The Russian researchers RECEIVED SILICON of 1.5 times more resistant to radiative forcing than MADE usual way.
In the Moscow State Institute of Steel and Alloys Ltd. in conjunction with researchers Sapfirem developed a technology for the production of silicon-resistant, resistant to radiation and temperature fields. Created on the basis of these materials, semiconductor devices are functioning in the fields of ionizing radiation: in space, nuclear reactors, etc.
The technical result, which the researchers have made is to increase the lifetime of the minority charge carriers, reducing the spread of the electrical resistivity and the volume of a single crystal silicon maintaining these parameters in multicomponent external impacts during manufacture and operation of devices based on it in power electronics.
Similar advantages resistant silicon n-type conductivity is after processing polycrystalline silicon p-type conductivity by the floating zone melting mnogoprohodyaschey with the introduction of the molten zone temperature stabilizers with certain concentrations of impurities. After cooling to room temperature with a precision of neutron transmutation doped silicon single crystal is obtained n-type conductivity with the concentration of phosphorus in excess of 1.5-2 times the level of the residual concentration of boron.
As impurities temperature stabilizers were used rare earth or transition or isovalent elements.
Crystals grown by conventional semiconductors, silicon in particular, contain a large amount of impurities and defects, which are effective interaction during heat treatment and radiation effects lead to a major change in the electrical properties of semiconductors (the lifetime of nonequilibrium charge carriers, the concentration of free charge carrier mobility, etc.) and reduced reliability of the semiconductor device in extreme conditions and environments.
New technology makes it possible to obtain resistant silicon, which keeps the most important electrical parameters in multicomponent external influences.
And the additional doping impurities in the form of rare earth, transition or isovalent elements with concentrations of 1013-1014 cm-3 can significantly raise the thermal stability of the crystals in silicon.
These heat-stabilized admixture, such as rare earth elements form a silicon stable complexes with various residual impurities (O, C, S, etc.), most of which is displaced in the doping as volatile compounds.
During testing of semiconductor devices based on the new drug-resistant silicon elucidated the advantages that having a specific resistance of 12 kO × MSM and the lifetime of minority carriers more than 1,000 ms, are on the order of 1.5 higher resistance to radiation damage, and more than twice as high accumulated charge compared with a conventional silicon devices with similar parameters.
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