Langmuir desorption of the flows of evaporating components of III-V - GaAs group crystals of intrinsic conduction was studied using a mass spectrometric method for external exposure 011 electron subsystems by way of injection (extraction) of the charge carriers by means of a pointed electrical probe. The injection (or extraction) of charge carriers was carried out by passing a current of both polarities between two tungsten electrodes. The first electrode was placed directly under the ionisation chamber of the mass spectrometer at the sample centre, the second one was at the sample edge.

The typical relationships of flow change of evaporating components of NAs₁, NAs₂, NAs₄, when injecting the electrons, are demonstrated for the crystal temperature of 750 K. It is seen that the greatest influence of current on the evaporating components' flows takes place at I = + 50 mA on probe, i.e. at the extraction of electrons. The relationship between metal NGa and non-metal NAs is demonstrated at different crystal annealing temperature. It is seen that at low temperature the effect extent is increased.

The relationship of Ga and As concentration ratio change at crystal surface along the flow line of currents between probes was obtained by an Auger-spectrometric method (JAMP-IOSX). At current section 2 there is a depletion of 1.5 times of that current section 1, where the current was not passing.

Where the relative concentration distribution of Ga and As at section 2 as a function of depth is demonstrated, it is seen that the greatest change of stoichiometry reaches the depth of 1.5 - 2.0 µm.

In addition the changes of composition of crystals GaAs:H and microimpurity distribution of H with depth were analysed by the method of Time of Flight Mass-spectrometry with laser Excitation of the Specimen in the follow regimes: vacuum 10^-9 Torr, mass registration 1-300 amu, resolution 300, sensitivity ~10¹⁶ sm^-3, depth of analysis ~1 µm.