Automatic Defect Inspection System for Unpatterned Wafers EM-6479

The system is intended for automatic inspection of the unpatterned semiconductor wafer surface quality.

The inspection of micro defects and micro roughness is performed through spiral scanning of the surface of a rotating and moving wafer by a focused laser ray.

Micro defects and micro roughness sizes evaluation is performed through the magnitude of diffused light intensiveness and assessed in relative units.

A relative unit is defined through calibration of the system with test wafers.

The system can function in two modes:

• Sorting
• Research

In the sorting mode the machine performs automatic inspection of the surface and sorts wafers according to the

given quality parameters:

• the permissible quantity of the micro defects given size
• the permissible area of the wafers surface with the given size of micro roughness

In the research mode two color maps of the wafer surface are showed on the display:

• the map of particles distribution where the size of particles is given through an adequate colour;
• the map of micro roughness where the degree of roughness is given through adequate colour.

Specifications

Wafer diameter 150, 200mm Minimum defect size 0.15 µm Min. practicle detection probability 0.95 Throughput 100 wph Dimensions 1235x800x1300 mm Weight 220 kg

Operation Conditions

Clean room Class 10 Temperature 20...24°C Temperature variation ± 1°C Relative humidity 50 ± 10% Maximal consumed power 0.7 kW