In Situ Control of Native Oxide Growth for Semiconductor Processes

1992 ◽  
Vol 259 ◽  
Author(s):  
Mizuho Morita ◽  
Tadahiro Ohmi

ABSTRACTIn situ control methods of native oxide growth on Si surfaces at room temperature and during the temperature ramp-up are proposed for metal/Si contact formation, lowtemperature Si epitaxy, and very-thin thermal oxide film formation, based on analyses of factors dominating the oxide growth. Low-resistance W/Si contacts are formed by N2 gas sealed processing of HF cleaning right before W chemical vapor deposition(CVD). Highquality epitaxial Si films are grown at a low temperature of 550°C using Si2H6 molecular flow pre-showering to suppress the oxide growth caused by water or oxygen in a CVD reactor. Very thin gate oxide films with high insulating performance are realized by the preoxidation step at 300°C to form one-molecular-layer oxide for passivation and by the subsequent temperature ramp-up step in ultraclean Ar gas to prevent oxide growth and an increase of surface microroughness before the thermal oxidation step.

1999 ◽  
Vol 587 ◽  
Author(s):  
K. Chang ◽  
S.G. Thomas ◽  
T-C. Lee ◽  
R.B. Gregory ◽  
D. O'meara ◽  
...  

AbstractIndustrial feasibility of an in-situ-doped (ISD) polycrystalline Si process using chemical vapor deposition for advanced BiCMOS technologies is presented. ISD As-doped amorphous and polycrystalline Si layers have been deposited on Si substrates at 610°C and 660°C, respectively, with the deposition rate varying from 120 to 128Å /minute. Samples are compared on the basis of having been subjected to a substrate preclean prior to deposition using an HF solution and an in-situ H2 bake. TEM micrographs reveal the presence of a thin (10-15 Å) native oxide at the deposited layer/substrate interface for samples not precleaned. This is confirmed for both the amorphous and polycrystalline Si depositions. However, for the 610°C-deposited samples given the substrate preclean, a polycrystalline structure with partial epitaxial layer growth is observed. Twins and stacking faults are found at the poly Si/single crystal Si interface, causing interfacial roughness. Post-deposition annealing of the Si films typically generates grain growth, but RBS-channeling characterization of the annealed Si provides evidence of some recrystallization, the extent of which is affected by the original growth condition. Analysis shows that the amorphous deposition at 610°C results in a mixture of epitaxial and polycrystalline Si. Epitaxial realignment of the polycrystalline Si film by post deposition annealing can result in significantly improved device performance.


1989 ◽  
Vol 146 ◽  
Author(s):  
Paihung Pan ◽  
Ahmad Kermani ◽  
Wayne Berry ◽  
Jimmy Liao

ABSTRACTElectrical properties of thin (12 nm) SiO2 films with and without in-situ deposited poly Si electrodes have been studied. Thin SiO2 films were grown by the rapid thermal oxidation (RTO) process and the poly Si films were deposited by the rapid thermal chemical vapor deposition (RTCVD) technique at 675°C and 800°C. Good electrical properties were observed for SiO2 films with thin in-situ poly Si deposition; the flatband voltage was ∼ -0.86 V, the interface state density was < 2 × 1010/cm2/eV, and breakdown strength was > 10 MV/cm. The properties of RTCVD poly Si were also studied. The grain size was 10-60 rim before anneal and was 50-120 rim after anneal. Voids were found in thin (< 70 nm) RTCVD poly Si films. No difference in either SiO2 properties or poly Si properties was observed for poly Si films deposited at different temperatures.


1999 ◽  
Vol 591 ◽  
Author(s):  
I.M. Vargas ◽  
J.Y. Manso ◽  
J.R. Guzmán ◽  
B.R. Weiner ◽  
G. Morell

ABSTRACTWe employed in situ ellipsometry in the monitoring of surface damage to monocrystalline silicon (Si) substrates under hydrogen plasma conditions. These measurements were complemented with spectroscopic ellipsometry and Raman spectroscopy, in order to characterize the surface conditions. It was found that heating the Si substrate to 700°C in the presence of molecular hydrogen produces etching of the native oxide layer, which is typically 10 Å thick. When the already hot and bare silicon surface is submitted to hydrogen plasma, it deteriorates very fast, becoming rough and full of voids. Modeling of the spectroscopic ellipsometry data was used to obtain a quantitative physical picture of the surface damage, in terms of roughness layer t ickness and void fraction. The results indicate that by the time a thin film starts to grow on these silicon surfaces, like in the chemical vapor deposition of diamond, the roughness produced by the hydrogen plasma has already determined to a large extent the rough nature of the film to be grown.


1992 ◽  
Vol 282 ◽  
Author(s):  
Steven P. Kowalczyk ◽  
Michael Ldgdlund ◽  
Mats Fahlman ◽  
William R. Salaneck

ABSTRACTPalladium acetylacctonate has received much consideration as a possible precursor for chemical vapor deposition of metallic palladium films for a variety of microelectronic applications. We have studied the adsorption and decomposition of palladium acetylacetonate ongold, polyimide, silicon and silver surfaces to understand the initial mechanisms of metallic palladium film formation. In situ x-ray photoelcctron spectroscopy was used to characterized the films after adsorption and their decomposition after thermal treatment or laser irradiation.


Author(s):  
J. L. Kenty

An AEI EM6 electron microscope was modified for the in situ chemical vapor deposition (CVD) of Si films by pyrolysis of SiH4 gas. The environmental cell was so constructed that 100 μm dia. apertures placed 1.6 mm apart formed the top and bottom of the CVD microchamber and permitted a gas flow of up to 0.4 cm3 (STP)/min at up to 10 torr. A current of 2 amps through a single 200 mesh Ti grid of 0.003 mm2 net cross sectional area is sufficient to heat the sample to ~1200°C. Some temperature-heater power calibration experiments were performed by observing the melting point of evaporated metal films.


1993 ◽  
Vol 311 ◽  
Author(s):  
S. Habermehl ◽  
S. S. He ◽  
Y. L. Chen ◽  
G. Lucovsky

ABSTRACTThe microstructure of Si thin films, deposited on in-situ cleaned Si(100) surfaces by remote plasma-enhanced chemical-vapor deposition (RPECVD), is dependent on the process pressure, substrate temperature and H2 flow rate. Surface characterization by on-line low energy electron diffraction, LEED, has been used to detect changes in the character of the deposited films which can either be amorphous, microcrystalline or crystalline, hereafter designated as a-Si, Sμc-Si, and c-Si, respectively. We have used these results to generate phase diagrams for the Si microstructure as a function of the process pressure and substrate temperature, including the flow rate of H2 as an additional deposition parameter.


1991 ◽  
Vol 9 (3) ◽  
pp. 1073-1082 ◽  
Author(s):  
Ronald S. Nowicki ◽  
Patrice Geraghty ◽  
David Harris ◽  
Gayle Lux ◽  
David J. Johnson

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