Suchergebnisse

The stress-migration phenomenon in films of alloy Al–Si which is observed at a current of high density (an order 105 А/mm2) is investigated. By results of researches the technical decision which allows quality raise of obtained film structures is offered. Its essence consists in formation in films the traps for migrating atoms of aluminium at course of a current of high density at the expense of formation the passive layer of TiN on the metal layer surface, for example, Al–1,5 %Si. In the presence of advanced relief of a surface of modern integrated circuits, for example with sub-micron sizes of the topology elements, the thickness and structure of metal current-carrying films on relief steps differs from what are located on planar sites. It leads to occurrence of essential gradients of mechanical pressure which are stress-migration motive power. As it is known, that temperature factor of linear expansion of aluminium is approximately 20 times, than SiO2, that causes active generation of dot defects in a layer of the alloy on the base of aluminium which is much more plastic than SiO2. Under the influence of a gradient of residual pressure, dot defects, existed in films, for example vacancies, come to movement mainly on border of metal - dielectric and in due course under the influence of a current of high density lead to formation of group defects in an alloy film, in particular emptiness, hills etc. Since stress-migration processes on these sites occur most intensively, as a result there is a rupture of films mainly on steps of a topological relief. Results of the research have passed approbation and can be used at manufacturing of silicon semi-conductor devices and integrated microcircuits.

vThe possibilities and methods of creating a stable defective structure, including dislocation structure near the zones of p–n-transitions of silicon diodes of noise generators on plates with crystallographic orientations (111) and (001) have been investigated. The effective distribution control of uncontrolled impurities in monocrystalline silicon is achieved by forming a stable dislocation structure in its volume. In order to obtain the reproducible characteristics of noise generator diodes, it is necessary that the dislocation density be homogeneous throughout the plate area. Since the density of dislocations is slightly lower at the edge of the dislocation trail than in the middle, this means that the dislocation traces formed by the adjacent melting zones with the help of a laser beam should overlap. On the basis of experimental studies, it has been established that the necessary degree of uniformity of the density of defects generated is achieved by compliance with the condition of a = (1.5–5.0)d, where a is a step, d is a width of the laser spot on the wafer. The melting process was carried out in a nitrogen environment using a laser hettering unit. The real width of the melting zone turns out to be slightly larger than the diameter of the laser spot due to the thermal conductivity of the silicon and is about 10 μm. Increased dislocation generation on the Si3N4 inclusions, as opposed to dislocations on the Si–SiO2 border, leads to an additional expansion of the dislocation track at the work surface of the plate of noise diodes. The presence of the stable dislocation structure, as well as the presence of impurities and secondary metal atoms in the noise diodes ND 103L structure are confirmed by the secondary ion mass spectroscopy (SIMS) method. The results of the study have been tested at Corporation "INTEGRAL" (Belarus) and can be used in the manufacture of silicon noise diodes.