US3884642A — Radiantly heated crystal growing furnace

Claim 1

Independent Claim 215 words

IN A FURNACE FOR PROCESSING SEMICONDUCTOR MATERIALS: A. MEANS DEFINING AN AXIALLY EXTENDING CHAMBER HAVING A WALL FABRICATED OF A MATERIAL WHICH IS TRANSPARENT TO HEAT ENERGY OF A PREDETERMINED WAVELENGTH; B. BOAT MEANS DISPOSED WITHIN THE CHAMBER FOR HOLDING A SEMICONDUTOR MATERIAL; C. TRAVELING HEAT SOURCE MEANS COMPRISING A GENERALLY ANNULAR HEATING ELEMENT HOLDER MOVABLE AXIALLY OF THE CHCHAMBER AND HAVING A PLURALITY OF INWARDLY FACING AXIALLY EXTENDING RECESSES, A PLURALITY OF AXIALLY EXTENDING RADIANT HEATING ELEMENTS MOUNTED IN THE RECESSES AND ELEMENTS SPACED ABOUT THE INNER PERIPHERY OF THE HEATING ELEMENT HOLDER FOR DELIVERING RADIANT HEAT ENERGY OF THE PREDETERMINED WAVELENGTH TO AN AXIALLY LIMITED PORTION OF THE MATERIAL HELD BY THE BOAT MEANS TO MELT THE SAME, THE WALLS OF SAID RECESSES SERVING TO REFLECT HEAT ENERGY TO WARD THE MATERIAL IN THE BOAT, AND AIR PASSAGEWAYS COMMUNICATING WITH THE RECESS IN THE HEATING ELEMENT HOLDER FOR DIRECTING AIR TO THE LAMPS ND CHAMBER WALL TO COOL THE SAME; MEANS FOR MOVING THE TRAVELING HEAT SOURCE MEANS AXIALLY OF THE CHAMBER; ANF E. THE RELATIVE AMOUNTS OF HEAT DELIVERED BY THEHEATING ELEMENTS BEING ADUSTABLE WHEREBY THE DISTRIBUTION OF HEAT PERIPHERALLY OFTHE CHAMBER CAN BE SET TO PROVIDE DESIRED MOLTEN ZONE AND FREEZING FRONT CONTOURS IN THE MATERIAL HELD BY THE BOAT MEANS.

Claim 2

Dependent Claim 215 words

IN A FURNACE FOR PROCESSING SEMICONDUCTOR MATERIALS: A. MEANS DEFINING AN AXIALLY EXTENDING CHAMBER HAVING A WALL FABRICATED OF A MATERIAL WHICH IS TRANSPARENT TO HEAT ENERGY OF A PREDETERMINED WAVELENGTH; B. BOAT MEANS DISPOSED WITHIN THE CHAMBER FOR HOLDING A SEMICONDUTOR MATERIAL; C. TRAVELING HEAT SOURCE MEANS COMPRISING A GENERALLY ANNULAR HEATING ELEMENT HOLDER MOVABLE AXIALLY OF THE CHCHAMBER AND HAVING A PLURALITY OF INWARDLY FACING AXIALLY EXTENDING RECESSES, A PLURALITY OF AXIALLY EXTENDING RADIANT HEATING ELEMENTS MOUNTED IN THE RECESSES AND ELEMENTS SPACED ABOUT THE INNER PERIPHERY OF THE HEATING ELEMENT HOLDER FOR DELIVERING RADIANT HEAT ENERGY OF THE PREDETERMINED WAVELENGTH TO AN AXIALLY LIMITED PORTION OF THE MATERIAL HELD BY THE BOAT MEANS TO MELT THE SAME, THE WALLS OF SAID RECESSES SERVING TO REFLECT HEAT ENERGY TO WARD THE MATERIAL IN THE BOAT, AND AIR PASSAGEWAYS COMMUNICATING WITH THE RECESS IN THE HEATING ELEMENT HOLDER FOR DIRECTING AIR TO THE LAMPS ND CHAMBER WALL TO COOL THE SAME; MEANS FOR MOVING THE TRAVELING HEAT SOURCE MEANS AXIALLY OF THE CHAMBER; ANF E. THE RELATIVE AMOUNTS OF HEAT DELIVERED BY THEHEATING ELEMENTS BEING ADUSTABLE WHEREBY THE DISTRIBUTION OF HEAT PERIPHERALLY OFTHE CHAMBER CAN BE SET TO PROVIDE DESIRED MOLTEN ZONE AND FREEZING FRONT CONTOURS IN THE MATERIAL HELD BY THE BOAT MEANS.

Claim 3

Dependent Claim 15 words

The furance of claim 1 in which the radiant heating elements are high intensity lamps.

Claim 4

Dependent Claim 75 words

a plurality of axially extending high intensity lamps mounted in the axially extending recesses and spaced peripherally about the tube; E. means for moving the traveling heater means axially along said chamber; and F. control means for adjusting the relative amounts of heat energy produced by the lamps whereby the distribution of heat peripherally of the tube can be ajdusted to provide desired molten zone and freezing front contrours in the material in the boat.

Claim 5

Dependent Claim 75 words

a plurality of axially extending high intensity lamps mounted in the axially extending recesses and spaced peripherally about the tube; E. means for moving the traveling heater means axially along said chamber; and F. control means for adjusting the relative amounts of heat energy produced by the lamps whereby the distribution of heat peripherally of the tube can be ajdusted to provide desired molten zone and freezing front contrours in the material in the boat.

Claim 6

Dependent Claim 160 words

In a furnace for preparing a semiconductor compound having at least one metallic constituent and at least one volatile constituent: A. a substantially horizontal elongated tube defining an axially extending chamber; B. a boat disposed within the chamber for holding the compound and/or its constituents; c. a fixed heating coil disposed coaxially of the chamber and outside the tube for heating materials with the chamber; D. heater means disposed coaxially of the chamber and outside the tube for delivering radiant heat energy of a predetermined wavelength to a portion of the material in the boat to melt the same, said traveling heater means including ''1. a lamp holder movable axially of the chamber, said lamp holder comprising an annular body having a plurality of radially spaced inwardly facing axially extending recesses formed therein, the walls of said recesses serving to reflect heat energy toward the material in the boat, and air passageways in the body communicating with the recesses, and

Claim 7

Dependent Claim 160 words

In a furnace for preparing a semiconductor compound having at least one metallic constituent and at least one volatile constituent: A. a substantially horizontal elongated tube defining an axially extending chamber; B. a boat disposed within the chamber for holding the compound and/or its constituents; c. a fixed heating coil disposed coaxially of the chamber and outside the tube for heating materials with the chamber; D. heater means disposed coaxially of the chamber and outside the tube for delivering radiant heat energy of a predetermined wavelength to a portion of the material in the boat to melt the same, said traveling heater means including ''1. a lamp holder movable axially of the chamber, said lamp holder comprising an annular body having a plurality of radially spaced inwardly facing axially extending recesses formed therein, the walls of said recesses serving to reflect heat energy toward the material in the boat, and air passageways in the body communicating with the recesses, and

Claim 8

Dependent Claim 79 words

The furnace of claim 3 in which the lamp holder comprises an annular body having A. a plurality of inwardly facing axially extending recesses in which the lamps are mounted, the walls of said recesses serving to reflect heat energy toward the material in the boat, B. air passageways in the body communicating with the recesses, and C. a window formed in the body to permit the melted portion of the material to be viewed externally of the chamber.

Claim 9

Dependent Claim 24 words

The furnace of claim 3 in which one end of the tube is closed by a removable closure anD sealed by a reusable seal.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-05-19	1978-11-18	1979-05-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-05-19	1982-11-18	1983-05-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-05-19	1986-11-18	1987-05-20	$7700.00	Window Closed / Lapsed

Radiantly heated crystal growing furnace

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