Observation of using laser direct writing to fabricate nano-grooves on GaAs substrate

In this paper, we presented a study of fabricating nano-grooves on GaAs substrate through laser direct writing (LDW). GaAs (001) substrate with homo-deposition of 500nm buffer layer was linearly scanned (pixel by pixel) by a focused UV laser (405nm) to directly create nano-grooved structures. The dependence of laser power and dwelling time (the exposure duration for each scanning pixel) on the patterned grooves were carefully observed. First, with the fixed setting of dwelling time at 10000ns, the laser power was varied from 110mW to 140mW. It can be found that there is an ablation threshold power between 115mW-120mW. As the power exceeds 125mW, as well as the depth, the average full width at half maximum (FWHM) of grooves could be effectively turned with a positive correlation to the power. Then, with the fixed setting of power at 130mW, a wide dwelling time variation from 10000ns to 10ns was systematically investigated. It is observed, in the range of 10ns-4000ns, the average depth can be continuously tuned by the dwelling time following an approximately linear positive relation, but once above 4000ns, the average depth will be saturated at ~77nm. While for the average FWHM, the saturation will show up early just when the dwelling time is above 100ns and the saturated value is ~90nm. Moreover, if the dwelling time is set too small (below 50ns), a by-product of nano-dots can form in the grooves.

[1]  Hiromoto Susawa,et al.  GaAs/GaAlAs surface emitting IR LED with Bragg reflector grown by MOCVD , 1991 .

[2]  Jungwoo Oh,et al.  Fabrication of three-dimensional GaAs antireflective structures by metal-assisted chemical etching , 2016 .

[3]  Hubert Jerominek,et al.  Diffractive optical elements fabricated by laser direct writing and other techniques , 1993, Optics & Photonics.

[4]  Qian Liu,et al.  Grayscale photomask fabricated by laser direct writing in metallic nano-films. , 2009, Optics express.

[5]  C. Zheng,et al.  Realization of III–V Semiconductor Periodic Nanostructures by Laser Direct Writing Technique , 2017, Nanoscale Research Letters.

[6]  Yong‐Lai Zhang,et al.  Designable 3D nanofabrication by femtosecond laser direct writing , 2010 .

[7]  Wen-Fei Dong,et al.  Fabrication and multifunction integration of microfluidic chips by femtosecond laser direct writing. , 2013, Lab on a chip.

[8]  L. Guo.  Recent progress in nanoimprint technology and its applications , 2004 .

[9]  Kuan Chen,et al.  Electron beam lithography in nanoscale fabrication: recent development , 2003 .

[10]  Dennis W. Prather,et al.  Fabrication of microchannel using planar photolithography , 2005, SPIE MOEMS-MEMS.

[11]  V. F. Dryakhlushin,et al.  Near-field optical lithography method for fabrication of the nanodimensional objects , 2005 .

[12]  Meng-Hua Yen,et al.  Crack-free direct-writing on glass using a low-power UV laser in the manufacture of a microfluidic chip , 2005 .

[13]  Jau-Yang Wu,et al.  Huge positive magnetoresistance in a gated AlGaAs∕GaAs high electron mobility transistor structure at high temperatures , 2008 .

[14]  Zhenhe Ma,et al.  Fabrication of coaxial plasmonic crystals by focused ion beam milling and electron-beam lithography , 2013 .

[15]  Efficient diffractive optical elements in chalcogenide glass layers fabricated by direct DUV laser writing , 2007 .

[16]  S. Sauvage,et al.  Infrared photodetection with semiconductor self-assembled quantum dots , 2003 .

[17]  Wei Wu,et al.  Fabrication of 5 nm linewidth and 14 nm pitch features by nanoimprint lithography , 2004 .

[18]  Andrew M. Minor,et al.  Focused Ion Beam Microscopy and Micromachining , 2007 .

[19]  Christophe Vieu,et al.  Electron beam lithography: resolution limits and applications , 2000 .

[20]  C. Reno,et al.  GaAs Laser Diode Pumped Nd:YAG Laser. , 1974, Applied optics.