摘要 |
A microlens structure and a method of fabrication thereof are provided. The method comprises forming a layer of microlens material over a substrate, which has photo-sensitive elements formed therein. The microlens material, which comprises a photo-resist material, is exposed in accordance with a desired pattern a plurality of times. The energy used with each exposure process is less than the energy required if a single exposure is used. Furthermore, the masks used for each exposure may differ. In an embodiment, the masks are varied so as to create a notch in the upper corner of the microlens. The microlens structure may have a height less than about 0.5 um and/or a gap between microlenses less than about 0.2 um. In an embodiment, one or more dielectric layers having a combined thickness greater than about 3.5 um are interposed between the photo-sensitive elements and the microlenses.
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