Effect of pulsed laser annealing on the properties of (Ga,Mn)As layers

Creation of GaMnAs ferromagnetic semiconductor by combined laser method

“…It also may be expected that the thinner the GaMnAs layer is, the higher the probability of such modification is. This conclusion is supported by the results reported by us earlier in [11] for GaMnAs/GaAs structures with manganese content Y Mn ∼ 0.13−0.15 (technological assessment) produced by the pulsed laser deposition method in gas atmosphere at 330 • C and exposed to eximer laser. In particular, it has been shown that considerable changes in the ferromagnetic MnAs inclusions occur for a structure with 150 nm GaMnAs layer.…”

“…The initial laser exposure simulation conditions were defined by the optical properties of the GaMnAs layer in the eximer laser wavelength (reflectance and absorbance, loss of emission due to scattering caused by rough surface), thermal conductivity coefficient and layer thickness [15]. Moreover, the obtained temperature dependences of the thermal conductivity coefficient (k) of the initial heteronanostructures with GaMnAs layer were used and it was found that, for the temperature range from 20 to 100 • C, the thermal conductivity coefficient of GaMnAs was 1.5−2 as low as for GaAs (at 20 • C k was equal to 38.5 and 59 W/m • K for (Ga, Mn)As and GaAs, respectively) [11]. Calculations of the temperature distribution along the sample thickness and in time taking into account this data have shown that a temperature close to the GaAs melting temperature (1515 K) may be achieved in the subsurface thin GaMnAs layer (10−20 nm) due to laser emission absorption.…”

“…In particular, it has been shown that considerable changes in the ferromagnetic MnAs inclusions occur for a structure with 150 nm GaMnAs layer. Due to these changes, no response from MnAs phase is recorded in the X-ray diffraction spectrum, clusters are not visible on the high resolution transmission electron microscopy image of the annealed sample and the magnetic field dependence of magnetization at room temperature shows the absence of ferromagnetization [11].…”

“…Combination of pulsed laser deposition and postgrowth laser annealing methods are of particular interest. Previously, we have published findings of a similar study of structures produced by pulsed laser deposition method at low pressure in gas atmosphere (hydrogen with addition of arsine) that feature a GaMnAs layer thickness from 150 to 400 nm and were subjected to postgrowth pulsed laser annealing [11].…”

Создание ферромагнитного полупроводника GaMnAs комбинированным лазерным методом

“…Особый интерес представляет сочетание методов импульсного лазерного нанесения и послеростового лазерного отжига. Ранее нами были опубликованы результаты подробного исследования сформированных методом импульсного лазерного нанесения при пониженном давлении в газовой атмосфере (водород с добавлением арсина) структур, отличающихся толщиной слоя GaMnAs (от 150 до 400 nm) и подвергавшихся послеростовому импульсному лазерному отжигу [11]. Были продемонстрированы новые возможности определения механизмов и процессов, способствующих дополнительной электрической активации введенной примеси, увеличению температуры Кюри, понижению концентрации дефектов в слоях и воздействию на кластеры второй фазы (MnAs).…”