Quantum‐mechanical estimates of the speed of field ionization of shallow impurity levels

1980 ◽  
Vol 37 (1) ◽  
pp. 111-113 ◽  
Author(s):  
Siddheswar Chaudhuri ◽  
Darryl D. Coon ◽  
Gustav E. Derkits
Keyword(s):  
Field Ionization ◽  
Quantum Mechanical ◽  
Shallow Impurity

Field ionization IR spectroscopy of shallow impurity levels

1985 ◽  
Vol 53 (12) ◽  
pp. 1144 ◽  
Author(s):  
D.D. Coon ◽  
S.D. Gunapala ◽  
R.P.G. Karunasiri ◽  
H.-M. Muehlhoff
Keyword(s):  
Ir Spectroscopy ◽  
Field Ionization ◽  
Shallow Impurity

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

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