If you read the patent [1], you would see that a lot of the claims are around the process and environment that is necessary to get the proper doping. In partic

If you read the patent [1], you would see that a lot of the claims are around the process and environment that is necessary to get the proper doping. In particular, it seems to involve some rather specific pressure control within the crucible as well as control of the amount of oxygen in the crucible by using argon as a buffer gas. This patent is less about the use of gallium to dope the silicon as it is about a specific and precise manufacturing process that is necessary to prevent the whole ingot from having too much resistance or having a lifetime worse than a boron-doped silicon ingot. [1] https://patents.google.com/patent/US6815605B1/en https://patents.google.com/patent/US6815605B1/en