Effect of excimer laser annealing on the structural properties of silicon germanium films

2004 ◽  
Vol 19 (12) ◽  
pp. 3503-3511 ◽  
Author(s):  
Sherif Sedky ◽  
Jeremy Schroeder ◽  
Timothy Sands ◽  
Tsu-Jae King ◽  
Roger T. Howe
Keyword(s):  
Surface Roughness ◽  
Excimer Laser ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Film Structure ◽  
Excimer Laser Annealing ◽  
Pressure Chemical ◽  
Columnar Grain

We investigated the use of a pulsed excimer laser having a wavelength of 248 nm, a pulse duration of 38 ns, and an average fluence between 120 and 780 mJ/cm2 to locally tailor the physical properties of Si1−xGex (18% < x < 90%) films deposited by low-pressure chemical vapor deposition at temperatures between 400 and 450 °C. Amorphous as-deposited films showed, after laser annealing, strong {111} texture, a columnar grain microstructure, and an average resistivity of 0.7 mΩ cm. Atomic force microscopy indicated that the first few laser pulses resulted in a noticeable reduction in surface roughness, proportional to the pulse energy. However, a large number of successive pulses dramatically increased the surface roughness. The maximum thermal penetration depth of the laser pulse is demonstrated to depend on the fluence and the film structure being either polycrystalline or amorphous. Finally, a comparison between excimer laser annealing and metal-induced crystallization and rapid thermal annealing is presented.

Pulsed Laser Annealing of Silicon-Germanium Films

2002 ◽  
Vol 741 ◽  
Author(s):  
Sherif Sedky ◽  
Jeremy Schroeder ◽  
Timothy Sands ◽  
Roger Howe ◽  
Tsu-Jae King
Keyword(s):  
Surface Roughness ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Pulsed Laser Annealing ◽  
Pressure Chemical ◽  
Noticeable Reduction ◽  
Columnar Grain

ABSTRACTIn this work, we investigate the possibility of using pulsed laser annealing to locally tailor the physical properties of Si1-xGex (18% < × < 90%) prepared by low pressure chemical vapor deposition (LPCVD) at 400°C. Films which were amorphous as deposited showed, after laser annealing, strong {111} texture and a columnar grain microstructure and an average resistivity of 0.7 mΩ.cm. AFM showed that the first few laser pulses result in a noticeable reduction in surface roughness, which is proportional to the pulse energy. However, a large number of successive pulses dramatically increases the surface roughness.

The Recrystallization Depth Control of the Excimer-Laser-Recrystallized Poly-Crystalline Silicon Film

1999 ◽  
Vol 557 ◽  
Author(s):  
Kee-Chan Park ◽  
Kwon-Young Choi ◽  
Jae-Hong Jeon ◽  
Min-Cheol Lee ◽  
Min-Koo Han
Keyword(s):  
Laser Beam ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Silicon Film ◽  
Film Structure ◽  
Excimer Laser Annealing ◽  
Silicon Oxide Layer ◽  
Thin Oxide Film

AbstractA novel method to control the recrystallization depth of amorphous silicon (a-Si) film during the excimer laser annealing (ELA) is proposed in order to preserve a-Si that is useful for fabrication of poly-Si TFT with a-Si offset in the channel. A XeCl excimer laser beam is irradiated on a triple film structure of a-Si thin native silicon oxide (~20Å)/thick a-Si layer. Only the upper a-Si film is recrystallized by the laser beam irradiation, whereas the lower thick a-Si film remains amorphous because the thin native silicon oxide layer stops the grain growth of the poly-crystalline silicon (poly-Si). So that the thin oxide film sharply divides the upper poly-Si from the lower a-Si.

Poly-Resistor Thin Film Formation by Excimer Laser Micromachine

2015 ◽  
Vol 780 ◽  
pp. 17-21
Author(s):  
A.F.M. Anuar ◽  
Yufridin Wahab ◽  
M.Z. Zainol ◽  
H. Fazmir ◽  
M. Najmi ◽  
...  
Keyword(s):  
Thin Film ◽  
Excimer Laser ◽  
Laser Energy ◽  
Film Formation ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Beam Size ◽  
Silicon Thin Film ◽  
Pressure Chemical ◽  
Krf Excimer Laser

A simple theoretical model and resistor fabrication for calculating the resistance of a polycrystalline silicon thin film is presented. The resistance value for poly-resistor is perfomed in terms of polysilicon thickness and its total area. The KrF excimer laser micromachine is used in assisting the resistor formation for a low pressure chemical vapor deposition (LPCVD) based polysilicon. Laser micromachine with three main parameters is used to aid the fabrication of the poly-resistor; namely as the pulse rate (i.e. number of laser pulses per second), laser beam size and laser energy. These parameters have been investigated to create the isolation between materials and also to achieve the desired poly-resistor shape. Preliminary results show that the 35 um beam size and 15 mJ of energy level is the most effective parameter to produce the pattern. Poly-resistor formation with 12 and 21 number of squares shows the total average resistance of 303.52 Ω and 210.14 Ω respectively. The laser micromachine process also significantly reduce the total time and number of process steps that are required for resistor fabrication.

Ultra-Low Temperature Poly-Si Thin Film by Excimer Laser Recrystallization For Flexible Substrates

2003 ◽  
Vol 769 ◽  
Author(s):  
Sang-Myeon Han ◽  
Min-Cheol Lee ◽  
Su-Hyuk Kang ◽  
Moon-Young Shin ◽  
Min-Koo Han
Keyword(s):  
Low Temperature ◽  
Excimer Laser ◽  
Inductively Coupled Plasma ◽  
Laser Annealing ◽  
Silicon Film ◽  
Chemical Vapor ◽  
Plastic Substrate ◽  
Excimer Laser Annealing ◽  
Plasma Chemical Vapor Deposition ◽  
Laser Recrystallization

AbstractAn ultra-low temperature (< 200°C) polycrystalline silicon (poly-Si) film is fabricated for the plastic substrate application using inductively coupled plasma chemical vapor deposition (ICP-CVD) and excimer laser annealing. The precursor active layer is deposited using the SiH4/He mixture at 150°C (substrate). The deposited silicon film consists of crystalline component as well as hydrogenated amorphous component. The hydrogen content in the precursor layer is less than 5 at%. The grain size of the precursor active silicon film is about 200nm and it is increased up to 500nm after excimer laser irradiation.

Ultra-Shallow Junction Formation by Excimer Laser Annealing of Ultra-Low Energy B Implanted in Si

2003 ◽  
Vol 765 ◽  
Author(s):  
G. Fortunato ◽  
L. Mariucci ◽  
V. Privitera ◽  
A. La Magna ◽  
S. Whelan ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Laser Pulses ◽  
Low Energy ◽  
Excimer Laser Annealing ◽  
High Resolution Tem ◽  
Ultra Shallow Junctions ◽  
Dopant Redistribution ◽  
Melt Duration

AbstractFormation of ultra-shallow junctions by excimer laser annealing (ELA) of ultra-low energy (1keV –250 eV) B implanted in Si has been investigated. High resolution TEM has been used to assess the as-implanted damage and the crystal recovery following ELA. The electrical activation and redistribution of B in Si during ELA has been studied as a function of the laser energy density (melt depth), the implant dose and the number of laser pulses (melt duration). Under appropriate ELA conditions, ultra-shallow profiles, extending to a depth as low as 35 nm with an abrupt profile (2.5 nm/dec), have been achieved. A significant amount of the implanted dopant was lost from the sample following ELA. However, the dopant that was retained in crystal material was fully activated following rapid re-solidification. We developed a theoretical model, that considers the dopant redistribution during melting and regrowth, showing that the fraction of the implanted dopant not activated during ELA was lost from the sample through out diffusion. The lateral distribution of the implanted B following laser annealing has been studied with 2-D measurements, using selective etching and cross-section TEM on samples where the implanted dopant was confined by using test structures including windows opened in silicon dioxide masks and patterned gate stack structures.

Selected Area Epitaxial Regrowth of Amorphous Si/(100) Si Structures by Laser Annealing

1985 ◽  
Vol 49 ◽  
Author(s):  
A. Christou ◽  
C. Varmazis ◽  
T. Efthimiopoulos ◽  
C. Fotakis
Keyword(s):  
Surface Roughness ◽  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Leakage Currents ◽  
Excimer Laser Annealing ◽  
Epitaxial Regrowth ◽  
Amorphous Si

AbstractExcimer laser KrF (248 nm) annealing at 93 mj/cm2 and 175 mJ/cm2 has been found to recrystallize amorphous silicon on (100)Si. The major impurities introduced by excimer laser annealing are carbon, while surface roughness remains as a major problem. Channel mobilities measured on MOSFETs processed on epitaxially regrown silicon were 98-115 cm2/v.s. Leakage currents between recrystallized silicon regions were 1-2 uA/cm2.

Polycrystalline Silicon Films on SiO2 Substrate Treated by Excimer Laser Annealing

2013 ◽  
Vol 750-752 ◽  
pp. 946-951
Author(s):  
Chun Yan Duan ◽  
Bin Ai ◽  
Rong Xue Li ◽  
Chao Liu ◽  
Jian Jun Lai ◽  
...  
Keyword(s):  
Grain Size ◽  
Excimer Laser ◽  
Polycrystalline Silicon ◽  
Laser Annealing ◽  
Laser Energy ◽  
Chemical Vapor ◽  
Excimer Laser Annealing ◽  
Before And After ◽  
Si Films ◽  
Polycrystalline Silicon Films

Selected area laser-annealed polycrystalline silicon (p-Si) thin films were prepared by a 248 nm excimer laser. 1 μm thick p-Si films with grain size less than 100 nm were deposited on SiO2substrate by chemical vapor deposition using atmospheric pressure (APCVD). Grain sizes before and after annealing was examined by scanning electron microscopy (SEM) and the mechanism of grain growth was discussed in detail. The maximum grain size of a selected area laser-annealed p-Si film can be increased from 100 nm up to 2.9 μm on SiO2substrate by using appropriate laser energy densities. It indicated that silicon grains in laser-annealed regions had grown up competitively with three stages.

Sign in / Sign up

Export Citation Format

Share Document