Medium dose simox over a wide BOX thickness range by a multiple implant, multiple anneal process
AssigneeInternational Business Machines Corporation
InventorsHarold J. Hovel, Maurice H. Norcott, Devendra K. Sadana
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Abstract
A method of fabricating a high-quality silicon-on-insulator (SOI) substrate material having a buried oxide (BOX) region that has a thickness of about 300 nm or less is provided. The method employs multiple implant, multiple annealing steps to form the high-quality SOI substrate. In particular the inventive method includes at least a first oxygen ion implant where a primary oxide seed region is formed, a first annealing step, a second oxygen ion implant where a BOX-adjusting oxide seed region is formed and a second annealing step. The annealing steps convert the seed regions into buried oxide regions.
Claims20
A method of forming a silicon-on-insulator (SOI) substrate comprising the steps of:
- forming a primary oxide seed region into a Si-containing substrate, said primary oxide seed region comprising at least damaged clusters intermixed with oxide precipitates;
- subjecting said Si-containing substrate containing said primary oxide seed region to a first annealing step to convert the primary oxide seed region into a first buried oxide region;
- forming a BOX-adjusting oxide seed region into said Si-containing substrate proximate to said first buried oxide region;
- and
- subjecting said Si-containing substrate to a second annealing step to convert said BOX-adjusting oxide seed region and said first buried oxide region into a second buried oxide region, said second buried oxide region is thicker, and of improved quality, than the first buried oxide region.
A method of forming a high-quality silicon-on-insulator (SOI) substrate comprising the steps of:
- performing a first oxygen ion implant into a Si-containing substrate, said first oxygen ion implant is carried out at an ion dose of from about 1E17 to about 8E17 cm−2 and at a temperature of from about 200° to about 700° C.;
- performing a second oxygen ion implant on said Si-containing substrate, said second ion implant is carried out at an ion dose of from about 1E13 to about 5E15 cm−2 and at, temperature of from about 4K to about 150° C.;
- subjecting said Si-containing substrate to a first annealing step;
- performing a third oxygen ion implant, said third oxygen ion implant is carried out at an ion dose of from about 1E17 to about 8E17 cm−2 and at a temperature of from about 200° to about 700° C.;
- and
- subjecting said Si-containing substrate to a second annealing step.
Dependencies are inferred from the claim text.