Materials and components for solid-state Electronics.

Ever growing technology progress requires the specialists capable of working out, producing and applying the materials and components for solid-state electronics.

This kind of specialists should possess the knowledge of the physics, structure and properties of such materials as metals and their alloys, monocrystals and different films, nonconductive materials, superconductors and components for solid-state electronics.

To understand the inner structure of these materials and the laws of their formation and existence the students of our university take such subjects as:

- solid-state physics;

- microelectronics technology, materials of electronic engineering;

- materials study;

- the technology of electronic instrument making

- the fundamentals of vacuum technology;

- laser engineering and technology;

- the physics of semiconductor devices;

- the fundamentals of circuitry and designing of integrated circuits;

- mathematical modeling of technological processes and so on.

This kind of fundamental training enables the graduates from our university to work as:

- the researchers and developers of the new materials such as metal alloys, semiconductors, dielectrics, composite materials and so on;

- the researchers and developers of the new technological processes for obtaining the materials of a high degree purity, monocrystals, alloys, semiconductor structures, devices and integrated circuits;

- the technologists for production of radio-electronic components and materials;

- the technologists for thermal processing of metals and alloys.

The MBSTU graduates get the qualification of engineer-technologist after almost 6 years of study and after extra year are given that of engineer-developer.

Those who made good progress in the course of studies may continue their education in the post-graduate courses.

The main fields of research are

1. The research and development of the materials and deices for solid-state electronics;

2. The formation of functional surfaces with the use of highly concentrated energy sources;

3. Mathematical modeling of technological processes.

Ion Implantation.

This is the method of doping of a slice or an epitaxial layer by bombarding it with impurity ions accelerated to an energy enough to enable the ions to penetrate rather deep into the slice bulk. The depth of the penetration of ions depends on their energy and mass. The larger the energy of ions, the greater the thickness of the implanted layer. The increased ion energy, however, produces more radiation defects, which impair the electrophysical properties of a crystal.

The impurity concentration in the implanted layer depends on the current density in the ion beam and the process duration, or what is called the exposure time. The time of exposure ranges from a few seconds to 3 to 5 min and over, sometimes to 1 or 2 h, depending on the current density and the desired impurity concentration. It stands to reason that the longer exposure of a slice to the ion beam leads to a greater number of radiation defects.

Since the area of the ion beam is merely 1 or 2 mm, which is much smaller than the area of a slice, the ion implantation setup must have a special deflection system to scan the beam, that is to deflect it smoothly or stepwise and in an adequate sequence along all the lines of the slice containing integrated circuits.

After completion of the doping process, the slice should be subjected to annealing at 500 to 800 C to ensure ordering of the silicon crystal lattice and eliminate the inevitably present radiation induced defects, if only partially. At the annealing temperature, the diffusion processes change somewhat the profile of distribution.

Ion implantation, like diffusion, can be overall and local (selective). In the latter, more typical case, the irradiation (ion bombardment) is performed through masks in which the free path of ions must be much shorter than that in silicon. The materials of masks can be silicon oxide and aluminum which find extensive uses in IC fabrication. An important merit of ion implantation is that ions, travelling along the straight line, penetrate only into the slice bulk at right angles to the surface and do not affect the regions under the mask.

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