Solar cell fabrication using extruded dopant-bearing materials
First Claim
1. A system for fabricating a wafer-based semiconductor device on a substrate, the system comprising:
- means for extruding a first dopant bearing paste and a second dopant bearing paste on a surface of the semiconductor substrate such that the first dopant bearing paste forms a first extruded structure on a first surface area of the semiconductor substrate, and such that the second dopant bearing paste forms a second extruded structure on a second surface area of the semiconductor substrate, wherein the first and second surface areas are separated by a third surface area, and wherein the first dopant bearing paste includes a first dopant of a first dopant type, and the second dopant bearing paste includes a second dopant of a second dopant type andmeans for heating the semiconductor substrate such that the first dopant diffuses through the first surface area into the semiconductor substrate, thereby forming a first doped region, and such that the second dopant diffuses through the second surface area into the semiconductor substrate, thereby forming a second doped region.
2 Assignments
0 Petitions
Accused Products
Abstract
Wafer-based solar cells are efficiently produced by extruding a dopant bearing material (dopant ink) onto one or more predetermined surface areas of a semiconductor wafer, and then thermally treating the wafer to cause diffusion of dopant from the dopant ink into the wafer to form corresponding doped regions. A multi-plenum extrusion head is used to simultaneously extrude interdigitated dopant ink structures having two different dopant types (e.g., n-type dopant ink and p-type dopant ink) in a self-registered arrangement on the wafer surface. The extrusion head is fabricated by laminating multiple sheets of micro-machined silicon that define one or more ink flow passages. A non-doping or lightly doped ink is co-extruded with heavy doped ink to serve as a spacer or barrier, and optionally forms a cap that entirely covers the heavy doped ink. A hybrid thermal treatment utilizes a gaseous dopant to simultaneously dope exposed portions of the wafer.
75 Citations
12 Claims
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1. A system for fabricating a wafer-based semiconductor device on a substrate, the system comprising:
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means for extruding a first dopant bearing paste and a second dopant bearing paste on a surface of the semiconductor substrate such that the first dopant bearing paste forms a first extruded structure on a first surface area of the semiconductor substrate, and such that the second dopant bearing paste forms a second extruded structure on a second surface area of the semiconductor substrate, wherein the first and second surface areas are separated by a third surface area, and wherein the first dopant bearing paste includes a first dopant of a first dopant type, and the second dopant bearing paste includes a second dopant of a second dopant type and means for heating the semiconductor substrate such that the first dopant diffuses through the first surface area into the semiconductor substrate, thereby forming a first doped region, and such that the second dopant diffuses through the second surface area into the semiconductor substrate, thereby forming a second doped region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for fabricating a wafer-based semiconductor device on a substrate, the system comprising:
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means for extruding a first dopant bearing material and a second dopant bearing material on a surface of the semiconductor substrate such that the first dopant bearing material forms a first extruded structure on a first surface area of the semiconductor substrate, and such that the second dopant bearing material forms a second extruded structure on a second surface area of the semiconductor substrate, wherein the first and second surface areas are separated by a third surface area, and wherein the first dopant bearing material includes a first dopant of a first dopant type, and the second dopant bearing material includes a second dopant of a second dopant type, means for heating the semiconductor substrate such that the first dopant diffuses through the first surface area into the semiconductor substrate, thereby forming a first doped region, and such that the second dopant diffuses through the second surface area into the semiconductor substrate, thereby forming a second doped region, means for depositing a passivation layer on the surface of the semiconductor substrate over the first and second doped regions, means for laser ablating portions of the passivation layer such that a plurality of contact openings are defined through the passivation layer to each of the first and second surface areas, means for disposing a conductive contact structure into each of the contact openings, and means for disposing metal line structures onto an upper surface of the passivation layer such that each metal line structure contacts a group of said contact structures that are disposed over a corresponding one of said first and second doped regions.
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12. A system for fabricating a wafer-based semiconductor device on a substrate, the system comprising:
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means for extruding a first dopant bearing material and a second dopant bearing material on a surface of the semiconductor substrate such that the first dopant bearing material forms a first extruded structure on a first surface area of the semiconductor substrate, and such that the second dopant bearing material forms a second extruded structure on a second surface area of the semiconductor substrate, wherein the first and second surface areas are separated by a third surface area, and wherein the first dopant bearing material includes a first dopant of a first dopant type, and the second dopant bearing material includes a second dopant of a second dopant type, means for heating the semiconductor substrate such that the first dopant diffuses through the first surface area into the semiconductor substrate, thereby forming a first doped region, and such that the second dopant diffuses through the second surface area into the semiconductor substrate, thereby forming a second doped region, means for depositing a passivation layer on the surface of the semiconductor substrate over the first and second doped regions, means for removing portions of the passivation layer such that a plurality of contact openings are defined through the passivation layer to each of the first and second surface areas, means for disposing a conductive contact structure into each of the contact openings, and means for disposing at least one metal line structure onto an upper surface of the passivation layer such that said metal line structure contacts said first doped region by way of said conductive contact structure.
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Specification