Real-time Optical Monitoring of GaxIn1−xP/GaP Heterostructures on Silicon

1995 ◽  
Vol 406 ◽  
Author(s):  
N. Dietz ◽  
U. Rossow ◽  
D. E. Aspnes ◽  
N. Sukidi ◽  
K. J. Bachmann
Keyword(s):  
Fine Structure ◽  
Surface Reaction ◽  
Laser Light ◽  
Amplitude Ratio ◽  
Reflectance Spectroscopy ◽  
Chemical Beam Epitaxy ◽  
Optical Monitoring ◽  
Difference Spectroscopy ◽  
Combined Application ◽  
Reflectance Difference Spectroscopy

AbstractIn this paper we report the combined application of p-polarized reflectance spectroscopy (PRS), reflectance difference spectroscopy (RDS), and laser light scattering (LLS) to investigate the heteroepitaxy of GaxIn 1−xP/GaP on Si by pulsed chemical beam epitaxy (PCBE) with tertiarybutylphosphine (TBP), triethylgallium (TEG), and trimethylindium (TMI) precursors. Both, PRS and RDS follow the growth process with submonolayer resolution utilizing a periodic fine structure signal, which is caused by a periodic alteration of thickness and composition of an ultra-thin surface reaction layer during the periodic TEG and TBP exposure of the surface. After the transition from GaP growth to GaxIn 1−xP growth, the RDS oscillations are reoriented after about five precursor cycles in a new oscillation periodicity, where the response to the TBP pulse has the opposite direction. The ratio of the changes in the amplitudes of RDS signals as a response to TEG and TMI surface exposure is used to estimate the composition fo GaxIn 1−xP. The PRS fine structure is maintained after switching to GaxIn 1−xP growth with a separate feature for each TEG and TMI surface exposure. The amplitude ratio of these features changes during growth.

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.

scholarly journals Real-time Characterization of the Optical Properties of an ultra-thin Surface Reaction Layer during Growth

1996 ◽  
Vol 441 ◽  
Author(s):  
N. Dietz ◽  
N. Sukidib ◽  
C. Harrisb ◽  
K. J. Bachmann
Keyword(s):  
Optical Properties ◽  
Fine Structure ◽  
Reaction Layer ◽  
Surface Reaction ◽  
Turning Points ◽  
Growth Conditions ◽  
Chemical Beam Epitaxy ◽  
Modulated Phase ◽  
Interference Oscillations

AbstractThe average optical properties of an ultra-thin surface reaction layer (SRL) during growth by pulsed chemical beam epitaxy (PCBE) can be quantitatively accessed by p-polarized reflectance spectroscopy (PRS), as demonstrated on the example of heteroepitaxial GaP growth. Under PCBE growth conditions, the surface of the substrate is exposed to pulsed ballistic beams of tertiarybutyl phosphine [TBP, (C4H9)PH2] and triethylgallium [TEG, Ga(C2H5)3]. The pulsed precursor supply causes a period in composition and thickness modulated SRL, monitored as a fine structure that is superimposed on interference oscillations, resulting from back reflection at the substratelayer interface with increasing layer thickness. The amplitude of this fine structure undergoes a period amplitude modulation and exhibits turning points at which the response to the first precursor pulse changes sign. The turning points can be characterized by the expression R4(Φmax)=R4(Φmin), which describes the maximal and minimal values of the temporally modulated phase factor in the SRL, using a four layer stack description. The positions of these turning points are not affected by the thickness of the SRL, which allows the computation of the average complex dielectric function of the SRL independent of its thickness. In the next step, the average thickness of the SRL can be extracted from the amplitude of the observed fine structure.

In situ reflectance difference spectroscopy of N-plasma doped ZnTe grown by molecular beam epitaxy

1998 ◽  
Vol 73 (26) ◽  
pp. 3857-3859 ◽  
Author(s):  
D. Stifter ◽  
M. Schmid ◽  
K. Hingerl ◽  
A. Bonanni ◽  
M. Garcia-Rocha ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Difference Spectroscopy ◽  
Reflectance Difference Spectroscopy
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