Wafer boat

Claim 2

A carrier frame for supporting a series of rows of silicon crystal wafers comprising a rectangular glass plate (30), a large number of regularly spaced longitudinal glass rods (25) mounted in uniformly spaced parallel relation on said plate to provide a multiplicity of narrow Wafer-receiving slots (29), each having a height at least several times its width and a series of lateral spacer rods (31, 32) welded to said longitudinal rods and spaced apart a distance which is at least 20 times the width of said slots, said longitudinal rods having flattened vertical side faces (27) forming the sides of said slots.

Claim 3

A carrier frame as defined in claim 1 wherein said longitudinal rods (25) are welded to each other along longitudinal weld lines (16) which are spaced apart a distance which is at least 20 times the width of said slots.

Claim 4

A carrier frame as defined in claim 1 wherein said longitudinal rods (25) have a height of about 0.05 to about 0.2 inch and a length of about one-third foot to about 3 feet and are spaced apart to provide wafer-receiving slots (29) with a width of about 0.005 to about 0.03 inch.

Claim 5

A carrier frame as defined in claim 3 wherein said lateral rods (32) are spaced apart a distance of about 0.5 inch to about 1.5 inch.

Claim 6

A carrier frame as defined in claim 1 wherein the end portions of said lateral spacer rods (31, 32) are rigidly connected by welds (33, 34) to the glass plate (30).

Claim 7

A carrier frame as defined in claim 1 wherein said glass rods (25) have a cross-sectional width of about 0.03 inch to about 0.1 inch.

Claim 8

A carrier frame as defined in claim 1 wherein said glass rods (25) are formed of quartz glass and have a cross-sectional height of about 0.04 inch to about 0.2 inch.

Claim 9

A process of forming a carrier frame for a series of rows of silicon crystal wafers comprising clamping at least 10 straight glass rods of vertically elongated cross section having flattened side faces in a row with said side faces in engagement with vertical shim strips having a uniform thickness corresponding to the thickness of the silicon crystal wafers, welding said rods in fixed parallel positions while they are so clamped, and thereafter removing said shim strips.

Claim 10

A process of forming a carrier frame for a series of rows of silicon crystal wafers comprising clamping at least 10 straight glass rods of vertically elongated cross section having flattened side faces in a row with said side faces in engagement with vertical shim strips having a uniform thickness corresponding to the thickness of the silicon crystal wafers, welding said rods in fixed parallel positions while they are so clamped, and thereafter removing said shim strips.

Claim 11

A process as defined in claim 8 wherein said glass rods are welded together substantially along transverse weld lines to provide welds bridging the spaces between the rods.

Claim 12

A process as defined in claim 8 wherein said glass rods are welded in place on a silica glass frame member to provide welds extending between said rods and said frame member.

Claim 13

A process as defined in claim 10 wherein transverse silica glass rods are placed on the upper surfaces of said first-named glass rods, and the end portions of said transverse rods are welded to said frame member to provide said last-named welds.

Claim 14

A process as defined in claim 8 wherein said shim strips are placed in rows corresponding in number to the number of rows of wafers to be supported and clamping pressure is applied to the glass rods independently at each of said rows while the rods are welded in place.

Claim 15

A process as defined in claim 8 wherein said glass rods (25) are formed by grinding the opposite side faces of drawn quartz glass rods having a diameter of about 0.3 inch to about 1 inch and thereafter heating and redrawing said rods to a width of about 0.05 to about 0.2 inch.

Claim 16

A process as defined in claim 8 & 5 wherein said glass rods (25) are formed by cutting strips of rectangular cross section from a piece of quartz glass, said strips having a width of about 0.3 to about 1 inch and a thickness of about 0.1 to about 0.5 inch, and thereafter heating and drawing said strips.

Claim 17

A carrier frame as defined in claim 1 wherein said lateral spacer rods are mounted on at least 10 of said glass rods having a length of at least 4 inches and are arranged to engage and support 5 to 20 lateral rows of said wafers.

Claim 18

A rigid carrier frame (B) for supporting at least five closely spaced lateral rows of silicon crystal wafers (w) comprising at least 10 closely spaced longitudinal glass rods (25) mounted in closely spaced parallel relation in a row to provide a multiplicity of narrow slots (29) for receiving the wafers (w) and holding them in upright positions, each slot having a height at least several times its width, and a series of wafer-engaging lateral spacer rods (31,32) rigidly mounted above said longitudinal rods and spaced apart a distance which is at least 20 times the width of said slots, each of said longitudinal rods (25) having a length of at least 4 inches and having an opposed pair of smooth flattened wafer-engaging side faces (27) forming the sides of the wafer-receiving slots (20) at the opposite sides of such rod.

Claim 19

A rigid carrier frame (B) for supporting at least five closely spaced lateral rows of silicon crystal wafers (w) comprising at least 10 closely spaced longitudinal glass rods (25) mounted in closely spaced parallel relation in a row to provide a multiplicity of narrow slots (29) for receiving the wafers (w) and holding them in upright positions, each slot having a height at least several times its width, and a series of wafer-engaging lateral spacer rods (31,32) rigidly mounted above said longitudinal rods and spaced apart a distance which is at least 20 times the width of said slots, each of said longitudinal rods (25) having a length of at least 4 inches and having an opposed pair of smooth flattened wafer-engaging side faces (27) forming the sides of the wafer-receiving slots (20) at the opposite sides of such rod.

Claim 20

A silica-glass carrier frame for supporting at least five closely spaced lateral rows of silicon crystal wafers comprising at least 10 closely spaced longitudinal glass rods mounted in closely spaced parallel relation in a row to provide a multiplicity of narrow slots for receiving the wafers and holding them in upright parallel positions, each slot having a height at least several times its width, and a series of lateral silica-glass spacer means welded to said longitudinal rods and providing a rigid connection from each longitudinal rod to the next adjacent rod, said lateral spacer means being spaced apart a distance which is at least 20 times the width of said slots, each of said longitudinal rods having a length of at least 4 inches and having an opposed pair of flattened wafer-engaging side faces forming the sides of the wafer-receiving slots at the opposite sides of such rod, and means carried above said spacer means for engaging the wafers in each of said lateral rows to hold them in lateral alignment in each row.

Claim 21

A silica-glass carrier frame for supporting at least five closely spaced lateral rows of silicon crystal wafers comprising at least 10 closely spaced longitudinal glass rods mounted in closely spaced parallel relation in a row to provide a multiplicity of narrow slots for receiving the wafers and holding them in upright parallel positions, each slot having a height at least several times its width, and a series of lateral silica-glass spacer means welded to said longitudinal rods and providing a rigid connection from each longitudinal rod to the next adjacent rod, said lateral spacer means being spaced apart a distance which is at least 20 times the width of said slots, each of said longitudinal rods having a length of at least 4 inches and having an opposed pair of flattened wafer-engaging side faces forming the sides of the wafer-receiving slots at the opposite sides of such rod, and means carried above said spacer means for engaging the wafers in each of said lateral rows to hold them in lateral alignment in each row.

Claim 22

A silica-glass wafer carrier frame as defined in claim 17 wherein said last-named means comprises lateral silica glass rods welded to said frame.

Claim 23

A process of forming a silica-glass carrier frame (B) for at least eight closely spaced lateral rows of silicon crystal wafers (w) comprising holding 10 to 25 straight silica-glass rods (25) of vertically elongated cross section having flattened side faces (27) and a length of at least 4 inches in fixed regularly spaced positions in a single row (50) with said side faces spaced apart a fixed distance of about 0.005 inch to about 0.03 inch corresponding to the thickness of the silicon crystal wafers (w), welding said rods (25) together along at least nine transverse weld lines (15) while they are held in such fixed positions to provide welds (16) bridging the spaces (29) between the rods, said weld lines being regularly spaced and spaced apart a distance which is at least 20 times said fixed distance between the rods, said rods being formed from silica-glass rods of elongated cross section having rough opposed flattened side faces with a width of about 0.3 inch to about 1 inch by heating and drawing said rods to reduce the cross-sectional size while maintaining the same relative cross-sectional shape and to provide the resulting drawn rods (25) with straight smooth flattened side faces (27) having a width of about 0.05 inch to about 0.2 inch.

Claim 24

A process of forming a silica-glass carrier frame (B) for at least eight closely spaced lateral rows of silicon crystal wafers (w) comprising holding 10 to 25 straight silica-glass rods (25) of vertically elongated cross section having flattened side faces (27) and a length of at least 4 inches in fixed regularly spaced positions in a single row (50) with said side faces spaced apart a fixed distance of about 0.005 inch to about 0.03 inch corresponding to the thickness of the silicon crystal wafers (w), welding said rods (25) together along at least nine transverse weld lines (15) while they are held in such fixed positions to provide welds (16) bridging the spaces (29) between the rods, said weld lines being regularly spaced and spaced apart a distance which is at least 20 times said fixed distance between the rods, said rods being formed from silica-glass rods of elongated cross section having rough opposed flattened side faces with a width of about 0.3 inch to about 1 inch by heating and drawing said rods to reduce the cross-sectional size while maintaining the same relative cross-sectional shape and to provide the resulting drawn rods (25) with straight smooth flattened side faces (27) having a width of about 0.05 inch to about 0.2 inch.