Dual-beam laser thermal processing of silicon photovoltaic materials

2016 ◽  
Author(s):  
Brian J. Simonds ◽  
Anthony Teal ◽  
Tian Zhang ◽  
Josh Hadler ◽  
Zibo Zhou ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Beam Laser ◽  
Photovoltaic Materials ◽  
Dual Beam ◽  
Laser Thermal Processing

Laser thermal processing for shallow junction and silicide formation

1998 ◽  
Author(s):  
Somit Talwar ◽  
Gaurav Verma ◽  
Kurt H. Weiner ◽  
Carol Gelatos
Keyword(s):  
Thermal Processing ◽  
Silicide Formation ◽  
Shallow Junction ◽  
Laser Thermal Processing

Effect of Laser Thermal Processing on Defect Evolution in Silicon

2002 ◽  
Vol 717 ◽  
Author(s):  
Erik Kuryliw ◽  
Kevin S. Jones ◽  
David Sing ◽  
Michael J. Rendon ◽  
Somit Talwar
Keyword(s):  
Point Defects ◽  
Thermal Processing ◽  
Defect Formation ◽  
Secondary Ion Mass Spectrometry ◽  
Laser Energy ◽  
Process Window ◽  
Loop Formation ◽  
Transmission Electron ◽  
Ultra Shallow Junctions ◽  
Laser Thermal Processing

AbstractLaser Thermal Processing (LTP) involves laser melting of an implantation induced preamorphized layer to form highly doped ultra shallow junctions in silicon. In theory, a large number of interstitials remain in the end of range (EOR) just below the laser-formed junction. There is also the possibility of quenching in point defects during the liquid phase epitaxial regrowth of the melt region. Since post processing anneals are inevitable, it is necessary to understand both the behavior of these interstitials and the nature of point defects in the recrystallized-melt region since they can directly affect deactivation and enhanced diffusion. In this study, an amorphizing 15 keV 1 x 1015/cm2 Si+ implant was done followed by a 1 keV 1 x 1014/cm2 B+ implant. The surface was then laser melted at energy densities between 0.74 and 0.9 J/cm2 using a 308 nm excimer-laser. It was found that laser energy densities above 0.81 J/cm2 melted past the amorphous-crystalline interface. Post-LTP furnace anneals were performed at 750°C for 2 and 4 hours. Transmission electron microscopy was used to analyze the defect formation after LTP and following furnace anneals. Secondary ion mass spectrometry measured the initial and final boron profiles. It was observed that increasing the laser energy density led to increased dislocation loop formation and increased diffusion after the furnace anneal. A maximum loop density and diffusion was observed at the end of the process window, suggesting a correlation between the crystallization defects and the interstitial evolution.

Temperature and Stress Analysis of Dual-Beam Laser Cladding on Gray Cast Iron Surface

Applied laser ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 288-293
Author(s):  
刘衍聪 Liu Yancong ◽  
范常峰 Fan Changfeng ◽  
尹晓丽 Yin Xiaoli ◽  
杨光辉 Yang Guanghui ◽  
许鹏云 Xu Pengyun
Keyword(s):  
Cast Iron ◽  
Stress Analysis ◽  
Laser Cladding ◽  
Gray Cast Iron ◽  
Iron Surface ◽  
Gray Cast ◽  
Beam Laser ◽  
Dual Beam

Effect of Energy Ratio on Dual Beam Laser Welding Characteristics

2017 ◽  
Vol 44 (3) ◽  
pp. 0302003
Author(s):  
马国龙 Ma Guolong ◽  
李俐群 Li Liqun ◽  
陈彦宾 Chen Yanbin
Keyword(s):  
Laser Welding ◽  
Energy Ratio ◽  
Beam Laser ◽  
Dual Beam

Influence of Temperature Distribution of Ceramic Coating Using Top-Hat Assistant Laser Beam in Dual-Beam Laser Cladding

2014 ◽  
Vol 41 (7) ◽  
pp. 0703012
Author(s):  
吴东江 Wu Dongjiang ◽  
褚洋 Chu Yang ◽  
牛方勇 Niu Fangyong ◽  
马广义 Ma Guangyi ◽  
庄娟 Zhuang Juan
Keyword(s):  
Temperature Distribution ◽  
Laser Beam ◽  
Laser Cladding ◽  
Ceramic Coating ◽  
Influence Of Temperature ◽  
Beam Laser ◽  
Dual Beam

Investigation of Fluid Flow and Heat Transfer in 3D Dual-Beam Laser Keyhole Welding

2010 ◽  
Author(s):  
Jun Zhou ◽  
Hai-Lung Tsai
Keyword(s):  
Heat Transfer ◽  
Laser Welding ◽  
Welding Process ◽  
Solidification Process ◽  
Melt Flow ◽  
Single Beam ◽  
Keyhole Welding ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Keyhole Welding

Dual-beam laser welding has become an emerging joining technique. Studies have demonstrated that it can provide benefits over conventional single-beam laser welding, such as increasing keyhole stability, slowing down cooling rate and delaying the humping onset to a higher welding speed. It is also reported to be able to improve weld quality significantly. However, due to its complexity the development of this promising technique has been limited to the trial-and-error procedure. In this study, mathematical models are developed to investigate the heat transfer, melt flow, and solidification process in three-dimensional dual-beam laser keyhole welding. Effects of key parameters, such as laser-beam configuration on melt flow, weld shape, and keyhole dynamics are studied. Some experimentally observed phenomena, such as the changes of the weld pool shape from oval to circle and from circle to oval during the welding process are analyzed in current study.

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