Method for producing a chalcogenide-semiconductor layer of the ABC
View Patent ↗A method of monitoring the chalcogenation process in which the chalcogenide semiconductor layer is produced by initially sequentially depositing the two precursor layers of elements A and B and thereafter carrying out a chalcogenizing process with a simultaneous optical process control in which the layer sequence A B is irradiated by light from at least one coherent light source, the light diffusely scattered at the surface is detected and the scattered light signal measured as a function of time is evaluated such that characteristic changes in the layer developing during the chalcogenation are assigned to four characteristic points of the scattered light signal curve.
1. A method of producing a chalcogenide semiconductor layer of the ABC 2 type, comprising the steps of:
sequentially depositing two metallic precursor layers from elements A and B;
chalcogenizing the deposited layers;
simultaneously irradiating the layers with light from at least one source of coherent light;
detecting measuring scattered light reflected from the layers;
evaluating the measured scattered light as a function of time; and
assigning precursor transformation of the compound AB 2 to A 11 B 9 to a first point;
assigning surface chalcogenation of the formed layer in which formation of the phase ABC 2 has been initiated to a second point;
assigning the complete formation of ABC 2 in the case of a precursor layer without excess A or the complete phase separation of ABC 2 and the foreign phase A x C y in the case of a precursor layer with excess A to a third point; and
assigning the transformation of the foreign phase A x C y to foreign phase A C to a fourth point.
2. The method of claim 1 , wherein the element A is one of Cu and Ag, the element B is one of In, Ga and Al, and the element C is one of S and Se.
3. The method of claim 1 , wherein the chalcogenizing surfaces is irradiated by light material of different wavelengths from different sources.
4. The method of claim 3 , wherein the scattered light is measured in dependence of time as a difference signal formed by subtraction of the amplitude of the light from the different sources impinging upon the layer.