An apparatus for depositing materials onto a micro-device workpiece
includes a gas source system configured to provide a first precursor, a
second precursor, and a purge gas. The apparatus can also include a valve
assembly coupled to the gas source system. The valve assembly is
configured to control a flow of the first precursor, a flow the second
precursor, and a flow of the purge gas. Another component of the
apparatus is a reaction chamber including an inlet coupled to the valve
assembly, a workpiece holder in the reaction chamber, and an outlet
downstream from the workpiece holder. The apparatus also includes a
monitoring system and a controller. The monitoring system comprises a
radiation source that directs a selected radiation through the reaction
chamber and a detector that senses a parameter of the radiation directed
through the reaction chamber. The controller is operatively coupled to
the monitoring system and the valve assembly. The controller contains
computer operable instructions to terminate the flow of the first
precursor, the flow of the second precursor and/or the flow of the purge
gas based on the parameter sensed by the monitoring system in real-time
during a deposition cycle of a workpiece.