Конструирование и технология электронно-вычислительной аппаратуры (1065432), страница 4
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Ex. 18. Разделите текст В на абзацы и озаглавьте их. Используйте заголовки в качестве плана для пересказа текста.
Ex. 19. Докажите правильность или ошибочность суждений. Используйте следующие выражения.
I don't agree with it, It goes without saying....
The point is that ... That's right
I can also add.... I'm not sure•.•.
On the contrary....
1. One of the main limitations of photolithography is imperfect contact between the photomask and substrate, which leads to various destortion of the pattern.
2. The use of short wave radiation in itself can solve both the problem of decreasing the size of circuit elements and the problem of pattern alignment.
3. X-radiation lithography is presently in wide spread use in the semiconductor technology.
4. Nanoelectronics is the most forward-looking of several modern approaches to the development of small, reliable electronic systems.
5. It is out of the question to expect to have integrated elements with dimensions lying in the nanometer range.
Ex. 20 Переведите письменно текст за 10 минут.
Last years have seen the emergency of electron beam lithography. The essence of the technique is the following. A focused electron beam of computer-controlled intensity scans, line by line, the substrate surface coated with a resist. At the points which must be "exposed" the current of the beam is the highest, and at the points which must be "unexposed" the current is the smallest or equal to zero. The electron beam diameter is directly dependent on the beam current: the smaller the beam diameter, the lower the current. However, the exposure time grows with a decreasing current. Therefore an increase in resolution (decrease in the beam diameter) tends to lengthen the process.
Unit IV. Text A - Thin Film Déposition
Text В - Electrolytic deposition
Grammar Revision - Gerund
Terminology
Vacuum evaporation - вакуумное напыление
rarefied.. gas - разреженный газ
cathode sputtering - катодное распыление
Ion – plasma sputtering - ионное осаждение
chemical vapor deposition - химическое осаждение газовой фазы
anodyzing - анодированиеanodic oxidation - анодное окисление
thin film deposition - осавдение тонких пленок
Preliminary exercises
Ex. 1. Образуйте и переведите:
а) существительные, от данных глаголов: to contain, to process, to evaporate, to deposit, to accumulate, to depend, to require, to determine
в) антонимы следующих слов: charge (v), appear (v) ,possible, simple, difference, necessary, advantage, increase
Ex. 2, Прочитайте данные слова и переведите их без словаря, учитывая их интернациональную основу:
vacuum setup, cathode, method, absorb, condense, resistor, positive ions, electrode, anode, hybrid, integration, dielectric
Ex. 3, Прочитайте текст А и перечислите приведенные в тексте основные методы осаждения тонких пленок.
Thin Film Deposition
I, One of the basic stages in the fabrication of integrated circuits is the process of deposition of thin films. In semiconductor integrated circuits, thin films are deposited on the oxide coat of a silicon slice to interconnect individual components, blocks, and devices and also serve as termination areas, i.e contact or bonding pads for oonnection to IС leads.
2. A few methods are available for the deposition of thin filma.
Vacuum evaporation. This method uses the same vacuumsetups as the method of cathode sputtering, except that in the latter the cathode replaces the heater. Both methods are very popular. The process is run in a vacuum chamber evacuated to a very high vacuum. The essence of the process is the following. An electron beam or any other heating source melts down a metal which evaporates and adsorbs (condenses) on the surface of a substrate placed nearly, thus coating the substrate with a thin layer of the evaporant. By replacing the evaporant and masks through which the material adheres to the substrate it is possible to produce in the single cycle of operations a large number of conductors, resistors and capacitors, i.e. to fabricate integrated circuits.
3. Cathode sputtering. The source material for the film serves here as a cathode bombarded by positive ions of a rarefied gas. The ions falling on the cathode give up energy to the atoms and molecules of the material and thus knock out the atoms from the cathode. The knockout atoms move toward the high-potential positive electrode (anode), which is the substrate on which the atoms accumulate to form a thin film.
4. To sputter insulating and semiconducting materials, a high-frequency field is built up between the electrodes. By changing the potential of the hf field it is possible to sequentially bombard the target (cathode) with positive ions and to cancel
the stored positive charge with highly mobile electrons. .
5. Ion-plasma sputtering. This method does not in principle differ from the method of cathode sputtering. The only difference is that a glow discharge is built up in the gap between cathode and anode. The process begins after initiating the discharge and applying voltage to the coil of the heater containing the source material. The rate of deposition grows until the velocity of reactively sputtered ions reaches the velocity of ions near the substrate. The process gives a film that adheres more strongly to the substrate than is the casé with cathode sputtering.
It finds use for the deposition of films of chemical compounds, such as silicon nitride
6. Chemical vapor deposition. This method relies on chemical reactions between two or more substances or on chemical decomposition. Chemical deposition from the vapor phase can produce all the three types of thin film, namely, insulator (silicon oxide ), conductor and semiconductor .
7. Anodizing. Anodic oxidation is the most popular method of anodising for obtaining thin films of hybrid circuits. Formation on a tantalum film of the tantalum oxide that acts as a capa-
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