Copper film growth by chemical vapor deposition. Electrical and optical measurements in real time, and studies of morphology

The deposition of copper by low pressure chem. vapor deposition (CVD) from Cu bis-hexafluoroacetylacetonate is monitored in real time and in situ by the measurement of the optical reflectivity and elec. resistance of the growing metal film. Changes of the deposit morphol. during growth were analyzed by interrupting the CVD process at different stages and observing the samples by transmission electron microscopy. Pure copper is deposited at 400 Deg and 1 mbar total reactor pressure of helium, precursor, and water vapor. Two successive regimes are distinguished in the deposition: island formation and continuous film growth. The transition between these two regimes is visible in the real time specular reflectance measurement. The copper deposition rate is twice higher during the island growth than during the continuous film growth at the applied conditions. The influence of a metal seeding layer (from 0.001 monolayer to 1 monolayer) on the Cu deposition is shown both in the real time measurements and in the ex situ anal. of films.