Effect of surface kinetics on the step coverage during chemical vapor deposition

1999 ◽  
Vol 14 (6) ◽  
pp. 2377-2380 ◽  
Author(s):  
Gyeong Soon Hwang ◽  
Sang Heup Moon ◽  
Suk Woo Nam ◽  
Chee Burm Shin

Profile evolution simulations during chemical vapor deposition based on a 2D continuum model reveal that the type of surface kinetics plays an important role in determining step coverage of films deposited in high aspect ratio trenches and vias. Linear surface kinetics, resulting from an adsorption rate limited process, is found to cause difficulty in bringing about conformal step coverage in deep narrow trenches without reducing the growth rate considerably. Under such condition, void-free filling cannot be achieved while maintaining a growth rate acceptable to integrated circuit (IC) manufacturing. The numerical study also suggests that the high tendency of the precursor for chemical equilibrium on a surface, resulting in nonlinear kinetics by a surface reaction limited process, is crucial to achieve a uniform step coverage as typically observed in SiO2 deposition from tetraethylorthosilicate (TEOS).

1998 ◽  
Vol 514 ◽  
Author(s):  
Chee Burm Shin ◽  
Gyeong Soon Hwang

ABSTRACTProfile evolution simulations during chemical vapor deposition based on a 2-D continuum model reveal that the type of surface kinetics plays an important role as a measure of determining step coverage of films deposited in a high aspect ratio trench or via. The linear surface kinetics, resulting from adsorption rate limitation, is found to be difficult to bring about conformal step coverage in a deep narrow trench without reducing the growth rate considerably; that is, under such a condition void free filling can not be achievable with holding an appropriate growth rate. High tendency of the precursor for chemical equilibrium on a surface, tending to cause the non-linear surface kinetics by surface reaction limitation, is mainly responsible for the significant improvement of step coverage in TEOS-based depositions.


Author(s):  
J. Meng ◽  
S. Wong ◽  
Y. Jaluria

A numerical study has been carried out on the metalorganic chemical vapor deposition (MOCVD) process for the fabrication of gallium nitride (GaN) thin films, which range from a few nanometers to micrometers in thickness. The numerical study is also coupled with an experimental study on the flow and thermal transport processes in the system. Of particular interest in this study is the dependence of the growth rate of GaN and of the uniformity of the film on the flow, resulting from the choice of various design and operating parameters involved in the MOCVD process. Based on an impingement type rotating-disk reactor, three-dimensional simulations have been preformed to indicate the deposition rate increases with reactor pressure, inlet velocity, and wafer rotating speed, while decreases with the precursor concentration ratio. Additionally, a better film uniformity is caused by reducing the reactor pressure, inlet velocity and wafer rotating speed, and increasing precursor concentration ratio. With the impact of wafer temperature included in this study as well, these results are expected to provide a quantitative basis for the prediction, design, and optimization of the process for the fabrication of GaN devices. The flow and the associated transport processes are discussed in detail on the basis of the results obtained to suggest approaches to improve the uniformity of thin film, minimize fluid loss, and reduce flow recirculation that could affect growth rate and uniformity.


Author(s):  
Jiandong Meng ◽  
Yogesh Jaluria

A numerical study has been carried out to characterize the metalorganic chemical vapor deposition (MOCVD) growth of Gallium Nitride (GaN) in a rotating-disk reactor. The major objective of this work is to examine the dependence of the growth rate and thin film uniformity on the primary parameters. First of all, for a rotating-disk system, the governing equations involved are obtained. Then, with the effect of thermal buoyancy included and based on the detailed mathematical model and chemical reaction mechanisms, the 3D simulation study is conducted for a rotating reactor. A comparison between the predicted growth rate and experimental data is presented. In addition, the effect of various primary operating and design parameters on the growth rate of GaN and thin-film uniformity is also examined. This provides further insight into the reactor performance and the characteristics of the entire process. The results obtained can also form the basis for the future design and optimization of this system.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 426
Author(s):  
Byeong-Kwan Song ◽  
Hwan-Young Kim ◽  
Kun-Su Kim ◽  
Jeong-Woo Yang ◽  
Nong-Moon Hwang

Although the growth rate of diamond increased with increasing methane concentration at the filament temperature of 2100 °C during a hot filament chemical vapor deposition (HFCVD), it decreased with increasing methane concentration from 1% CH4 –99% H2 to 3% CH4 –97% H2 at 1900 °C. We investigated this unusual dependence of the growth rate on the methane concentration, which might give insight into the growth mechanism of a diamond. One possibility would be that the high methane concentration increases the non-diamond phase, which is then etched faster by atomic hydrogen, resulting in a decrease in the growth rate with increasing methane concentration. At 3% CH4 –97% H2, the graphite was coated on the hot filament both at 1900 °C and 2100 °C. The graphite coating on the filament decreased the number of electrons emitted from the hot filament. The electron emission at 3% CH4 –97% H2 was 13 times less than that at 1% CH4 –99% H2 at the filament temperature of 1900 °C. The lower number of electrons at 3% CH4 –97% H2 was attributed to the formation of the non-diamond phase, which etched faster than diamond, resulting in a lower growth rate.


2016 ◽  
Vol 869 ◽  
pp. 721-726 ◽  
Author(s):  
Divani C. Barbosa ◽  
Ursula Andréia Mengui ◽  
Mauricio R. Baldan ◽  
Vladimir J. Trava-Airoldi ◽  
Evaldo José Corat

The effect of argon content upon the growth rate and the properties of diamond thin films grown with different grains sizes are explored. An argon-free and argon-rich gas mixture of methane and hydrogen is used in a hot filament chemical vapor deposition reactor. Characterization of the films is accomplished by scanning electron microscopy, Raman spectroscopy and high-resolution x-ray diffraction. An extensive comparison of the growth rate values and films morphologies obtained in this study with those found in the literature suggests that there are distinct common trends for microcrystalline and nanocrystalline diamond growth, despite a large variation in the gas mixture composition. Included is a discussion of the possible reasons for these observations.


2012 ◽  
Vol 717-720 ◽  
pp. 105-108 ◽  
Author(s):  
Wan Shun Zhao ◽  
Guo Sheng Sun ◽  
Hai Lei Wu ◽  
Guo Guo Yan ◽  
Liu Zheng ◽  
...  

A vertical 3×2〞low pressure chemical vapor deposition (LPCVD) system has been developed to realize fast epitaxial growth of 4H-SiC. The epitaxial growth process was optimized and it was found that the growth rate increases with increasing C/Si ratio and tends to saturate when C/Si ratio exceeded 1. Mirror-like thick 4H-SiC homoepitaxial layers are obtained at 1500 °C and C/Si ratio of 0.5 with a growth rate of 25 μm/h. The minimum RMS roughness is 0.20 nm and the FWHM of rocking curves of epilayers grown for 1 hour and 2 hours are 26.2 arcsec and 32.4 arcsec, respectively. These results indicate that high-quality thick 4H-SiC epilayers can be grown successfully on the off-orientation 4H-SiC substrates.


1995 ◽  
Vol 10 (2) ◽  
pp. 320-327 ◽  
Author(s):  
R.A. Levy ◽  
E. Mastromatteo ◽  
J.M. Grow ◽  
V. Paturi ◽  
W.P. Kuo ◽  
...  

In this study, films consisting of B-N-C-H have been synthesized by low pressure chemical vapor deposition using the liquid precursor triethylamine borane complex (TEAB) both with and without ammonia. When no NH3 is present, the growth rate was observed to follow an Arrhenius behavior in the temperature range of 600 to 800 °C with an apparent activation energy of 11 kcal/mol. A linear dependence of growth rate is observed as a function of square root of flow rate for the TEAB range of 20 to 60 sccm, indicating that the reaction rate is controlled by the adsorption of borane. The addition of NH3 to TEAB had the effect of lowering the deposition temperature down to 300 °C and increasing the apparent activation energy to 22 kcal/mol. Above 650 °C, the carbon concentration of the deposits increased significantly, reflecting the breakup of the amine molecule. X-ray diffraction measurements indicated the films to be in all cases amorphous. Infrared spectra of the films showed absorption peaks representing the vibrational modes of B-N, B-N-B, B-H, and N-H. The index of refraction varied between 1.76 and 2.47, depending on composition of the films. Films deposited with no NH3 above 700 °C were seen to be compressive while films below that temperature were tensile. In the range of 350 to 475 °C, the addition of NH3 to TEAB resulted in films that were mildly tensile, while below 325 °C and above 550 °C, the films were found to be compressive. Both the hardness and Young's modulus of the films decreased with higher temperatures, reflecting the influence of the carbon presence.


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