| According to the features of using ion beam etching to fabricate blazed grating, the measure of etching homogenous grating mask to fabricate Echelle is studied. The main contents are as follows:Firstly, the characteristics and significance of the Echelle are presented. And two methods of fabricating Echelle are introduced. The development and progress home and abroad of fabricating Echelle are investigated.The ion beam etching and ion source system are reviewed. The segment motion algorithm is introduced briefly. The process of forming groove profile by segment motion algorithm and the measure dealing with the segments intersection in the process are analyzed. Some cases of deleting the point on the surface corner and the edge are also discussed.We have analyzed the ideal homogeneous grating mask for Echelle with blazing angle 55° in theory. Because of the difficulties of fabricating the homogeneous grating mask used in large blaze angle groove, a new idea was proposed through the simulation using segment motion algorithm, which is producing anti-blaze angle. And in the practical application the anti-blaze angle will be used as the blaze angle.The methods in fabricating homogeneous grating mask are discussed in detail. The homogeneous grating mask fabricated by RIE and the groove we analyzed are compared. Photoresist and chrome double mask are used in fabricating homogeneous grating mask. To etch chrome mask, ion beam etching and wet etching are considered. The advantages and disadvantages of these two methods are compared.In the experiment, the homogeneous grating mask is fabricated by RIE etching. Then the homogeneous grating mask is etched in an angle by Ar ion beam etching. A 801p/mm echelle with the blaze angle of 52.5° and anti-blaze angle of 27.8° has been made. The diffraction efficiency in the incident wavelength of 450nm-700nm is theoretically calculated. And differences of the ideal groove and the actually produced groove are compared in diffraction efficiency. |
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