Method and apparatus for analyzing contaminative element concentrations

A contaminative element concentration analyzing apparatus, comprising:

• X-ray irradiating means for irradiating an X-ray upon a substrate to be analyzed at a predetermined incident angle;
• X-ray detecting means for detecting fluorescent X-ray generated by elements when the irradiated X-ray is total reflected from a surface of the substrate, to obtain an observed waveform;
• peak separating means for separating peaks of the fluorescent X-ray generated by contaminative elements to be analyzed from the fluorescent X-ray waveform detected by said X-ray detecting means;
• and
• concentration detecting means for detecting concentrations of the contaminative elements to be analyzed on the basis of the peaks separated by said separating means,
• wherein said separating means comprises:
• first detecting means for detecting a peak of the detected contaminative element from the waveform detected by said X-ray detecting means;
• second detecting means for detecting presence or absence of other peaks within a predetermined number of channels before and after the peak detected by said first detecting means;
• extracting means, when said second peak detecting means detects other peaks, for extracting the numbers of channels and signal intensities between the respective peaks;
• evaluation value calculating means for calculating evaluation values Yi on assumption that the respective detected peaks are true peaks in accordance with
• Yi=.SIGMA.i.vertline.P-Pi.vertline.x Ci
• where
• P:
• channel number of tentative peaks
• Pi:
• channel number between the peaks
• Ci:
• signal intensity at channel number Pi;
• and
• peak discriminating means for comparing the evaluation values Yi calculated by said evaluation calculating means with each other to discriminate the peak having the minimum evaluation value Yi as a true peak.