介质多层膜热处理分析

由薄膜压缩应力产生模型和薄膜总应力的组成出发,分析了要改变薄膜的本征应力热处理必须有足够的能量即激活能。当热处理能量低于激活能时,只能改变薄膜热应力,与处理时间无关。热应力与处理温度有线性关系,建立了波长变化量与温度变化量间的关系模型。当热处理能量高于激活能时,本征应力改变,进而波长的改变与时间有关。实验结果表明,从200~300℃的各1,2,5 h保温处理下,波长从1.4 nm线性地增大到4.15 nm,波长变化与处理时间无关。在350℃分别进行1,2,5 h的处理情况下,波长的改变量分别为4.75 nm,5.07 nm,5.7 nm。保温时间短的,波长增量也小。400℃各种处理时,波长的改变基本上与350℃的处理结果类似。充分说明了在较低温度处理时,薄膜应力只有热应力的改变;较高温度处理时,本征应力才会改变。

Annealing analysis of dielectric thin film

According to the formation model of compressed stress of thin film and the composition of whole stress of thin film, it is concluded that in order to change the intrinsic stress sufficient annealing energy is necessary, and this energy is called excitation energy. Only thermal stress can be changed when the annealing energy is less than excitation energy, and whole stress change is independent of the annealing time. But the intrinsic stress changes as the annealing energy is higher than excitation energy, and the variation of the wavelength depends on the annealing time.Based on the linear relation ship between thermal stress and annealing temperature, one model of the relation ship between the variation of the wavelength and of the temperature was built up. Experimental results show that the variation of the wavelength increases from 1.4 nm to 4.15 nm when samples are exposed to the environment where the temperature changes from 200℃ to 300℃ and keeps for 1, 2 and 5 h at every 50℃ between this range, and the variation of the wavelength has nothing to do with the annealing time. The variation of the wavelength is 4.75 nm, 5.07 nm and 5.7 nm when samples stay at 350℃ for 1, 2 and 5 h correspondingly. The increment of the wavelength is slight if samples are treated for a short time. Experimenting at 400℃, the result is the same as that of 350℃. It is concluded that low temperature can only change thermal stress of thin film while high temperature can change intrinsic stress.