Diagnostic in CVD processes by IR pyrometry

The control of CVD processes requires in situ analysis techniques and real time monitoring to identify the chemical species involved in the mechanism, to determine the growth kinetics and more generally to detect and analyze the dynamics of any event occurring during the growth of the film. We demonstrate through four representative examples that IR pyrometry allows to answer to the last two items, which make it an attractive diagnostic tool for CVD processes, simple to use, sensitive at nanometric scale, economic and being able to operate either under atmospheric or low pressure. Thus, we monitored the initial stages of the growth of conducting diffusion barriers CrCxNy on Si and as a second example, we have followed their heat treatment to detect possible phase transformations. The case of MOCVD of Fe reveals the high sensitivity of this diagnostic technique. Indeed, the abrupt changes of the pyrometric signal correlate remarkably to changes in the growth mode. Lastly, the characteristic oscillations due to multireflexions at the interfaces observed in the first stages of the growth of transparent TiO2 film allow the real time determination of the growth rate. These examples show the great diagnostic potentialities of IR pyrometry for the optimization and the control of CVD processes

MOCVD of Cr3(C,N)2 and CrSixCy Films Growth and Characterization

CrCxNy and CrSixCy thin films were deposited under low pressure by metallorganic chemical vapor deposition (MOCVD) in the temperature ranges 380-450°C and 450-500°C, respectively, using Cr(NEt2)4 and CrCH2SiMe34 as single-source precursors.The growth was achieved in a cold-wall vertical reactor using, respectively, H2 and He as the carrier gases. Both types of films exhibit a mirrorlike surface morphology and are amorphous asdeposited. The CrCxNy layers start to crystallize at 600°C after annealing for 1 h under vacuum,whereas it is necessary to reach 650°C under H2 atmosphere. In both cases, the original ternary phase Cr3(C0.8N0.2)2 crystallizes. The resistivity of as-deposited amorphous CrCxNy films is typically 600. cm, and it decreases to 150 #. cm after annealing upon the formation of polycrystalline Cr3#C,N#2 films. The CrSixCy layers have a very stable amorphous structure until 850°C for 4 h. In spite of their metallic appearance, they exhibit a high resistivity compared to the Cr3#C,N#2 films. The main characteristics of these Cr-based layers is presented and discussed

Cr-based MOCVD layers as conducting diffusion barriers for copper metallization

Two types of amorphous Cr-based thin films, CrCxNy and CrSixCy, were grown by low pressure MOCVD on Si substrates using respectively Cr(NEt2)4 and Cr[CH2SiMe3]4 as single-source precursor in the low temperature range 400-420 °C and 475-500 °C. Their properties as conducting diffusion barrier against Cu were investigated and the results are discussed. CrSixCy exhibits a better thermal stability and a good Cu wettability but a high resistivity, which is detrimental for this application. CrCxNy has a low resistivity, a satisfactory stability up to 650 °C without undesirable interfacial reactions and an excellent conformality