Method of providing sacrificial spacer for micro-mechanical devices
First Claim
1. A method of fabricating a micro-mechanical device having a moveable element which is movably supported by a support element, the support element being on, and having a free end spaced away from, a substrate, comprising the steps of:
- rendering the free end of the support element radiant energy-reflective;
depositing a photoresist layer on the substrate to an initial thickness sufficient to cover the free end of the support element;
flood exposing the free surface of said photoresist layer to radiant energy without the use of a mask;
developing the photoresist to produce a substantially planar, continuous element-supportive surface which includes the free end of the support element and the free surface of the remaining, reduced-in-thickness photoresist;
fabricating the moveable element from materials deposited on the element-supportive surface; and
removing the remaining photoresist.
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Accused Products
Abstract
A method of fabricating micro-mechanical devices that use support elements (13) raised from a substrate (15), to support moveable elements (11). First, support elements (13) having reflective top surfaces (31) are fabricated. A layer of photoresist material (41) is then deposited over the support elements (13), to a thickness that substantially covers their reflective top surfaces (31). The photoresist layer (41) is exposed, which results in the areas (61) over the support elements (13) being more highly exposed than the areas (62) between the support elements (13). This permits a subsequent developing step that can be controlled to the purpose of removing the photoresist between the support elements (13) to a height planar with the reflective top surfaces of the support elements, while guaranteeing that the photoresist will be removed over the support elements (13).
314 Citations
18 Claims
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1. A method of fabricating a micro-mechanical device having a moveable element which is movably supported by a support element, the support element being on, and having a free end spaced away from, a substrate, comprising the steps of:
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rendering the free end of the support element radiant energy-reflective; depositing a photoresist layer on the substrate to an initial thickness sufficient to cover the free end of the support element; flood exposing the free surface of said photoresist layer to radiant energy without the use of a mask; developing the photoresist to produce a substantially planar, continuous element-supportive surface which includes the free end of the support element and the free surface of the remaining, reduced-in-thickness photoresist; fabricating the moveable element from materials deposited on the element-supportive surface; and removing the remaining photoresist. - View Dependent Claims (2, 3, 4)
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5. A method of fabricating a micro-mechanical device having at least one moveable element, using a maskless sacrificial spacer, comprising the steps of:
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fabricating on a substrate, at least one support element for supporting said moveable element, said support element extending upwardly from said substrate and having a reflective top surface; depositing a photoresist layer over said support element and on the surrounding substrate, said photoresist layer having a thickness that is greater than the distance between said reflective top surface and said substrate such that it covers said reflective top surface of said support element; exposing said photoresist layer with a substantially uniform exposure; developing said photoresist layer such said photoresist layer is removed down to a height that is substantially the same as the height of said reflective top surface of said support element, thereby forming a substantially planar surface comprised of said reflective top surface of said support element and of the top surface of the remaining photoresist material on said surrounding substrate; fabricating said moveable element on said planar surface; and removing said remaining photoresist material after said moveable element has been fabricated. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
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13. A method of manufacturing a digital micro-mirror device having at least one deflectable mirror element, comprising the steps of:
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fabricating on a substrate, at least one support post for supporting said mirror element, said support post extending upwardly from said substrate and having a reflective top surface; depositing a photoresist layer over said support post and on the surrounding substrate, said photoresist layer having a thickness such that it covers said reflective top surface of said support post; exposing said photoresist layer; developing said photoresist layer such that said photoresist layer is removed down to a height that is substantially the same as the height of said support post, thereby forming a substantially planar surface comprised of said reflective top surface of said support post and of the top surface of the remaining photoresist material on said surrounding substrate; fabricating said deflectable mirror element on said planar surface; and removing said remaining photoresist material after said deflectable mirror element has been fabricated. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification