Selective Laser Annealing For Device Processing

1982 ◽  
Vol 13 ◽  
Author(s):  
I.D. Calder ◽  
A.A. Naem ◽  
H.H. Naguib
Keyword(s):  
Plasma Etching ◽  
Laser Annealing ◽  
Wet Etching ◽  
Laser Crystallization ◽  
Initial Value ◽  
Step Potential ◽  
Device Processing ◽  
Potential Applications ◽  
Polysilicon Films ◽  
Ar Coating

ABSTRACTSelective laser crystallization of undoped polysilicon films has been achieved through the use of a patterned Si3N4 anti-reflection (AR) coating. The recrystallized poly-Si beneath the AR cap exhibits an etch rate 50–90% lower than the surrounding uncapped material, allowing anisotropic etching of poly-Si for the fabrication of MOSFET gates. Undercut is reduced by at least a factor of two from unannealed material. Annealed edge profiles are uniform within ±0.03μm for plasma etching (±0.05 for wet etching) compared to ±0.1μm (± 0.25μm for wet etching) for unannealed regions. The sheet resistivity of 0.5μm films doped by phosphorus diffusion was reduced from an initial value of 82±5 Ω/□ to 40±8 Ω/□ when the dopant was diffused into recrystallized poly-Si and to a final value of 10.2 ± 0.2 Ω/□; after a further laser activation step. Potential applications in VLSIC processing are discussed.

A Chemical Perspective of GaN Polarity: The use of Hydrogen Plasma Dry Etching Versus NaOH Wet Etching to Determine Polarity

2002 ◽  
Vol 722 ◽  
Author(s):  
Maria Losurdo ◽  
MariaMichela Giangregorio ◽  
Pio Capezzuto ◽  
Giovanni Bruno ◽  
Gon Namkoong ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Plasma Etching ◽  
Hydrogen Plasma ◽  
Dry Etching ◽  
Surface Reactivity ◽  
Wet Etching ◽  
Hydrogen Treatment

AbstractThe use of dry hydrogen plasma etching is evaluated for determination of GaN polarity and critically compared to wet etching in NaOH. It is shown that hydrogen plasma etching is effective in revealing inversion domains (IDs) and some types of dislocations. This is because the surface morphology is unchanged by the hydrogen treatment, and, hence, the surface reactivity is not masked.

Mapping of Process-Induced Dopant Redistributions by Electron Holography

2004 ◽  
Vol 10 (4) ◽  
pp. 462-469 ◽  
Author(s):  
Wolf-Dieter Rau ◽  
Alexander Orchowski
Keyword(s):  
Semiconductor Device ◽  
Device Fabrication ◽  
Electron Holography ◽  
Dopant Diffusion ◽  
Fundamental Parameters ◽  
Device Processing ◽  
Device Structures ◽  
Before And After ◽  
Potential Applications ◽  
Junction Potential

We present and review dopant mapping examples in semiconductor device structures by electron holography and outline their potential applications for experimental investigation of two-dimensional (2D) dopant diffusion on the nanometer scale. We address the technical challenges of the method when applied to transistor structures with respect to quantification of the results in terms of the 2Dp–njunction potential and critically review experimental boundary conditions, accuracy, and potential pitfalls. By obtaining maps of the inner electrostatic potential before and after anneals typically used in device processing, we demonstrate how the “vertical” and “lateral” redistribution of boron during device fabrication can directly be revealed. Such data can be compared with the results of process simulation to extract the fundamental parameters for dopant diffusion in complex device structures.

scholarly journals Etch Processing of III-V Nitrides

1999 ◽  
Vol 4 (S1) ◽  
pp. 902-913 ◽  
Author(s):  
Charles R. Eddy
Keyword(s):  
Plasma Etching ◽  
Microwave Power ◽  
Ohmic Contacts ◽  
High Density ◽  
Etching Process ◽  
Ion Energy ◽  
Plasma Etching Process ◽  
Device Processing ◽  
The Impact ◽  
Density Plasma

As III-V nitride devices advance in technological importance, a fundamental understanding of device processing techniques becomes essential. Recent works have exposed various aspects of etch processes. The most recent advances and the greatest remaining challenges in the etching of GaN, AlN, and InN are reviewed. A more detailed presentation is given with respect to GaN high density plasma etching. In particular, the results of parametric and fundamental studies of GaN etching in a high density plasma are described. The effect of ion energy and mass on surface electronic properties is reported. Experimental results identify preferential sputtering as the leading cause of observed surface non-stoichiometry. This mechanism provides excellent surfaces for ohmic contacts to n-type GaN, but presents a major obstacle for Schottky contacts or ohmic contacts to p-type GaN. Chlorine-based discharges minimize this stoichiometry problem by improving the rate of gallium removal from the surface. In an effort to better understand the high density plasma etching process for GaN, in-situ mass spectrometry is employed to study the chlorine-based high density plasma etching process. Gallium chloride mass peaks were monitored in a highly surface sensitive geometry as a function of microwave power (ion flux), total pressure (neutral flux), and ion energy. Microwave power and pressure dependencies clearly demonstrate the importance of reactive ions in the etching of wide band gap materials. The ion energy dependence demonstrates the importance of adequate ion energy to promote a reasonable etch rate (≥100-150 eV). The benefits of ion-assisted chemical etching are diminished for ion energies in excess of 350 V, placing an upper limit to the useful ion energy range for etching GaN. The impact of these results on device processing will be discussed and future needs identified.

Alternative Materials for Micro-Electro-Mechanical Device Construction

1992 ◽  
Vol 276 ◽  
Author(s):  
R. H. Hackeit ◽  
L. E. Larson
Keyword(s):  
Plasma Etching ◽  
Silicon Oxide ◽  
Metal Films ◽  
Device Processing ◽  
Low Temperature Processing ◽  
Alternative Materials ◽  
Lift Off ◽  
Mechanical Devices ◽  
Silicon Based ◽  
Process Constraints

ABSTRACTIn order to integrate micro actuators with III-V semiconductor devices, we have devised Micro-Electro-Mechanical devices (MEM's), constructed from materials and processes common to existing III-V device processing. These processes are substantially different from silicon based processes because of the requirements for low temperature processing and the use of gold-based metallizations.Our material choices include, vacuum deposited and plated metal films, silicon oxide and nitride dielectric layers, and polyimide layers and structures. Sacrificial layers are implemented with photoresist rather than the more common silicon dioxide. The processes available are based on the ‘lift off’ of unwanted areas of the metal films, wet plating of metals through openings in photoresist masks, and wet and plasma etching of metals and dielectrics.This paper will discuss why we are using these materials, the process constraints imposed by the materials, the measurement of some of the material properties, and will relate some progress in applications.

Laser Crystallization and Annealing of Ferroelectric Thin Films

1995 ◽  
Vol 397 ◽  
Author(s):  
J.S. Zhu ◽  
X.M. Lu ◽  
X. Liu ◽  
W. Tian ◽  
Z. Yang ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Laser Annealing ◽  
Ferroelectric Phase ◽  
Ferroelectric Thin Films ◽  
Laser Crystallization ◽  
Amorphous Films ◽  
Krf Laser

ABSTRACTFerroelectric PbZr0.44Ti0.56O3 film with pure ferroelectric phase was fabricated by Ar3+ and KrF laser crystallization technique from as-deposited amorphous films, with the substrate at room temperature. Laser annealing technique was also used to improve the quality of BaTiO3 (BT) films.

Low-Temperature Polycrystalline Silicon Thin-Film Transistors and Circuits on Flexible Substrates

MRS Bulletin ◽  
2006 ◽  
Vol 31 (6) ◽  
pp. 461-465 ◽  
Author(s):  
P.C. van der Wilt ◽  
M.G. Kane ◽  
A.B. Limanov ◽  
A.H. Firester ◽  
L. Goodman ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Defect Density ◽  
Solid Phase ◽  
Flexible Substrates ◽  
Full Potential ◽  
Laser Crystallization ◽  
Silicon Thin Film ◽  
Excimer Laser Annealing ◽  
Si Films

AbstractLow-defect-density polycrystalline Si on flexible substrates can be instrumental in realizing the full potential of macroelectronics. Direct deposition or solid-phase crystallization techniques are often incompatible with polymers and produce materials with high defect densities. Excimer-laser annealing is capable of producing films of reasonable quality directly on polymer and metallic substrates. Sequential lateral solidification (SLS) is an advanced pulsed-laser-crystallization technique capable of producing Si films on polymers with lower defect density than can be obtained via excimer-laser annealing. Circuits built directly on polymers using these SLS films show the highest performance reported to date.

Lateral Grain Growth in the Excimer Laser Crystallization of Poly-Si

1994 ◽  
Vol 321 ◽  
Author(s):  
H. Kuriyama ◽  
K. Sano ◽  
S. Ishida ◽  
T. Nohda ◽  
Y. Aya ◽  
...  
Keyword(s):  
Grain Size ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Field Effect Mobility ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Short Processing Time ◽  
Low Temperature Processing ◽  
Excimer Laser Crystallization ◽  
Annealing Method

ABSTRACTWe have succeeded in obtaining nondoped, thin poly-Si film (thickness ∼500Å) with excellent crystallinity and large grain size (Maximum grain size ∼4.5 μ m) by an excimer laser annealing Method, which offers the features of low-temperature processing and a short processing time. The grain size distribution shrinks in the region around 1.5 μ m and this poly-Si film exhibits a strong (111) crystallographic orientation. Poly-Si thin film transistors using these films show quite a high field effect mobility of 440cm2/V · s below 600°C process.

A Novel Excimer Laser Crystallization Method of Poly-Si Thin Film by Grid Line Electron Beam Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
C-M Park ◽  
M-C Lee ◽  
J-H Jeon ◽  
M-K Han
Keyword(s):  
Thin Film ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Ion Beam ◽  
Growth Effect ◽  
Beam Irradiation ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Transmission Electron ◽  
Si Thin Film

AbstractExcimer laser annealing technique is proposed to increase the grain size and controlling the microstructure of polycrystalline silicon (poly-Si) thin film. Our method is based on the lateral grain growth during laser annealing. Our specific grid ion beam irradiation method was designed to maximize the lateral growth effect and arrange the location of grain boundaries. We observed well-arranged poly-Si grains up to micrometer order by transmission electron microscopy (TEM).

Study of Copper Surface Preparation by Sequential Atomic Layer Wet Etching and Laser Annealing Treatments

2017 ◽  
Vol 80 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Akihisa Iwasaki ◽  
Yuya Akanishi ◽  
Fulvio Mazzamuto ◽  
Els Kesters ◽  
Quoc Toan Le ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Surface Preparation ◽  
Atomic Layer ◽  
Copper Surface ◽  
Wet Etching
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