초록 ▼

An ion-cut machine and method for slicing silicon ingots into thin wafers for solar cell manufacturing is set forth, amongst other embodiments and applications. One embodiment comprises two carousels: first carousel (100) adapted for circulating workpieces (55) under ion beam (10) inside target vacu

An ion-cut machine and method for slicing silicon ingots into thin wafers for solar cell manufacturing is set forth, amongst other embodiments and applications. One embodiment comprises two carousels: first carousel (100) adapted for circulating workpieces (55) under ion beam (10) inside target vacuum chamber (30) while second carousel (80) is adapted for carrying implanted workpieces through a sequence of process stations that may include annealing (60), cleaving (70), slice output (42), ingot replacement (52), handle bonding, cleaning, etching and others. Workpieces are essentially swapped between carousels. In one embodiment, the swapping system comprises a high throughput load lock (200) disposed in the wall of the vacuum chamber (30), a vacuum swapper (110) swapping workpieces between first carousel (100) and load lock (200), and an atmospheric swapper (90) swapping workpieces between load lock (200) and second carousel (80).

대표청구항 ▼

1. A machine for slicing workpieces with an ion beam, comprising: a. a target vacuum chamber,b. an ion beam of preselected energy,c. a first carousel inside said target vacuum chamber adapted for circulating a plurality of workpieces, numbering M, through said ion beam,d. a plurality of stations com

1. A machine for slicing workpieces with an ion beam, comprising: a. a target vacuum chamber,b. an ion beam of preselected energy,c. a first carousel inside said target vacuum chamber adapted for circulating a plurality of workpieces, numbering M, through said ion beam,d. a plurality of stations comprising at least: i. a workpiece swapping station,ii. a cleaving station,e. a second carousel adapted for circulating workpieces sequentially from station to station,f. a workpiece swapping means operable for transferring an implanted workpiece from said first carousel to said workpiece swapping station of said second carousel, and transferring a fresh workpiece from said workpiece swapping station of said second carousel to said first carousel,wherein: i. said first carousel is repeatedly advanced by N workpieces, exposing some workpieces to said ion beam and implanting ions in a layer at a preselected depth therein,ii. following each advancement, said workpiece swapping means transfers an implanted workpiece from said first carousel to said workpiece swapping station of said second carousel, and transfers a fresh workpiece from said workpiece swapping station of said second carousel to said first carousel,iii. upon receiving said implanted workpiece, said second carousel is advanced, moving each of its workpieces to a subsequent station, and thereby moving one workpiece to said cleaving station, wherein workpiece material above said layer is separated from the underlying workpiece, thereby forming a slice,whereby each workpiece is repeatedly implanted and cleaved, producing a plurality of slices. 2. The machine of claim 1 wherein N and M are co-prime, whereby, in steady-state operation, each said implanted workpiece will receive substantially identical treatment by said ion beam. 3. The machine of claim 1 wherein said second carousel is located outside said target vacuum chamber, said workpiece swapping means comprising: a. a load lock coupled to said target vacuum chamber,b. a vacuum swapping means disposed inside said target chamber between said first carousel and said load lock, operable for transferring: i. an implanted workpiece from said first carousel to said load lock,ii. a fresh workpiece from said load lock to said first carousel,c. an atmospheric swapping means disposed outside said target chamber, between said load lock and said second carousel, operable for transferring: i. an implanted workpiece from said load lock to said second carousel,ii. a fresh workpiece from said second carousel to said load lock. 4. The machine of claim 1 wherein said second carousel is located inside said target vacuum chamber, said machine further comprising: a. a load lock coupled to target vacuum chamber, said load lock operable to receive at least one slice and transfer said at least one slice out of vacuum,b. a transfer mechanism disposed inside said target vacuum chamber, adapted to transfer a slice from said second carousel to said load lock. 5. The machine of claim 1 wherein said second carousel is located inside said target vacuum chamber, said machine further comprising: a. at least one load lock coupled to said target vacuum chamber, said at least one load lock operable to transfer workpieces into or out of vacuum,b. at least one transfer mechanism disposed inside said target chamber between said at least one load lock and said second carousel, adapted to transfer workpieces between said second carousel and said at least one load lock,whereby new workpieces may be fed into said machine, the remnant of fully-sliced workpieces may be removed from said machine, and dummy workpieces may be inserted into, or removed from, the stream of workpieces at selected locations. 6. The machine of claim 1 wherein said plurality of stations further comprises at least one station selected from the group consisting of: a. an annealing station adapted for heating a workpiece,b. a bonding station adapted for bonding a handle substrate to a workpiece,c. a cleaning station adapted for cleaning a slice,d. a slice removal station adapted for removing a slice from said second carousel,e. a workpiece input and output station adapted for transferring a fresh workpiece or dummy workpiece to said second carousel, and for removing the remnant of a fully sliced workpiece or dummy workpiece from said second carousel. 7. The machine of claim 2 wherein N is changed over time to compensate for changes in workpiece temperature arising from the gradual thinning of the workpieces as they are sliced. 8. The machine of claim 1 wherein said first carousel further comprises: a. a sealed conduit,b. a coolant circulated through said conduit,c. a thermal coupling means disposed between said first carousel and each of the workpieces thereupon,whereby heat is efficiently transferred from the workpieces to said coolant. 9. The machine of claim 8 wherein said thermal coupling means is a gas. 10. The machine of claim 1 wherein said load lock is provided with at least one movable wall, wherein the internal volume of said load lock is adjusted in accordance with the size of the workpiece contained therein, whereby the quantity of gas to be pumped out of said load lock is minimized. 11. A machine for slicing workpieces with an ion beam, comprising: a. a target vacuum chamber,b. an ion beam of preselected energy,c. a first carousel inside said target vacuum chamber adapted for circulating a plurality of workpieces, numbering M, through said ion beam,d. a plurality of stations comprising at least: i. a workpiece swapping station,ii. a cleaving station,e. a second carousel adapted for circulating workpieces sequentially from station to station,f. at least one buffer adapted for receiving and supporting a plurality of workpieces,g. a first workpiece swapping means operable for transferring workpieces between said first carousel and said at least one buffer,h. a second workpiece swapping means operable for transferring workpieces between said second carousel and said at least one buffer,wherein: i. said first carousel is advanced, exposing all M workpieces equally to said ion beam and implanting ions in a layer at a preselected depth therein,ii. following each advancement of said first carousel, said first workpiece swapping means is operated to transfer all M implanted workpieces from said first carousel to said at least one buffer and to transfer M fresh workpieces from said at least one buffer to said first carousel,iii. said second carousel is advanced, moving each of its workpieces to a subsequent station, thereby moving one workpiece to said cleaving station, wherein material above the implanted layer is separated from the workpiece, thereby forming a slice, and moving one workpiece to said workpiece swapping station,iv. following each advancement of said second carousel, said second workpiece swapping means is operated to exchange the workpiece in said workpiece swapping station with an implanted workpiece in said buffer,whereby each workpiece is repeatedly implanted on said first carousel and cleaved on said second carousel, producing a plurality of slices. 12. The machine of claim 11 wherein said second carousel is disposed inside said target vacuum chamber, said machine further comprising: a. at least one load lock coupled to said target vacuum chamber, said at least one load lock operable to transfer workpieces into or out of vacuum,b. at least one transfer mechanism disposed inside said target chamber between said at least one load lock and said second carousel, adapted to transfer workpieces between said second carousel and said at least one load lock,c. A slice removal load lock coupled to said target vacuum chamber, said slice removal load lock operable to transfer slices into or out of vacuum,d. a slice transfer mechanism disposed inside said target chamber between said slice removal load lock and said second carousel, adapted to transfer slices between said second carousel and said slice removal load lock,whereby new workpieces may be fed into said machine, slices may be removed from said machine, the remnant of fully-sliced workpieces may be removed from said machine, and dummy workpieces may be inserted into, or removed from, the stream of workpieces at selectable locations. 13. The machine of claim 11 wherein said second carousel is disposed outside said target vacuum chamber, said machine further comprising at least one load lock coupled to said target vacuum chamber and disposed between said first workpiece swapping means and said second workpiece swapping means, each said at least one buffer being disposed within a said at least one load lock, whereby each load lock containing a buffer defines a batch load lock.