Surface inspection method and apparatus therefor

A method of inspecting a substrate surface having a known reflectivity to detect the diameters of particles on the substrate surface, comprising the steps of:

• irradiating light on said substrate surface;
• collecting scattered light from said substrate surface,
• detecting said scattered light collected, and
• compensating for detection sensitivity of said scattered light in accordance with a compensation control signal on the basis of intensity of regularly reflected light from said substrate surface corresponding to reflectivity of said substrate surface so that the particle diameters on the substrates can be detected correctly even when the reflectivities of the substrate surface differ from each other.

An apparatus for inspecting a substrate surface, having a known reflectivity to detect the diameters of particles on the substrate surface, comprising:

• a light source irradiating light on said substrate surface,
• means for collecting scattered light from said particles,
• a photomultiplier tube for detecting said scattered light collected by said collecting means,
• a detector circuit for detecting an amplitude of said scattered light,
• means for outputting a compensation control signal corresponding to said reflectivity of said substrate surface on the basis of intensity of said scattered light from said substrate surface, and
• means for compensating for detection sensitivity of said photomultiplier tube in accordance with reflectivity of said substrate surface, so that the particle diameters on the substrates can be detected correctly even when the reflectivities of the substrate surfaces differ from each other.

An apparatus for inspecting a substrate surface having a known reflectivity to detect the diameters of particles on the substrate surface, comprising:

• a light source irradiating light on said substrate surface,
• means for collecting scattered light from said substrate surface,
• a photomultiplier tube for detecting said scattered light collected by said collecting means, and
• a detector circuit for detecting amplitude of said scattered light,
• means for outputting a compensation control signal corresponding to said reflectivity of said substrate surface on the basis of intensity of a regularly reflected light from said substrate surface,
• a detector circuit for detecting amplitude of said scattered light,
• means for compensating a detection sensitivity of said photomultiplier tube in accordance with a reflectivity of said substrate surface, so that the particle diameters on the substrates can be detected correctly even when the reflectivities of the substrate surfaces differ from each other.