PVT法同质籽晶AlN晶体生长

为了获得高质量AlN晶体,通过物理气相传输(PVT)法,采用AlN籽晶进行AlN晶体生长,并通过双温区加热装置对衬底与原料之间的温差进行调节。研究结果表明,籽晶形核阶段,随着AlN籽晶与原料顶温差的减小,AlN的形核机制呈现三种模式,分别为岛生长模式、畴生长模式和螺旋位错生长模式;晶体生长阶段,通过增加AlN籽晶与原料顶温差来提高晶体生长速率,采用10℃/h的变温速率将温差从10℃增加为30℃时,AlN晶体生长模式不变,仍然保持螺旋位错生长模式,该生长模式下获得的AlN晶体结晶质量最高,(0002)面摇摆曲线半峰宽(FWHM)约为55 arcsec。

AlN Crystal Growth with the Homogenous Seed by PVT Method

In order to obtain high-quality,AlN crystals were grown using AlN seed crystals by the physical vapor transmission(PVT)method.And the temperature difference between the substrate and the raw materials was adjusted by a dual-temperature zone heating device.The research results show that during the nucleation stage of the seed crystals,with the decrease of the temperature difference between the AlN seed crystals and the top of the raw materials,the nucleation mechanism of the AlN presents three modes,namely island growth mode,domain growth mode and screw dislocation growth mode.Furthermore,during the crystal grown stage,the crystal growth rate is increased by increasing the temperature difference between the AlN seed crystals and the top of the raw materials.When the temperature difference is increased from 10℃to 30℃at a temperature change rate of 10℃/h,the growth mode of the AlN crystals is unchanged,and the screw dislocation growth mode is still maintained.The AlN crystals obtained in the growth mode have the highest crystal quality,and the full width at half maximum(FWHM)of the(0002)plane rocking curve is about 55 arcsec.