Varian Semiconductor Equipment Associates, Inc.

Applied Materials, Inc.

Nicholas P T Bateman

Benjamin B Riordon

Atul Gupta

William Tyler Weaver

John W Graff

Bon-Woong Koo

Timothy J Miller

Vikram M Bhosle

Russell J Low

John A Frontiero

Peter F Kurunczi

Paul Sullivan

Frank Sinclair

Charles T Carlson

Peter Lawrence Kellerman

Deepak Arabagatte Ramappa

Kevin M Daniels

Steven M Anella

Christopher J Leavitt

Julian G Blake

Svetlana Radovanov

Paul J Murphy

Christopher R Hatem

Robert J Mitchell

Christopher A Rowland

Frederick M Carlson

Helen L Maynard

Jun Seok Lee

Deven Raj Mittal

Min-Sung Jeon

Russell L Low

William T Levay

Vikram M Bholse

Benjamin Riordan

Benjamin D Riordon

An apparatus and method of processing a workpiece is disclosed, where a sacrificial capping layer is created on a top surface of a workpiece. That workpiece is then exposed to an ion implantation process, where select species are used to passivate the workpiece. While the implant process is ongoing, radicals and excited species etch the sacrificial capping layer. This reduces the amount of etching that the workpiece experiences. In certain embodiments, the thickness of the sacrificial capping layer is selected based on the total time used for the implant process and the etch rate. The total time used for the implant process may be a function of desired dose, bias voltage, plasma power and other parameters. In some embodiments, the sacrificial capping layer is applied prior to the implant process. In other embodiments, material is added to the sacrificial capping layer during the implant process.

Sacrificial capping layer for passivation using plasma-based implant process

A method for improving the ion beam quality in an ion implanter is disclosed. In some ion implantation systems, contaminants from the ion source are extracted with the desired ions, introducing contaminants to the workpiece. These contaminants may be impurities in the ion source chamber. This problem is exacerbated when mass analysis of the extracted ion beam is not performed, and is further exaggerated when the desired feedgas includes a halogen. The introduction of a diluent gas in the ion chamber may reduce the deleterious effects of the halogen on the inner surfaces of the chamber, reducing contaminants in the extracted ion beam. In some embodiments, the diluent gas may be germane or silane.

Method of improving ion beam quality in an implant system

An apparatus and methods of improving the ion beam quality of a halogen-based source gas are disclosed. Unexpectedly, the introduction of a noble gas, such as argon, to an ion source chamber may increase the percentage of desirable ion species, while decreasing the amount of contaminants and halogen-containing ions. This is especially beneficial in non-mass analyzed implanters, where all ions are implanted into the workpiece. In one embodiment, a first source gas, comprising a dopant and a halogen is introduced into an ion source chamber, a second source gas comprising a hydride, and a third source gas comprising a noble gas are also introduced. The combination of these three source gases produces an ion beam having a higher percentage of pure dopant ions than would occur if the third source gas were not used.

Boron implanting using a co-gas

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.

Techniques for processing a substrate

A method of processing a solar cell is disclosed, where a chained patterned ion implant is performed to create a workpiece having a lightly doped surface having more heavily doped regions. This configuration may be used in various embodiments, such as for selective emitter solar cells. Additionally, various mask sets that can be used to create this desired pattern are also disclosed. The mask set may include one or more masks that have an open portion and a patterned portion, where the union of the open portions of the masks comprises the entirety of the surface to be implanted. The patterned portions of the masks combine to create the desired pattern of heavily doped regions.

Complementary traveling masks

A method of processing a solar cell is disclosed, where the edges of the solar cell are covered, coated or masked during the ion implantation process and/or the screen printing process. This covering may be a substance that blocks the penetration of ions during implantation, or may be a substance that resists the diffusion of fritted metal paste during the metallization process. In some embodiments, the edges are covered during both of these processes. In further embodiments, the same material may perform both functions.

Dielectric coating of the edge of a solar cell

A method of forming an interdigitated back contact solar cell is described. The method uses a deposition process to create a doped glass layer on the substrate, which, when diffused, created either the emitter or back surface fields. The deposition process may also create an oxide layer on top of the doped glass layer. This oxide layer serves as a mask for a subsequent ion implant. This ion implant directs ions having the opposite conductivity of the doped glass layer into exposed regions of the substrate. A thermal process is used to diffuse the dopant from the doped glass layer into the substrate and repair any damage caused by the ion implant.

Method of forming an interdigitated back contact solar cell

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.

Techniques for manufacturing devices

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.

Substrate processing based on resistivity measurements

A method of processing a workpiece is disclosed, where the ion chamber is first coated with the desired dopant species and another species. Following this conditioning process, a feedgas, which comprises fluorine and the desired dopant, is introduced to the chamber and ionized. Ions are then extracted from the chamber and accelerated toward the workpiece, where they are implanted without being first mass analyzed. The other species used during the conditioning process may be a Group 3, 4 or 5 element. The desired dopant species may be boron.

Method for implant productivity enhancement

A first species selectively dopes a workpiece to form a first doped region. In one embodiment, a selective implant is performed using a mask with apertures. A soft mask is applied to the first doped region. A second species is implanted into the workpiece to form a second implanted region. The soft mask blocks a portion of the second species. Then the soft mask is removed. The first species and second species may be opposite conductivities such that one is p-type and the other is n-type.

Aligning successive implants with a soft mask

Methods to form complementary implant regions in a workpiece are disclosed. A mask may be aligned with respect to implanted or doped regions on the workpiece. The mask also may be aligned with respect to surface modifications on the workpiece, such as deposits or etched regions. A masking material also may be deposited on the implanted regions using the mask. The workpiece may be a solar cell.

Implant alignment through a mask

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.

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Reading, MA, United States of America

Nicholas P T Bateman