用偏振差分透射谱技术测量半导体晶体片应力分布

Research of the inner strain distribution in semiconductor wafers by Transmitted Differential Spectroscopy

利用偏振差分透射谱测量了2英寸圆形GaAs晶片、自支撑GaN衬底和蓝宝石衬底等的双折射分布,通过弹光效应换算得到了晶片内部残余应力分布。测量得到的应力反映的是晶片各个点的[110]和[110]方向的应变差。实验测量得到的GaAs晶片和自支撑GaN衬底的[110]和[110]的应变差最大可以达到10-5数量级。蓝宝石衬底的可以达到10-6数量级。因此TDS可以对透明或者半透明晶片的应力分布实现快速、实时、无损、高灵敏度检测。

The anisotropic strain distribution in semi-transparent GaAs, GaN and sapphire wafers were studied by Transmitted Differential Spectroscopy （TDS）. The strain difference between [ 110 ] and [ 110 ] directions at every position of the wafers can be quantitatively obtained in room temperature. The maximum strain difference between [110] and [110] of the GaAs and the free-standing GaN wafers attains to the order of 10^-5 ,the sapphire wafer＇s attains to the order of 10^-6. So the anisotropic strain of transparent and semi-transparent wafers can be detected by TDS in real time , with high speed, high sensitivity and without damage.