Characterization of the effects of different capping layer structures on the laser recrystallization of silicon by using electrical test structures and Raman spectroscopy

Polycrystalline silicon on insulator is laser-recrystallized using three different capping layer structures on separate wafers. The capping layer structures used include a 6-nm nitride layer, a combination of 64-nm nitride and 20-nm oxide layers, and 50-nm nitride antireflection periodic stripes oriented parallel to the direction of laser scanning. Electrical characteristics are measured by metal-oxide-semiconductor (MOS) silicon-on-insulator (SOI) test structures fabricated in the laser-recrystallized silicon films. Measurement of carrier mobilities, MOS interface properties, leakage currents, and ring oscillator delay times are compared for wafers having different capping layer structures. Stress in each case is characterized using a Raman spectrometer with microprobe.