纳米压印制作半导体激光器的分布反馈光栅

分布反馈(DFB)光栅的制作是半导体激光器芯片的关键工艺,通过纳米压印技术在InP基片表面涂覆的光刻胶上压印出DFB光栅图形,并分别通过湿法腐蚀和干法刻蚀技术将光栅图形转移到InP基片上。所制作的DFB光栅周期为240nm(对应于1 550nm波长的DFB激光器),光栅中间具有λ/4相移结构。采用纳米压印技术制作的DFB光栅相对于通常双光束干涉法制作的光栅具有更好的均匀性以及更低的线条粗糙度,而且解决了双光束干涉法无法制作非均匀光栅的技术难题。相对于电子束直写光刻法,采用纳米压印技术制作DFB光栅具有快速与低成本的优势。采用纳米压印技术在InP基片上成功制作具有相移结构的DFB光栅,为进一步进行低成本高性能的半导体激光器芯片的制作奠定了良好基础。

DFB Gratings for Semiconductor Laser Diodes by Nanoimprint Lithography

The fabrication of distributed feedback(DFB) gratings is a key process for semiconductor laser chips.The DFB gratings were fabricated on the photoresist on the InP substrate surface,and the grating patterns were transferred to the InP substrate by wet and dry etching process respectively.The period of the DFB grating is 240 nm(corresponding to 1 550 nm wavelength DFB lasers),and a λ/4 phase-shift is located in the center of the grating.Compared with the double-light beam interfering method,the DFB gratings fabricated by nanoimprint lithography have better uniformity and lower line roughness,and the technical problem that the non-uniform gratings are not fabricated by double-light beam interfering method is solved.Com-pared with the electron beam direct writing lithography,the DFB gratings fabricated by nanoimprint lithography have advantages of rapidity and low cost.The DFB gratings with phase-shift structures are successfully fabricated on InP substrates by nanoimprint lithography,which lay a good foundation for further fabricating semiconductor laser chips of low cost and high performance.