Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/04—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools
  • B28D5/045—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools by cutting with wires or closed-loop blades
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D57/00—Sawing machines or sawing devices not covered by one of the preceding groups B23D45/00 - B23D55/00
  • B23D57/0007—Sawing machines or sawing devices not covered by one of the preceding groups B23D45/00 - B23D55/00 using saw wires
  • B23D57/0023—Sawing machines or sawing devices not covered by one of the preceding groups B23D45/00 - B23D55/00 using saw wires with a plurality of saw wires or saw wires having plural cutting zones
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D57/00—Sawing machines or sawing devices not covered by one of the preceding groups B23D45/00 - B23D55/00
  • B23D57/003—Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts
  • B23D57/0038—Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts of frames; of tables
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D57/00—Sawing machines or sawing devices not covered by one of the preceding groups B23D45/00 - B23D55/00
  • B23D57/003—Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts
  • B23D57/0053—Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts of drives for saw wires; of wheel mountings; of wheels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
  • B28D5/0064—Devices for the automatic drive or the program control of the machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
  • B28D5/007—Use, recovery or regeneration of abrasive mediums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
  • B28D5/0076—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material for removing dust, e.g. by spraying liquids; for lubricating, cooling or cleaning tool or work
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T83/00—Cutting
  • Y10T83/04—Processes
  • Y10T83/0448—With subsequent handling [i.e., of product]

Definitions

• the invention relates to a wire saw device and a method for operating such a wire saw device. More particularly, the invention relates to a wire saw device for cutting silicon wafers from silicon ingots.
• wire saw devices for cutting thin slices, e.g. semiconductor wafers, from a piece to be sawed, e.g. an ingot or block of semiconductor material.
• a stretched wire is both guided and tensioned by wire guide cylinders.
• These wire guide cylinders are generally covered with a layer of synthetic resin and are scored with grooves having very precise geometry and size.
• the wire is spirally wound about the wire guide cylinders and forms between two wire guide cylinders at least one layer of parallel wires, also called a web or wire web. In the web, the distance between two consecutive wires fixes the thickness of the slices. During the sawing process, the wire is moved with considerable speed.
• a wire saw device for sawing semiconductor material.
• the wire saw device includes a wire guide device comprising at least four wire guide cylinders and being adapted to guide wires for forming at least one wire web for sawing the semiconductor material and forming a first and a second working area; and two or more wire management units for providing each a wire to the wire guide device, wherein each of the wire guide cylinders has a plurality of grooves wherein adjacent grooves have a distance of 400 ⁇ m or below.
• a wire saw device for sawing semiconductor material.
• the wire saw device includes a wire guide device adapted to guide a wire for forming at least one wire web for sawing the semiconductor material, and at least one wire management unit, typically two or more wire management units, for providing a wire to the wire guide device, wherein the wire guide device and the wire management unit or wire management units are adapted to provide the at least one wire web such that an effective cutting area rate of 12 nrVh or more is provided.
• a method for in-situ cleaning of semiconductor wafers includes attaching a semiconductor material block to a beam having at least one conduit for feeding cleaning fluid, sawing, with a wire saw device, the semiconductor material block to obtain a plurality of semiconductor wafers and further sawing the beam such that fluid communication between the at least one conduit and a space between the semiconductor wafers is established, and supplying cleaning fluid to the at least one conduit to clean the semiconductor wafers.
• a method for demounting semiconductor wafers from a beam after sawing is provided.
• the method includes sawing, with a wire saw device, the semiconductor material block in a direction of a predefined slicing plane to obtain a plurality of semiconductor wafers, sawing a beam to which said semiconductor wafers are attached in the direction of the predefined slicing plane, and sawing the beam in a direction substantially perpendicular of the predefined slicing plane.
• a method for in-situ treatment of semiconductor wafers includes attaching a semiconductor material block to a beam; sawing, with a wire saw device, the semiconductor material block to obtain a plurality of semiconductor wafers, wherein the sawing is conducted in an enclosure supplying cleaning fluid to clean the semiconductor wafers within the enclosure; and collecting the cleaning fluid in a wafer box.
• Embodiments are also directed at apparatuses for carrying out the disclosed methods and including apparatus parts for performing each described method step. These method steps may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the invention are also directed at methods by which the described apparatus operates. It includes method steps for carrying out every function of the apparatus.
• FIG. 1 shows a schematic front view of a wire saw device according to an embodiment.
• Fig. 2 shows a schematic top view of a wire saw device according to an embodiment.
• Fig. 2 A shows a schematic view of a wire guiding cylinder having a plurality of grooves.
• FIG. 3 shows a schematic front view of a wire saw device according to another embodiment.
• Fig. 4A shows a schematic top view of a wire saw device according to the embodiment shown in Fig. 3.
• Fig. 4B shows a schematic side view of a wire saw device according to the embodiment shown in Fig. 4A.
• FIG. 5 A shows a schematic top view of a wire saw device according to a further embodiment.
• Fig. 5B shows a schematic side view of a wire saw device according to the embodiment shown in Fig. 5A.
• Fig. 6 shows a schematic side view of a wire guide cylinder according to an embodiment.
• Fig. 7 shows a schematic front view of a wire saw device according to a further embodiment.
• Fig. 8 shows a nozzle arrangement according to an embodiment.
• FIG. 9 shows a schematic perspective view of a modular cutting head according to an embodiment.
• Figs. 1OA and 1OB show embodiments of a wire breakage detection unit.
• Fig. 11 shows embodiments of a wafer box and wafer baskets.
• Fig. 12 shows a schematic front view of a wire saw device according to an embodiment.
• Fig. 13 shows a detail of a beam according to an embodiment.
• Fig. 14 is a flow diagram of a cleaning method according to an embodiment.
• Fig. 15 is a flow diagram of a dismounting method according to an embodiment.
• a wire management unit will be understood as a device handling the supply of wire to a working area a wire saw device.
• the wire management unit includes a wire guide for transporting and guiding the wire in a wire moving direction while the wire management unit provides control of the wire tension.
• the wire provided by the wire management unit forms a wire web as described above.
• a wire web will be considered as the web formed by a single wire management unit. It should be understood that a wire web may contain more than one working areas which are defined as areas in which a sawing process is performed.
• Fig. 1 shows a schematic front view of a wire saw device 100 according to an embodiment.
• Wire saw device 100 has a wire guide device 110 including four wire guide cylinders 112, 114, 116, 118.
• a wire management unit 130 provides a wire to the wire guide cylinders 112, 114, 116, 118.
• the wire management unit 130 includes a supply coil 134 on which a wire reservoir, typically holding several hundred kilometers of wire, is provided. Fresh wire 230 is fed to wire guide device 110 from supply coil 134.
• wire management unit 130 includes a take-up spool 138 on which the used wire 240 is recoiled. In the embodiment shown in Fig.
• wire management unit 130 includes further devices such as low inertia pulleys (not shown) and tension arms (not shown) for wire tension regulation. In some embodiments, digital coders are provided on the tension arms.
• Fig. 2 shows a schematic top view of wire saw device 100.
• the wire is spirally wound about the wire guide cylinders 112, 114 and forms between the two wire guide cylinders a layer 200 of parallel wires.
• This layer is typically referred to as a wire web 200.
• wire guide cylinders 112, 114, 116, 118 are covered with a layer of synthetic resin and are scored with grooves having very precise geometry and size. The distance between the grooves, or the pitch of the grooves, determines the spacing Dl between two adjacent strings or lines of wire. This distance Dl also determines the maximum thickness of the slices cut by the wire saw device.
• the slices may be about 10 ⁇ m to 40 ⁇ m thinner than the distance Dl.
• the wire thickness is between 120 ⁇ m and 140 ⁇ m while distance Dl is from 120 ⁇ m to 300 ⁇ m, typically in the range of 200 ⁇ m to 250 ⁇ m.
• the grooves may have a pitch or distance of below 300 ⁇ m. Accordingly, the thickness of the wire is of the same order as the distance Dl.
• the pitch or distance of the groove results in spacing between adjacent wires of about from 120 ⁇ m to 200, typically of 160 ⁇ m or smaller.
• embodiments described herein may provide a very large cutting area and a very large cutting rate
• a wire guiding cylinder 112 has a plurality of grooves 112g being configured to guide a wire 20Oi forming a wire web.
• the pitch i.e. the distance of the grooves is denoted as P in Fig. 2A
• the distance or spacing between the wires which corresponds to the maximum wafer thickness is provided by the distance between adjacent wires, which is denoted as Dl.
• Dl the distance between adjacent wires
• the pitch i.e. the distance between grooves
• the distance between adjacent wires can be in a range of 120 ⁇ m to 300 ⁇ m, for example, 200 ⁇ m to 250 ⁇ m or even 220 ⁇ m or less
• the resulting wafer thickness can be in a range of 100 ⁇ m to 250 ⁇ m, for example, 180 ⁇ m to 220 ⁇ m or even 200 ⁇ m or below.
• the groove pitch and the groove geometry is typically adapted to a wire thickness and wire type and is adapted to the wafer thickness.
• a wire saw device having wire guiding cylinders with grooves is generally adapted for specific wafer thicknesses and wire diameters by the groove pitch and the groove geometry.
• the values for the groove pitch, the wire thicknesses and/or the wafer thicknesses can be insofar predetermined by the configuration of the wire saw device.
• each wire guide cylinder 112, 114, 116, 118 is connected to a motor 122, 124, 126, 128 (shown in broken lines in Fig. 1).
• wire guide cylinders 112, 114, 116, 118 are directly driven by motors 122, 124, 126, 128.
• each wire guide cylinder 112, 114 may be directly mounted to the motor shaft 123, 125 of the corresponding motor 122, 124. In some embodiments one or more of the motors are water-cooled.
• the motors 122, 124, 126, 128 drive the wire guide cylinders 112, 114, 116, 118 so that the wire guide cylinders rotate about their longitudinal axis.
• the wire in wire web 200 is transported into a wire transport direction 215, 225.
• the transport speed of the wire is relatively high for example as much as 20 m/s.
• one of the motors, e.g. motor 122, serves as a master motor whereas the remaining motors 124, 126, 128 serve as slave motors.
• master motor 122 controls the operation of slave motors 124, 126, 128 so that slave motors 124, 126, 128 follow master motor 112.
• master motor 122 controls the operation of slave motors 124, 126, 128 so that slave motors 124, 126, 128 follow master motor 112.
• two or more spools are provided for forming at least one wire web.
• two, three or even four spools can be used to provide the wire.
• a method of sawing thinner wafers e.g., in a range of 100 ⁇ m to 170 ⁇ m can be provided.
• the thinner wafers can also be sawed at higher speed, such as having a material feed rate is in the range of 2 ⁇ m/s to 12 ⁇ m/s, typically about 5 ⁇ m/s to 7 ⁇ m/s.
• the load on each wire can be reduced by having two or more spools and, thus, two or more wires.
• the load is increased as compared to a dual wire web due to the increase of the wafer surface are to wire surface area.
• the increased load can result in lower cutting speeds.
• using two or more wires can increase the cutting speed, e.g., such that an effective cutting area or a cutting area rate of 12 m 2 /h or more can be provided.
• thinner wires can be used, for example wires having a thickness of 80 ⁇ m to 120 ⁇ m, while the cutting area is increased.
• the wire thickness reduces during usage of the wire.
• the wire may be thinned until breakage of the wire results. Accordingly, the use of two wires to build a wire web, for example, a continuous wire web, on the one hand reduced the load on the wire and thereby allows for higher cutting speeds and, on the other hand, allows for thinner wires, which allows for smaller wire distance and thereby increased cutting area.
• some embodiments which can be combined with other embodiments described herein, can include a wire having a thickness of 120 ⁇ m or 100 ⁇ m or less, can include, for example, a diamond wire, and/or can have a grooves configured for wires of 120 ⁇ m or less.
• the wire saw device 100 includes four wire guide cylinders 112, 114, 116, 118 which guide the wire so that it forms web 200.
• the material to be sawed e.g. blocks 302, 304, 306, 308 of semiconductor material
• the material to be sawed e.g. blocks 302, 304, 306, 308 of semiconductor material
• the material to be sawed is attached to a holder.
• silicon ingots 302, 304, 306, 308 may be mounted to a support mechanism which is not shown in Fig. 1 but will be explained later.
• the blocks 302, 304, 306, 308 are lowered toward web 200.
• the wire is transported in wire moving direction 215, 225 at a considerable speed, e.g.
• the moving wire abrades the semiconductor material and, thus, saws blocks 302, 304, 306, 308 into thin slices having a maximum width Dl. Such slices may for example be used as wafers in semiconductor industry.
• the total length of wire in the wire web being in contact with the material to be sawed at a time may be referred to as the effective wire cutting length. In some embodiments, the effective wire cutting length is 700 m or above, particularly the effective wire cutting length may be more than 900 m.
• the speed with which the material to be sawed is lowered into the wire web may be referred to as the material feed rate, hi some embodiments, the material feed rate is in the range of 2 ⁇ m/s to 12 ⁇ m/s, typically about 5 ⁇ m/s to 7 ⁇ m/s.
• wire web 200 includes a first working area 210 and a second working area 220.
• the sawing process can be simultaneously carried out in both working areas 210, 220 so that capacity, i.e. the amount of semiconductor material, of the sawing device 100 is improved.
• each working area 210, 220 is sufficiently large such that two blocks 302, 304; 206, 308 of semiconductor material can be processed in each working area 210; 220.
• the working length of web 200 in a working area 210, 220 along the wire moving direction 215, 225 is between 500 mm to 600 mm.
• the wire guide device 110 and the at least one wire management unit 130 are adapted to provide a wire web 200 such that an effective cutting area or cutting rate of 12 m 2 /h or more is provided.
• the total cut surface sawed in one cut is about 160 m 2 .
• the number of wafers obtained within a single cut is 5,000 or more.
• the footprint of the machine is about 10 to 14 m 2 .
• wire saw devices according to embodiments described herein provide improved efficiency and higher throughput compared with conventional wire saw devices.
• Fig. 3 shows a schematic front view of a wire saw device 102 according to another embodiment.
• Wire saw device 102 includes a further wire management unit 140 which is similar to wire management unit 130 described above.
• Second wire management unit 140 includes a wire supply coil 144 and a take-up spool 148.
• Wire supply coil 144 provides fresh wire 238 and take-up spool 148 recoils used wire 248.
• first management unit 130 provides a first wire for forming a first wire web 204 while second wire management unit 140 provides a second wire for forming a second wire web 208.
• First web 204 is located at the front end side of the wire guide cylinders 112, 114 and second web 208 is located at the rear end side of wire guide cylinders 112, 114 adjacent to motors 122, 124.
• first web 204 two adjacent strings or lines of wire are spaced by distance Dl while in second web 208 two adjacent strings or lines of wire are spaced by a distance D2. Furthermore, first and second webs 204, 208 are spaced by a distance DW. However, distances Dl. D2, and DW are defined by the grooves in wire guide cylinders 112, 114. Since these grooves are equidistant, distances Dl and D2 can be identical, and also DW may be selected to be identical. Furthermore, the wire guide cylinders drive both the first and second web 204, 208 so that the wire speed is identical for the first and second web 204, 208. Furthermore, the wire transport directions of the first and second webs 204, 208 will be identical.
• first wire management unit 140 is a mirrored with respect to first wire management unit 204, the wire feeding direction and wire recoil directions are reversed. Furthermore, first wire web 204 is fed in the middle of the wire guide cylinder
• first and second webs 204, 208 have identical properties and appear as a single continuous web 200.
• a composite web 200 is formed by the first and second webs 204, 208 wherein the composite web is continuous in its properties so that there exists no difference to a single web with respect to the cutting process.
• composite web 200 is adapted for cutting the blocks of semiconductor material.
• Embodiments including a composite web 200 formed from separate wire webs 204, 208 are advantageous in that wire length of one web in a working area 210, 220 is only half of the length compared to a single wire web as it is shown in Fig. 2. When using the same amount of wire in the wire reservoir, the wire length which can be utilized for sawing is doubled.
• the distance DW between a first portion of a web and a second portion of the web, both forming a continuous web can be the same as the distance Dl or the distance D2.
• the spacing between adjacent wires of the first and the second web may be e.g., 300 ⁇ m or below, typically 200 ⁇ m to 250 ⁇ m.
• FIG. 4B shows a schematic side view of a wire saw device according to the embodiment shown in Fig. 4A.
• first wire web 204 and second wire web 208 are arranged in a row on wire guide cylinder 112.
• a first or front block 302F of semiconductor material is located in the working area of first web 204.
• a second or rear block 302R of semiconductor material is located in the working area of second web 208.
• front block 302F is cut by first web 204 and rear block 302R is cut by rear web 208.
• each of the blocks will have a longitudinal length of about 250 mm and will have a surface of 156 mm by 156 mm. It should be understood that the same arrangement of two consecutive blocks of semiconductor material can also be chosen for the other positions 304, 306, and 308.
• the sawing device shown in Fig. 3 is adapted to simultaneously saw 8 blocks of semiconductor material, namely two upper front blocks 302F, 304F with working area 210 of first web 204, two lower front blocks 306F, 308F with working area 220 of first web 204, two upper rear blocks 302R, 304R with working area 210 of second web 208, and two lower rear blocks 306R, 308R with working area 220 of second web 208.
• Fig. 5A shows a schematic top view of a wire saw device according to a further embodiment.
• the overall configuration is similar to the embodiment shown in Figs. 4A and 4B.
• the longitudinal length of first and second webs 204 and 208 is reduced in that gaps of width G are provided at the beginning and the end of the webs.
• gap G should be understood as a region without wire web but grooves on the wire guide cylinders.
• the gaps G on wire guide cylinder 112 are not used for providing a wire web.
• each of the first and second wire webs 204, 208 has a reduced longitudinal length compared to the arrangement shown in Fig. 4A as is also indicated by the dashed lines.
• FIG. 5B shows a schematic side view of a wire saw device according to the embodiment shown in Fig. 5 A.
• the hatched areas of front block 302F and rear block 302R indicate portions of semiconductor material which will not be cut by first and second webs 204, 208.
• the front and rear ends of the semiconductor blocks 302F, 302R can be ignored in the sawing process. Since semiconductor blocks often contain impurities and hard spots in these portions, the risk of wire breakage can be reduced.
• "cropping" of the blocks, i.e. cutting off head and tail, before wafering may be omitted. Thus, the number of operations can be reduced.
• Fig. 6 shows a schematic side view of a wire guide cylinder according to an embodiment.
• wire guide cylinder 112 is not exactly cylindrically but has the shape of a double cone. Each cone has a smaller diameter DS at a small diameter end and a large diameter DL at a large diameter end. The cones are arranged so that the small diameter end of the rear cone and the large diameter end of the front cone adjoin each other.
• the front cone of wire guide cylinder 112 is adapted to guide first web 204 and the rear cone of wire guide cylinder 112 is adapted to guide second web 208.
• the difference DD between the small diameter DS and the large diameter DL is chosen such that a loss of tension within the wire between the feeding end of the wire web and the recoil end of the wire web is compensated.
• a loss of tension may occur due to wear off of the wire during the sawing process.
• an additional length of about 1 mm may be required to compensate the tension loss.
• the 1 mm additional length will be equally distributed between the four wire guide cylinders. Accordingly, the difference DD will be 0.25 mm for each cylinder, adding up to a total of 1 mm additional length at the large diameter end of the cone.
• Fig. 7 shows a schematic front view of a wire saw device 104 according to a further embodiment.
• the wire guide device 110 is adapted to form two working areas 210, 220 of wire web 200.
• Wire saw device 104 further includes a first holder 410 and a second holder 420.
• First and second holders 410, 420 each are adapted to hold blocks of material to be sawed.
• First holder 410 holds upper blocks 302, 304 and second holder 420 holds lower blocks 306, 308.
• First holder 410 is located above first working area 210 of web 200 and second holder 420 is located above second working area 220 of web 200.
• First and second holders 410, 420 are adapted to advance their respective blocks to web 200 during the sawing process. For example, first and second holders 410, 420 are lowered so that the respective semiconductor blocks contact web 200.
• the movement of first holder 410 is independent of the movement of second holder 420.
• the first and second holders 410, 420 can be moved independently relative to the corresponding working areas 210, 220 of the wire web 200.
• first and second holders 410, 420 can be separately driven and controlled.
• first and second holders 410, 420 Such independent movement of first and second holders 410, 420 is useful since the wire of web 200 not only abrades the semiconductor material of blocks 302, 304, 306, 308 but also the surface coating of the wire guide cylinders. Due to this abrasion, the diameter of the wire guide cylinders reduces with time. As a result, the plane of upper working area 210 lowers while the plane of lower working area 220 moves up. In other words, the upper and lower working areas 210, 220 of web 200 approach each other moving in opposite directions. In order to control the sawing process and, in particular, take account of the above-described effect of abrasion, the upper and lower holders 410, 420 can be controlled independently. For example, upper holder 410 may be lowered more and lower holder 420 may be lowered less in order to compensate for the reduced diameter effect.
• Fig. 8 shows a detail of the upper working area 210 and, particularly, a nozzle arrangement according to an embodiment.
• the wire in working area 210 moves from a starting side 201 of the working area 210 to an end side 202 of the working area 210 in a wire moving direction 215.
• a first nozzle 510 is mounted in the vicinity of the starting side 201.
• First nozzle 510 is adapted to apply slurry 500 to the wire web 200.
• slurry 500 contains abrasive particles for which the wire acts as a carrier.
• First nozzle 510 is adapted to apply slurry 500 before the wire moves along substantially the first half from the starting side 201 to the end side 202 in wire moving direction 215.
• first nozzle 510 is adapted to apply slurry 500 before the wire cuts through semiconductor block 302.
• a second nozzle 520 is mounted between the starting side 201 and the end side 202.
• second nozzle 520 is adapted for applying slurry 500 to the wire web 200.
• second nozzle 520 is located such that the slurry is applied before the wire moves along substantially the second half from the starting side 201 to the end side 202 in wire moving direction 215.
• second nozzle 520 may be located about halfway between the wire guide cylinders. In another embodiment, second nozzle 520 is located between first block 302 and second block 304. Thus, second nozzle 520 can apply slurry 500 to the web after the wire has cut through first block 302 and before this part of the wire cuts through second block 304. Since the slurry applied by first nozzle 510 is at least partially used by cutting first block 302, the additional application of slurry 500 by second nozzle 520 improves the sawing properties of the sawing device. However, the distance of second nozzle 520 from the wire web 200 is independent of the sawing process of sawing the semiconductor material 302, 304.
• second nozzle 520 is not lowered together with the semiconductor blocks 302, 304 but maintains a fixed position with respect to web 200.
• the distance DN between second nozzle 520 and the web remains substantially constant.
• second nozzle 520 will typically not be mounted to a holder or similar mechanism adapted to lower the material to be sawed. Since the distance of second nozzle 520 from the wire web is independent of the sawing process, slurry can be applied to web 200 under constant conditions and with constant quality.
• Fig. 9 shows a schematic perspective view of a modular cutting head 700 according to an embodiment.
• Modular cutting head 700 includes a left portion holder 710, a right portion holder 720, and a column 730 to which the left portion holder 710 and the right portion holder 720 can be mounted.
• Left portion holder 710 includes a front portion 712 and a rear portion 714. Front portion 714 and rear portion 716 are connected via a beam.
• the beam of left portion holder 710 is hidden in Fig. 7 but beam 726 of right portion holder 720 is shown.
• the beam of left portion holder 710 is formed similar to beam 726.
• Front portion 712 of left portion holder 710 includes an upper opening 717 and a lower opening 718.
• rear portion 714 of left portion holder 710 includes an upper opening 719 and a lower opening.
• the upper openings 717, 719 of left portion holder 710 are coaxially aligned with each other.
• the lower openings of left portion holder 710 are coaxially aligned with each other.
• the openings of left portion holder 710 are adapted so that wire guide cylinders can be mounted between front portion 712 and rear portion 714.
• a connector 715 protrudes from the front portion 712 of left portion holder in a direction perpendicular of the beam.
• Right portion holder 720 is very similar to left portion holder and contains a connector 725 protruding toward connector 715 of left portion holder 710.
• Both connectors 715, 725 are adapted to form together a rigid connection between the left and right portion holders 710, 720.
• column 730 includes a protruding beam 735 extending substantially parallel with the beams of left and right portion holders 710, 720.
• beam 735 and the beams of the left and right portion holders 710, 720 are adapted to be rigidly fixed to each other.
• column 730 and the rear portions of the left and right portion holders 710, 720 are adapted to be rigidly fixed to each other.
• column 730 is mounted on a platform 740.
• the left portion holder 710 and the right portion holder 720 define an adjustable length between each other and, thus, of the wire web 200 in the wire moving direction 215.
• the lateral distance between left portion holder 710 and right portion holder 720 may be adjusted using connectors 715 and 725.
• the connectors 715, 725 may be adjustable themselves.
• different sets of left and right portion holders 710, 720 may be manufactured, each set defining a different length for the working area(s) between the left and right portion holders.
• the cutting head modularity may allow a configuration in which four smaller ingots or two larger ingots may be processed, or a configuration in which two smaller ingots or two larger ingots may be processed.
• Figs. 1OA and 1OB show embodiments of a wire breakage detection unit 800.
• Wire breakage detection unit 800 can be electrically biased with respect to the wire web.
• Wire breakage detection unit 800 has a plurality of biased portions 810 and a plurality of openings 820 between the biased portions.
• wire breakage detection unit 800 is an electrically conductive plate with a plurality of slits 820 forming a fence of electrical conductive portions 810. Slits 820 may be either formed as vertical slits (Fig. 10A) or horizontal slits (Fig. 10B). Typically, wire breakage detection unit 800 is located between the wire guide cylinders and the wire management unit. In one embodiment, wire breakage detection unit 800 is connected to ground potential 830. In this embodiment, a voltage is applied to wire web 200. During normal operation, wire web 200 and wire breakage detection unit 800 have no contact. However, in the event of a wire breakage the loose end of the wire will touch wire breakage detection unit 800, thus grounding wire web 200.
• wire breakage detection unit 800 an electric potential is applied to wire breakage detection unit 800, and wire web 200 is grounded. Likewise, a contact between the loose end of the broken wire and the wire breakage detection unit 800 can be detected. However, inside the cutting area a considerable amount of slurry is applied to the web. Due to the wire speed and due to the sawing process, a mixture of slurry and abraded material splashes inside the sawing device. Accordingly, slurry and abraded material may accumulate on a wire breakage detection unit 800, thus deteriorating the electrical contact between wire and plate. However, slurry and/or abraded material can exit through the openings 820 so that the surface of wire breakage detection unit 800 facing the working area is not as contaminated as for a full plate. As a result, reliability and accuracy of wire breakage detection is improved.
• Fig. 11 shows embodiments of a wafer box 900 and wafer baskets 930, 940.
• Wafer box 900 is adapted to collect slurry 500 applied by nozzles 510, 520 and, in some embodiments, is also be adapted to collect a cleaning liquid, e.g. water, polyethylene glycol (PEG) or any other suitable cleaning liquid known in the art.
• wafer box 900 includes a first drain line 10 and a second drain line 920.
• First drain line 10 includes a first valve 915
• second drain line 920 includes a second valve.
• First drain line 910 is adapted to conduct slurry 500 and, in some embodiments, is connected to a slurry tank (not shown) so that the slurry 500 in wafer box 900 can be recycled.
• the slurry tank has a capacity of several hundred liters, e.g. between 500 to 900 liters, and is mounted on wheels.
• Second drain line 920 is adapted to conduct a cleaning liquid, particularly water, polyethylene glycol (PEG) or any other suitable cleaning liquid known in the art.
• PEG polyethylene glycol
• slurry and cleaning liquid do not mix, e.g. for an oil-based slurry and water being used as a cleaning liquid.
• second valve 925 may be closed during the sawing process while slurry 500 is applied.
• the slurry applied during the sawing process may be drained via first drain line 910 when the first valve 915 is open.
• first valve 915 is closed and second valve 925 may be opened.
• a cleaning liquid may be applied to the sawed blocks 302, 304 of semiconductor material.
• the cleaning liquid is collected in wafer box 900 and may be drained via second drain line 920 when the second valve 925 is open.
• the cleaning can be conducted in- situ.
• the wafer box and/or an enclosure can be used to guide cleaning fluid in the wire saw device and to avoid contamination of components by the cleaning fluid.
• the in-situ cleaning is conducted in a wire saw device having a distance between grooves for adjacent wires in the guiding cylinders of 200 ⁇ m to 400 ⁇ m, e.g. 300 ⁇ m or below. For wafers being thin, which correlates with a small wire groove spacing, wafer breakage is getting more and more serious.
• a transfer in a separate cleaning chamber may result in a higher percentage of wafers being damaged and reduces the throughput.
• An in-situ cleaning can also be conducted to reduce the probability of wafers adhering together after the wires have removed from between the wafers. This would further complicate a remote cleaning of the wafer and may result in further increased wafer breakage or damage as compared to in-situ cleaning of thin wafers.
• some embodiments of wire saw devices may include at least one element of the group selected from: wafer boxes, enclosures for cleaning the wafers therein, different drain lines for slurry and cleaning fluid, respectively, cleaning fluid rinse nozzles, and combinations thereof; and wire guiding cylinders with a distance between grooves for adjacent wires in the guiding cylinders of200 ⁇ m to 400 ⁇ m.
• some embodiments which can be combined with other embodiments described herein, can include a wire having a thickness of 120 ⁇ m or less, can include, for example, a diamond wire, and/or can have a grooves configured for wires of 120 ⁇ m or less.
• wafer baskets 930, 940 are provided within wafer box 900.
• Wafer baskets are adapted to accommodate the sawed blocks 302, 304 of semiconductor material. After the sawing process, the blocks contain a plurality of wafers which are still connected to holder 410.
• the present application discloses methods of in-situ dismounting these wafers from holder 410.
• Wafer baskets 930, 940 are adapted to hold the wafers after being dismounted.
• wafer baskets 930, 940 have openings 935, 945 through which slurry and/or cleaning liquid may enter and/or exit the interior of wafer baskets 930, 940.
• wafer baskets 930, 940 are formed by a metal frame following the edges of a rectangular box. Furthermore, wafer baskets 930, 940 are removably inserted into wafer box 900 so that wafer baskets 930, 940 together with the wafers can be removed from within wafer box 900.
• wafer box 900 includes a front door (not shown) located at the front end of the sawing device opposite to the motors. Thus, the wafer baskets can easily be removed from within wafer box 900 via the front door.
• the wafer baskets 930, 940 are mounted on rails inside wafer box 900.
• Fig. 12 shows a schematic front view of a wire saw device 108 according to an embodiment.
• the wire saw device 108 includes an enclosure 180 surrounding at least partially the working areas in which the semiconductor material is sawed into semiconductor wafers.
• wire saw device 108 includes a cleaning means for in-situ cleaning of the semiconductor wafers within the enclosure 180.
• the cleaning means includes a beam 400 with conduits 405 as it is shown in Fig. 13.
• the lower portion of a beam 400 has a plurality of conduits 405.
• a plurality of substantially parallel longitudinal conduits 405 may be formed in beam.
• a cleaning liquid can be supplied to the conduits 405.
• a fluid communication between conduits 405 and the space between adjacent wafers may be established.
• the wafers may be rinsed with cleaning liquid to remove remnants of slurry and/or abraded material from the wafer surfaces.
• the cleaning liquid can be collected in wafer boxes 900 and the cleaned wafers may be accommodated in wafer baskets 930, 940.
• the cleaning means and the separating means are integral in that the dismounting of the wafers is accomplished by supplying hot water to the conduits 405 after wafer cleaning has been performed. The hot water deglues the wafers from beam 400 so that the wafers are collected in wafer baskets 930, 940 which can be removed, e.g., via a front door in wafer box 900.
• the connection between the wafers and beam 400 is cut by wire web 200 as will be explained in more detail below. Also in this case, the dismounted wafers will be collected in wafer baskets 930, 940.
• Fig. 14 is a flow diagram of a cleaning method 1100 according to an embodiment.
• the cleaning method is a method for in-situ cleaning of semiconductor wafers within an enclosure of a wire saw device.
• the method 1100 includes a step 1110 of attaching a semiconductor material block to a beam having at least one conduit for feeding cleaning fluid.
• the semiconductor material block is sawed with a wire saw device to obtain a plurality of semiconductor wafers.
• the beam is sawed such that fluid communication between the at least one conduit and a space between the semiconductor wafers is established.
• the wire web may cut into the at least one conduit to provide the fluid communication.
• the sawing is stopped when the wire web is located within the at least one conduit.
• cleaning fluid is supplied to the at least one conduit to clean the semiconductor wafers.
• the cleaning liquid is water.
• the cleaning liquid is polyethylene glycol (PEG).
• PEG polyethylene glycol
• any other suitable cleaning liquid known in the art may be used either alone or in a mixture with other cleaning liquids.
• the cleaning liquid is supplied for 8 to 20 min, particularly for 10 to 15 min.
• the cleaning liquid is supplied at an amount of 6 1/min up to 12 1/min.
• the cleaning liquid is water having a temperature below 50°C.
• a dismounting liquid is further supplied to the at least one conduit after step 1140.
• the semiconductor wafers are detached from the beam and, e.g., can be collected in wafer baskets.
• the dismounting liquid is hot water having a temperature of 70°C or higher, particularly of 80 0 C to 90°C.
• the dismounting liquid is supplied for 8 to 20 min, particularly 10 to 15 min.
• the dismounting liquid is supplied at an amount of 6 1/min up to 12 1/min.
• the semiconductor wafers are supported by a wafer basket while being dismounted from the beam.
• Fig. 15 is a flow diagram of a dismounting method 1200 according to an embodiment.
• the dismounting method is a method for dismounting semiconductor wafers from a beam after sawing.
• the method 1200 includes a step 1210 of sawing, with a wire saw device, a semiconductor material block in a direction of a predefined slicing plane to obtain a plurality of semiconductor wafers.
• the beam to which the semiconductor wafers are attached is sawed in the direction of the predefined slicing plane. After this step 1220, the sawed wafers are still attached to a beam.
• the beam is sawed in a direction substantially perpendicular to the predefined slicing plane in step 1230.
• the cutting direction is changed from being perpendicular to the plane of the wire web to being in the plane of the wire web.
• the beam is cut perpendicular to the slicing plane for at least the thickness of one semiconductor wafer. Since each wafer is connected to the beam only by a bar as thick as the wafer itself, it is sufficient that the perpendicular cut has only the length of the wafer thickness to cut though this bar. Thus, the wafers are dismounted from the beam.
• the semiconductor wafers are supported by a wafer basket while the beam is cut.
• a separation can be conducted in-situ.
• the in-situ separation is conducted in a wire saw device having a distance between grooves for adjacent wires in the guiding cylinders of 200 ⁇ m to 400 ⁇ m.
• wafer breakage is getting more and more serious. Accordingly, a transfer in a further wafer separation chamber may result in a higher percentage of wafers being damaged and reduces the throughput.
• An in-situ wafer separation can also be conducted to reduce the probability of wafers adhering together after the wires have removed from between the wafers. This would further complicate a remote cleaning of the wafer and may result in further increased wafer breakage or damage as compared to in-situ cleaning of thin wafers.
• a wire saw device for sawing at least one block of semiconductor material comprises a wire guide device adapted to guide a wire for forming at least one wire web, at least two wire management units each adapted for providing a wire to the wire guide device, wherein a first wire management unit of the at least two wire management units provides a first wire for forming a first wire web and a second wire management unit of the at least two wire management units provides a second wire for forming a second wire web, wherein the first and second wire webs together form a composite wire web, the composite wire web being continuous and being adapted for cutting the at least one block of semiconductor material.
• the wire saw device includes a first unwinding spool and a first winding spool and a second unwinding spool and a second winding spool. Further, a first holder for holding two blocks of semiconductor material, the first holder being configured to saw the two blocks in the first working area and a second holder for holding two further blocks of semiconductor material, the second holder being configured to saw two blocks in the second working area.
• first and the second holder, each holding a block of semiconductor material may each be separated such that two sub-holders are configured to saw a block in the first working area and two sub- holders are configured to saw a block in the second working area.
• the one or more holders for holding blocks of semiconductor materials can be moved independent from each other with regard to the surface of the wire web during operation. Thereby, for the event that one block of semiconductor material can not be sawed, for example, because of impurities in the semiconductor material that can not be sawed, the remaining holders can be moved for cutting of the semiconductor material. This reduces the loss of material in the event that problems might occur during cutting.
• a large cutting area and a large effective cutting rate e.g. of 12 nvVh or more can be provided.
• two working areas can be provided, e.g., by four wire guiding cylinders; two wire management units and thereby two wires can be used to form the web; all wire guiding cylinders can be driven by a motor, typically in a master-slave modus; a small groove distance of the plurality of groove in the wire guiding cylinders can be used based on a reduce abrasion of the wire; and a high cutting speed can be realized based on a reduced area per wire.
• a diamond wire can be used for the wire saw device.
• a wire saw device for sawing semiconductor material comprises a wire guide device adapted to guide a wire for forming at least two working areas of at least one wire web, at least one wire management unit for providing a wire to the wire guide device, and at least two holders for holding each at least one block of semiconductor material, each holder of the at least two holders corresponding to a working area of the at least one wire web, wherein the at least two holders can be moved independently relative to the corresponding working areas of the at least one wire web.
• a wire saw device for sawing semiconductor material comprises a wire guide device adapted to guide a wire for forming at least one wire web, wherein the wire in a working area of the wire web moves from a starting side of the working area to an end side of the working area in a wire moving direction, a first nozzle mounted in the vicinity of the starting side for providing slurry on the wire web before the wire moves along substantially the first half in wire moving direction from the starting side of the working area to the end side of the working area, and a second nozzle mounted between the starting side and the end side for providing slurry on the wire web before the wire moves along substantially the second half in wire moving direction from the starting side of the working area to the end side of the working area, wherein the distance of the second nozzle from the wire web is independent of the sawing process of sawing the semiconductor material.
• a wire saw device for sawing semiconductor material comprises a cutting head, a wire guide device adapted to guide a wire for forming at least one wire web, wherein the wire in a working area of the wire web moves from a starting side of the working area to an end side of the working area in a wire moving direction, wherein the cutting head includes a left portion holder for holding at least a first cylinder of the wire guide device and a right portion holder for holding at least a second cylinder of the wire guide device, and wherein the left portion holder and the right portion holder define an adjustable length of the wire web along the wire moving direction.
• a wire saw device for sawing semiconductor material comprises a wire guide device adapted to guide a wire for forming at least one wire web, and a wire breakage detection unit being adapted to be biased for wire breakage detection, wherein the wire breakage detection has a plurality of biased portions and a plurality of openings between the biased portions.
• the wire breakage detection unit is an electrical conductive plate with a plurality of openings.
• the plurality of openings is a plurality of slits forming a fence of electrical conductive portions.
• a wire saw device for sawing semiconductor material comprises a wire guide device adapted to guide a wire for forming at least one wire web for sawing the semiconductor material, an enclosure in which the semiconductor material is sawed into semiconductor wafers, and a cleaning means for in-situ cleaning of the semiconductor wafers within the enclosure.
• the cleaning means is a cleaning and separating means for in-situ cleaning of the semiconductor wafers within the enclosure and for in-situ separation of the semiconductor wafers within the enclosure.
• the wire saw device may comprise a wafer box for collecting slurry and/or cleaning liquid.
• the wafer box includes at least one outlet valve for cleaning liquid and at least one outlet valve for slurry so that cleaning liquid and slurry may be separately removed from the wafer box.
• the wire saw device comprises a wafer basket adapted for holding the wafers, particularly after dismounting the wafers from a beam to which they have been attached during the sawing process.
• a sidewall and/or a bottom wall of the wafer basket comprises at least one opening through which slurry and/or cleaning liquid may be dispensed from the wafer basket.
• the wafer basket is accommodated within the wafer box.
• the wafer box comprises at least one door through which the wafer basket may be removed from the wafer box.
• a method for in-situ cleaning of semiconductor wafers comprises attaching a semiconductor material block to a beam having at least one conduit for feeding cleaning fluid, sawing, with a wire saw device, the semiconductor material block to obtain a plurality of semiconductor wafers and further sawing the beam such that fluid communication between the at least one conduit and a space between the semiconductor wafers is established, and supplying cleaning fluid to the at least one conduit to clean the semiconductor wafers.
• the wire web cuts into the at least one conduit to provide the fluid communication.
• the sawing is stopped when the wire web is located within the at least one conduit.
• the beam comprises a plurality of cylindrical conduits arranged in parallel.
• the cleaning liquid is water.
• the cleaning liquid is polyethylene glycol (PEG).
• the cleaning liquid may be another cleaning liquid known in the art which may be used either alone or in a mixture with a suitable other cleaning liquid, hi a further embodiment which may be employed separately or in combination with any of the embodiments or features described herein, the cleaning liquid is supplied for 8 to 20 min, particularly 10 to 15 min. According to another embodiment which may be employed separately or in combination with any of the embodiments or features described herein, the cleaning liquid is supplied at an amount of 6 1/min up to 12 1/min. According to still another embodiment which may be employed separately or in combination with any of the embodiments or features described herein, the cleaning liquid is water having a temperature below 50°C.
• a dismounting liquid is further supplied to the at least one conduit so that the semiconductor wafers are detached from the beam.
• the dismounting liquid is hot water having a temperature of 70°C or higher, particularly of 80°C to 90°C.
• the dismounting liquid is supplied for 8 to 20 min, particularly 10 to 15 min.
• the dismounting liquid is supplied at an amount of 6 1/min up to 12 1/min.
• the semiconductor wafers are supported by a wafer basket while being dismounted from the beam.
• a method for dismounting semiconductor wafers from a beam after sawing comprises sawing, with a wire saw device, the semiconductor material block in a direction of a predefined slicing plane to obtain a plurality of semiconductor wafers, sawing a beam to which said semiconductor wafers are attached in the direction of the predefined slicing plane, and sawing the beam in a direction substantially perpendicular of the predefined slicing plane.
• the beam is cut perpendicular to the slicing plane for at least the thickness of one semiconductor wafer.
• the semiconductor wafers are supported by a wafer basket while the beam is cut.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)

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• 2008
  • 2008-04-14 EP EP20080154493 patent/EP2110216B1/en active Active
• 2009
  • 2009-04-09 US US12/937,708 patent/US20110132345A1/en not_active Abandoned
  • 2009-04-09 JP JP2011504552A patent/JP5508395B2/ja active Active
  • 2009-04-09 WO PCT/IB2009/005220 patent/WO2009127932A2/en not_active Ceased
  • 2009-04-09 KR KR1020107025486A patent/KR20110007188A/ko not_active Withdrawn
  • 2009-04-09 CN CN2009801223926A patent/CN102067288B/zh not_active Expired - Fee Related
  • 2009-04-13 TW TW98112231A patent/TW200952060A/zh unknown

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