Mass Spectrometry Study of the Temperature Dependence of Pt Film Growth by Atomic Layer Deposition

作者：Erkens I J M^*; Mackus A J M; Knoops H C M; Smits P; van de Ven T H M; Roozeboom F; Kessels W M M

来源：ECS Journal of Solid State Science and Technology, 2012, 1(6): P255-P262.

DOI：10.1149/2.006206jss

Insights into the temperature dependence of atomic layer deposition (ALD) of Pt using (methylcyclopentadienyl) trimethylplatinum, (MeCp)PtMe3, precursor and O-2 are presented, based on a study of reaction products by time-resolved quadrupole mass spectrometry (QMS) measurements. Above 250 degrees C, Pt ALD proceeds through unhindered O-2 dissociation at the Pt surface, inducing complete and instantaneous combustion of the precursor ligands. Quantification of the QMS data revealed that at 300 degrees C, approximately 20% of the C-atoms react during the precursor pulse, forming mainly CH4 (similar to 18%) balanced by CO2 (similar to 2%). The remaining 80% of the C-atoms are combusted during the O-2 pulse. Time-resolved data indicated that the combustion reactions compete with the hydrogenation reactions for the available surface carbon. Combustion reactions were found to be dominant, provided that a sufficient amount of chemisorbed oxygen is available. When the temperature drops below 250 degrees C, deposition becomes hindered by the presence of a carbonaceous surface layer of partially fragmented and dehydrogenated precursor ligands, formed during the precursor pulse. The carbonaceous layer limits dissociative chemisorption of O-2 and hence combustion reactions (leading to CO2) whereas reduced surface reactivity also limits (de-)hydrogenation reactions (leading to CH4). Below 100 degrees C, the carbonaceous layer fully prevents O-2 dissociation and ALD of Pt cannot proceed.

• 出版日期2012