Laser annealing systems and methods with ultra-short dwell times

摘要

Laser annealing systems and methods for annealing a semiconductor wafer with ultra-short dwell times are disclosed. The laser annealing systems can include one or two laser beams that at least partially overlap. One of the laser beams is a pre-heat laser beam and the other laser beam is the annealing laser beam. The annealing laser beam scans sufficiently fast so that the dwell time is in the range from about 1 μs to about 100 μs. These ultra-short dwell times are useful for annealing product wafers formed from thin device wafers because they prevent the device side of the device wafer from being damaged by heating during the annealing process. Embodiments of single-laser-beam annealing systems and methods are also disclosed.

主权项

1. An ultra-fast laser annealing system for annealing a semiconductor wafer having a wafer surface, comprising:
a primary laser system that forms a primary image on the wafer surface at a first wavelength, wherein the primary image increases an amount of absorption of light at a second wavelength; a secondary laser system that forms a secondary image on the wafer surface at the second wavelength, wherein the secondary image resides at least partially within the primary image; and wherein the secondary laser system includes a scanning optical system that scans the secondary image over the wafer surface to define a scan path, wherein the secondary image has a dwell time of between 1 μs and 100 μs, thereby causing the wafer surface to reach a peak annealing temperature TAP between 350° C. and 1250° C.