Cu/SiO2逐层沉积增强无杂质空位诱导InGaAsP/InGaAsP量子阱混杂

研究了Cu/SiO_2逐层沉积增强的无杂质空位诱导InGaAsP/InGaAsP多量子阱混杂(QWI)行为。在多量子阱(MQW)外延片表面,采用等离子体增强的化学气相沉积(PECVD)不同厚度的SiO_2,然后溅射5 nm Cu,在不同温度下进行快速热退火(RTA)诱发量子阱混杂。通过光荧光(PL)谱表征样品在QWI前后的变化。实验结果表明,当RTA温度小于700℃时,PL谱峰值波长只有微移,且变化与其他参数关系不大;当RTA温度大于700℃时,PL谱峰值波长移动与介质层厚度和RTA时间都密切相关,当SiO_2厚度为200 nm,退火温度为750℃,时间为200 s时,可获得54.3 nm的最大波长蓝移。该种QWI方法能够诱导InGaAsP MQW带隙移动,QWI效果与InGaAsP MQW中原子互扩散激活能、互扩散原子密度以及在RTA过程中热应力有关。

InGaAsP/InGaAsP Quantum Well Intermixing Induced by Impurity Free Vacancy Enhanced Through Cu/SiO_2 Deposition

InGaAsP/InGaAsP multiple quantum well intermixing(QWI)behavior induced by impurity free vacancy enhanced through Cu/SiO2 deposition was investigated.On the surface of the multiple quantum well(MQW)epitaxial wafer,different thickness of SiO2 were grown by plasma-enhanced che-mical vapor deposition(PECVD),then 5 nm of Cu was sputtered,after rapid thermal annealing(RTA)at different temperatures,QWI was induced.Changes of the samples before and after QWI process were characterized by photoluminescence(PL)spectra.The experimental results show that the peak wavelength of the PL spectrum shifts slightly when the RTA temperature is less than 700 ℃,and the change has little relationship with other parameters.When the RTA temperature is greater than 700 ℃,the peak wavelength shift of the PL spectrum is closely related to the thickness of dielectric layer and RTA time.When the SiO2 thickness is 200 nm,and the wafer is annealing at 750 ℃ for 200 s,the maximum wavelength blue shift is 54.3 nm.The QWI method can induce the band gap shift of InGaAsP MQW.The QWI effect is related to atomic interdiffusion activation energy,interdiffusion atom density and thermal stress in the RTA process.