Method and device for monitoring the etching operation for a regular depth structure in a semiconductor substrate

A device for monitoring an etching operation for a regular depth structure in a semiconductor substrate, comprising:

• a radiation source for large-area irradiation of the semiconductor substrate in a region of the depth structure during the etching operation at a predetermined angle of incidence with respect to a surface of the semiconductor substrate with an electromagnetic radiation whose wavelength lies in an infrared region;
• a radiation detector for continuous detection of the intensity of reflected radiation at an angle of reflection, corresponding to the angle of incidence, with respect to the surface of the semiconductor substrate;
• and
• an evaluation unit for determination of the depth of the etched structure and/or of a quality of the etched structure with regard to regularity thereof from the recorded intensity profile.

A method for monitoring an etching operation for a regular depth structure in a semiconductor substrate, comprising:

• continuously irradiating of the semiconductor substrate in a region of the depth structure during the etching operation at a predetermined angle of incidence with respect to a surface of the semiconductor substrate with an electromagnetic radiation whose fixedly predetermined wavelength lies in an infrared region;
• continuously detecting of intensity of the reflected radiation at an angle of reflection, corresponding to the angle of incidence, with respect to the surface of the semiconductor substrate;
• and
• continuously determining the depth of the etched structure and/or of the quality of the etched structure with regard to regularity thereof from the continuously recorded intensity profile.