Laser Recrystallization of Polycrystalline Silicon in Recessed Structures

The pulsed-laser recrystallization of polysilicon in recessed structures, consisting of a silicon film deposited on a patterned oxide layer on a heat sink, is investigated for the first time. The different thermal environments created by the recess area, when compared to those outside this area, causes the recessed silicon to cool first. The different cooling rates in the continuous silicon film creates lateral temperature gradients, producing large elongated grains. Additionally, the recessed structure can lead to different film microstructures within the recessed area compared to outside this area. This structure is therefore capable of grain engineering different microstructures for polysilicon.