Continuous-wave laser-induced diffusion in silicon

1985 ◽  
Vol 63 (6) ◽  
pp. 886-889
Author(s):  
P. Schvan ◽  
R. E. Thomas
Keyword(s):  
Laser Beam ◽  
High Speed ◽  
Continuous Wave ◽  
Scanning Speed ◽  
Processing Technique ◽  
Continuous Wave Laser ◽  
Large Area ◽  
Incident Laser Power ◽  
Cw Laser ◽  
Novel Processing

A novel processing technique to form shallow p-n junctions using a continuous-wave (cw) laser beam scanned over a large area is described. The results of computer simulation of the heat-flow problem were used to find the optimum condition for cw laser-induced liquid-phase diffusion. High-speed scanning of the laser beam and the application of phosphosilica glass as a diffusion source, which also acts as an antireflective coat, are essential parts of the process. The optimum incident laser power was around 7.5 W with a scanning speed of 100 cm/s. This process produced junction depths of around 0.2–0.4 μm. Reliable contacts to the shallow diffusions were made using tungsten silicide formed prior to the aluminum deposition. The p-n junctions formed by this technique showed good diode characteristics with breakdown voltages over 35 V and leakage current around 10−5 A/cm2.

Spatial Continuous Wave Laser and Spatiotemporal VCSEL for High-Speed Long Haul Optical Wireless Communication Channels

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd Elnaser A. Mohammed ◽  
Ehab Salah El-Din ◽  
P. Yupapin
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Continuous Wave ◽  
Propagation Distance ◽  
Q Factor ◽  
Optical Wireless Communication ◽  
Continuous Wave Laser ◽  
Optical Wireless ◽  
Cw Laser ◽  
Improvement Ratio

AbstractThis study has presented spatial continuous wave laser and spatiotemporal vertical cavity surface emitting laser (VCSEL) for high speed long haul optical wireless communication channels. Possible data rates range from 40 Gb/s to 250 Gb/s over propagation distance ranges from 500 km to 2500 km. The optical wireless communication (OWC) system performance is tested through the measurement of maximum Q-factor, minimum bit error rate (BER) and signal to noise ratio (SNR). It is observed that spatiotemporal VCSEL has presented better performance than CW laser in the OWC system, especially for long haul transmission applications. It is observed that SNR improvement ratio ranges from 8.15 % to 19 % by using spatiotemporal VCSEL than CW laser for bit rate of 40 Gb/s over propagation distance ranges from 500 km to 2500 km. Max. Q-factor improvement ratio ranges from 4.62 % to 13.71 % by using spatiotemporal VCSEL than CW laser for data rate of 40 Gb/s over propagation distance ranges from 500 km to 2500 km. So it is clear that spatiotemporal VCSEL is more suitable for long haul OWC applications than other optical sources.

Fabrication of microlenses in Ag-doped glasses by a focused continuous wave laser beam

2003 ◽  
Vol 93 (5) ◽  
pp. 2343-2348 ◽  
Author(s):  
I. Antonov ◽  
F. Bass ◽  
Yu. Kaganovskii ◽  
M. Rosenbluh ◽  
A. Lipovskii
Keyword(s):  
Laser Beam ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Doped Glasses ◽  
Wave Laser

Low-Pass Spatial Filtering for Continuous-Wave Laser Beam by Reflection Volume Phase Gratings

2010 ◽  
Vol 30 (6) ◽  
pp. 1554-1559
Author(s):  
郑光威 Zheng Guangwei ◽  
谭吉春 Tan Jichun ◽  
何焰蓝 He Yanlan ◽  
郑浩斌 Zheng Haobin ◽  
王晓东 Wang Xiaodong ◽  
...  
Keyword(s):  
Laser Beam ◽  
Continuous Wave ◽  
Spatial Filtering ◽  
Continuous Wave Laser ◽  
Volume Phase ◽  
Low Pass ◽  
Wave Laser

scholarly journals Comparison of different system technologies for continuous-wave laser beam welding of copper

Procedia CIRP ◽  
2020 ◽  
Vol 94 ◽  
pp. 587-591
Author(s):  
Eric Punzel ◽  
Florian Hugger ◽  
Robert Dörringer ◽  
Thorm Lembit Dinkelbach ◽  
Andreas Bürger
Keyword(s):  
Laser Beam ◽  
Continuous Wave ◽  
Laser Beam Welding ◽  
Continuous Wave Laser ◽  
Wave Laser

Mechanisms of the blue emission of NaYF4:Tm3+ nanoparticles excited by an 800 nm continuous wave laser

2016 ◽  
Vol 18 (37) ◽  
pp. 25905-25914 ◽  
Author(s):  
Hongxin Zhang ◽  
Tianqing Jia ◽  
Xiaoying Shang ◽  
Shian Zhang ◽  
Zhenrong Sun ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Laser Excitation ◽  
Blue Emission ◽  
Quantum Transition ◽  
Continuous Wave Laser ◽  
Cw Laser ◽  
Wave Laser

Simultaneous multiwavelength excitation and the quantum transition principle are utilized to study the blue emission mechanisms of NaYF4:Tm3+ UCNPs under 800 nm CW laser excitation.

Laser-Induced Damage of Polycrystalline Silicon Optically Powered MEMS Actuators

2005 ◽  
Author(s):  
Justin R. Serrano ◽  
Leslie M. Phinney ◽  
Carlton F. Brooks
Keyword(s):  
Polycrystalline Silicon ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Mems Devices ◽  
Optical Mems ◽  
Thermal Actuators ◽  
Incident Laser Power ◽  
Mems Actuators ◽  
Laser Induced Damage ◽  
Time Required

Optical MEMS devices are commonly interfaced with lasers for communication, switching, or imaging applications. Dissipation of the absorbed energy in such devices is often limited by dimensional constraints which may lead to overheating and damage of the component. Surface micromachined, optically powered thermal actuators fabricated from two 2.25 μm thick polycrystalline silicon layers were irradiated with 808 nm continuous wave laser light with a 100 μm diameter spot under increasing power levels to assess their resistance to laser-induced damage. Damage occurred immediately after laser irradiation at laser powers above 275 mW and 295 mW for 150 μm diameter circular and 194 μm by 150 μm oval targets, respectively. At laser powers below these thresholds, the exposure time required to damage the actuators increased linearly and steeply as the incident laser power decreased. Increasing the area of the connections between the two polycrystalline silicon layers of the actuator target decreases the extent of the laser damage. Additionally, an optical thermal actuator target with 15 μm × 15 μm posts withstood 326 mW for over 16 minutes without exhibiting damage to the surface.

Continuous-wave laser beam fanning in organic solutions: a novel phenomenon

1994 ◽  
Vol 19 (24) ◽  
pp. 2068 ◽  
Author(s):  
Hossin Abdeldayem ◽  
Mehdi Moghbel ◽  
P. Chandra Sekhar ◽  
M. C. George ◽  
P. Venkateswarlu ◽  
...  
Keyword(s):  
Laser Beam ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Wave Laser ◽  
Organic Solutions

Evaporative Cutting of a Semitransparent Body With a Moving CW Laser

1988 ◽  
Vol 110 (4a) ◽  
pp. 924-930 ◽  
Author(s):  
H. Abakians ◽  
M. F. Modest
Keyword(s):  
Laser Beam ◽  
Integral Method ◽  
Continuous Wave ◽  
Nonlinear Partial Differential Equations ◽  
Groove Depth ◽  
Surface Heat ◽  
Heat Losses ◽  
Gaussian Laser Beam ◽  
Cw Laser ◽  
Partial Evaporation

The formation of a groove by partial evaporation of a moving semi-infinite and semitransparent solid is considered. Evaporative removal of material is achieved by focusing a high-power, highly concentrated Gaussian laser beam of continuous wave (CW) onto the surface of the solid. Surface heat losses due to radiation and convection are assumed to be negligible, and conductive losses are treated in an approximate fashion using a simple integral method. The relevant nonlinear partial differential equations are solved numerically, and results for groove depth and shape are presented for a variety of laser and solid parameters.

scholarly journals Dual Laser Beam Asynchronous Dicing of 4H-SiC Wafer

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1331
Author(s):  
Zhe Zhang ◽  
Zhidong Wen ◽  
Haiyan Shi ◽  
Qi Song ◽  
Ziye Xu ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Laser Beam ◽  
Continuous Wave ◽  
Fe Model ◽  
Cw Laser ◽  
Thermal Stress Field ◽  
Simulation And Experiment ◽  
Mechanical Breaking ◽  
Sic Wafer ◽  
Dual Laser

SiC wafers, due to their hardness and brittleness, suffer from a low feed rate and a high failure rate during the dicing process. In this study, a novel dual laser beam asynchronous dicing method (DBAD) is proposed to improve the cutting quality of SiC wafers, where a pulsed laser is firstly used to introduce several layers of micro-cracks inside the wafer, along the designed dicing line, then a continuous wave (CW) laser is used to generate thermal stress around cracks, and, finally, the wafer is separated. A finite-element (FE) model was applied to analyze the behavior of CW laser heating and the evolution of the thermal stress field. Through experiments, SiC samples, with a thickness of 200 μm, were cut and analyzed, and the effect of the changing of continuous laser power on the DBAD system was also studied. According to the simulation and experiment results, the effectiveness of the DBAD method is certified. There is no more edge breakage because of the absence of the mechanical breaking process compared with traditional stealth dicing. The novel method can be adapted to the cutting of hard-brittle materials. Specifically for materials thinner than 200 μm, the breaking process in the traditional SiC dicing process can be omitted. It is indicated that the dual laser beam asynchronous dicing method has a great engineering potential for future SiC wafer dicing applications.

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