Semiconductor micro and nanofabrication lithography techniques for application in microelectronics as well as in micromechanics and optoelectronics can gain significantly from using a dry resist process, since it enables the deposition of a very uniform lithographically sensitive layer on a potentially very small area. This would otherwise be extremely difficult to achieve by using a traditional spin coated resist, such as poly(methylmethacrylate) (PMMA). We demonstrate the use of an electron sensitive sterol based evaporated electron beam resist to fabricate high-resolution features (down to 100 nm) on a small surface area. This electron beam resist has a sensitivity comparable to PMMA and is deposited using a simple thermal evaporation. Two practical applications are explored: first, this resist makes it possible to fabricate a Fresnel zone plate lens on the tip of an optical fiber in order to demonstrate the principle and the potential of highly efficient coupling of diode laser emission into the fiber; second, we use this evaporated electron beam resist in order to pattern an optical diffractive element on the facet of a semiconductor laser.

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A critical issue in fabricating arrays of holes is to achieve high-aspect-ratio structures. Formation of ordered arrays of nanoholes in silicon nitride was investigated by the use of ultrathin hard etch mask formed by nickel pulse reversal plating to invert the tonality of a dry e-beam resist patterned by e-beam lithography. Ni plating was carried out using a commercial plating solution based on nickel sulfamate salt without organic additives. Reactive ion etching using SF 6 /CH 4 was found to be very effective for pattern transfer to silicon nitride. Holes array of 100 nm diam, 270 nm period, and 400 nm depth was fabricated on a 5ϫ5 mm 2 area.

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