Well-Resolved Band-Edge Photoluminescence from Strained Si1–xGex Layers Grown by Rapid Thermal Chemical Vapor Deposition

1991 ◽  
Vol 220 ◽  
Author(s):  
J. C. Sturm ◽  
P. V. Schwartz ◽  
H. Manoharan ◽  
Q. Mi ◽  
L. C. Lenchyshyn ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Quantum Wells ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
Band Edge ◽  
Strained Layers ◽  
Alloy Scattering ◽  
Thermal Chemical Vapor Deposition ◽  
Band Edge Luminescence

ABSTRACTWell resolved band-edge luminescence of excitons in silicon-germanium alloy strained layers, quantum wells, and superlattices has been observed in films grown by Rapid Thermal Chemical Vapor Deposition. The signal is due to bound excitons at low temperatures and free excitons at higher temperatures, and has a strong no-phonon signal which is caused by alloy scattering. Bandgaps inferred from photoluminescence agree well with those measured by absorption spectroscopy, inferring that a no-phonon process dominates the band-edge absorption.

Defect-Free Band-Edge Photoluminescence in SiGeC Strained Layers Grown by Rapid Thermal Chemical Vapor Deposition

1995 ◽  
Vol 379 ◽  
Author(s):  
C. W. Liu ◽  
A. St. Amour ◽  
J. C. Sturm ◽  
Y. R. J. Lacroix ◽  
M. L. W. Thewalt
Keyword(s):  
Chemical Vapor Deposition ◽  
Quantum Wells ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Band Edge ◽  
Strained Layers ◽  
Thermal Chemical Vapor Deposition ◽  
Free Band ◽  
First Time ◽  
Excitation Conditions

ABSTRACTThe defect-free band-edge photoluminescence at both 30K and 77K was observed for the first time in Si/SiGeC/Si quantum wells. The SiGeC samples were prepared by rapid thermal chemical vapor deposition (RTCVD) by using methylsilane as carbon source added in a dichlorosilane and germane mixture. Deep photoluminescence around 0.8 eV, previously reported by Boucaud et al., was no longer observed under any excitation conditions. Compared to control Si/SiGe/Si quantum wells, the initial effect of adding the C is to decrease the bandgap of the host SiGe layers, despite the fact that the diamond has a large bandgap.

Rapid Thermal Chemical Vapor Deposition of Polycrystalline Silicon-Germanium Films on SiO2 and Their Properties

1995 ◽  
Vol 403 ◽  
Author(s):  
V. Z-Q Li ◽  
M. R. Mirabedini ◽  
R. T. Kuehn ◽  
D. Gladden ◽  
D. Batchelor ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Grain Structure ◽  
Germanium Content ◽  
Thermal Chemical Vapor Deposition ◽  
Nucleation Sites

AbstractIn this work, polycrystalline SiGe has been viewed as an alternative gate material to polysilicon in single wafer processing for the deep submicrometer VLSI applications. We studied deposition of the silicon-germanium (SiGe) films with different germanium concentrations (up to 85%) on SiO2 in a rapid thermal chemical vapor deposition reactor using GeH4 and SiH4/H2 gas mixture with the temperature ranging from 550°C to 625°C. Since the SiGe RTCVD process is selective toward oxide and does not form nucleation sites on the oxide easily, an in-situ polysilicon flash technique is used to provide the necessary nucleation sites for the deposition of SiGe films with high germanium content. It was observed that with the in-situ polysilicon flash as a pre-nucleation seed, the SiGe deposited on SiO2 forms a continuous polycrystalline layer. Polycrystalline SiGe films of about 2000Å in thickness have a columnar grain structure with a grain size of approximately 1000Å. Compositional analyses from Auger Electron Spectroscopy (AES) and Rutherford backscattering (RBS) show that the high germanium incorporation in the SiGe films has a weak dependence on the deposition temperature. It is also noted that the germanium content across the film thickness is fairly constant which is a critical factor for the application of SiGe films as the gate material. Lastly, we found that the surface morphology of SiGe films become smoother at lower deposition temperature.

Selective Deposition of Silicon and Silicon-Germanium Alloys by Rapid Thermal Chemical Vapor Deposition

1996 ◽  
Vol 429 ◽  
Author(s):  
John M. Grant ◽  
Ming Ang ◽  
Lynn R. Allen
Keyword(s):  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
Native Oxide ◽  
Initiation Time ◽  
Selective Deposition ◽  
Thermal Chemical Vapor Deposition ◽  
Oxide Removal

AbstractSelective deposition of SiGe alloys by rapid thermal deposition has been studied using a commercially available Rapid Thermal Chemical Vapor Deposition (RTCVD) cluster tool. The precursors used in this work were dichlorosilane and germane diluted in either hydrogen or argon. An initial characterization was performed to find the appropriate temperature and GeH4 flow ranges to deposit epitaxial layers with low surface roughness. For layers with higher germanium concentration lower deposition temperatures are required to minimize surface roughness. The effects of the dilutant gas on the deposition were examined. An H2 dilutant affects the deposition by consuming chlorine released by the SiCl2H2 and forming HCI. When Ar is used as the dilutant, more chlorine is available for other reactions that can result in etching of the silicon surface. Finally, the effects of pre-deposition treatment were determined. When compared to a wet HF dip, a gas/vapor phase HF/methanol native oxide removal treatment appears to increase the initiation time for the epitaxial deposition reaction. This is most likely due to increased fluorine termination of the surface. When a wet HF or HF/methanol native oxide removal is followed by a UV-Cl2 process, the deposition reaction initiation time is reduced. The UV-Cl2 process was also found to etch silicon through the native oxide.

Structural and Optical Properties of Sigec Alloys and Multi-Quantum Wells Grown by Rapid Thermal Chemical Vapor Deposition

1995 ◽  
Vol 379 ◽  
Author(s):  
P. Boucaud ◽  
C. Guedj ◽  
F. H. Julien ◽  
D. Bouchier ◽  
J. Boulmer ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Quantum Wells ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Localized States ◽  
Structural And Optical Properties ◽  
Thermal Chemical Vapor Deposition ◽  
Strong Segregation

ABSTRACTWe have investigated structural and optical properties of SiGeC layers. Bulk and multiquantum wells heterostructures were grown by rapid thermal chemical vapor deposition. The photoluminescence of these structures exhibits two distinct features : deep level photoluminescence associated with localized states and bandedge photoluminescence which gives an indication of the band gap variation due to carbon incorporation in substitutional sites. In the case of multiquantum wells heterostructures, a strong segregation is reported as the growth temperature is decreased. An alternate technique to incorporate carbon in SiGe layers, the pulsed laser induced epitaxy with an excimer laser, is presented. The incorporation of carbon in substitutional sites is evidenced by Raman spectroscopy. As the laser flux is increased, new Raman lines associated to carbon-induced disorder are observed in the spectra.

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