Abstract: This invention relates to a method of fabricating a bonded product comprising at least two components that are bonded together, the method comprising the steps of: a) bringing the components together; and b) heating the components; wherein at least one of the components comprises a nanomaterial and wherein steps (a) and (b) are performed in such a manner that the components are bonded together by heating at least part of the nanomaterial. The method allows the components to be welded together at lower temperatures than for prior art methods. The method also provides a more reliable form of bonding and improves the strength of the bond formed.

Abstract: Biomaterial, for example bioactive silicon, may be fabricated by anodizing a silicon wafer to produce a wafer having a porous silicon region. In vitro experiments have shown that certain types of porous silicon cause the deposition of apatite deposits both on the porous silicon and neighboring areas of bulk silicon when immersed in a simulated body fluid solution. This deposition of apatite provides an indication that porous silicon of appropriate form is bioactive, and therefore also biocompatible. A form of porous silicon is dissolved in the simulated body fluid solution and this is an indication of a resorbable biomaterial characteristic. In addition to porous silicon, certain types of polycrystalline silicon exhibit bioactive characteristics. Bioactive silicon may be used in the fabrication of biosensors for in vitro or in vivo applications. The bioactivity of the bioactive silicon may be controlled by the application of an electrical potential thereto.

Abstract: Bioactive silicon comprising a porous form of silicon which when in vivo elicits a specific biological response that results in the formation of a bond between living tissue and the silicon. The deposition of apatite provides an indication that the porous silicon is bioactive and therefore biocompatible. Bioactive silicon may be used in the fabrication of biosensors for in vitro or in vivo applications.

Abstract: An electroluminescent silicon device (10) includes a silicon structure (12) which comprises a bulk silicon layer (14) and a porous silicon layer (16). The porous layer (16) has merged pores (20) which define silicon quantum wires (18). The quantum wires (18) have a surface passivation layer (22). The porous layer (16) exhibits photoluminescence under ultra-violet irradiation. The porous layer (16) is pervaded by a conductive material such as an electrolyte (24) or a metal (48). The conductive material (24) ensures that an electrically continuous current path extends through the porous layer (16); it does not degrade the quantum wire surface passivation (22) sufficiently to render the quantum wires (18) non-luminescent, and it injects minority carriers into the quantum wires. An electrode (26) contacts the conductive material (24) and the bulk silicon layer has an Ohmic contact (28). When biased the electrode (26) is the anode and the silicon structure (12) is the cathode.

Abstract: The invention provides a method of producing silicon with about 100% substitutionality of very high concentrations of carbon up to about 10.sup.21 cm.sup.-3, which has good quality recrystallized layers containing low levels of residual damage, and which avoids precipitation of mobile carbon. This method, compatible with current state-of-the-art VLSI silicon technology, comprises the sequential steps of: implanting a silicon wafer with carbon ions, and two step annealing of the implanted silicon wafer.

Abstract: An electroluminescent silicon device comprises a light emitting diode (10). The diode (10) includes a p.sup.+ semiconductor contact (42) and a n.sup.- layer (32), forming a p-n junction (43) therebetween. The n.sup.- layer (32) is carbon-doped and irradiated with an electron beam having electrons with energies of between 150 and 400 keV to form G-centres. The diode (10) is electroluminescent when forward biassed, radiative recombination occuring at the G-centres. The invention reconciles the conflicting requirements of creating luminescent defect centres by irradiation while avoiding damage to electronic properties. The device may be an integrated light emitting diode (200) incorporated in a CMOS microcircuit. Photon output from the diode (200) may be relayed to other parts of a CMOS microcircuit by an integrated waveguide (224).