Фазовый переход alpha-beta в примесной фазе монокристалла кремния SiO-=SUB=-2-=/SUB=-

Thermal oxidation of a silicon single crystal in the temperature range of 293 – 1293 K was studied using high – temperature X – ray diffraction directly on the beam. An anomaly in the intensity and angular position of diffuse scattering from the surface of the single crystal was found. The anomaly is explained by the oxidation of the silicon surface according to the Dill Grove model, including the process of thermal oxidation and sublimation of the oxide layer depending on temperature. It was found that in the bulk of a single crystal (silicon medium) in this temperature range, there is a - b phase transition in the crystalline phase of silicon dioxide, similar to the a - b transition of quartz in the atmosphere.

MODIFICATION OF SILICON SURFACE UNDER INFLUENCE OF RADIATION OF A NANOSECOND ULTRAVIOLET LASER

Методами оптической профилометрии и сканирующей электронной микроскопии исследовано воздействие излучения наносекундного ультрафиолетового лазера (λ - 355 нм, длительность импульса 10 нс, энергия в импульсе - до 8 мДж, частота следования импульсов до 100 Гц) на монокристалл кремния. При плотности энергии ≥ 1,2 Дж/см наблюдалось образование плазменного факела и кратера. При плотности энергии ≥ 0,2 Дж/см, возникают очаги микропробоя на дефектах обработки и зафиксированы следы неконтролируемого поднятия поверхности. Облучение сканирующим пучком лазера при плотности энергии 0, 2 Дж/см образует микрократеры на поверхности размером несколько мкм. С увеличением плотности энергии размер микропробоев увеличивался, и при плотности энергии ≥ 0,7 Дж/смвоздействие сканирующим лучом образует сплошную зону повреждений. The effect of radiation of a nanosecond ultraviolet laser (λ = 355 nm, pulse duration 10 ns, pulse energy up to 8 mJ, pulse repetition rate - up to 100 Hz) on a silicon single crystal has been investigated by methods of the optical profilometry and scanning electron microscopy. At an energy density of ≥ 1,2 J/cm, formation of the plasma torch and crater was observed. At an energy density of ≥ 0,2 J/cm, pockets of microbreakdown appeared on processing defects, and traces of uncontrolled surface uplift were recorded. Irradiation with a scanning laser beam at an energy density of 0,2 J/cm forms microcraters on a surface with a size of several microns. With an increase in the energy density, the size of the microbreakdowns increased, and at an energy density ≥ 0,7 J/cm, the impact of the scanning beam forms a continuous damage zone.