Surfactant-Mediated Growth of SiGe/Si Quantum-Well Structures Studied by Photoluminescence Technique and Secondary Ion Mass Spectrometry

1995 ◽  
Vol 399 ◽  
Author(s):  
S. Nilsson ◽  
H. P. Zeindl ◽  
D. Krüger ◽  
J. Klatt ◽  
R. Kurps
Keyword(s):  
Mass Spectrometry ◽  
Quantum Well ◽  
Secondary Ion Mass Spectrometry ◽  
Near Band Edge ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
Ion Mass Spectrometry ◽  
Dimensional Growth ◽  
Temperature Window ◽  
Secondary Ion

ABSTRACTIn this investigation, surfactant-mediated growth of SiGe/Si single quantum-well structures is studied by photoluminescence and secondary ion mass spectrometry. The samples were grown by molecular-beam epitaxy and Sb was used as a surfactant. The photon energy of the SiGe-related near-band-edge photoluminescence was used to probe the action of Sb as a surfactant to promote two-dimensional growth and to reduce segregation of Ge during growth. First, the "growth-temperature window" at which Sb acts preferentially as a surfactant was determined. Then, at this optimized temperature of 700°C, the influence of different Sb coverages was investigated and it was found that 0.5 monolayer was a sufficient coverage to obtain full surfactant action. Ge concentration depth profiles obtained by secondary ion mass spectrometry confirmed the effect of surfactant-mediated growth and, in addition, the unintentional incorporation of the Sb surfactant during growth was determined quantitatively. In a final experiment the effect of deposition of Sb on either the lower or the upper heterointerface is addressed.

Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

1990 ◽  
Vol 48 (2) ◽  
pp. 308-309
Author(s):  
Bruno Schueler ◽  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Time Of Flight ◽  
Biological Tissues ◽  
Polymer Surfaces ◽  
Tof Sims ◽  
Secondary Ions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

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