Scanning Tunneling Microscopic Study of the Growth Process in Photochemical Vapor Deposition of Aluminum Film

1990 ◽  
Vol 201 ◽  
Author(s):  
Mitsugu Hanabusa ◽  
Kouji Sahara
Keyword(s):  
Vacuum Ultraviolet ◽  
Early Stage ◽  
Aluminum Hydride ◽  
Wavelength Dependence ◽  
Aluminum Film ◽  
Scanning Tunneling ◽  
Horizontal Growth ◽  
Ultraviolet Photons ◽  
Photochemical Vapor Deposition ◽  
Deuterium Lamp

AbstractAluminum thin films were photodeposited on silicon wafer from dimethyl-aluminum hydride under illumination of the ultraviolet photons generated by a deuterium lamp with a distinguished wavelength dependence. Namely, the growth rates increase linearly with vapor pressure under illumination of the l60-nm vacuum ultraviolet band from the lamp, while the growth starts above 0.3 mTorr only with the 240-nm band. To study the early stage of photo-deposition of Al, we constructed a scanning tunneling microscope and observed Al, islands. Steep sides were observed on islands with the distinguished boundary between vertical and horizontal growth. The shape of islands formed in the illuminated region and in the dark area was identical, thus indicating the absence of photo-induced migration effects.

Low Temperature OMVPE of ZnSe from Alkyl Sources Using a Plasma Disk Lamp

1988 ◽  
Vol 129 ◽  
Author(s):  
K. L. Tokuda ◽  
B. Pihlstrom ◽  
D. W. Kisker ◽  
M. Lamont Schnoes ◽  
G. J. Collins
Keyword(s):  
Growth Process ◽  
Vacuum Ultraviolet ◽  
Source Material ◽  
Organometallic Vapor Phase Epitaxy ◽  
Impurity Incorporation ◽  
High Quality ◽  
Selenium Compound ◽  
Ultraviolet Photons ◽  
Reduced Toxicity ◽  
Source Materials

ABSTRACTThe growth of high quality ZnSe by organometallic vapor phase epitaxy (OMVPE) has generally been hindered because of parasitic source pre-reactions or relatively high source decomposition temperatures. In this work, we have used vacuum ultraviolet photons generated by a disk-plasma lamp to assist the ZnSe growth process using diethylselenium and diethylzinc as source materials. This approach has resulted in satisfactory growth rates and high material quality at temperatures as low as 250°C, without the limitations of prereaction typically observed when H2Se is used for the selenium source material. In addition, the alkyl selenium compound offers advantages due to reduced toxicity compared to H2Se. This new, low-growth-temperature process thus offers the possibility of improved stoichiometry and impurity incorporation control as well as a reduced thermal effect on the underlying substrate during growth. At the same time, the advantages of excellent morphology and uniformity typically exhibited by the alkylbased growth processes are retained.

Low temperature shallow junction formation using vacuum ultraviolet photons during rapid thermal processing

1997 ◽  
Vol 70 (13) ◽  
pp. 1700-1702 ◽  
Author(s):  
R. Singh ◽  
K. C. Cherukuri ◽  
L. Vedula ◽  
A. Rohatgi ◽  
S. Narayanan
Keyword(s):  
Low Temperature ◽  
Thermal Processing ◽  
Vacuum Ultraviolet ◽  
Rapid Thermal Processing ◽  
Shallow Junction ◽  
Junction Formation ◽  
Ultraviolet Photons

Anomalously Low Light Scattering in the Na2O-Nb2O5-SiO2 Glass-Ceramics

2008 ◽  
Vol 39-40 ◽  
pp. 273-276 ◽  
Author(s):  
Michael Shepilov ◽  
Olga Dymshits ◽  
Valerii V. Golubkov ◽  
Alexander A. Zhilin
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Extinction Coefficient ◽  
Early Stage ◽  
Glass Ceramics ◽  
Wavelength Dependence ◽  
Interference Effects ◽  
Low Light ◽  
Isothermal Heat Treatments ◽  
Crystallization Stage

An evolution of the structure of three glasses of Na2O-Nb2O5-SiO2 system in the course of isothermal heat treatments at 660–700°C and the extinction coefficient of the material were studied. Spinodal phase separation was found to be a primary process followed by precipitation of nano-sized NaNbO3 crystalline phase. It was found that the spectral dependence of the extinction coefficient in the wavelength range λ= 400–800 nm corresponds to light scattering by spinodal structure at the phase separation stage and by independent Rayleigh scatterers (NaNbO3 nanocrystals) at the early stage of crystallization. The extinction coefficient increases at the first half of the crystallization stage and then decreases. At the late stage of crystallization and for the final glass-ceramics, the extinction coefficient α is 10–20 times smaller than that calculated for independently scattering nanocrystals and is characterized by anomalous wavelength dependence (α ∝ λ−6). The model for calculation of extinction coefficient is proposed, in which the interference effects in light scattering by nanocrystals are taken into account. On this basis, the variation of extinction coefficient in the course of crystallization and its wavelength dependence are explained.

Metallic Na formation in/on NaCl crystals with irradiation by electron or vacuum ultraviolet photons

1997 ◽  
Vol 49 (6) ◽  
pp. 609-615 ◽  
Author(s):  
Shigehiro Owaki ◽  
Shigeko Koyama ◽  
Masao Takahashi ◽  
Masao Kamada ◽  
Ryouichi Suzuki
Keyword(s):  
Vacuum Ultraviolet ◽  
Ultraviolet Photons

Wavelength-Dependent Area Selectivity in Photochemical Vapor Deposition of Aluminum Films

1989 ◽  
Vol 158 ◽  
Author(s):  
Mitsugu Hanabusa ◽  
Masashi Ikeda
Keyword(s):  
Gas Phase ◽  
Vapor Deposition ◽  
Emission Spectra ◽  
Nucleation Mechanism ◽  
Photochemical Reactions ◽  
Aluminum Films ◽  
Thickness Profile ◽  
Uv Photons ◽  
Photochemical Vapor Deposition ◽  
Deuterium Lamp

ABSTRACTThickness profile of aluminum thin films deposited from dimethylaluminum hydride on silicon substrate changed with wavelengths of light chosen from the wide emission spectra of a deuterium lamp. Under illumination of the VUV around 160 nm deposits were formed preferentially in illuminated regions, while such area selectivity was lost and uniformly thick films were deposited all over the substrate when the UV around 240 nm was used. The observed area selectivity can be interpreted as arising from a wavelength-dependent nucleation mechanism; namely, surface photochemical reactions leading to nucleation are induced only by the VUV, while the UV photons are capable of producing photofragments in gas phase responsible for nucleation.

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