Hydrogen as the cause of pit formation during laser recrystallization of siliconhyphen;onhyphen;insulator films

摘要

The formation of pits during laser recrystallization of siliconhyphen;onhyphen;insulator films has been studied in detail. Hydrogen originating from the decomposition of hydrogen bonds in the capping material or in the insulating layer is identified as being the cause of the formation of pits in the recrystallized silicon. These pits are the result of the formation of hydrogen gas bubbles in the molten zone near the solidification interface. A mechanism for the formation of the pits is presented. The dependence of the pit formation on capping layer material composition, annealing conditions, layer thickness, preheating temperature, scan velocity, and silicon film thickness is studied. Also hydrogenhyphen;containing insulating layers are discussed. Some recommendations are made to prevent pit formation.