Research:
Electronic materials and processes

Programmable/Combinatorial Chemical Vapor Deposition

We are developing a new paradigm for chemical vapor deposition (CVD) reactors, a mainstay of semiconductor manufacturing.  Gas delivery showerhead designs enable 2-D programmable variation of fluxes across the wafer, with two different applications.  First, this allows uniformity to be achieved at a desired process design point. Second, it enables combinatorial variation of conditions across the wafer, expediting materials and process discovery in an era of increasingly complex new materials sets.  Real-time, in-situ sensors (mass spectometry), modeling, and simulation are major features essential in our program to achieve the promise of this new approach.

Atomic layer deposition (ALD)

Atomic layer deposition has become a key process for the future thin film materials technologies because it enables atomic-level control in materials deposition along with unprecedented conformality, i.e. uniformity of thickness over even extreme 3-D topography. By producing alternating exposures to two or more CVD reactant gases, each exposure cycle involves self-limiting adsorption/reaction on the surface, leading to thickness and conformality control.  We are pursing ALD reactor designs which mimic manufacturing designs for high rate gas cycling, along with in-situ chemical diagnostics and metrology for improved understanding and control of the process.  Applications include ultrathin metal layers, high-K dielectrics, and low temperature deposition of films for semiconductors, microfluidics, MEMS, and nanotechnology.

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Semiconductor Materials, Processing, and Characterization

We are investigating key issues in semiconductor materials and processing science and technology.  One such issue is the formation of low-K dielectric materials as insulators for advanced interconnects.  We have studied the material transformations which occur in spin-cast precursors during thermal curing, in which both components of the precursor change profoundly.  The matrix polymer cross-links to form low-K material while the porogen component retains its nanopore structure.  At higher temperatures the porogen material decomposes, volatilizes, and leaves a nanopore structure that reduces the effective dielectric constant significantly.  Measurement of surface properties and gas phase product evolution reveal the thermal reaction kinetics of these transformations.

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Selected Accomplishments

Thermal transformations in formation of nanoporous low-K dielectric films
Reactor design for spatially programmable chemical vapor deposition
Real-time chemical sensing and metrology in atomic layer deposition

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Students

Laurent Henn-Lecordier (MSE grad, staff)
Erin Robertson (MSE grad)
Parag Banerjee (MSE grad)
Nicholas Mostovych (MSE undergrad)
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Collaborators

Ray Adomaitis (ChE/ISR)
Robert Briber (MSE)
FCS group, ITC-irst, Trento, Italy
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Support

MKS Instruments
CoSMIC NSF International Materials Institute

NSF Information Technology Research
Autonomous Province of Trentino/ITC-irst, Trento, Italy
Inficon

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Selected Publications

" Thin Film Transformations and Volatile Products in the Formation of Nanoporous Low-K PMSSQ-based Dielectric ", P. Lazzeri, L. Vanzetti, M. Anderle, M. Bersani, J. J. Park, Z. Lin, R. M. Briber, G. W. Rubloff, H. C. Kim, R. D. Miller, J. Vac. Sci. Technol. B 23, 908-917 (May/Jun 2005).

" Development of a Spatially Controllable Chemical Vapor Deposition Reactor with Combinatorial Processing Capabilities ", J. O. Choo, R. A. Adomaitis, L. Henn-Lecordier,Y. Cai, and G. W. Rubloff, Rev. Sci. Instr. 76, 062217-1 to 062217-10 (June 2005).

" Data Management and Visualization of X-ray Diffraction Spectra from Thin Film Ternary Compound Spreads ", I. Takeuchi, C. J. Long, O. O. Famodu, M. Murakami, J. Hattrick-Simpers, G. W. Rubloff, M. Stukowski, and K. Rajan, Rev. Sci. Instr. 76, 062223-1 to 062223-8 (June 2005).

" Simulation-Based Design and Experimental Evaluation of a Spatially Controllable Chemical Vapor Deposition Reactor ", Jae-Ouk Choo, Raymond A. Adomaitis , Gary W. Rubloff , Laurent Henn-Lecordier , and Yijun Liu, AIChE J. 51 (2) 572-584 (Feb 2005).

" ToF-SIMS studies of nanoporous PMSSQ materials: kinetics and reactions in the processing of low-K dielectrics for ULSI applications ", P. Lazzeri, G. W. Rubloff, L. Vanzetti, R. M. Briber, M. Anderle, M. Bersani, J. J. Park, H.-C. Kim, W. Volksen, R. D. Miller, and Z. Lin, Surface and Interface Analysis 36, 304-310 (2004).

" Material Characterization and the Formation of Nanoporous PMSSQ Low-K Dielectrics ", P. Lazzeri, L. Vanzetti, E. Iacob, M. Bersani, M. Anderle, J. J. Park, Z. Lin, R. M. Briber, G. W. Rubloff, and R. D. Miller, Proc. 2003 International Conference on Characterization and Metrology for ULSI Technology, Austin, TX, March 24-28, 2003, ed. by D. G. Seiler et. al., AIP Conf. Proc. Vol. 683, ISBN 0-7354-0152-7 (AIP, Melville NY , 2003), 551-555.

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Patents

"Spatially programmable microelectronics process equipment using segmented gas injection showerhead with exhaust gas recirculation", Raymond A. Adomaitis, John N. Kidder, Jr., and Gary W. Rubloff, U.S. Patent No. 6,821,910, issued Nov. 23, 2004.

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On this page

Combinatorial CVD and ALD

Atomic layer deposition (ALD)

Semiconductor materials, processing, and characterization

Selected Accomplishments

Students

Collaborators

Support

Selected Publications

Patents

Research

Overview

Biological microsystems and biomaterials

Nanostructures and energy applications

Electronic materials and processes

Nanomanufacturing



Contact

Gary W. Rubloff
301 405-3011
office: 1128 Kim Bldg
mail: 2145 AV Williams Bldg
University of Maryland
College Park, MD 20742-3285