scholarly journals New ultrahigh vacuum setup and advanced diagnostic techniques for studying a-Si:H film growth by radical beams

2004 ◽  
Vol 808 ◽  
Author(s):  
J.P.M. Hoefnagels ◽  
E. Langereis ◽  
M.C.M. van de Sanden ◽  
W.M.M. Kessels
Keyword(s):  
Real Time ◽  
Surface Science ◽  
Spectroscopic Ellipsometry ◽  
Atomic Hydrogen ◽  
Film Growth ◽  
Ultrahigh Vacuum ◽  
Deposition Process ◽  
Diagnostic Techniques ◽  
Hot Wire ◽  
Optical Diagnostic

ABSTRACTA new ultrahigh vacuum setup is presented which is designed for studying the surface science aspects of a-Si:H film growth using various advanced optical diagnostic techniques. The setup is equipped with plasma and radical sources which produce well-defined radicals beams such that the a-Si:H deposition process can be mimicked. In this paper the initial experiments with respect to deposition of a-Si:H using a hot wire source and etching of a-Si:H by atomic hydrogen are presented. These processes are monitored by real time spectroscopic ellipsometry and the etch yield of Si by atomic hydrogen is quantified to be 0.005±0.002 Si atoms per incoming H atom.

Mapping the Phase-Change Parameter Space of Hot-Wire CVD Si:H Films Using In-Situ Real Time Spectroscopic Ellipsometry

2002 ◽  
Vol 715 ◽  
Author(s):  
Dean H. Levi ◽  
Brent P. Nelson ◽  
John D. Perkins
Keyword(s):  
Surface Roughness ◽  
Real Time ◽  
Parameter Space ◽  
Spectroscopic Ellipsometry ◽  
Film Growth ◽  
Growth Parameter ◽  
Ex Situ ◽  
Degree Of Crystallinity ◽  
Hot Wire

AbstractIn-situ real-time spectroscopic ellipsometry (RTSE) provides detailed information on the evolution of the structural and optical properties of Si:H films during film growth. We have used in-situ RTSE to characterize the film morphology and crystallinity of hot-wire CVD (HWCVD) Si:H films as a function of hydrogen dilution R=[H]/[H+SiH4], substrate temperature Ts, and film thickness db. Transitions from one mode of film growth to another are indicated by abrupt changes in the magnitude of the surface roughness during film growth. The degree of crystallinity of the film can be determined from the bulk dielectric function. We have studied the growth parameter space consisting of R from 0 to 12, Ts from 150°C to 550°C, and db from 0 to 1 um. For each set of R and Ts values, the structural evolution of the film can be characterized by the shape of the surface roughness thickness ds versus bulk thickness db curve. In contrast to studies done by Collins et al on PECVD growth of Si:H films, our studies of HWCVD growth find no conditions where ds remains constant after coalescence of the initial nucleation centers. Most of the films grown within the range of parameters studied exhibit a secondary nucleation and coalescence signature. The transition between a-Si:H and uc-Si:H growth is near the R=3 to R=4 dividing line. Initial coalescence of purely uc-Si:H material doesn't occur until R>8. We have verified the RTsE crystallinity classification using ex-situ Raman scattering.

A mechanism of CVD diamond film growth deduced from the sequential deposition from sputtered carbon and atomic hydrogen

1994 ◽  
Vol 9 (6) ◽  
pp. 1546-1551 ◽  
Author(s):  
Darin S. Olson ◽  
Michael A. Kelly ◽  
Sanjiv Kapoor ◽  
Stig B. Hagstrom
Keyword(s):  
Growth Mechanism ◽  
Atomic Hydrogen ◽  
Film Growth ◽  
Deposition Process ◽  
Cvd Diamond ◽  
Surface Growth ◽  
Diamond Surface ◽  
Hydrogen Flux ◽  
Sequential Deposition ◽  
Disordered Carbon

We describe a growth mechanism of CVD diamond films consisting of a series of surface reactions. It is derived from experimental observations of a sequential deposition process in which incident carbon flux and atomic hydrogen flux were independently varied. In this sequential process, film growth rate increased with atomic hydrogen exposure, and a saturation in the utilization of carbon was observed. These features are consistent with a surface growth process consisting of the following steps: (i) the carburization of the diamond surface, (ii) the deposition of highly disordered carbon on top of this surface, (iii) the etching of disordered carbon by atomic hydrogen, (iv) the conversion of the carburized diamond surface to diamond at growth sites by atomic hydrogen, and (v) the carburization of newly grown diamond surface. The nature of the growth sites on the diamond surface has not been determined experimentally, and the existence of the carburized surface layer has not been demonstrated experimentally. The surface growth mechanism is the only one consistent with the growth observed in conventional diamond reactors and the sequential reactor, while precluding the necessity of gas phase precursors.

Microstructural Identification of SiNx Films by Real-Time Ellipsometry

1997 ◽  
Vol 472 ◽  
Author(s):  
G. Soto ◽  
E. C. Samano ◽  
R. Machorro ◽  
M. Avalos ◽  
L. Cota
Keyword(s):  
Real Time ◽  
Film Growth ◽  
Incidence Angle ◽  
Polarization State ◽  
Sample Surface ◽  
Deposition Process ◽  
Slight Variation ◽  
Si Substrates ◽  
Amorphous Si

ABSTRACTReal-time ellipsometry has shown to be a powerful tool to analyze thin films during processing. It is non-disturbing and its sensitivity lies in the submonolayer range. In fact, a slight variation in the film microstructure might result in a significant change of the polarization state of the reflected beam from the sample surface. SiNx layers have been grown on glass, quartz, KC1 and Si substrates by laser ablating a Si3N4 sintered target in vacuum and N2 environment. The film growth was monitored by real time ellipsometry at a fixed wavelength, and a fixed incidence angle. Once the deposition process is completed, the refractive index was obtained by perfoming in situ spectroellipsometric measurements in the 1.5 to 5 eV photon-energy range. The best curve fitting of the experimental data is used to find the film composition: a mixture of Si3N4, polycrystalline Si, and amorphous Si. The films composition and micro structure inferred from ellipsometric data are compared to those obtained by in-situ surface techniques and TEM, respectively.

Hot-wire deposition of a-Si:H thin films on wafer substrates studied by real-time spectroscopic ellipsometry and infrared spectroscopy

2008 ◽  
Vol 516 (5) ◽  
pp. 511-516 ◽  
Author(s):  
P.J. van den Oever ◽  
J.J.H. Gielis ◽  
M.C.M. van de Sanden ◽  
W.M.M. Kessels
Keyword(s):  
Thin Films ◽  
Infrared Spectroscopy ◽  
Real Time ◽  
Spectroscopic Ellipsometry ◽  
Hot Wire
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