitaxy (MBE) is an experimental technique utilized
for layer-by-layer growth of thin films of various quantum materials.
10. A single firing of the effusion cell results in an atomic layer of the well
material.
29 Put down subtitles and key sentences for each paragraph. Work in
groups of 3-4 students to discuss the main ideas of the article.
30 Get ready with a say how quantum physics theories contribute to technologies and innovations of optoelectronics applications (lasers, semiconductors, etc.)
31 Write the summary to the text. Make use of Appendix 3.
32 Get prepared with the presentation on quantum physics contributions
into the field of optoelectronics market. Make use of Appendix 2.
47
Appendix 1
Participle
Present Participle (-ing)
Forms of the Participle
Active Voice Passive Voice Simple Passive Voice Perfect
operating being operated having been operated
developing being developed having been developed
integrating being integrated having been integrated
In the sentence Present Participle acts as part of the Verb (Predicate) and
an Attribute to an Object.
Participial Clause performs two functions, of an Attribute to an Object
and Adverbial Modifier to a Verb.
Present Participle + Object
Object + -ing Attributive Clause / -ing Attributive Clause + Object
V + O + - ing
Verb + -ing Adverbial Clause
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e.g. Oxford physicists are pioneering two different technological approaches
for the ‘processors’ that could form a quantum computer.
One outstanding problem is the effect of nuclear spin on the underlying
lattice of atoms that forms the QD.
While carrying on the experiment we noticed the bulb light / lighting.
For example, a circularly polarized photon will either excite the QD or
not, depending on whether the electron is spinning up or down.
Using coherent nonlinear optical spectroscopy techniques, arbitrary
states of quantum entanglement can be formed within a single dot.
Past Participle (-ed)
Past Participle + Object / Object + Past Participle
have + O + ed
-ed Attributive Clause / -ed Adverbial Clause + Object
Main Clause + -ed Adverbial Clause / -ed Adverbial Clause + Main Clause
e.g. In the neutral ground state of an undoped and unexcited QD, all the single-particle valence states are filled with electrons, while all the conduction
states are empty.
Researchers study these QDs with far-infrared spectroscopy and with
transport techniques, such as conductance measurements.
An exciton excited in the presence of this extra electron contains three
particles and is sometimes called a trion (X-).
USB flash drives are more easily transported than external hard drives
because they use solid-state technology, meaning that they don’t have fragile
moving parts that can break if dropped.
Another option is to have a flash card reader permanently connected to
your PC.
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For the case of entanglement shown in the figure, the spectral lineshape
has a distinctive interference shape.
Substates give rise to fine structure, which usually shows up as a doublet,
as shown in the inset.
Four years ago, Loss and DiVincenzo proposed that chains of coupled
QDs could be used as registers of quantum bits, provided certain two-qubit
rotations could be developed.
-ing form
Simple interfering
Progressive
Perfect having interfered
Perfect Progressive
not +ing as the Negative Form
In the sentence -ing form is used as:
Subject e.g. However, formatting erases any existing files on a disk.
Object e.g. Electronics is a branch of physics and electrical engineering
that deals with the emission, behavior, and effects of electrons and with electronic devices.
Part of the Verb e.g. Wait at least ten seconds to ensure that the drive has
stopped spinning.
Adverbial Modifier of Manner / Circumstances
e.g. RAM capacity can be expanded by adding extra chips usually contained
in small circuit boards called DIMMs.
One can inject a QD with two, three, or more additional electrons while
continuing to probe the QD through the exciton's optical spectrum.
Common verbs followed by -ing-form: enjoy, mind, suggest, stop, finish,
recommend, consider, admit, deny, avoid, risk, imagine, fancy; give up, put
off, go on, carry on, keep, keep on.
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