Memc Electronic Materials, Inc.

Corner Star Limited

Sunedison, Inc.

Joseph C Holzer

Paolo Mutti

Bayard K Johnson

Steve A Markgraf

Seamus A McQuaid

Robert J Falster

Robert A Falster

Harold W Korb

Massimiliano Olmo

Daniela Gambaro

Marco Cornara

Lu Fei

Steven Lawrence Kimbel

Jeffrey Louis Libbert

Tirumani N Swaminathan

Hariprasad Sreedharamurthy

Zheng Lu

Salvador Zepeda

Luciano Mule'Stagno

Milind S Kulkarni

Jihong John Chen

Richard G Schrenker

Robert H Fuerhoff

Kyong-Min Kim

Sadasivam Chandrasekhar

Larry E Drafall

Roger W Shaw

Luciano Mule&prime;Stagno

Klaus Drescher

Steve J Ferguson

Benjamin M Meyer

Robert Falster

An apparatus for doping a melt of semiconductor or solar-grade material is provided. The apparatus includes a seed chuck, a seed crystal connected to the seed chuck, and a dopant container connected to the seed chuck. The seed chuck defines a first end of the apparatus, and the seed crystal defines a second end of the apparatus. The seed crystal is configured to initiate crystal growth when placed in contact with the melt. The dopant container is positioned between the first end and the second end of the apparatus, and defines a reservoir for holding dopant therein. The dopant container is configured to dispense liquid dopant into the melt when positioned proximate the melt. The dopant container and the seed crystal are connected to the seed chuck simultaneously.

Apparatus and method for doping a semiconductor melt comprising a seed chuck, a seed crystal connected to the seed chuck, and a dopant container connected to the seed chuck between a first and second end of the apparatus

A system for growing silicon crystals that facilitates controlling a shape of a melt-solid interface is described. The crystal growing system includes a heated crucible including a semiconductor melt from which a monocrystalline ingot is grown according to a Czochralski process. The ingot is grown on a seed crystal pulled from the melt. The method includes applying an unbalanced cusped magnetic field to the melt, and rotating the ingot and the crucible in the same direction while the ingot is being pulled from the melt.

Controlling a melt-solid interface shape of a growing silicon crystal using an unbalanced magnetic field and iso-rotation

A method of continuously measuring an elevation and shape of an unmelted polycrystalline silicon island during a silicon meltdown process. The method comprises projecting a focused bright light on the silicon island to produce a bright dot on the silicon island. The method also includes electronically determining an elevation and a shape of the silicon island by tracking the bright dot during the meltdown process.

Method and device for continuously measuring silicon island elevation

The present invention is directed to a process for producing a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process either comprises exposing the wafer's front and back surfaces to different atmospheres, or thermally annealing two wafers in a face-to-face arrangement.

Process for forming low defect density, ideal oxygen precipitating silicon

The present invention is directed to a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects.

Low defect density, ideal oxygen precipitating silicon

Epitaxial wafers comprising a single crystal silicon substrate comprising agglomerated vacancy defects and having an axially symmetric region in which silicon self-interstitials are the predominant intrinsic point defect and which is substantially free of agglomerated defects, and an epitaxial layer which is deposited upon a surface of the substrate and which is substantially free of grown-in defects caused by the presence of agglomerated intrinsic point defects on the substrate surface upon which the epitaxial layer is deposited.

Single crystal silicon wafer having an epitaxial layer substantially free from grown-in defects

The present invention is directed to a process for producing a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process including growing a single crystal silicon ingot from molten silicon, and as part of the growth process, controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325&#xb0; C., and (iii) a cooling rate of the crystal from a solidification temperature to about 1,050&#xb0; C., in order to cause the formation of an axially symmetrical segment which is substantially free of agglomerated intrinsic point defects. A silicon wafer is then sliced from the ingot, subjected to a heat-treatment to form crystal lattice vacancies in the front surface and bulk layers of the wafer and cooled at a rate sufficient to cause a non-uniform vacancy concentration profile in the wafer such that a thermal treatment at a temperature in excess of 750&#xb0; C., is capable of forming in the wafer a denuded zone in the front surface layer and oxygen clusters or precipitates in the bulk zone with the concentration of the oxygen clusters or precipitates in the bulk layer being primarily dependant upon the concentration of vacancies.

Process for producing low defect density, ideal oxygen precipitating silicon

The present invention relates to a process for growing a single crystal silicon. The process including controlling a growth velocity, v, and an average axial temperature gradient, G, during the growth of the constant diameter portion of the crystal over the temperature range from solidification to a temperature of no less than about 1325&#xb0; C., to cause the formation of a first axially symmetrical region in which vacancies, upon cooling of the ingot from the solidification temperature, are the predominant intrinsic point defect and which is substantially free of agglomerated intrinsic point defects, wherein the first axially symmetric region has a width of at least about 50% of the radius of the constant diameter portion of the ingot.

Vacancy, dominsated, defect-free silicon

A process for heat treating a silicon wafer to dissolve B-type agglomerated interstitial defects present therein. The process includes heating the silicon wafer at a temperature for a time sufficient to dissolve B-defects, the wafer being heated to said temperature at a rate sufficient to prevent B-defects from becoming stabilized such that these defects are rendered incapable of being dissolved.

Method for producing czochralski silicon free of agglomerated self-interstitial defects

The present invention relates to an epitaxial wafer comprising single crystal silicon substrate and an epitaxial layer deposited thereon. The substrate comprises an axially symmetric region which is free of agglomerated intrinsic point defects and wherein silicon self-interstitials are the predominant intrinsic point defect in the axially symmetric region. The present invention further relates to a process for producing such an epitaxial wafer.

Low defect density epitaxial wafer and a process for the preparation thereof

The present invention relates to a single crystal silicon, in wafer and ingot form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects. The region extends from a circumferential edge of the wafer or constant diameter region of an ingot, axially inwardly toward a central axis such that the entire wafer, a constant diameter portion of the ingot, or an annular-shaped portion of wafer or ingot is free of agglomerated intrinsic point defects. The present invention further relates to these axially symmetric regions wherein silicon self-interstitials are the predominant intrinsic point detect.

Low defect density regions of self-interstitial dominated silicon

The present invention is directed to an epitaxial wafer comprising a single crystal silicon substrate having an axially symmetric region in which silicon self-interstitials are the predominant intrinsic point defect and which is substantially free of agglomerated defects, and an epitaxial layer which is deposited upon a surface of the substrate and which is substantially free of grown-in defects caused by the presence of agglomerated silicon self-interstitial defects on the substrate surface upon which the epitaxial layer is deposited.

Epitaxial wafer substantially free of grown-in defects

The present invention is directed to a process for producing a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process including growing a single crystal silicon ingot from molten silicon, and as part of the growth process, controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G , during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325&deg; C., and (iii) a cooling rate of the crystal from a solidification temperature to about 1,050&deg; C., in order to cause the formation of an axially symmetrical segment which is substantially free of agglomerated intrinsic point defects. A silicon wafer is then sliced from the ingot, subjected to a heat-treatment to form crystal lattice vacancies in the front surface and bulk layers of the wafer and cooled at a rate sufficient to cause a non-uniform vacancy concentration profile in the wafer such that a thermal treatment at a temperature in excess of 750&deg; C., is capable of forming in the wafer a denuded zone in the front surface layer and oxygen clusters or precipitates in the bulk zone with the concentration of the oxygen clusters or precipitates in the bulk layer being primarily dependant upon the concentration of vacancies.

The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects, and a process for the preparation thereof. The process including controlling growth conditions, such as growth velocity, v, instantaneous axial temperature gradient, G , and the cooling rate, within a range of temperatures at which silicon self-interstitials are mobile, in order to prevent the formation of these agglomerated defects. The control of G is accomplished by controlling heat transfer at the melt/solid interface.

Low defect density silicon and a process for producing low defect density silicon wherein V/G0 is controlled by controlling heat transfer at the melt/solid interface

The present invention relates a process for the preparation of single crystal silicon, which contains an axially symmetric region which is free of agglomerated intrinsic point defects. The process for growing the single crystal silicon including controlling the ratio v/G , where v is the growth velocity and G is the average axial temperature gradient during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325&deg; C., and a cooling rate of the crystal from a solidification temperature to about 1,050&deg; C., in order to cause the formation of an axially symmetrical segment which is substantially free of agglomerated intrinsic point defects. The control of V/G accomplished by controlling heat transfer at the melt/solid interface.

Growing community of inventors

St. Charles, MO, United States of America

Joseph C Holzer