Maskless Doping Technique for Solar Cells
First Claim
1. A method of implanting ions into a substrate so as to create a non-uniform dopant dose without a fixed masking layer on said substrate, comprising:
- a. Providing an ion implantation system for forming an ion beam having one dimension greater than its second dimension;
b. Exposing a first portion of said substrate to said ion beam;
c. Implanting a first dose of ions in said first portion;
d. Exposing a second portion of said substrate to said ion beam; and
e. Implanting a second dose of ions in said second portion, where said second dose of ions is different than said first dose of ions.
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Accused Products
Abstract
A improved, lower cost method of producing solar cells utilizing selective emitter design is disclosed. The contact regions are created on the substrate without the use of lithography or masks. The method utilizes ion implantation technology, and the relatively low accuracy requirements of the contact regions to reduce the process steps needed to produce a solar cell. In some embodiments, the current of the ion beam is selectively modified to create the highly doped contact regions. In other embodiments, the ion beam is focused, either through the use of an aperture or via adjustments to the beam line components to create the necessary doping profile. In still other embodiments, the wafer scan rate is modified to create the desired ion implantation pattern.
50 Citations
25 Claims
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1. A method of implanting ions into a substrate so as to create a non-uniform dopant dose without a fixed masking layer on said substrate, comprising:
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a. Providing an ion implantation system for forming an ion beam having one dimension greater than its second dimension; b. Exposing a first portion of said substrate to said ion beam; c. Implanting a first dose of ions in said first portion; d. Exposing a second portion of said substrate to said ion beam; and e. Implanting a second dose of ions in said second portion, where said second dose of ions is different than said first dose of ions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of implanting ions into a substrate, so as to create a non-uniform dopant dose on the implant surface, comprising:
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a. Providing an ion implantation system, capable of producing an ion beam having one dimension greater than a second dimension, and comprising a substrate holder to move a substrate relative to said ion beam; b. Exposing the entire surface of said substrate to a uniform dose of ions by moving said substrate relative to said ion beam until entire wafer has been exposed; c. Exposing a first portion of said substrate to a second dose of ions; d. Moving said substrate relative to said ion beam; and e. Exposing a second portion of said substrate to a third dose of ions. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of varying beam transmission in an ion implanter system, wherein said ion implanter system comprises an adjustable beamline component, wherein an adjustment of said component changes the effective beam current incident on said substrate, said method comprising:
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a. Adjusting said component to a first setting when said ion beam is exposed to said first portion of said substrate; and b. Adjusting said component to a second setting when said ion beam is exposed to said second portion of said substrate. - View Dependent Claims (24, 25)
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Specification