Title Page
Contents
Abstract 12
1. Introduction 14
2. Simulation and experiment details 17
2.1. Simulation details 17
2.1.1. Simulation design 17
2.1.2. Simulation theory 20
2.1.3. Thermal distribution according to scanning speed 23
2.2. Experiment details 26
2.2.1. Laser annealing system 26
2.2.2. Raman spectroscopy 27
2.2.3. Spectroscopic ellipsometry 28
2.2.4. Atomic force microscopy (AFM) 28
3. Laser-Power Dependence of Poly-Silicon Crystallization Characteristic Using NULA 30
3.1. Introduction 30
3.2. Simulation results 31
3.3. Experiment and analysis 33
3.4. Results and discussions 37
4. Comparative Study on Crystallinity of Laser-annealed Polysilicon Thin Films for Various Laser Sources 38
4.1. Introduction 38
4.2. Simulation results 40
4.2.1. Temperature distribution according to laser-power of NULA, GLA, BLDA 40
4.2.2. Temperature distribution for comparing NULA, GLA, BLDA 44
4.3. Experiment and analysis 48
4.3.1. Crystallinity of poly-Si using Raman spectra according to laser-power of NULA, GLA, BLDA 50
4.3.2. Crystallinity of poly-Si using Raman spectra for comparing NULA, GLA, BLDA 56
4.3.3. Crystallinity of poly-Si using spectroscopic ellipsometry for comparing NULA, GLA, BLDA 59
4.4. Results and discussions 62
5. Conclusions 64
6. References 66
Table 2.1. Material parameters used for thermal simulation. 22
Table 4.1. Fitting results of Raman spectra of poly-Si samples... 56
Figure 2.1. Schematic of the laser annealing experiment for an a-Si/ SiO₂ thin... 17
Figure 2.2. Schematic of the laser characteristics for NULA.... 18
Figure 2.3. Schematic of the laser characteristics for GLA.... 19
Figure 2.4. Schematic of the 3-dimentional laser beam shape for BLDA. 20
Figure 2.5. Simulated temperature profile on the sample surface as a function... 24
Figure 2.6. Laser annealing system 26
Figure 2.7. Raman spectroscopy equipment 27
Figure 3.1. Simulated temperature profile on the sample surface as a function... 31
Figure 3.2. Simulated temperature profile as a function of the sample depth (z... 32
Figure 3.3. Raman spectra of an a-Si sample before annealing, a reference c-... 34
Figure 3.4. AFM images on the sample area of 20 x 20 μ㎡ for (a) an a-Si... 35
Figure 3.5. RMS roughness determined from AFM images as a function of the... 36
Figure 4.1. Simulated temperature profile in the direction of the sample depth... 41
Figure 4.2. Simulated temperature profile as a function of the sample depth (z... 44
Figure 4.3. Simulated temperature profile on the sample surface for NULA... 46
Figure 4.4. Raman spectra of poly-Si sample annealed by thermal furnace for... 50
Figure 4.5. Raman spectra of poly-Si samples annealed NULA at (a) 0.75 W,... 51
Figure 4.6. Raman spectra of poly-Si samples annealed GLA at (a) 2.2 W, (b)... 52
Figure 4.7. Raman spectra of poly-Si samples annealed BLDA at (a) 480 mW,... 53
Figure 4.8. Optical constant spectra of the laser-annealed poly-Si samples with... 59
Figure 4.9. Crystalline volume fraction (fc) for NULA 1W, GLA 2.7 W, BLDA... 62