Other

Sage Wise 66 (pty) Ltd

Johan F Prins

Rex J Keddy

Tom L Nam

Leong T Nam

The invention provides circuits and electronic devices which comprise an electrical flow path, at least part of which is formed by a body of a substrate material at least part of which is a doped part having a surface and implanted atoms at or below the surface, at least part of the surface defining a low resistance section of the electrical flow path.

Electrical conductor

Method of making a contact to a diamond

A crystalline substrate such as diamond, cubic boron nitride or silicon carbide is doped with a dopant atom such as boron, phosphorus or arsenic. The method includes the steps of creating a first damaged layer containing vacancies and interstitial atoms in the crystal lattice of the crystalline substrate, implanting the dopant atoms under conditions to create a second damaged layer separate from the first damaged layer and containing the dopant atoms, and causing the dopant atoms in the second layer to diffuse out of that layer and into vacancies in the first layer and thereby occupy substitutional positions in that layer.

Doping in crystalline diamond substrates

A method of doping diamond with relatively large atoms such as aluminium, phosphorus, arsenic and antimony is provided. The method involves implanting the dopant atoms at a low temperature to create a damaged region of point defects in the form of vacancies and interstitial dopant atoms within the crystal lattice of the diamond, and annealing the diamond to reduce the lattice damage and cause dopant interstitial atoms to diffuse into lattice positions. The implantation dose will be low and such as to create density of implanted dopant atoms of no greater than 2.5.times.10.sup.18 cm.sup.3.

Diamond doping

A method of manufacturing a radiation sensor element. The method includes providing a diamond body which comprises crystalline diamond material which has a nitrogen impurity concentration of less than 150 ppm. The body is typically a synthetic diamond manufactured by a high temperature/high pressure process, or by a chemical vapour deposition process. The body is hydrogenated to cause atomic hydrogen to be incorporated into the diamond crystal lattice. Hydrogenation can be carried out by ion implantation, or by exposing the body to a hydrogen plasma. Where the sensor element is to be used as a counting diamond, electrical contacts are formed on the body, for example by ion implantation.

Method of manufacturing a radiation sensor element

A method of producing a doped diamond, typically a boron doped diamond, is provided. The method involves multiple cold implantation/rapid annealing steps. A doped diamond can be produced containing a high concentration of dopant atoms.

A diamond film is grown on a substrate by providing a non-diamond substrate which has a face-centered cubic (fcc) crystal structure and small crystal lattice mismatch with the lattice of diamond, implanting carbon atoms into the crystal lattice of the substrate and causing the implanted carbon atoms to diffuse out of the substrate and grow epitaxially on the surface of the substrate. The preferred substrate is an fcc metal such as copper, nickel, fcc iron, fcc cobalt or fcc chromium.

Diamond growth

The invention provides a method of preparing a detector which is sensitive to ionizing radiation or atomic emissions. The method includes the steps of forming at least two discrete conductive regions on a counting diamond by ion implantation, at a temperature below 500.degree. C. Subsequently, contacts are applied to the conductive regions to allow charged carriers liberated by the radiation to be detected by an electronic circuit. The invention extends to a detector prepared according to the method. An example of a detector according to the invention comprised a synthetic diamond having a paramagnetic nitrogen impurity concentration of less than 150 parts per million. Two conductive regions were formed on the diamond by bombardment with carbon ions, and contacts were formed on the conductive regions by the applications of silver-loaded epoxy paint.

Forming contacts on diamonds

A diamond or diamond-like material containing a p-type semi-conducting layer, an n-type semi-conducting layer and a p-n junction for use as a photovoltaic cell, particularly a solar cell. The material may be included in a suitable unit for generating electric power when exposed to appropriate radiation.

Growing community of inventors

Johannesburg, Transvaal, South Africa

Johan F Prins