METHOD AND APPARATUS FOR DETECTION OF FOREIGN SUBSTANCES ON WAFER

Japanese Patent JP2973598

B2

PURPOSE: To facilitate counting of extra-fine foreign substance particles on a wafer surface whose sizes are abut 0.05μm by a method wherein the object wafer is exposed to a supersaturation vapor pressure state in a condensation chamber and the sizes of the foreign substance particles are enlarged by condensation reaction with the particles as nuclei and the number of the enlarged uncle is counted.
CONSTITUTION: A wafer 1 is conveyed into a condensation chamber 12 and cooled to a predetermined temperature by a stage 21 whose temperature is controlled. Then alcohol is introduced into the chamber 12 from an alcohol bottle 23 through a flow rate controller 22 so as to obtain an approximate saturation vapor pressure. As the temperature of the wafer 1 is so controlled as to be several degrees to scores of degrees lower than the temperature of the side walls of the condensation chamber 12, the alcohol vapor near the wafer surface is cooled and put into a supersaturation state. If there are foreign substances on the wafer surface, alcohol is condensed with the foreign substances as nuclei and the sizes of the foreign substances are enlarged to the extent from 0.5μm to several microns. The wafer 1 is conveyed into a foreign substance counting chamber 13 and the number of the foreign substance particles is counted. With this constitution, the number of the foreign substances can be counted easily and the control and improvement of an LSI manufacturing process can be well managed.

KUBOTA MASABUMI
NISHIO MIKIO

JP15443091A

November 08, 1999

June 26, 1991

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MATSUSHITA DENKI SANGYO KK

G01N21/88; G01N21/94; H01L21/66; H01S3/00; (IPC1-7): H01L21/66; G01N21/88; H01S3/00

JP3266445A
JP2192750A
JP1251733A

Fumio Iwahashi (2 others)

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