Because of the further integration of semiconductor devices, airborne molecular contaminants (AMC's) in cleanroom air have become of serious problem as they strongly affect device properties. We developed two analysis methods of boron ; filter collecting method for particulate boron and solution absorption method for both particulate and gaseous boron. The result of filter collecting method was compared with that of solution absorption method. There were two comparison results. One case in which boron concentration measured by the solution absorption method was higher than that by the filter collecting method, indicating the existence of gaseous boron compounds. The other case in which both methods gave a similar concentration, suggesting that boron existed mainly in particulate state. Gaseous boron compounds are 1) boron trifluoride emitted from borosilicate glass fibers of high efficiency particulate air filters (HEPA) by the attack of hydrogen fluoride, and 2) boron hydroxide emitted by a reaction of crystallized boron oxide in borosilicate glass with water and/or alcohol vapor in cleanroom. In a well-controlled cleanroom, boron concentration was below 0.1 ng/m3, which meets the cleanliness required for 0.25 μm logic manufacturing process.
