Self-aligned process for fabricating imprint templates containing variously etched features

A method of processing a substrate to fabricate a microlens imprint template comprising:

• overlaying the substrate with a mask having a plurality of through apertures;
• applying a resist to a first portion of the apertures leaving a second portion of the apertures unmasked;
• performing an anisotropic dry etch of the substrate through the second portion of unmasked apertures thereby forming first features in the substrate;
• removing the resist on the first portion of the apertures and applying a resist over the first features;
• performing a first isotropic wet etch of the substrate through the first portion of the apertures in the mask thereby forming second features as microlens hemispheres in the substrate;
• removing the mask from over the second features;
• and,
• performing a second isotropic etch to the second features to change an aspect ratio of the microlens hemispheres.