Device and method for manufacturing a particulate filter with regularly spaced micropores
AssigneeUniversity of Houston
InventorsJohn C. Wolfe, Paul Ruchhoeft
Life of this patent
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Abstract
Various embodiments disclose devices and methods for fabricating microporous particulate filters with regularly space pores wherein sheet membrane substrates are exposed to energetic particle radiation through a mask and the damaged regions removed in a suitable developer. The required depth of field is achieved by using energetic particles to minimize diffraction and an energetic particle source with suitably small diameter.
Claims30
A lithographic exposure device for fabricating a microporous filter membrane, said microporous filter membrane not supported by a solid substrate, comprising:
- means for exposing a membrane substrate to a beam comprising at least one energetic particle, wherein said energetic particle has an energy level greater than about 10 keV;
- means for applying a high emissivity coating to said membrane substrate prior to exposing said membrane substrate to said beam;
- means for conveying said membrane substrate;
- and
- a mask positioned between said membrane substrate and at least one source of said at least one energetic particle, said beam comprising at least one particle transmitted through said mask.
A lithographic exposure device for fabricating a microporous filter membrane, said microporous filter membrane not supported by a solid substrate, comprising:
- a radiation source directed at least partially on a membrane substrate, wherein said radiation source's emitted radiation comprises a beam of at least one energetic particle, wherein said energetic particle has an energy level greater than about 10 keV;
- a device for applying a high emissivity coating to a membrane substrate prior to exposure to said radiation source;
- a device for conveying said membrane substrate comprising at least one supply reel and at least one take-up reel;
- and
- a mask positioned between said membrane substrate and at least one source of said at least one energetic particle, said beam comprising at least one particle transmitted through said mask.
A process for fabricating a microporous filter membrane, said microporous filter membrane not supported by a solid substrate, said process comprising the steps of:
- conveying a membrane substrate in a stepwise fashion adjacent a mask;
- applying a high emissivity coating to said membrane substrate;
- damaging said membrane substrate with at least one beam comprising at least one energetic particle emitted from at least one radiation source directed at least partially through said mask, wherein said energetic particle has an energy level greater than about 10 keV, and wherein said damaging occurs after said application of said high emissivity coating to said membrane substrate;
- and
- removing said damaged membrane substrate with an etchant.
A process for fabricating a microporous filter membrane, said process comprising the steps of:
- applying an intermediate mask layer and a resist coating to a membrane substrate;
- applying a high emissivity coating to said membrane substrate;
- conveying said membrane substrate in a stepwise fashion adjacent a mask;
- exposing said resist coating with at least one beam comprising at least one energetic particle emitted from at least one radiation source directed at least partially through said mask, wherein said energetic particle has an energy level greater than about 10 keV, and wherein said exposure occurs after said application of said high emissivity coating to said membrane substrate;
- developing said resist coating;
- etching said resist coating's pattern through said intermediate mask layer;
- and
- etching said intermediate mask layer's pattern into said membrane substrate.
Dependencies are inferred from the claim text.