scholarly journals Measurement and Simulation of Boron Diffusivity in Strained Si1 –xGex Epitaxial Layers

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 317-321 ◽  
Author(s):  
K. Rajendran ◽  
W. Schoenmaker
Keyword(s):  
Annealing Temperature ◽  
Chemical Vapor ◽  
Empirical Expression ◽  
Strained Si ◽  
Chemical Effects ◽  
Pressure Chemical ◽  
Experimental Values ◽  
Boron Diffusivity ◽  
Rapid Pressure ◽  
Good Agreement

Diffusion of boron in compressively strained Si1 –xGex alloy layers grown by rapid pressure chemical vapor deposition has been studied as a function of the composition for 0.0006 ≤ x ≤ 0.15 and annealing temperature. The comparison of the Si1 –xGex samples to the Si samples after rapid thermal and furnace annealing revealed a retarded B diffusion inside the strained Si1 –xGex layers. The influence of the Ge content on the dopant diffusion was also measured and simulated, demonstrating that the diffusion of B was found to decrease with the Ge alloy content and annealing temperature. A simple empirical expression for the B retardation is presented and incorporated into a diffusion model for dopants in heterostructures. Good agreement between the measured and simulated diffusivity that includes the model for strain and chemical effects are obtained. By comparing with experimental values, our extracted (by using experiment and simulation) B diffusivity predicted a lower value (retardation).

Variation de la contrainte des verres de silice sous cycle thermique

1992 ◽  
Vol 70 (10-11) ◽  
pp. 830-833
Author(s):  
H. Bouchard ◽  
A. Azelmad ◽  
J. F. Currie ◽  
M. Meunier
Keyword(s):  
Initial Stress ◽  
Vapor Deposition ◽  
Boron Content ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Boron Doping ◽  
Pressure Chemical ◽  
Phosphosilicate Glass ◽  
Borophosphosilicate Glass

Using an in situ technique, stress was measured as a function of annealing temperature to investigate the effect of phosphorous and boron doping of silicon dioxide glass films deposited by low-pressure chemical vapor deposition (LPCVD). It was found that the initial stress of phosphosilicate glass is independent of the amount of phosphorus present, while the boron content influences the initial stress in borophosphosilicate glass. The stress increases to a maximum, σm, corresponding to a temperature Tm, above which the onset of viscous flow reduces the stress to zero at a temperature T0. All these parameters are dependant on dopant concentrations. The observed mechanical behavior is discussed in terms of film viscosity.

Photoluminescence of SnO2 Films Prepared by APCVD

2005 ◽  
Vol 475-479 ◽  
pp. 3701-3704 ◽  
Author(s):  
Feng Ji ◽  
Jin Ma ◽  
Yu Heng Wang ◽  
Hong-Lei Ma ◽  
Xihu Yu ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Emission Mechanism ◽  
Rutile Structure ◽  
Atmosphere Pressure ◽  
Pressure Chemical

SnO2 films were prepared by atmosphere pressure chemical vapor deposition (APCVD) method. The preparation, structure and photoluminescence (PL) properties of the SnO2 films were investigated. All the obtained films were polycrystalline with the rutile structure. A violet (396 nm) and a blue (446 nm) photoluminescence peaks were observed at room temperatures. The intensity of the PL peaks located at 3.13 eV decreased with increasing the annealing temperature. The emission mechanism of the SnO2 films has been investigated.

Reduced Pressure - Chemical Vapor Deposition of high Ge content (20% - 55%) SiGe virtual substrates

2004 ◽  
Vol 809 ◽  
Author(s):  
Y. Bogumilowicz ◽  
J.M. Hartmann ◽  
F. Laugier ◽  
G. Rolland ◽  
T. Billon ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Root Mean Square Roughness ◽  
Misfit Dislocations ◽  
Strained Si ◽  
Reduced Pressure ◽  
Pressure Chemical

ABSTRACTWe have studied the strain state, film and surface morphology of SiGe virtual substrates (Ge concentrations in-between 20% and 55%) grown by reduced pressure – chemical vapor deposition. The macroscopic degree of strain relaxation of those virtual substrates is equal to 97.2 ± 1.5%. The misfit dislocations generated to relax the lattice mismatch between Si and SiGe are mostly confined inside the graded layer. Indeed, the threading dislocations density obtained for Ge concentrations of 20% and 26% is indeed typically of the order of 7.5 ± 2.5 105 cm−2. Low surface root mean square roughness have been obtained, with values in-between 2 and 5 nm. In order to check the electronic quality of our layers, we have grown a MODFET-like heterostructure, with a buried tensile-strained Si channel 8 nm thick embedded inside SiGe 26%. We have obtained a well-behaved 2-dimensional electron gas in the Si channel, with electron sheet densities and mobilities at 1.45K of 5.4×1011 cm−2 and 212 000 cm2 V−1 s−1, respectively.

Thermal Stability Of SiGe/Si Quantum Well Structures Grown By APCVD

1998 ◽  
Vol 533 ◽  
Author(s):  
Q. X. Zhao ◽  
O. Nur ◽  
U. Södervall ◽  
C. J. Patel ◽  
M. Willandera ◽  
...  
Keyword(s):  
Quantum Well ◽  
Atmospheric Pressure ◽  
Annealing Temperature ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Quantum Well Structures ◽  
Pressure Chemical ◽  
Different Temperatures ◽  
Secondary Ion ◽  
Thermal Stability Of

AbstractSingle and double Si1-xGexx/Si quantum well (QW) structures, which were grown by atmospheric pressure chemical vapor deposition (APCVD), are characterized by photoluminescence and secondary ion mass spectrometry. Systematic post-growth annealing treatments were carried out at temperatures between 600°C and 1100°C in pure N2 ambient. The interdiffusion between the Si layer and the Si1-xGex, well layers occurs at the annealing temperature around 900°C. The diffusion coefficient is deduced at different temperatures from SIMS measurements for single QW structures. The activation energy is about 3.9 eV in the temperature range between 950°C and 1100°C. The double QW structures show a similar value, but the accurate value is more difficult to obtain because it is more complicated to analyze the SIMS profile of the double QW structures. The intensity of the exciton recombination related to carriers confined in the double QW structures decreases with increasing annealing temperatures and becomes strongly suppressed at 750°C. When the annealing temperature is increased further, the intensity of the QW emission recovers. The results indicate that nonradiative centers were generated at annealing temperature of about 750°C

Thermal Stress in Doped Silicate Glasses (B,P) Deposited by PECVD and LPCVD

1993 ◽  
Vol 308 ◽  
Author(s):  
H. Bouchard ◽  
A. Azelmad ◽  
J.F. Currie ◽  
M. Meunier ◽  
S. Blain ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Stress Measurement ◽  
Chemical Vapor ◽  
In Situ Stress ◽  
In Situ Stress Measurement ◽  
Pressure Chemical

ABSTRACTUsing an in situ stress measurement technique which measures stress as a function of annealing temperature, we have investigated the effect of phosphorous and boron doping of silicon dioxide glass films deposited by low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced chemical vapor deposition (PECVD). The stress at room temperature is σi. Upon heating, it increases to a maximum, σm, corresponding to a temperature Tm, above which the stress is reduced to zero at a temperature T0. All these parameters plus the expansion coefficient are dependent on dopant concentrations and deposition technique.

Spectroscopic ellipsometry and photoluminescence from Si1−xGex alloys grown by atmospheric-pressure chemical vapor deposition

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1194-1198
Author(s):  
J. E. Hulse ◽  
N. L. Rowell ◽  
A. Wang ◽  
F. Namavar ◽  
C. H. Perry
Keyword(s):  
Chemical Vapor Deposition ◽  
Spectroscopic Ellipsometry ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Optical Constants ◽  
Near Infrared ◽  
Chemical Vapor ◽  
Strained Si ◽  
Phonon Line ◽  
Pressure Chemical

Si1−xGex layers grown using atmospheric pressure chemical vapor deposition have been characterized using both room temperature spectroscopic ellipsometry (SE) and low-temperature photoluminescence (PL). Single layers of Si0.9Ge0.1, 30, 100, 1000, and 2000 nm thick on p+ Si(100) wafers were investigated to determine the effect of strain on the indirect and direct optical transitions. The thinner two layers were pseudomorphic and the thicker ones relaxed. The samples were examined by spectroscopic ellipsometry, which allowed the optical constants to be determined from the ultraviolet to near infrared (3.5–1.8 eV). Using optical constants available from the literature for cubic Si1−xGex, the thicknesses of the alloy layers were verified. From our optical constants and the published calibration curves for normal incidence reflectivity at 633 nm and for the energy of the E1 transition (both a function of x), we found that the average germanium concentration appeared to be significantly below the nominal 10% for these samples. Phonon-resolved PL spectra were observed at 2 K for the thicker three samples with the transition from strained to unstrained layers clearly visible in the shift of the Si1−xGex band gap as seen from the energy of the no-phonon line. Dislocation lines appeared only for the relaxed material and the no-phonon line widths were ~4 times smaller for the strained Si1−xGex material.

Raman Studies of Microstructural Changes in Amorphous Silicon-Boron Alloys Due to Annealing

1989 ◽  
Vol 164 ◽  
Author(s):  
G. Yang ◽  
P. Bai ◽  
Y.-J Wu ◽  
B. Y. Tong ◽  
S. K. Wong ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Boron Content ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Alloy Films ◽  
Si Substrates ◽  
Pressure Chemical ◽  
Crystalline Component

AbstractCrystallization of amorphous Sil−x.Bx alloy films by annealing is studied. Amorphous Sil−xBx. alloy films with composition of boron x ranging from 0.01 to 0.5 are deposited on Si substrates at a temperature of 480° in a low pressure chemical vapor deposition (LPCVD) system. Three films with the boron contents, 1%, 7% and 45%, are used in this study. The films are annealed in a nitrogen ambient for 30 minutes at temperatures between 600°C and 900°C. Raman spectra of the silicon vibrational mode serve as a indicator for the microstructure of the Sil−xBx, alloy films. Quantitative estimates of the volume fraction of the crystalline silicon component in respect to the amorphous silicon component in the films are calculated based on the silicon TO mode. The results show that while for the film with the boron content of 1% crystallization occurs at the annealing temperature of 500°C, the annealing temperature of 7000C is required to observe crystallization in the films with the boron contents of 7% and 45%. As the annealing temperature increases, the volume fraction of the crystalline component increases. For a given annealing temperature, the rate of crystallization depends inversely on the boron content in the films.

Schottky Barrier Heights of A1/p-Sil-xGex

1995 ◽  
Vol 379 ◽  
Author(s):  
R. L. Jiang ◽  
J. Li ◽  
X. C. Zhou ◽  
J. N. Liu ◽  
Y. D. Zheng
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Height ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Schottky Contacts ◽  
Rapid Thermal Process ◽  
Strained Si ◽  
Strained Layers ◽  
Barrier Heights ◽  
Pressure Chemical

ABSTRACTElectrical properties of Al/p-Sil-xGex Schottky contacts were investigated. The Sil-xGexstrained layers were grown by using Rapid Thermal Process/Very Low Pressure-Chemical Vapor Deposition. It was found that Schottky barrier height decreased with increasing Ge fraction. The decrement is in accordance with the decrement of the bandgap of the strained Sil-xGex. The Fermi level at the interface is pinned at about 0. 43eV below the conduction band. The influence of strain relaxation for SiGe alloy layers and the Si cap layers on the properties of Schottky contacts were also investigated.

Sign in / Sign up

Export Citation Format

Share Document