Measurement of critical dimensions using X-ray diffraction in reflection mode

A method for X-ray analysis, comprising:

• directing a beam of X-rays to impinge on an area of a planar sample that comprises a feature having sidewalls perpendicular to a plane of the sample, the sidewalls having a thin film thereon;
• detecting a spectrum of the X-rays scattered from the sample due to the feature;
• and
• analyzing the spectrum to measure a characteristic of the thin film on the sidewalls.

Apparatus for X-ray analysis of a sample having a periodic feature on a surface thereof, the apparatus comprising:

• an X-ray source, which is adapted to direct a beam of X-rays to impinge on an area of the surface containing the periodic feature;
• a detector, which is adapted to receive the X-rays scattered from the surface in a reflection mode so as to detect a spectrum of diffraction in the scattered X-rays as a function of azimuth;
• and
• a signal processor, which is adapted to analyze the spectrum of diffraction by measuring an angular separation between side lobes in the spectrum in order to determine a dimension of the feature.

Apparatus for X-ray analysis of a planar sample that includes a feature having sidewalls perpendicular to a plane of the sample, the sidewalls having a thin film thereon, the apparatus comprising:

• an X-ray source, which is adapted to direct a beam of X-rays to impinge on an area of the sample containing the feature;
• a detector, which is adapted to detect a spectrum of the X-rays scattered from the sample due to the feature;
• and
• a signal processor, which is adapted to analyze the spectrum to measure a characteristic of the thin film on the sidewalls.

A cluster tool for producing microelectronic devices, comprising:

• a fabrication station, which is adapted to form a periodic feature on a surface of a semiconductor wafer;
• and
• an inspection station, comprising:
• an X-ray source, which is adapted to direct a beam of X-rays to impinge on an area of the surface containing the periodic feature;
• a detector, which is adapted to receive the X-rays scattered from the surface in a reflection mode so as to detect a spectrum of diffraction in the scattered X-rays as a function of azimuth;
• and
• a signal processor, which is adapted to analyze the spectrum of diffraction by measuring an angular separation between side lobes in the spectrum in order to determine a dimension of the feature.

Apparatus for producing microelectronic devices, comprising:

• a production chamber, which is adapted to receive a semiconductor wafer;
• a fabrication device, which is adapted to form a periodic feature on a surface of the semiconductor wafer within the chamber;
• an X-ray source, which is adapted to direct a beam of X-rays toward the semiconductor wafer in the production chamber so as to impinge on an area of the surface containing the periodic feature;
• a detector, which is adapted to receive the X-rays scattered from the surface in a reflection mode so as to detect a spectrum of diffraction in the scattered X-rays as a function of azimuth;
• and
• a signal processor, which is adapted to analyze the spectrum of diffraction by measuring an angular separation between side lobes in the spectrum in order to determine a dimension of the feature.