초록 ▼

Embodiments of the invention also generally provide a solar cell formation process that includes the formation of metal contacts over heavily doped regions that are formed in a desired pattern on a surface of a substrate. Embodiments of the invention also provide an inspection system and supporting

Embodiments of the invention also generally provide a solar cell formation process that includes the formation of metal contacts over heavily doped regions that are formed in a desired pattern on a surface of a substrate. Embodiments of the invention also provide an inspection system and supporting hardware that is used to reliably position a similarly shaped, or patterned, metal contact structure on the patterned heavily doped regions to allow an Ohmic contact to be made. The metal contact structure, such as fingers and busbars, are formed on the heavily doped regions so that a high quality electrical connection can be formed between these two regions.

대표청구항 ▼

1. A solar cell formation process, comprising: positioning a substrate on a substrate receiving surface, wherein the substrate has a first surface and a patterned doped region formed thereon;determining the actual position of the patterned doped region on the substrate, wherein determining the actua

1. A solar cell formation process, comprising: positioning a substrate on a substrate receiving surface, wherein the substrate has a first surface and a patterned doped region formed thereon;determining the actual position of the patterned doped region on the substrate, wherein determining the actual position comprises: emitting electromagnetic radiation towards the first surface; andreceiving electromagnetic radiation at a first wavelength from a region of the first surface;aligning one or more features in a screen printing mask to the patterned doped region using information received from the determined actual position of the patterned doped region on the substrate; anddepositing a layer of material through the one or more features and onto at least a portion of patterned doped region after aligning the one or more features to the patterned doped region. 2. The solar cell formation process of claim 1, wherein the layer comprises a conductive material, the substrate comprises silicon, and the patterned doped region has a dopant concentration greater than about 1×1018 atoms/cm3. 3. The solar cell formation process of claim 1, wherein receiving electromagnetic radiation at a first wavelength is performed by an optical detector that is positioned adjacent to the first surface and the emitted electromagnetic radiation is provided to a second surface that is opposite the first surface. 4. The solar cell formation process of claim 1, wherein the determining the actual position of the patterned doped region comprises capturing an optical image of two or more alignment marks disposed on a surface of the substrate, and determining the difference in position of each of alignment marks to an ideal position to determine the offset based on the optical image. 5. The solar cell formation process of claim 4, wherein the ideal position of the alignment marks is determined with respect to the at least one feature of the substrate prior to printing the first layer. 6. The solar cell formation process of claim 4, wherein at least three alignment marks are formed on the surface of the substrate using a screen printing process. 7. The solar cell formation process of claim 6, wherein the comparing the actual position of the alignment marks comprises constructing a first reference line between two of the alignment marks and constructing a second reference line between a third alignment mark and the first reference line, wherein the second reference line is perpendicular to the first reference line. 8. The solar cell formation process of claim 1, wherein positioning a substrate on a substrate receiving surface comprises: receiving a substrate on a first surface of a support material;moving the support material across a surface of the substrate support using an actuator coupled to the supporting material; andevacuating a region behind the first surface of the support material to hold the substrate disposed on the first surface against the substrate support; andaligning features in a screen printing mask to the patterned doped region further comprises positioning the substrate held on the first surface of the support material under the screen printing mask. 9. The solar cell formation process of claim 1, wherein determining the actual position of the patterned doped region on the substrate further comprises: positioning the substrate receiving surface or a screen printing mask so that a portion of the emitted electromagnetic radiation passes through one or more features formed in the screen printing mask and the first surface of the substrate disposed on the substrate receiving surface before it is received by a detector,wherein aligning the one or more features in a screen printing mask to the patterned doped region comprises adjusting the position of the feature formed in the screen printing mask to a portion of the patterned doped region formed on the substrate. 10. The solar cell formation process of claim 9, wherein the portion of the patterned doped region formed on the substrate comprises two or more nested elements that have a gap formed there between, wherein at least one of the two or more nested elements has a first width, andthe feature formed in the screen printing mask has a second width that is smaller than the first width. 11. The solar cell formation process of claim 9, wherein determining the actual position of the patterned doped region on the substrate further comprises detecting the variation in intensity of the emitted electromagnetic radiation received by the detector from two or more regions of the patterned doped region. 12. A solar cell formation process, comprising: disposing a masking material in a pattern on a first surface of a substrate;etching a portion of the first surface while the masking material is disposed on the first surface, wherein the masking material substantially inhibits the etching of a plurality of regions of the first surface over which the masking material is disposed;capturing an optical image of a portion of the first surface;aligning features in a screen printing mask to at least a portion of the plurality of regions using the information received from the captured optical image; anddepositing a layer of material through the features and onto at least a portion of the plurality of regions. 13. The solar cell formation process of claim 12, wherein the masking material comprises a first dopant material. 14. The solar cell formation process of claim 13, further comprising: heating the substrate and masking material to cause the first dopant material to diffuse into the first surface and form a patterned doped region, wherein heating the substrate and the masking material is performed after etching the portion of the first surface. 15. The solar cell formation process of claim 13, further comprising diffusing an amount of the first dopant material into a portion of the first surface after etching a portion of the first surface. 16. The solar cell formation process of claim 12, wherein capturing an optical image of a portion of the first surface comprises capturing an optical image of two or more alignment marks disposed on a surface of the substrate, and determining the difference in position of each of alignment marks to an ideal position to determine the offset based on the optical image. 17. The solar cell formation process of claim 14, wherein the substrate comprises silicon and the patterned doped region has a dopant concentration greater than about 1×1018 atoms/cm3. 18. The solar cell formation process of claim 12, further comprising: heating the substrate and masking material to cause a first dopant material disposed in the masking material to diffuse into the first surface and form a patterned doped region, wherein capturing an optical image of a portion of the patterned doped region comprises: emitting electromagnetic radiation towards the first surface; andreceiving electromagnetic radiation at a wavelength between about 850 nm and about 4 μm from a region of the first surface. 19. The solar cell formation process of claim 12, wherein capturing the optical image of the portion of the patterned doped region further comprises noting the difference in the intensity of the electromagnetic radiation reflected from or transmitted through a portion of the first surface that was covered by the masking layer and a portion of the first surface that was not covered by the masking layer during the process of etching a portion of the first surface. 20. The solar cell formation process of claim 12, further comprising: diffusing a first amount of a first dopant atom into the first surface of the substrate to form a first doped region before disposing the masking material on the first surface; anddiffusing a second amount of a second dopant atom into the first surface to form a second doped region after disposing the masking material on the first surface and etching the portion of the first surface. 21. The solar cell formation process of claim 20, wherein the first dopant atom and second dopant atom are each selected from a group of elements consisting of phosphorous, arsenic antimony, boron, aluminum and gallium. 22. The solar cell formation process of claim 20, wherein the first dopant atom and the second dopant atom are the same type of dopant atom, and the first amount of the first dopant atom in the first doped region is greater than the second amount of the second dopant atom in the second doped region. 23. A solar cell formation process, comprising: etching a portion of a first surface of a substrate;depositing a first layer over a portion of the etched first surface;removing a portion of the deposited first layer disposed over the etched first surface to expose a region of the substrate;delivering a dopant containing material to the exposed region of the substrate to form a doped region within the substrate;capturing an image of a portion of the first surface of the substrate, wherein the image comprises a portion of the exposed region and a portion of the etched first surface;aligning features in a screen printing mask to the exposed region using information received from the captured image; anddepositing a layer of material through the features and onto at least a portion of the patterned doped region after they are aligned to the exposed region. 24. The solar cell formation process of claim 23, wherein capturing an image of a portion of the first surface comprises capturing an optical image of two or more alignment marks disposed on a surface of the substrate, and determining the difference in position of each of alignment marks to an ideal position to determine the offset based on the optical image. 25. The solar cell formation process of claim 23, wherein capturing an optical image of a portion of the patterned doped region comprises: emitting electromagnetic radiation towards the first surface; andreceiving electromagnetic radiation at a wavelength between about 850 nm and about 4 μm from a region of the first surface. 26. The solar cell formation process of claim 23, wherein the first layer comprises a material selected from a group consisting of silicon nitride (SiN), amorphous silicon (a-Si) and silicon dioxide (SiO2). 27. The solar cell formation process of claim 23, wherein the first layer comprises a second layer disposed over the first surface of the substrate and a third layer disposed over the second layer, wherein the second layer comprises a material selected from a group consisting of silicon nitride (SiN) and silicon dioxide (SiO2), and the third layer comprises amorphous silicon (a-Si).