Kathryn M Fisher

US Patent:

8440494, May 14, 2013

Filed:

May 20, 2011

Appl. No.:

13/112465

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Jun Liu - Irvington NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US
George G. Totir - Newtown CT, US
James Vichiconti - Peekskill NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 21/00

US Classification:

438 71, 438745, 257E21214

Abstract:

Alternative additives that can be used in place of isopropyl alcohol in aqueous alkaline etchant solutions for texturing a surface of a single-crystalline silicon substrate are provided. The alternative additives do not have volatile constituents, yet can be used in an aqueous alkaline etchant solution to provide a pyramidal shaped texture surface to the single-crystalline silicon substrate that is exposed to such an etchant solution. Also provided is a method of forming a textured silicon surface. The method includes immersing a single-crystalline silicon substrate into an etchant solution to form a pyramid shaped textured surface on the single-crystalline silicon substrate. The etchant solution includes an alkaline component, silicon (etched into the solution as a bath conditioner) and glycerol or ethylene glycol as an additive. The textured surface of the single-crystalline silicon substrate has (111) faces that are now exposed.

US Patent:

20110303274, Dec 15, 2011

Filed:

Jun 10, 2010

Appl. No.:

12/813087

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Nicholas C. M. Fuller - North Hills NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US
Xiaoyan Shao - Yorktown Heights NY, US
Jeffrey Hedrick - Montvale NJ, US

Assignee:

INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY

International Classification:

H01L 31/0236
H01L 31/18

US Classification:

136256, 438 98, 257E3113, 257E31124

Abstract:

The present disclosure provides a method of forming a back side surface field of a solar cell without utilizing screen printing. The method includes first forming a p-type dopant layer directly on the back side surface of the semiconductor substrate that includes a p/n junction utilizing an electrodeposition method. The p/n junction is defined as the interface that is formed between an n-type semiconductor portion of the substrate and an underlying p-type semiconductor portion of the substrate. The plated structure is then annealed to from a P++ back side surface field layer directly on the back side surface of the semiconductor substrate. Optionally, a metallic film can be electrodeposited on an exposed surface of the P++ back side surface layer.

US Patent:

20120305066, Dec 6, 2012

Filed:

Jun 6, 2011

Appl. No.:

13/154058

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Qiang Huang - Sleepy Hollow NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US

Assignee:

INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY

International Classification:

H01L 31/0224
H01L 31/18

US Classification:

136256, 438 72, 257E3112

Abstract:

A photovoltaic device, such as a solar cell, including a copper-containing-grid metallization structure that contains a metal phosphorus layer as a diffusion barrier is provided. The copper-containing-grid metallization structure includes, from bottom to top, an electroplated metal phosphorus layer that does not include copper or a copper alloy located within a grid pattern formed on a front side surface of a semiconductor substrate, and an electroplated copper-containing layer. A method of forming such a structure is also provided.

US Patent:

20120318341, Dec 20, 2012

Filed:

Jun 14, 2011

Appl. No.:

13/159897

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Qiang Huang - Sleepy Hollow NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US
David L. Rath - Stormville NY, US

Assignee:

INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY

International Classification:

H01L 31/0216
H01L 31/18

US Classification:

136256, 438 29, 257E31119

Abstract:

Processes for fabricating photovoltaic devices in which the front side contact metal semiconductor alloy metallization patterns have a uniform thickness at edge portions as well as a central portion of each metallization pattern are provided. In one embodiment, a method of forming a photovoltaic device is provided that includes a p-n junction with a p-type semiconductor portion and an n-type semiconductor portion one on top of the other, wherein an upper exposed surface of one of the semiconductor portions represents a front side surface of the semiconductor substrate; forming a plurality of patterned antireflective coating layers on the front side surface of the semiconductor surface to provide a grid pattern including a busbar region and finger regions; forming a mask atop the plurality of patterned antireflective coating layers, the mask having a shape that mimics each patterned antireflective coating; electrodepositing a metal layer on the busbar region and the finger regions; removing the mask; and performing an anneal, wherein during the anneal metal atoms from the metal layer react with semiconductor atoms from the busbar region and the finger regions forming a metal semiconductor alloy.

US Patent:

20120325312, Dec 27, 2012

Filed:

Sep 6, 2012

Appl. No.:

13/605768

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Nicholas C. M. Fuller - North Hills NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US
Xiaoyan Shao - Yorktown Heights NY, US
Jeffrey Hedrick - Montvale NJ, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 31/0224
H01L 31/0264
H01L 31/0236

US Classification:

136256, 136252, 136262

Abstract:

The present disclosure provides a method of forming a back side surface field of a solar cell without utilizing screen printing. The method includes first forming a p-type dopant layer directly on the back side surface of the semiconductor substrate that includes a p/n junction utilizing an electrodeposition method. The p/n junction is defined as the interface that is formed between an n-type semiconductor portion of the substrate and an underlying p-type semiconductor portion of the substrate. The plated structure is then annealed to from a P++ back side surface field layer directly on the back side surface of the semiconductor substrate. Optionally, a metallic film can be electrodeposited on an exposed surface of the P++ back side surface layer.

US Patent:

20130014812, Jan 17, 2013

Filed:

Jul 14, 2011

Appl. No.:

13/182880

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Qiang Huang - Sleepy Hollow NY, US
Satyavolu S. Papa Rao - Poughkeepsie NY, US
Ming-Ling Yeh - Baltimore MD, US

Assignee:

INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY

International Classification:

H01L 31/06
H01L 31/18

US Classification:

136255, 438 72, 257E31119

Abstract:

A photovoltaic device is provided that includes a semiconductor substrate including a p-n junction with a p-type semiconductor portion and an n-type semiconductor portion one on top of the other. A plurality of patterned antireflective coating layers is located on a p-type semiconductor surface of the semiconductor substrate, wherein at least one portion of the p-type semiconductor surface of the semiconductor substrate is exposed. Aluminum is located directly on the at least one portion of the p-type semiconductor surface of the semiconductor substrate that is exposed.

US Patent:

20140000693, Jan 2, 2014

Filed:

Feb 28, 2013

Appl. No.:

13/780887

Inventors:

Kathryn C. Fisher - Brooklyn NY, US
Harold J. Hovel - Katonah NY, US
Qiang Huang - Croton on Hudson NY, US
Young-hee Kim - Mohegan Lake NY, US
Susan Huang - Mount Kisco NY, US

Assignee:

INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY

International Classification:

H01L 31/0216

US Classification:

136256

Abstract:

A stack of a first anti-reflective coating (ARC) layer and a titanium layer is formed on a front surface of a semiconductor substrate including a p-n junction, and is subsequently patterned so that a semiconductor surface is physically exposed in metal contact regions of the front surface of the semiconductor substrate. The remaining portion of the titanium layer is converted into a titania layer by oxidation. A metal layer is plated on the metal contact regions, and a copper line is subsequently plated on the metal layer or a metal semiconductor alloy derived from the metal layer. A second ARC layer is deposited over the titania layer and the copper line, and is subsequently patterned to provide electrical contact to the copper line.