Abstract: A solar cell having a large region where reverse breakdown can occur is disclosed. Reverse breakdown tends to occur near areas where heavily doped n-type regions abut heavily doped p-type regions. Thus, by increasing the region where such a heavily doped p/n junction exists may improve the reverse breakdown characteristics of the solar cell. In addition, a method of making such solar cell is disclosed, where this heavily doped p/n junction is fabricated along at least a portion of the perimeter of the solar cell.

Abstract: Herein, an improved technique for processing a substrate is disclosed. In one particular exemplary embodiment, the technique may be achieved using a mask for processing the substrate. The mask may be incorporated into a substrate processing system such as, for example, an ion implantation system. The mask may comprise one or more first apertures disposed in a first row; and one or more second apertures disposed in a second row, each row extending along a width direction of the mask, wherein the one or more first apertures and the one or more second apertures are non-uniform.

Abstract: A system and method are disclosed for aligning substrates during successive process steps, such as ion implantation steps, is disclosed. Implanted regions are created on a substrate. After implantation, an image is obtained of the implanted regions, and a fiducial is provided on the substrate in known relation to at least one of the implanted regions. A thermal anneal process is performed on the substrate such that the implanted regions are no longer visible but the fiducial remains visible. The position of the fiducial may be used in downstream process steps to properly align pattern masks over the implanted regions. The fiducial also may be applied to the substrate before any ion implanting of the substrate is performed. The position of the fiducial with respect to an edge or a corner of the substrate may be used for aligning during downstream process steps. Other embodiments are described and claimed.

Abstract: The resistivity of a silicon boule may vary along its length, thereby making a uniform ion implantation process sub-optimal. A system and method for measuring a resistivity of a substrate, and processing the substrate based on that measured resistivity is disclosed. The system includes a resistivity measurement system, a controller and an ion implanting system, where the controller configures the ion implantation process based on the measured resistivity of the substrate.

Abstract: A system and method for determining the edge or region where a saw first enters a silicon brick, and using this information to process this region differently is disclosed. This region, referred to as the saw entry region, may be thinner, or have a rougher texture than the rest of the substrate. This difference may impact the substrate's ultimate performance. For example, if the substrate is processed as a solar cell, the performance of the saw entry region may be suboptimal.

Abstract: One method of implanting a workpiece involves implanting the workpiece with an n-type dopant in a first region with center and a periphery. The workpiece also is implanted with a p-type dopant in a second region complementary to the first region. This second region also has a center and a periphery. The periphery of the first region and the periphery of the second region at least partially overlap. A dose at the periphery of the first region or second region is less than a dose at the center of the first region or second region. The region of overlap may function as a junction where charge carriers cannot pass.

Abstract: A method of tailoring the dopant profile of a substrate by utilizing two different dopants, each having a different diffusivity is disclosed. The substrate may be, for example, a solar cell. By introducing two different dopants, such as by ion implantation, furnace diffusion, or paste, it is possible to create the desired dopant profile. In addition, the dopants may be introduced simultaneously, partially simultaneously, or sequentially. Dopant pairs preferably consist of one lighter species and one heavier species, where the lighter species has a greater diffusivity. For example, dopant pairs such as boron and gallium, boron and indium, phosphorus and arsenic, and phosphorus and antimony, can be utilized.

Abstract: Techniques for manufacturing a device are disclosed. In accordance with one exemplary embodiment, the technique may be realized as a method for forming a solar cell. The method may comprise: implanting p-type dopants into a substrate via a blanket ion implantation process; implanting n-type dopants into the substrate via the blanket ion implantation process; and performing a first annealing process to form the p-type region and performing a second annealing process to form a second n-type region.

Abstract: One method of implanting a workpiece involves implanting the workpiece with an n-type dopant in a first region with center and a periphery. The workpiece also is implanted with a p-type dopant in a second region complementary to the first region. This second region also has a center and a periphery. The periphery of the first region and the periphery of the second region at least partially overlap. A dose at the periphery of the first region or second region is less than a dose at the center of the first region or second region. The region of overlap may function as a junction where charge carriers cannot pass.

Abstract: An improved technique for processing a substrate is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for processing a substrate. The method may comprise ion implanting a substrate disposed downstream of the ion source with ions generated in an ion source; and disposing a first portion of a mask in front of the substrate to expose the first portion of the mask to the ions, the mask being supported by the first and second mask holders, the mask further comprising a second portion wound in the first mask holder.

Abstract: An improved bifacial solar cell is disclosed. In some embodiments, the front side includes an n-type field surface field, while the back side includes a p-type emitter. In other embodiments, the p-type emitter is on the front side. To maximize the diffusion of majority carriers and lower the series resistance between the contact and the substrate, the regions beneath the metal contacts are more heavily doped. Thus, regions of higher dopant concentration are created in at least one of the FSF or the emitter. These regions are created through the use of selective implants, which can be performed on one or two sides of the bifacial solar cell to improve efficiency.

Abstract: An improved bifacial solar cell is disclosed. In some embodiments, the front side includes an n-type field surface field, while the back side includes a p-type emitter. In other embodiments, the p-type emitter is on the front side. To maximize the diffusion of majority carriers and lower the series resistance between the contact and the substrate, the regions beneath the metal contacts are more heavily doped. Thus, regions of higher dopant concentration are created in at least one of the FSF or the emitter. These regions are created through the use of selective implants, which can be performed on one or two sides of the bifacial solar cell to improve efficiency.

Abstract: A system and method are disclosed for aligning substrates during successive process steps, such as ion implantation steps, is disclosed. Implanted regions are created on a substrate. After implantation, an image is obtained of the implanted regions, and a fiducial is provided on the substrate in known relation to at least one of the implanted regions. A thermal anneal process is performed on the substrate such that the implanted regions are no longer visible but the fiducial remains visible. The position of the fiducial may be used in downstream process steps to properly align pattern masks over the implanted regions. The fiducial also may be applied to the substrate before any ion implanting of the substrate is performed. The position of the fiducial with respect to an edge or a corner of the substrate may be used for aligning during downstream process steps. Other embodiments are described and claimed.

Abstract: An improved method of moving a mask to perform a pattern implant of a substrate is disclosed. The mask has a plurality of apertures, and is placed between the ion source and the substrate. After the substrate is exposed to the ion beam, the mask is indexed to a new position relative to the substrate and a subsequent implant step is performed. Through the selection of the aperture size and shape, the index distance and the number of implant steps, a variety of implant patterns may be created. In some embodiments, the implant pattern includes heavily doped horizontal stripes with lighter doped regions between the stripes. In some embodiments, the implant pattern includes a grid of heavily doped regions. In other embodiments, the implant pattern is suitable for use with a bus-bar structure.

Abstract: An improved bifacial solar cell is disclosed. In some embodiments, the front side includes an n-type field surface field, while the back side includes a p-type emitter. In other embodiments, the p-type emitter is on the front side. To maximize the diffusion of majority carriers and lower the series resistance between the contact and the substrate, the regions beneath the metal contacts are more heavily doped. Thus, regions of higher dopant concentration are created in at least one of the FSF or the emitter. These regions are created through the use of selective implants, which can be performed on one or two sides of the bifacial solar cell to improve efficiency.

Abstract: Various methods of utilizing the physical and chemical property differences between amorphized and crystalline silicon are used to create masks that can be used for subsequent implants. In some embodiments, the difference in film growth between amorphous and crystalline silicon is used to create the mask. In other embodiments, the difference in reflectivity or light absorption between amorphous and crystalline silicon is used to create the mask. In other embodiments, differences in the characteristics of doped and undoped silicon is used to create masks.

Abstract: An improved method of producing solar cells utilizes a mask which is fixed relative to an ion beam in an ion implanter. The ion beam is directed through a plurality of apertures in the mask toward a substrate. The substrate is moved at different speeds such that the substrate is exposed to an ion dose rate when the substrate is moved at a first scan rate and to a second ion dose rate when the substrate is moved at a second scan rate. By modifying the scan rate, various dose rates may be implanted on the substrate at corresponding substrate locations. This allows ion implantation to be used to provide precise doping profiles advantageous for manufacturing solar cells.

Abstract: In an ion implanter, an ion current measurement device is disposed behind a mask co-planarly with respect to a surface of a target substrate as if said target substrate was positioned on a platen. The ion current measurement device is translated across the ion beam. The current of the ion beam directed through a plurality of apertures of the mask is measured using the ion current measurement device. In this manner, the position of the mask with respect to the ion beam as well as the condition of the mask may be determined based on the ion current profile measured by the ion current measurement device.

Abstract: An improved method of implanting a solar cell is disclosed. A substrate is coated with a soft mask material. A shadow mask is used to perform a pattern ion implant and to set the soft mask material. After the soft mask material is set, the mask is removed and a blanket implant is performed.

Abstract: One method of implanting a workpiece involves implanting the workiece with an n-type dopant in a first region with center and a periphery. The workpiece also is implanted with a p-type dopant in a second region complementary to the first region. This second region also has a center and a periphery. The periphery of the first region and the periphery of the second region at least partially overlap. A dose at the periphery of the first region or second region is less than a dose at the center of the first region or second region. The region of overlap may function as a junction where charge carriers cannot pass.