Influence of Surface Pre-Cleaning on Electrical Properties of Rapid Thermal Oxide and Rapid Thermal Chemical Vapor Deposition Oxide

1992 ◽  
Vol 259 ◽  
Author(s):  
Xiaoli Xu ◽  
R. T. Kuehn ◽  
J. M. Melzak ◽  
G. A. Hames ◽  
J. J. Wortman ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Thermally Grown Oxide ◽  
Surface Cleaning ◽  
Breakdown Field ◽  
Wafer Surface ◽  
Thermal Chemical Vapor Deposition ◽  
Thermal Oxide

ABSTRACTVarious surface pre-cleaning processes for rapid thermal in-situ polysilicon/oxide/silicon stacked gate formation have been evaluated. MOS capacitors have been fabricated to assess the effects of surface pre-cleaning on the quality of both Rapid Thermal Oxide (RTO) and Rapid Thermal Chemical Vapor Deposition (RTCVD) oxide. Measurement results have shown that, 1) High temperature (≥ 900 °C) rapid thermal cleaning in Ar, H2 or high vacuum (10−8 Torr) ambients can lead to MOS gates with high leakage current if RTO is used to form the gate oxide, 2) The standard Huang clean and ultra-violet ozone (UV/O3) treatments can improve the film quality for both deposited and thermally grown oxide, and 3) Compared with RTO, the breakdown field of the RTCVD oxide is less dependent on the surface pre-cleaning treatment. These results indicate that silicon wafer surface cleaning techniques typically used for silicon epitaxial processes are not necessarily applicable to oxide film formation in RTP reactors.

Formation of Raised Source/Drain Junctions by Rapid Thermal Chemical Vapor Deposition

1995 ◽  
Vol 387 ◽  
Author(s):  
Mehmet C. Öztürk ◽  
Jimmie J. Wortman
Keyword(s):  
Chemical Vapor Deposition ◽  
Ion Implantation ◽  
Vapor Deposition ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Epitaxial Silicon ◽  
Selective Deposition ◽  
Thermal Chemical Vapor Deposition ◽  
Solid Diffusion ◽  
Diffusion Source

AbstractIn this paper, we present alternative uses of rapid thermal chemical vapor deposition (RTCVD) in forming junctions for the raised source/drain MOSFET. The results will include applications of epitaxial silicon, SixGe1−x and TiSi2 all selectively deposited in dedicated coldwalled, lamp heated high or ultra high vacuum RTCVD reactors. Two general approaches will be considered : 1) ultra shallow junction formation in silicon followed by a selective deposition process to form a raised contact, 2) selective deposition to obtain a layer that can be used as a solid diffusion source and as a sacrificial layer for self-aligned silicide formation. In the first approach, junctions are formed typically by low energy ion-implantation. In this paper, we present rapid thermal vapor phase doping (RTVPD) as an alternative to ion-implantation to form defect free ultra-shallow junctions in Si. The method involves exposing a silicon wafer to a dopant gas (such as B2H6) at a moderate temperature (∼600°C) for a short time and subsequent annealing for drive-in. This is followed by either selective epitaxy and conventional self-aligned TiSi2 formation or selective deposition of a low-resistivity C54 TiSi2 from TiCl4 and SiH4. In the second approach, first, a semiconductor (Si, polysilicon or SixGe1−x) is deposited selectively. If the material is undoped, doping can be achieved by ion-implantation. In-situ doping is also possible as will be shown with p- and n-type SixGe1−x at temperatures as low as 625°C using B2H6 or PH3. The doped layer is then used as a solid diffusion source to form the junctions by out-diffusion. Using these different approaches, we present examples of high quality junctions in Si as shallow as a few hundred angstroms. The techniques are compared based upon their robustness, complexity, equipment and thermal budget requirements.

Effect of Thin Films on Radiative Transport in Chemical Vapor Deposition Systems

1999 ◽  
Author(s):  
Sandip Mazumder ◽  
Alfred Kersch
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Wave Theory ◽  
Radiative Properties ◽  
Wafer Surface ◽  
Contributing Factors ◽  
Thermal Chemical Vapor Deposition ◽  
Wafer Substrate

Abstract The thermal behavior of a wafer during a Rapid Thermal Chemical Vapor Deposition (RTCVD) process depends on its spectral radiative properties, along with other factors. One of the major contributing factors is the thin film that is deposited on the wafer substrate. The presence of a thin film (of thickness anywhere above 0.1 nm) can drastically alter the radiative properties of the wafer surface, thereby leading to significantly different wafer temperatures. This article presents a model to simulate thin film effects in RTCVD processes. Radiative transfer is modeled using a Monte-Carlo ray-tracing technique. Radiative properties are calculated using fundamental Electromagnetic Wave Theory. Simulation results match remarkably well with experimental data, demonstrating the importance of thin film effects.

Silicon Nucleation on Silicon Dioxide and Selective Epitaxy In An Ultra-High Vacuum Raptid Thermal Chemical Vapor Deposition Reactor Using Disilane In Hydrogen

1993 ◽  
Vol 334 ◽  
Author(s):  
Katherine E. Violette ◽  
Mahesh K. Sanganeria ◽  
Mehmet C. Öztürk ◽  
Gari Harris ◽  
Dennis M. Maher
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Silicon Dioxide ◽  
Epitaxial Growth ◽  
Vapor Deposition ◽  
Strong Dependence ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Thermal Chemical Vapor Deposition

AbstractSilicon nucleation on silicon dioxide and selective silicon epitaxial growth (SEG) were studied in an ultra high vacuum rapid thermal chemical vapor deposition (UHV-RTCVD) reactor. Experiments were performed using 10% Si2H6 in H2 in a pressure range of 10 - 100 mTorr at 760°C. Under these conditions, the growth rate ranged from 75 to 330 nm/minute. Loss of selectivity via Si island formation on SiO2 was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealing a strong dependence on deposition pressure. Cross sectional transmission electron microscopy (XTEM) was employed to study the vertical oxide/epitaxy interface where faceting can occur. The incubation time for nucleation was found to increase from 10s to 70s as pressure is reduced from 100 mTorr to 10 mTorr, allowing thicker selective epitaxial film growth in spite of the reduced growth rates. This was attributed to the reduction in gas phase supersaturation of the Si containing species resulting in a lower density of adsorbed atoms on the SiO2 surface. This process shows a potential for chlorine free selective epitaxial growth and provides insight to the surface morphology of polycrystalline films deposited at low pressures.

TDDB Measurement of Gate SiO2 on 4H-SiC Formed by Chemical Vapor Deposition

2008 ◽  
Vol 600-603 ◽  
pp. 799-802 ◽  
Author(s):  
Keiko Fujihira ◽  
Shohei Yoshida ◽  
Naruhisa Miura ◽  
Yukiyasu Nakao ◽  
Masayuki Imaizumi ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Gate Oxide ◽  
Thermally Grown Oxide ◽  
Oxide Breakdown ◽  
Thermal Oxide ◽  
Field Oxide ◽  
Thermally Grown

The reliability of CVD gate oxide was investigated by CCS-TDDB measurement and compared with thermally grown gate oxide. Although the QBD of thermal oxide becomes smaller for the larger oxide area, the QBD of CVD oxide is almost independent of the investigated gate oxide area. The QBD at F = 50% of CVD oxide, 3 C/cm2, is two orders of magnitude larger for the area of 1.96×10-3 cm2 at 1 mA/cm2 compared to that of thermal oxide. More than 80% of the CVD oxide breakdown occurs at the field oxide edge and more than 70% of the thermal oxide breakdown in the inner gate area. These results suggest that the lifetime of CVD oxide is hardly influenced by the quality of SiC, while the defects and/or impurities in SiC affect the lifetime of thermally grown oxide.

Nucleation and Growth of Polycrystalline Silicon Films in an Ultra high Vacuum Rapid Thermal Chemical Vapor Deposition Reactor Using Disilane and Hydrogen

1994 ◽  
Vol 343 ◽  
Author(s):  
Katherine E. Violette ◽  
Mehmet C. Öztürk ◽  
Gari Harris ◽  
Mahesh K. Sanganeria ◽  
Archie Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Surface Morphology ◽  
Vapor Deposition ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Chemical Vapor Deposition Reactor ◽  
Thermal Chemical Vapor Deposition

A study of Si nucleation and deposition on SiO2 was performed using disilane and hydrogen in an ultra high vacuum rapid thermal chemical vapor deposition reactor in pressure and temperature ranges of 0.1 – 1.5 Torr and 625 – 750°C. The film analysis was carried out using scanning electron microscopy, transmission electron microscopy and atomic force microscopy. At lower pressures, an incubation time exists which leads to a retardation in film nucleation. At 750°C, the incubation time is 10s at 0.1 Torr and decreases to less than Is at 1.5 Torr. The nuclei grow and form three dimensional islands on S1O2, and as they coalesce, result in a rough surface morphology. At higher pressures, the inherent selectivity is lost resulting in a higher nucleation density and smoother surface morphology. For ˜ 2000 Å thick films, the root-mean-square surface roughness at 750ÅC ranges from 110Å at 0.1 Torr to 40Å at 1.5 Torr. Temperature also strongly influences the film structure through surface mobility and grain growth. At 1 Torr, the roughness ranges from 3Å at 625°C to 60Å at 750°C. The grain structure at 625°C/1Torr appears to be amorphous, whereas at 750°C the structure is columnar. The growth rate at 625°C/1.5 Torr is 1200 Å/min provides a surface roughness on the order of atomic dimensions which is comparable to or better than amorphous silicon deposited in LPCVD furnaces.

Low temperature selective silicon epitaxy by ultra high vacuum rapid thermal chemical vapor deposition using Si2H6, H2 and Cl2

1996 ◽  
Vol 68 (1) ◽  
pp. 66-68 ◽  
Author(s):  
Katherine E. Violette ◽  
Patricia A. O’Neil ◽  
Mehmet C. Öztürk ◽  
Kim Christensen ◽  
Dennis M. Maher
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Thermal Chemical Vapor Deposition ◽  
Silicon Epitaxy
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