GaAs/AlGaAs多层膜刻蚀的陡直度

Steepness of the etching of GaAs/AlGaAs multilayer

GaAs/AlGaAs多层膜的陡直度较大程度地关系到其实际应用效果,但在实际加工中较难控制,因此有必要研究刻蚀过程中一些主要因素对其陡直度的影响。结合具体工作情况,用AZ1500光刻胶作为掩模,GaAs/Al0.15Ga0.85As多层膜为刻蚀材料,分别使用湿法和干法对其进行刻蚀。湿法刻蚀的刻蚀剂为H3PO4+H2O2溶液,干法刻蚀采用感应耦合等离子体(ICP)刻蚀法,等离子体由Cl2+BCl3(蒸汽)混合气体电离形成。通过控制变量方法,发现湿法刻蚀中刻蚀剂配比和温度以及干法刻蚀中BCl3(蒸汽)流量对刻蚀陡直度的影响规律。由此得出,提高H3PO4所占比例和降低刻蚀温度虽然会降低刻蚀速率,但可以提高多层膜的陡直度;ICP刻蚀的陡直度优于湿法刻蚀,BCl3(蒸汽)的流量在一定范围内对刻蚀陡直度的影响较小。

The steepness of GaAs/AlGaAs multilayer is important to its practical applications,but it is difficult to control it,so it is necessary to research how some key factors affect the steepness in etching.Considering of specific condition,using AZ1500 photoresist as mask,this study etched GaAs/Al0.15Ga0.85As multilayer with wet etching and dry etching respectively.In wet etching,the etchant was H3PO4＋H2O2 solution;the dry etching was Inductive Coupled Plasma（ICP） etching.The plasma was produced by Cl2＋BCl3（steam）.With the control of the variables,the regular patterns of how the ratio of the etchant and the temperature affected the steepness in wet etching were discussed,as well as how the flow of the BCl3（steam） affected the steepness in ICP etching.According to this,although increasing the ratio of H3PO4 in the etchant and decreasing the temperature will decrease the etching rate,it makes the steepness better;the steepness in ICP etching is better than that in wet etching,in a specific range,the flow of BCl3（steam） can affect the steepness very slightly.