Transparent elastomeric, contact-mode photolithography mask, sensor, and wavefront engineering element

Abstract

A contact-mode photolithography phase mask includes a diffracting surface having a plurality of indentations and protrusions. The protrusions are brought into contact with a surface of positive photoresist, and the surface exposed to electromagnetic radiation through the phase mask. The phase shift due to radiation passing through the indentations as opposed to the protrusions is essentially complete. Minima in intensity of electromagnetic radiation are thereby produced at boundaries between the indentations and protrusions. The elastomeric mask conforms well to the surface of photoresist and, following development, features smaller than 100 nm can be obtained. Patterns including curved portions are obtained, as well as curved and/or linear patterns on non-planar surfaces. An elastomeric transparent diffraction grating serves also as a spatial light modulator photothermal detector, strain gauge, and display device. A technique for simplified photolithography is also described. A photoreactive, contoured surface is exposed to electricmagnetic radiation and contours in the surface alters the electromagnetic radiation to promote selective surface photoreaction. The contours can act as lenses, gratings, or the like, such that the photoreactive surface itself can selectively direct uniform radiation to promote selective photoreaction within itself. A photoresist layer having a contoured surface thus can be exposed to uniform radiation, without a mask, followed by development and lift-off to create a photoresist pattern that can be used in any of a variety of ways. The invention provides methods of making contoured, photoreactive surfaces, and contoured photoreactive surfaces themselves.