Research of critical-slowing-down during the pre-roughness process of GaAs surface

Pre-roughness process of GaAs surface was studied using reflection high energy electron diffraction and scanning tunneling microscopy. We found that there was distinct difference in surface morphology at different temperature( 570,560,550,540,530 ℃) under a special As BEP( 1.33 μPa). With the temperature decreasing,an obvious delay was discovered in pre-roughness process of GaAs surface,and this process should not onset when the temperature below530 ℃. The critical slowing down theory was introduced to explain experimental phenomena and calculated the critical temperature of GaAs( 001) roughening through the experiment data and the related theoretical model,and this theoretical result( 529 ℃) was kept with experiment consequence( 530 ℃).