Measuring Temporal Variation of Concentration of ALD Precursor TEMAZ in Process Chamber Using UV Absorption Method

The UV light densitometer was developed to measure concentration of gases having absorption in the ultraviolet region using UV absorption method. The developed densitometer was applied to monitor temporal variation of concentration of ALD precursor TEMAZ introduced into a chamber, where TEMAZ was introduced alternately with purge Ar gas to simulate ALD process. We could successfully capture temporal variation of gas concentration such as time delay in arrival of gas in the chamber due to presence of gas flow. Such phenomenon cannot be measured by the pressure gauge.