衬底温度对Ga液滴在Al0.4Ga0.6As表面形成纳米结构的影响

The effect of substrate temperature on the formation of nanostructures of Ga on Al0.4Ga0.6As surface

本文研究了不同衬底温度对Ga液滴在Al0.4Ga0.6As表面形成纳米结构的影响,当300℃≤T≤380℃时,Ga液滴演化成纳米孔(Nanohole)和盘状结构(diffusion halo),纳米结构的尺寸随温度升高而增大.当T≥385℃时,盘状结构消失,形成一定平坦的AlxGa1-xAs薄膜,Ga液滴在界面处继续向下刻蚀直至耗尽,形成平均直径为75 nm,平均孔深为5.52 nm的纳米孔.本文还通过盘状结构测出平均扩散长度△R,并拟合出Ga原子在Al0.4Ga0.6As表面的激活能EA=0.78(±0.01)eV和扩散前因子D0=0.15(×4.1±1)10-2 cm2s-1.

In this paper,the effects of substrate temperature on the formation of nanostructures of Ga droplets on the surface of Al0.4Ga0.6As were studied.When 300℃≤T≤380℃,the initial Ga droplets evolve from droplet to nanoholes and diffusion halos,and the sizes of nanostructures increase with increasing temperature.When T≥385℃,the diffusion halos disappear,a flat film of AlxGa1-xAs is formed;while at the interface,the Ga droplets etch constantly until they are completely consumed.Finally,the nanoholes with average diameter of 75 nm and depth of 5.52 nm are formed.The mean diffusion lengthΔR of diffusion halos is also measured.The activation energy EA=0.78(±0.01)eV for Ga on Al0.4Ga0.6As surface and the diffusivity prefactor of D0=0.15(×4.1±1)10-2 cm2s-1 are fitted from the experimental data.