Effects of Ion Implantation on Growth, Defect formation and Doping of Diamond

Ziel

- To understand the way diamond damages as a result of ion implantation;
- To study the role that temperature during or following the implantation has on the nature of the damage;
- To investigate the role that defects introduced into diamond in a controlled way by ion implantation have on subsequent homoepitaxial diamond growth;
- To devise ways of doping diamond p-type by implantation of boron ions and the search for suitable n-type dopants introduced into diamond by implantation.
- A comprehensive picture of the ion-beam induced transformation of diamond to graphite has been obtained, and a model for this transformation, based on a consideration of the damage produced around each ion track and the dependence of this damage on implantation temperature has been proposed.
- Good p-type doping of diamond has been achieved by Boron ion implantation followed by a proper annealing procedure, yielding record high hole mobilities of 385 cm2/V.sec (at RT) and the lowest compensation ratio of 0.05 ever reported for ion-implantation doped diamond.
- P-type activities, though with inferior electrical properties, have been obtained by B ion implantation of CVD (highly textured and non oriented polycrystalline) diamond films following the implantation - annealing procedures employed to Type IIa diamond (see above).
- Attempts to achieve n-type semiconductivity of diamond by Li, Na and P ion implantations, along the lines that have yielded good p-type conductivities in B implanted diamond have been, so far, fruitless. No useful conductivities could be measured. However some indications that P may act as a donor in diamond were obtained.

- Bias enhanced nucleation was applied to grow oriented diamond films on untreated silicon substrates leading to heteroepitaxially oriented diamond films.
- Homoepitaxial diamond films were grown on (100) natural diamond substrates to study the effect of ion implantation on diamond growth. In some cases isotopic 13CH4 was used for the deposition of isotopically labelled 13C-diamond. The substrate and film can thus be distinguished by their Raman spectra.
- The structural and morphological effects caused by the addition of boron or nitrogen to the gas mixture during CVD diamond growth were studied and are attributed to the influence of these dopants on the growth velocities in the <100> and the <111> direction respectively.
- Deep ion implantation was used to create an etchable graphitic layer that was either directly "lifted off" or has been lifted-of after overgrowth of the top, annealed, layer.

Follow-up

- Research in many of the above fields continues, though without the support of the EC. In particular the quest for n-type doping of diamond still requires much work, which is indeed ongoing in Israel;
- Growth of highly oriented thick diamond films, mainly for optical and thermal applications continues in Germany.
- Well-characterised diamond crystals or CVD diamond films are damaged by implantation of inert ions (C and Xe) at different temperatures;
- The outcome of the implantation is studied by various electrical and optical methods;
- Overgrow the damaged diamond surfaces with a homoepitaxial diamond layer (including 13C enriched layers) and characterise their properties;
- Utilise the knowledge gained from the above on damaging and annealing diamond for doping diamond by implanting potential dopant atoms (B for p-type and Li, Na, P... for n-type);
- Make use of graphitization of diamond and CVD diamond overgrowth for the realisation of thin single crystal diamond membranes by lift off techniques.

Programm/Programme

IC-ISC C - Activity (Euratom, EEC) on cooperation in science and technology, 1984-

Thema/Themen

Data not available

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

CSC - Cost-sharing contracts

Koordinator

Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung eV (FhG)

EU-Beitrag

Keine Daten

Adresse

Tullastraße 72
79108 Freiburg
Deutschland

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