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Dopant Profiling for Submicron Structures

Objective

The objective was to provide the capabilities necessary for the accurate determination of shallow dopant profiles as used in submicron devices by the further development of one specific electrical technique, spreading resistance measurement.
This involved the improvement and optimisation of the measurement operating conditions, the development and implementation of new software correction algorithms, the simulation and assessment of one- and two-dimensional carrier spilling effects, the preparation of special test structures using ion implantation and molecular beam epitaxy (MBE), and the intercomparison of the results of this technique with other electrical and non-electrical methods, such as secondary ion mass spectrometry (SIMS), Rutherford back scattering (RBS), neutron activation analysis (NAA), CVprofiling, and electrochemical CVprofiling(ECV).
Technological development in silicon microelectronics will be determined by:
shrinkage of the structure dimensions for higher speed and complexity (submicron and nanometre structures);
novel concepts for multifunctional devices or integrated circuits (IC) (3-dimensional integration of sensors, wave guides, or antennas with electronics);
enlargement of the material base: silicon germanium, III-V heterostructures, semiconductor metal and insulator combinations, artificial semiconductor structures as superlattices.
Molecular beam epitaxy (MBE) of silicon is a low temperature process which is capable of growing nearly all the structures needed for the above mentioned developments. Silicon MBE has been demonstrated for the preparation of sophisticated submicron structures. Improvements of characterisation techniques have been achieved, particularly with spreading resistance and defect etching, and promising tools for in situ monitoring have been presented.
This experience and progress in layer fabrication, material assessment and process control will be utilised for the generation of MBE material for high speed devices and integrated circuits with particular effort toward germanium heterodevices.

The objective was to provide the capabilities necessary for the accurate determination of shallow dopant profiles as used in submicron devices by the further development of one specific electrical technique, spreading resistance measurement. This involved the improvement and optimization of the measurement operating conditions, the development and implementation of new software correction algorithms, the simulation and assessment of one and two dimensional carrier spilling effects, the preparation of special test structures using ion implantation and molecular beam epitaxy (MBE), and the intercomparison of the results of this technique with other electrical and nonelectrical methods, such as secondary ion mass spectrometry (SIMS), Rutherford back scattering (RBS), neutron activation analysis (NAA), CV profiling, and electrochemical CV profiling (ECV). Experience has been gained in the deeper understanding of the physics of spreading resistance measurements, on the influence of the experimental conditions on the results, and the correction algorithms used for data interpretation. The limitations of the technique with respect to profiling special structures are now established. Transferability of the probe conditioning procedures, software programs and calibration techniques developed within this project have been demonstrated. This project has provided an optimized spreading resistance technique, which is required by technology development project.
Through the experimental and theoretical work effectuated, useful experience has been gained in the deeper understanding of the physics of spreading resistance measurements, on the influence of the experimental conditions on the results, and the correction algorithms used for data interpretation. The limitations of the technique with respect to profiling special structures are now established. Transferability of the probe conditioning procedures, software programs and calibration techniques developed within this project have been demonstrated.
This project has provided an optimised spreading resistance technique, which is required by technology development projects under the ESPRIT programme as well as by the European ITindustry as a whole.
Exploitation
The outputs from this project are detailed special reports describing the recommended hardware modifications and improved measurement procedures, a commercially available software package for improved data processing, the establishment of a spin-off commercial service centre (SAS) exploiting the results obtained within the project, and a good understanding of the fundamental possibilities and limitations of this profiling technique in respect of the type of profile to be analysed. The developed techniquesare also being exploited internally by the analytical services of IMEC and Daimler-Benz.

Coordinator

GEC-Marconi Materials Technology Ltd
Address
Elstree Way
WD6 1RX Borehamwood
United Kingdom

Participants (4)

Daimler-Benz AG
Germany
Address
Wilhelm-runge-straße 11
89013 Ulm
GEMETEC Aachen Gesellschaft für Medizintechnik und Organisation mbH
Germany
Address
Pauwelsstraße 19
52074 Aachen
IMEC VZW
Belgium
Address
Kapeldreef
3030 Heverlee
SAS Ltd
United Kingdom