Quantemol
Encyclopedia
Quantemol Ltd is based in University College London
initiated by Professor Jonathan Tennyson FRS and Dr. Daniel Brown in 2004. The company initially developed a unique software tool, Quantemol-N, which provides full accessibility to the highly sophisticated UK molecular R-matrix codes, used to model electron polyatomic molecule interactions. Since then Quantemol has widened to further types of simulation, with plasmas
and industrial plasma tools, in Quantemol-P and Quantemol-D.
electron-molecule scattering calculations. Quantemol-N calculates a variety of observables for electron molecule collisions including:
Experimentally, there are problems measuring large cross sections at low angles; this applies to any molecule with a large dipole moment. Being a simulation, this is not a problem for Quantemol-N.
One of the key fundamental processes in etch plasmas is the collision of low-energy electrons with molecules. But for many years the associated molecular data has been missing from the plasma researchers' toolkit. Measurements of these collisions are both expensive and difficult to perform, and their theoretical determination requires the use of sophisticated procedures based on the application of quantum mechanics.
The program couples molecular data and plasma models to provide full information on the various plasma processes. This gives users more insight into the problem than usually obtainable.
A variety of technical plasmas can be simulated; including plasma etch reactors
, plug-flow reactors and well-mixed reactors.
The plasma model in Quantemol-P is based on the zero-dimensional global-kinetics simulation code GLOBALKIN developed over a number of years by Kushner and co-workers.
With the Quantemol-D software the machine design can be driven by high-level physics based simulation, leading to fewer physical iterations of the machine. Thus a cheaper, more efficient design process is created, which also has less impact on the environment.
The software builds upon the respected Hybrid Plasma Equipment Model (HPEM) codes developed by leading plasma physicist Professor Mark Kushner and others, adding a number of needed systems for both expert and non-expert users. Quantemol-D includes user interface enhancements, extensive documentation and support, data visualisation, analysis, job control, batch process and design of experiment support.
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...
initiated by Professor Jonathan Tennyson FRS and Dr. Daniel Brown in 2004. The company initially developed a unique software tool, Quantemol-N, which provides full accessibility to the highly sophisticated UK molecular R-matrix codes, used to model electron polyatomic molecule interactions. Since then Quantemol has widened to further types of simulation, with plasmas
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
and industrial plasma tools, in Quantemol-P and Quantemol-D.
Quantemol-N
The Quantemol-N software system has been developed to simplify use of UK R-matrix codes. It provides an expert interface for non specialists to perform ab initioAb initio
ab initio is a Latin term used in English, meaning from the beginning.ab initio may also refer to:* Ab Initio , a leading ETL Tool Software Company in the field of Data Warehousing.* ab initio quantum chemistry methods...
electron-molecule scattering calculations. Quantemol-N calculates a variety of observables for electron molecule collisions including:
- Elastic cross sections
- Electronic excitation cross sections
- Electron impact dissociation rates
- Resonance parameters
- Radial charge density calculation
- Dissociative electron attachment cross sections
- Ionisation cross sections
- Differential cross sections
- Momentum transfer sections
- Vibration excitation cross sections
Applicable simulations
Quantemol-N is capable of tackling a variety of problems;- Closed shell molecules
- Open shell molecules, and radicals
- Neutral and positively charged species
- Molecules of up to 17 atoms. (NeopentaneNeopentaneNeopentane, also called dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is an extremely flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bath, or when compressed to a higher...
has been successfully simulated, with improvements allowing more atoms in the future, and rapid movement towards BiomoleculesBiomoleculeA biomolecule is any molecule that is produced by a living organism, including large polymeric molecules such as proteins, polysaccharides, lipids, and nucleic acids as well as small molecules such as primary metabolites, secondary metabolites, and natural products...
)
Accuracy
A study on the key benchmark molecule; water, gave results more accurate than obtainable experimentally (Faure et al. 2004).Experimentally, there are problems measuring large cross sections at low angles; this applies to any molecule with a large dipole moment. Being a simulation, this is not a problem for Quantemol-N.
Relevant Publications
- Jonathan Tennyson, Daniel B. Brown, James J. Munro, Iryna Rozum, Hemal N. Varambhia and Natalia Vinci
- Journal of Physics: Conference Series 86, 012001 (2007)
- doi: 1742-6596/86/1/012001
- Radmilovic-Radjenovic M, Petrovic ZL,
- ACTA PHYSICA POLONICA A, 117 (2010),745-747
- Varambhia HN, Faure A, Graupner K, et al.
- Monthly Notices of the Royal Astronomical Society, 403 (2010), 1409-1412
- M. Radmilovic-Radjenovic, H. N. Varambhia, M. Vranic, J. Tennyson, Z. Lj. Petrovic.
- Publ. Astron. Obs. Belgrade No. 84 (2008), 57-60
- Hemal N. Varambhia, James J. Munro and Jonathan Tennyson
- International Journal of Mass Spectrometry, 271, 1-7 (2008)
- Hemal N. Varambhia and Jonathan Tennyson
- Journal of Physics B: Atomic, Molecular and Optical Physics, 40, 1211-1223 (2007)
- 29 March 2005, by Harry Yeates, Electronics Weekly
- 15 March 2005, III-Vs Review
Quantemol-P
The etching of silicon wafers using gaseous plasmas underpins the rapid advance in computer technology that has powered the global economy, and will continue to do so for the foreseeable future. Currently, experimental testing is used to establish the relevant plasma mixes to generate the desired etch. Such testing is an expensive and time-consuming process even for relatively minor improvements in the processes. Simulation allows much of this process can be done outside of the reactor at reduced cost and improved efficiency. Quantemol-P provides users with a means to simulate these processes.One of the key fundamental processes in etch plasmas is the collision of low-energy electrons with molecules. But for many years the associated molecular data has been missing from the plasma researchers' toolkit. Measurements of these collisions are both expensive and difficult to perform, and their theoretical determination requires the use of sophisticated procedures based on the application of quantum mechanics.
Program use
Quantemol-P assists in the research for new plasma recipes and optimizes given processes by simulating etch machines. The simulation inputs used match those of the plasma processing tools: e.g. power, pressure, gas flow rate, time, volume.The program couples molecular data and plasma models to provide full information on the various plasma processes. This gives users more insight into the problem than usually obtainable.
A variety of technical plasmas can be simulated; including plasma etch reactors
Plasma etcher
A plasma etcher, or etching tool, is a tool used in the production of semiconductor devices. Plasma etcher produces a plasma from a process gas, typically oxygen or a fluorine bearing gas, using a high frequency electric field, typically 13.56 MHz. A silicon wafer is placed in the plasma etcher,...
, plug-flow reactors and well-mixed reactors.
The plasma model in Quantemol-P is based on the zero-dimensional global-kinetics simulation code GLOBALKIN developed over a number of years by Kushner and co-workers.
Relevant Publications
- James J. Munro and Jonathan Tennyson
- Journal of Vacuum Science and Technology A, 26, 865 (2008)
Quantemol-D
The development of new machinery underpins the development of new technology, as without newer, more advanced machines large scale manufacturing is not possible. Traditionally the development of such machinery is costly and wasteful, with many iteration cycles throughout the design process.With the Quantemol-D software the machine design can be driven by high-level physics based simulation, leading to fewer physical iterations of the machine. Thus a cheaper, more efficient design process is created, which also has less impact on the environment.
The software builds upon the respected Hybrid Plasma Equipment Model (HPEM) codes developed by leading plasma physicist Professor Mark Kushner and others, adding a number of needed systems for both expert and non-expert users. Quantemol-D includes user interface enhancements, extensive documentation and support, data visualisation, analysis, job control, batch process and design of experiment support.
See also
External links
- Quantemol Official Site
- Quantemol-N: an expert system for performing electron molecule collision calculations using the R-matrix method
- Calculations of Cross Sections Data for Scattering of Electrons on HBr
- Electron-impact rotational excitation of the carbon monosulphide (CS) molecule
- Cross-sections for the scattering of electrons with BF3
- R-matrix calculations of low-energy electron alkane collisions
- Electron collision with the HCN and HNC molecules using the R-matrix method
- Tool opens door to quantum modelling
- Quantemol-N from plasma etch and lasers to earth’s ionosphere
- Global plasma simulations using dynamically generated chemical models