Precision laser recording on a molybdenum films for diffractive microrelief formation

Abstract

The problem of reducing the thickness of the lines of contact pattern masks used in the formation of micro-relief of diffractive optical elements (DOEs) and produced by laser ablation of thin films of refractory metals. For contact mask of DOEs on molybdenum films with thickness of 40 nm using a laser ablation patterns recorded with elements of the picture width 0.25–0.3 µm. This is approximately 3 times smaller than the characteristic dimensions, obtained by thermochemical recording chromium films of the same thickness in the standard process. Reactive ion etching in an inductively coupled plasma through a mask was formed micro-relief height up to 300 nm in a quartz substrate. We have shown promising applications of thin films of molybdenum as a metallic mask in the formation of microrelief of DOEs.

The research of the properties of thin films of molybdenum to form the contact masks for diffractive optics elements

“…Most likely, their emergence with the removal of a significant portion of the substance from the area of reactive ablation recoil pressure PA-world jet [19]. As shown earlier, their height does not exceed the thickness of the film [15].…”

“…Based on [14], we proposed an approach based on the ablation areas of the film of molybdenum exposed to laser radiation [15].…”

Application of thin molybdenum films in contact masks for manufacturing the micro-relief of diffractive optical elements

“…Вероятнее всего, их образование связано с выносом значительной части вещества из области абляции реактивным давлением отдачи паровой струи [19]. Как было показано ранее, их высота не превыша-ет толщину плёнки [15].…”

“…Опираясь на [14], мы предложили подход, осно-ванный на абляции участков плёнки молибдена, под-вергнутых воздействию лазерного излучения [15].…”

The Efficiency of Optical Microstructures Formed on Molybdenum Films

“…In this respect is perspective thin films of molybdenum [6] as molybdenum has the following features are perspective: -low temperatures of oxidation of metal, and oxide sublimation; -high ratio of heat diffusivities metal/oxide. In works [10][11][12] the possibility of forming of optical microstructures by a laser ablation of thin films of molybdenum is shown. The effect of triple reducing the size of a zone of an ablation has been found (in comparison with diameter of a focal spot).…”