Real‐time monitoring of homoepitaxial and heteroepitaxial processes by p‐polarized reflectance spectroscopy

1995 ◽  
Vol 13 (1) ◽  
pp. 153-155 ◽  
Author(s):  
N. Dietz ◽  
A. Miller ◽  
K. J. Bachmann
Keyword(s):  
Real Time ◽  
Reflectance Spectroscopy ◽  
Real Time Monitoring ◽  
Polarized Reflectance

scholarly journals Polarization-dependent differential reflectance spectroscopy for real-time monitoring of organic thin film growth

2015 ◽  
Vol 86 (11) ◽  
pp. 113108 ◽  
Author(s):  
A. Navarro-Quezada ◽  
M. Aiglinger ◽  
E. Ghanbari ◽  
Th. Wagner ◽  
P. Zeppenfeld
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Film Growth ◽  
Reflectance Spectroscopy ◽  
Thin Film Growth ◽  
Organic Thin Film ◽  
Real Time Monitoring

Real-time Optical Monitoring of Epitaxial Growth Processes by p-Polarized Reflectance Spectroscopy

1995 ◽  
Vol 406 ◽  
Author(s):  
Nikolaus Dietz ◽  
Klaus J. Bachmannb
Keyword(s):  
Fine Structure ◽  
Epitaxial Growth ◽  
Real Time ◽  
Dielectric Function ◽  
Reaction Layer ◽  
Surface Reaction ◽  
Optical Probe ◽  
Reflectance Spectroscopy ◽  
Growth Processes ◽  
Polarized Reflectance

AbstractIn this paper we introduce a real-time optical probe technique, p-polarized reflectance spectroscopy (PRS), for the monitoring of epitaxial growth processes. GaP heteroepitaxy by pulsed chemical beam epitaxy (PCBE) is used as an example. PRS allows to follow the deposition process with submonolayer resolution, utilizing a fine structure that is superimposed to the interference oscillations in the reflected intensity. This fine structure is explained by the periodic alteration of the surface reaction chemistry under pulsed chemical precursor supply. In the case of epitaxial GaP growth, it is modeled for a four layer stack, including an ultra-thin surface reaction layer of periodically changing thickness do(t) and dielectric function εo(t) tied to the periodic surface exposure to tertiarybutyl phosphine (TBP) and triethylgallium (TEG) pulses, respectively. The imaginary part of the dielectric function, εO2, of this surface reaction layer can be determined directly from the distance of the inflection points in the fine structure, where the optical response to the first precursor pulse in the cycle sequence changes sign, from the closests interference minimum. The surface reaction kinetics can be studied by analyzing the decay time characteristic in the transients of the fine structure.

Real-Time Monitoring of Epitaxial Processes by Parallel-Polarized Reflectance Spectroscopy

MRS Bulletin ◽  
1995 ◽  
Vol 20 (5) ◽  
pp. 49-55 ◽  
Author(s):  
Nikolaus Dietz ◽  
Klaus J. Bachmann
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Normal Incidence ◽  
Optical Probe ◽  
Reflectance Spectroscopy ◽  
Industrial Applications ◽  
Monitoring And Control ◽  
Real Time Monitoring ◽  
Spectral Ellipsometry ◽  
Precise Control

The engineering of advanced micro-electronic circuits, optoelectronic devices, and integrated optical circuits requires precise control of the lateral dimensions and thicknesses of device features and of the stoichiometry and doping of epitaxial semiconductor regions. This is preferably achieved by real-time monitoring and control of the individual deposition and etching processes that constitute the processing sequence. The use of optical probe techniques for the real-time monitoring of etching and/or growth processes is favored because of their nondestructive character and their potential use in real-time feedback control. Some of these methods are ideal in monitoring the overall growth process and/or substrate temperature in industrial applications, requiring low cost and maintenance. For example, in situ reflectance-spectroscopy methods, such as dynamic optical reflectivity (DOS), spectral-resolved normal incidence reflectance spectroscopy (MRS), or pyrometric interferometry (PI), are successfully applied to various deposition processes and provide information on both the growth rate and the composition of the deposits. However, small changes in the reflectance (because of chemical interactions at the surface of the films with the reactants supplied from the vapor phase) are of the order of 10−3 to 10−4 and are hardly observable with normal-incidence reflectance techniques because of the high reflectivity of substrate/film interface, which is typically of the order of 40%–60% for many semiconductors.In order to increase the sensitivity to surface- and interface-related growth properties, alternative optical-observation methods such as reflectance difference spectroscopy (RDS), surface photoabsorption (SPA), and spectral ellipsometry (SE) have been developed.

Real-time monitoring of steady-state pulsed chemical beam epitaxy by p-polarized reflectance

1998 ◽  
Vol 183 (3) ◽  
pp. 323-337 ◽  
Author(s):  
K.J. Bachmann ◽  
N. Sukidi ◽  
C. Höpfner ◽  
C. Harris ◽  
N. Dietz ◽  
...  
Keyword(s):  
Steady State ◽  
Real Time ◽  
Chemical Beam Epitaxy ◽  
Real Time Monitoring ◽  
Polarized Reflectance

Real-time Monitoring of Hypoxic-Ischemic Brain Damage in Neonatal Rats Using Diffuse Light Reflectance Spectroscopy

2020 ◽  
Vol 27 (1) ◽  
pp. 172-181
Author(s):  
Sakiko Kinoshita ◽  
Satoko Kawauchi ◽  
Takeshi Nagamatsu ◽  
Izumi Nishidate ◽  
Tomoyuki Fujii ◽  
...  
Keyword(s):  
Real Time ◽  
Brain Damage ◽  
Reflectance Spectroscopy ◽  
Diffuse Light ◽  
Neonatal Rats ◽  
Real Time Monitoring ◽  
Ischemic Brain Damage ◽  
Ischemic Brain ◽  
Light Reflectance
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