摘要
报道了GaAs/AlAs的电感耦合等离子体(ICP)选择性干法刻蚀,刻蚀气体为SiCl4/SF6混合物.研究了在不同SiCl4/SF6气体配比、RF偏压电源功率和气室压力下,GaAs,AlAs的平均刻蚀速率与二者的选择比.合适的SiCl4/SF6气体比例(15/5sccm),低的RF偏压电源功率和高的气室压力将加强AlF3非挥发性生成物的形成,进而提高GaAs/AlAs的选择比.在SiCl4/SF6气体比例为15/5sccm,RF偏压电源功率为10W,主电源功率为500W,气室压力为2Pa时,GaAs/Al-As的选择比达1500以上.采用喇曼光谱仪对不同RF偏压电源功率和气室压力下,GaAs衬底被刻蚀面等离子体损伤进行了测试,表面形貌和被刻蚀侧壁分别采用原子力显微镜(AFM)和扫描电镜(SEM)进行观察.
Selective dry etching of GaAs/AlAs with SiCl4/SF6 mixtures by inductively coupled plasma （ICP） is reported. With different SiCl4/SF6 ratios, chamber pressure, and RF chuck power, the average etch rates of GaAs,AlAs, and their selectivity are studied. Proper gases ratios of SiCl4/SF6 （15/5sccm）, lower RF chuck power, and higher chamber pressure enhance the formation of AlF3 nonviolent produce and encourage to the selectivity of GaAs/AlAs. When the gases ratios of SiCl4/SF6 are at 15/5sccm, RF chuck power is 10W,source power is 500W, and chamber pressure is 2Pa, the selectivity of GaAs/AlAs reaches at least 1500, The plasma damage of etched GaAs substrate is conducted by Raman spectroscope under different RF chuck power and chamber pressure, atomic force microscope （AFM）,and scanning electron microscope （SEM） also have been applied to view the surface morphology and sidewall, respectively.
基金
国家自然科学基金资助项目(批准号:50775209
50535030)~~
