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GaN基脊型激光二极管(LD)的制备工艺中,面临的一个主要困难是p电极和窄脊结构的制备受到光刻对准精度的严重制约。设计和验证了一种基于背向曝光技术的激光器制备工艺。通过预先沉积一层200nm的铝作为挡光掩模和牺牲层,利用ICP蚀刻制备出宽为2.5μm的脊型结构,并使用PECVD沉积SiO2绝缘层。随后采用背向曝光实现二次光刻,将脊型图形精确地转移到电极窗口,继而采用湿法腐蚀SiO2绝缘层打开窗口,借助对的铝掩模腐蚀实现对残余绝缘层的辅助剥离,从而同时解决了目前脊型激光器电极窗口对准困难和绝缘层侧向腐蚀条件难于把握的问题。
A major difficulty in the fabrication of GaN-based laser diodes (LDs) is that the fabrication of p- and narrow-ridge structures is severely limited by the precision of lithographic alignment. A laser fabrication process based on back-exposure technology was designed and validated. By pre-depositing a layer of 200 nm of aluminum as a light-blocking mask and a sacrificial layer, a ridge structure having a width of 2.5 μm was prepared by ICP etching and a SiO 2 insulating layer was deposited by PECVD. Followed by back-exposure secondary lithography, the ridge pattern is accurately transferred to the electrode window, followed by wet etching SiO2 insulating layer to open the window, with the help of the aluminum mask etching assisted residual stripping of the residual layer to At the same time, it solves the problems that the ridge-shaped laser electrode window is difficult to be aligned and lateral corrosion conditions of the insulation layer are difficult to grasp.