摘要
提出了一种基于掩埋金属掩膜的表面光栅分布反馈半导体激光器制备工艺,该工艺方案可以减小器件工艺对光栅结构的影响,无需额外增加光栅保护工艺。在半导体外延片表面预先制作Ni-Au金属层,形成光栅的硬掩膜;完成波导和钝化层工艺后,去除波导结构表面的钝化层形成电极注入窗口的同时,露出掩埋的Ni-Au金属掩膜;在掩埋Ni-Au金属掩膜和钝化层的共同阻挡作用下,进行干法刻蚀工艺,在脊波导表面形成光栅结构。采用该工艺方案制备了光栅周期为10μm的高阶表面光栅DFB半导体激光器件。实验结果表明,与光刻胶作为表面光栅刻蚀掩膜的工艺相比,掩埋金属掩膜工艺方案保证了表面光栅的形貌,使光栅内的折射率具有更好的周期性分布,器件的单纵模半高全宽由0.56 nm降至0.23 nm,且在输入电流为1 A的情况下可以获得242 mW的输出功率。该工艺有效改善光栅的形貌,提升器件的光谱特性。
With the development of semiconductor laser technology,surface grating semiconductor laser devices’structure is becoming more complex.An independent micro nano process is often required to fabricate surface grating structures.There are some difficulties in the manufacturing process of ridge surface grating.Due to the ridge waveguide and other structures made in advance,the surface of epitaxial wafer presents a state of ups and downs,and the photoresist pattern edge as grating mask is prone to deformation,which destroys the grating morphology and affects the performance of grating.If the process scheme of etching the ridge waveguide first and then grating etching is adopted in the manufacturing process,the first etched ridge waveguide will make the surface of the epitaxial wafer uneven,resulting in uneven photoresist thickness after spin coating and damage the exposure pattern.Moreover,due to the uneven surface of the insulating dielectric layer produced after this process,it is difficult to corrode the insulating layer on the grating when corroding the insulating layer to form the electrode window,which will eventually affect the carrier injection and damage the output power of the semiconductor laser.Therefore,in the fabrication process of surface grating semiconductor laser,the fabrication process of surface grating is usually carried out first.However,this requires additional grating protection to avoid the subsequent device process damaging the grating structure,which will make the device preparation process cumbersome and not conducive to the preparation.In addition,during the subsequent fabrication of ridge waveguide,it is necessary to homogenize the photoresist again to expose the ridge waveguide.During the homogenization,the photoresist on the surface of epitaxial sheet can not be evenly distributed due to the grating structure existing in advance,which will affect the exposure of ridge waveguide and further lead to the residual photoresist in the grating groove during development,which is difficult to
作者
商宇
范杰
王海珠
邹永刚
马晓辉
SHANG Yu;FAN Jie;WANG Haizhu;ZOU Yonggang;MA Xiaohui(State Key Laboratory of High Power Semiconductor Laser,Changchun University of Science and Technology,Changchun 130022,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2022年第9期251-257,共7页
Acta Photonica Sinica
基金
吉林省科技发展计划项目(Nos.20210201030GX,20210201089GX)。
关键词
表面光栅
掩埋金属
掩膜
窄线宽
光谱
光栅形貌
远场光斑
Surface gratings
Buried metal
Mask
Narrow linewidth
Spectrum
Grating morphology
Far field spot
