Study On Fabricating Blazed Grating By Homogenous Grating Mask

For fabricating blazed grating by holographic ion beam etching, the etching processand the graph evolution of etching process is investigated theoretically and experimentally.The main contents are as follows:The development and progress home and abroad of fabricating technology on blazedgrating are presented, the ion beam etching and Kaufman ion source system are reviewed.The etching characteristic of photoresist, K9glass and quartz is studied, the etching rate ofmaterials is measured and analyzed as function of ion beam incidence angle in pure Ar andCHF3, respectively. It offers useful experiment gist and theoretical instruction for ion beametching process.Advanced segment motion algorithm is introduced in detail. On the basis of ignoringtwice effects, a simulating program for ion beam etching is established by advancedsegment motion algorithm and its feasibility is verified, the graph evolution ofhomogenous mask on the oblique ion beam etching is simulated in this program,simulation indicates good blazed grating can be fabricated by appropriate homogenousmask, it offers theoretical basis for rational design the duty cycle and depth of homogenousmask.For photoresist mask is difficult to control in traditional holographic ion beam etchingtechnology, the method with homogenous mask is presented to fabricate blazed grating,combination of Ar ion beam etching and CHF3reactive ion beam etching to fabricatehomogenous mask, which control effectively duty cycle and depth of mask. The blazedgratings of different blaze angle are designed theoretical and fabricated by homogenousmask method, the result indicates blazed grating of90°groove angle can be fabricated fordifferent angles.For experimental fabrication, a photoresist mask is produced by traditional holographic lithography, then homogenous mask is fabricated by combination Ar ion beametching and CHF3reactive ion beam etching, finally, blazed grating can be fabricated byoblique ion beam etching.20°blaze angle，68.5°anti-blaze angle and11°blaze angle,72°anti-blaze angle are fabricated, deposition aluminum reflective film on the grating, anddiffraction efficiency is measured in+1stLittrow angle.