@inproceedings{TallaridaKaravaevKolaneketal., author = {Tallarida, Massimo and Karavaev, Konstantin and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {In-situ experimental approach to the study of atomic layer deposition with atomic force microscope, X-ray photoelectron and X-ray absorption spectroscopy}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S.176}, abstract = {We describe our experimental approach to the investigation of atomic layer deposition (ALD). ALD is a powerful deposition technique for growing conformal thin films of composite materials with atomically accurate thickness on large area [1]. Despite the enormous industrial interest growing around ALD, its fundamental properties were not yet properly studied. We developed an ALD reactor for the in-situ investigations using XPS, XAS and AFM as experimental techniques. We studied the chemical-physical properties of the growing thin films after each deposition cycle. Here, we illustrate the recent results concerning the ALD of HfO2 obtained using different Hf-precursors on various substrates [2]. We show how the in-situ investigations could deliver an important insight into the fundamental characteristics of ALD and how these information could be used to modify and optimize the deposition parameters. [1] M. Leskel{\"a}, M. Ritala, Thin Solid Films, 409, 138, 2002; [2] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Appl. Phys. 104, 064116 (2008).}, language = {en} } @inproceedings{MichlingKolanekSchmeisseretal., author = {Michling, Marcel and Kolanek, Krzysztof and Schmeißer, Dieter and Tallarida, Massimo}, title = {A growth model for the HfO2 ALD process}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 294}, abstract = {In this contribution we report on our in-situ2 cycle-by-cycle (up to the 25 cycles) investigation of the HfO2 atomic layer deposition (ALD) process using the method of x-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS). We used Tetrakis-Dimethyl-Amino-Hafnium (TDMA-Hf) and H2O as precursors and p-type Si wafer with native oxide as a substrate. The XPS measurements were carried out at BESSY II in Berlin with primary energies of 150 eV and 640 eV and the EELS measurements were done with a primary energy of 50 eV. We measured the O1s, Si2p core level and the valence band including the Hf 4f core level. From the Hf4f to Si2p ratios taken at each energy we developed a growth model for the first monolayer and for the following layers too. From our data we conclude, that in the first monolayer up to the fourth ALD cycle an island growth occurs. The height of these islands is about 0,5nm. After the first monolayer is completed, a layer- by-layer growth can be expected. In order to proof this observation we have simulated the Hf/Si ratio for different excitation energies and found a very good agreement with our measurement data. The EELS data especially the evaluation of the loss function onset confirm our growth model.}, language = {en} }