Ipg Photonics Corporation

Ase Americas, Inc.

Rwe Schott Solar Gmbh

Other

Schott Solar Gmbh

Bernhard Piwczyk

Juris P Kalejs

Michael J Kardauskas

William Shiner

Individually operable laser diodes in an array are associated with optical fibers for treatment of a material. Each laser diode has a generally Gaussian or similar profile. A guide block receives optical fiber terminal distal ends and enables irradiation of a surface for treatment with overlapping profiles. A control system controls individual laser diodes to achieve desired illumination profiles for a given process. The process is performed in a suitable environment which may include a vacuum system, controlled gaseous environment, or in a doping medium such as a surface coating or even a liquid. Optional relay optics interposed between the terminal distal ends and the treatment material allows distant relaying and reimaging. An optical isolator assembly may be interposed between the relay optics and the treatment material. The system and related methods allow direct irradiation from laser diodes to treat materials.

Laser diode array with fiber optic termination for surface treatment of materials

A fiber laser system enables a method for treating a semiconductor material by preheating a wafer for laser annealing and gas immersion laser doping by a laser source. A long wave length fiber laser having a Gaussian or similar profile is applied in a full-width ribbon beam across an incident wafer. Preferably the wavelength is greater than 1 &#x3bc;m (micron) and preferably a Yb doped fiber laser is used. The process is performed in a suitable environment which may include doping species. The process ensures the temperature gradient arising during processing does not exceed a value that results in fracture of the wafer while also reducing the amount of laser radiation required to achieve controlled surface melting, recrystallization and cooling.

Method and system for pre-heating of semiconductor material for laser annealing and gas immersion laser doping

A method of semiconductor junction formation in RTA process for fabrication of solar cells provides for delivery of inert gases in the vicinity of the Si wafer while dopant species are being driven form a dopant source into the surface of the wafer irradiated by a laser beam. The laser beam is emitted by CW- or pulsed operated lasers including fiber lasers operative to provide annealing and diffusion operation. Optionally, the passivation of the surface and formation of the antireflection coating are performed simultaneously with the penetration the dopant species.

RTA for fabrication of solar cells

A method of semiconductor junction formation in Laser diffusion process for fabrication of solar cells provides for delivery of inert gases in the vicinity of the Si wafer while dopant species are being diffused form a dopant source into the surface of the wafer irradiated by a laser beam. The laser beam is emitted by CW- or pulsed operated lasers including fiber lasers. Optionally, the passivation of the surface and formation of the antireflection coating are performed simultaneously with the diffusion of the dopant species.

Laser diffusion fabrication of solar cells

An inexpensive method of coating silicon shot with boron atoms comprises (1) immersing silicon shot in an aqueous solution comprising a boric acid and polyvinyl alcohol, and (2) heating the solution so as to evaporate water and form a polymerized polyvinyl alcohol coating containing boron on the shot. A precise amount of this coated shot may then be mixed with a measured quantity of intrinsic silicon pellets and the resulting mixture may then be melted to provide a boron-doped silicon melt for use in growing p-type silicon bodies that can be converted to substrates for photovoltaic solar cells.

Coating silicon pellets with dopant for addition of dopant in crystal growth

An inexpensive method of coating silicon shot with boron atoms comprises (1) immersing silicon shot in a boron dopant spin-on solution comprising a borosilicate, a polymer precursor, and a volatile solvent, and (2) removing the solvent so as to leave a polymeric coating containing borosilicate on the shot. A precise amount of this coated shot may then be mixed with a measured quantity of silicon pellets and the resulting mixture may then be melted to provide a boron-doped silicon melt for use in growing p-type silicon bodies that can be converted to substrates for photovoltaic solar cells.

Process for coating silicon shot with dopant for addition of dopant in crystal growth

A novel method of etching a plurality of semiconductor wafers is provided which comprises assembling said plurality of wafers in a stack, and subjecting said stack of wafers to dry etching using a relatively high density plasma which is produced at atmospheric pressure. The plasma is focused magnetically and said stack is rotated so as to expose successive edge portions of said wafers to said plasma.

Etching of semiconductor wafer edges

An improved method and apparatus for laser cutting a thin fragile material using a high velocity assist gas to remove molten material and laser-generated debris is characterized by the high velocity assist gas exerting substantially zero force on the material being cut. An improved form of gas assist laser gas assist nozzle is shaped to achieve a supersonic gas flow velocity that is used advantageously to effect rapid removal of ejected gas and other materials.

Gas assisted laser cutting of thin and fragile materials

A method of cutting thin bodies of silicon so as to minimize edge damage comprises traversing said bodies with the beam of a pulsed laser in a vacuum or in the presence of forming gas or a noble gas.

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Dunbarton, NH, United States of America

Bernhard Piwczyk