Adjustments of Masks by Re-Flow
AssigneeCSG Solar AG
InventorsTrevor Lindsay Young, Rhett Evans
Life of this patent
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Abstract
As a step in performing a process on a structure, a hole pattern is provided in a thin layer of organic resin masking material formed over the structure to provide a process mask. A processing step is then performed through the openings in the mask, and after a processing step is completed the mask is adjusted by a re-flow process in which the structure is placed into an atmosphere of solvent vapor of a solvent of the mask material. By way of the reflow process, the mask material softens and re-flows to reduce the size of the openings in the mask causing edges of the surface areas on which the processing step was performed to be covered by the mask for subsequent processing steps.
Claims45
A method of modifying a hole pattern in an organic resin masking material formed over a structure as a step in performing a process on the structure, the method comprising the steps of:
- a) forming a mask by applying a thin layer of the organic resin masking material over the structure;
- b) forming openings in the mask to provide the hole pattern;
- c) performing a processing step on the surface areas of the structure exposed through the openings in the mask;
- d) placing the structure into an atmosphere of solvent vapour of a solvent of the masking material whereby the mask material softens and re-flows to reduce the size of the openings in the mask causing edges of the surface areas on which the processing step was performed to be covered by the mask for subsequent processing steps.
A method of processing a semiconductor structure wherein a hole pattern is provided in a masking material located over a supporting structure, and the masking material is an organic resin formed in a thin layer through which the openings are provided to form the hole pattern, the method comprising;
- a) lacing the supporting structure or substrate into an atmosphere of solvent vapour of a solvent of the mask material whereby the mask material softens and re-flows to reduce the size of the openings in the mask.
A method of forming a photovoltaic device structure in a silicon film deposited on a glass substrate, the film comprising an n+ type region closest the glass, a lightly doped region over the n+ type region and a p+ type region over the lightly doped region, the method comprising:
- a) dividing the silicon film into a plurality of cell regions by forming isolation grooves;
- b) forming a mask of organic resin in a thin layer over the silicon film;
- c) forming a first set of openings in the mask in locations where n type contacts are required;
- d) etching the silicon film in the first set of openings to expose at least some of the n+ type silicon;
- e) placing the substrate into an atmosphere of solvent vapour of a solvent of the mask material whereby the mask material softens and re-flows to reduce the size of the first openings in the mask.
- f) forming a second set of openings in the mask in locations where p type contacts are required;
- g) forming a metal layer over the surface of the mask and extending the metal into the first and second openings to contact the n+ type and p+ type silicon;
- h) forming isolation grooves in the metal to separate the contacts to the p type and n type silicon within each cell.
(canceled)
Dependencies are inferred from the claim text.