Using Rapid Thermal Processing to Induce Epitaxial Alignment of Polycrystalline Silicon Films on (100) Silicon

1986 ◽  
Vol 71 ◽  
Author(s):  
H.B. Harrison ◽  
S.T. Johnson ◽  
Y. Komem ◽  
C. Wong ◽  
S. Cohen
Keyword(s):  
Thermal Processing ◽  
Polycrystalline Silicon ◽  
Rapid Thermal Processing ◽  
Chemical Vapour ◽  
Treatment Phase ◽  
Growth Rate Constant ◽  
Pressure Chemical ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Initial Heat

AbstractUndoped polycrystalline silicon (poly-Si) films obtained by low pressure chemical vapour deposition (LPCVD) techniques have previously been demonstrated to align epitaxially with respect to the underlying (100) silicon substrate in the 1000-1100°C temperature regime. However the alignment rate at temperatures in excess of 1100°C is too rapid to be obtained by conventional furnace processing. Rapid Thermal Processing (RTP) offers an excellent technique of attaining this temperature in the requisite time and in this paper we report on the results of a study in which RTP has been used. Our results show an activation energy of ∼4.5eV, and that the growth rate constant is dramatically enhanced, without any alignment delay in the initial heat treatment phase, which is contrary to previous findings.

Fast Deposition of Polycrystalline Silicon Films by Hot-Wire CVD

1995 ◽  
Vol 377 ◽  
Author(s):  
A. R. Middya ◽  
A. Lloret ◽  
J. Perrin ◽  
J. Huc ◽  
J. L. Moncel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Polycrystalline Silicon ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hot Wire ◽  
Crystalline Orientation ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTPolycrystalline silicon thin films have been deposited at fast growth rates (50 Å/s) by hotwire chemical vapour deposition (HW-CVD) from SiH4/H2 gas mixtures at low substrate temperature (400–500°C). The surface morphology of these films consists of 0.5 – 2.0μm dendritic grains as seen by electron microscopy. The films have a columnar morphology with grains starting from the substrate either on glass or c-Si. Even the 150 nm thick initial layer is polycrystalline. The preferential crystalline orientation of the poly-Si film is apparently not governed by the radiative source but strongly depends on the type and orientation of the substrate. A strong hydrogen dilution (>90%) of silane is essential to obtain poly-Si films with optimal crystalline structure.

Properties of Gallium Implanted Furnace and Rapidly Annealed Polycrystalline Silicon

1987 ◽  
Vol 92 ◽  
Author(s):  
H.B. Harrison ◽  
A.P. Pogany ◽  
Y. Komem
Keyword(s):  
Electrical Conductivity ◽  
Phase Transformation ◽  
Liquid Phase ◽  
Long Range ◽  
Thermal Processing ◽  
Polycrystalline Silicon ◽  
Rapid Thermal Processing ◽  
Significant Movement ◽  
Lower Temperature ◽  
Polycrystalline Silicon Films

ABSTRACTPolycrystalline silicon films have been amorphized by implantation with 100keV Ga ions of doses 0.3 and 6×1015cm−2. These films were subsequently recrystallized using either a furnace for longer times lower temperature (∼30 mins, 600° C) or rapid thermal processing (RTP) for shorter times higher temperatures ( ≤ 30 sec, 800° C, 900° C) in an endeavour to suppress any long range movement of the Ga during the anneal phase. It is found that for both the furnace and RTP for temperatures ≤ 800°C no significant movement is observed and that the lower temperature anneal for the highest dose produces the highest electrical conductivity. By contrast however, annealing at 900° C, even though the initial conductivity is higher than for any other anneal we observe a significant reduction with time and extremely rapid movement of the dopant species throughout the original poly layer. An initial rationale for this behaviour is proposed in terms of a liquid phase transformation during annealing.

Photoconductive Polycrystalline Silicon Films on Glass Obtained by Hot-Wire CVD

1996 ◽  
Vol 420 ◽  
Author(s):  
A. R. Middya ◽  
J. Guillet ◽  
J. Perrin ◽  
J. E. Bouree
Keyword(s):  
Polycrystalline Silicon ◽  
Chemical Vapour ◽  
Columnar Structure ◽  
Silicon Films ◽  
High Deposition Rate ◽  
Hot Wire ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Deposited Films

AbstractTextured polycrystalline silicon films with columnar structure have been deposited on glass at low temperature (400–550°C) and high deposition rate (10 to 15 Å/s) by hot-wire chemical vapour deposition using SiH4-H2 gases. The homogeneity of the deposited layer is ± 5% on a 8 cm diameter. As deposited films have a poor photoconductivity. However hydrogen confinement in the films during the deposition or after the deposition is found to be the key for obtaining g.tc/poly-Si with a significant diffusion length. Eventually reasonable values of the mobility lifetime product (> 10−7 cm2/V) are obtained by in situ hydrogen passivation of poly-Si films after deposition. Efficient shifting of the Fermi level is achieved by in situ B or P doping. The incorporation of boron in poly-Si network strongly influences the morphology and the crystalline structure. Undoped films have a Hall mobility of 14 ± 5 cm2/V.s which decreases versus the carrier concentration.

Si-H Vibration Only at 2000 CM-1 in Fully Polycrystalline Silicon Films Made by Hwcvd

2000 ◽  
Vol 609 ◽  
Author(s):  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Polycrystalline Silicon ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Amorphous Region ◽  
Hot Wire ◽  
Wire Temperature ◽  
Stretching Vibration ◽  
Closed Structure ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTThe Si-H vibration in IR spectra of our device quality poly-Si films grown by hot-wire chemical vapour deposition (HWCVD) made at low wire temperature (Tw=1800 °C) is at 2000 cm−1 whereas in a poly-Si film made at high wire temperature (Tw=1900 °C) both 2000 cm−1 vibrations as well as 2100 cm−1 are observed. On the other hand, the Raman spectra (probing the upper part of the film) of Si-H stretching vibration measured for both these samples show only 2000 cm-1 mode. XTEM micrographs of these films show that whereas the low Tw film has a structure made of closely packed crystalline columns, the high Tw film has conical crystalline structures with amorphous region between them. The crystal cones meet each other towards the top of the film and form a closed structure. This is confirmed by Raman spectrum at 520 cm−1. We attribute the 2100 cm−1 mode to the Si-H bonds at the surface of the cones touching the amorphous regions. The Si-H vibration shifts to 2000 cm-1 when the crystalline cones coalesce with each other, as is the case in the upper part of both types of films.

Residual Stress of Silicon Films Deposited by Lpcvd From Silane

1998 ◽  
Vol 518 ◽  
Author(s):  
P. Temple-Boyer ◽  
E. Imbernon ◽  
B. Rousset ◽  
E. Scheid
Keyword(s):  
Residual Stress ◽  
Polycrystalline Silicon ◽  
Chemical Vapour ◽  
Silicon Films ◽  
Back Side ◽  
Deposition Parameters ◽  
Before And After ◽  
Pressure Chemical ◽  
Polycrystalline Silicon Films ◽  
Stress Variations

AbstractIn this paper, amorphous, semi-crystalline and polycrystalline silicon films have been deposited by low pressure chemical vapour deposition (LPCVD) from silane SiH4 by ranging the deposition temperature from 555 to 635°C and the total pressure from 100 to 300 millitorrs. Films residual stresses have been determined thanks to the formula of Stoney by measurements of the wafer curvature before and after removal of the back side deposition. The influences of the different deposition parameters are reported and major stress variations are evidenced. By studying the effects of a 600°C crystallisation anneal and by comparing them to those observed for amorphous silicon films deposited from disilane Si2H6, compressive and tensile stresses are respectively related to “surface” and “volume” crystallisation phenomena. The different stress values of amorphous and polycrystalline silicon have been estimated and, according to these results, solutions are finally proposed in order to have a real control of residual stress into silicon depositions and to obtain low stress (σ ≈ 0) polysilicon films.

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