Abstract: RPCVD apparatus for forming a film is disclosed including a showerhead having at least one gas chamber, one or more plasma inlets to deliver plasma from one or more plasma generators into a reaction chamber; and a plurality of gas inlets to deliver gas from at least one gas chamber into the reaction chamber. At least one of the plasma inlets is located at a position that is between a central region and an outer region of the showerhead and off-centre from an axis of rotation. The plasma generators generate plasma in line of sight of the susceptor and the plasma inlets have openings that are larger than openings of the gas inlets. The gas inlets are configured such that a combination of all of the spatial distributions of gas from the gas inlets provides a uniform distribution of gas density on the surface of a susceptor between a central region and an outer region of the susceptor, for a full rotation of the susceptor.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: An apparatus and method for forming a thin film on a substrate by RPCVD which provides for very low levels of carbon and oxygen impurities and includes the steps of introducing a Group VA plasma into a first deposition zone of a growth chamber, introducing a Group IIIA reagent into a second deposition zone of the growth chamber which is separate from the first deposition zone and introducing an amount of an additional reagent selected from the group consisting of ammonia, hydrazine, di-methyl hydrazine and a hydrogen plasma through an additional reagent inlet into the second deposition zone such that the additional reagent and the Group IIIA reagent mix prior to deposition.

Abstract: A plasma generator is described which employs a partial PBN liner not only to minimise the loss of energetic gas species during film formation but also to reduce boron impurity levels introduced into the growing film relative to the use of a complete PBN liner. The use of such a plasma generator in a film forming apparatus and method of forming a film is also described.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: Methods for fabricating semiconductor devices incorporating an activated p-(Al,In)GaN layer include exposing a p-(Al,In)GaN layer to a gaseous composition of H2 and/or NH3 under conditions that would otherwise passivate the p-(Al,In)GaN layer. The methods do not include subjecting the p-(Al,In)GaN layer to a separate activation step in a low hydrogen or hydrogen-free environment. The methods can be used to fabricate buried activated n/p-(Al,In)GaN tunnel junctions, which can be incorporated into electronic devices.

Abstract: A plasma generator is described which employs a partial PBN liner not only to minimise the loss of energetic gas species during film formation but also to reduce boron impurity levels introduced into the growing film relative to the use of a complete PBN liner. The use of such a plasma generator in a film forming apparatus and method of forming a film is also described.

Abstract: An apparatus and method for forming a thin film on a substrate by RPCVD which provides for very low levels of carbon and oxygen impurities and includes the steps of introducing a Group VA plasma into a first deposition zone of a growth chamber, introducing a Group IIIA reagent into a second deposition zone of the growth chamber which is separate from the first deposition zone and introducing an amount of an additional reagent selected from the group consisting of ammonia, hydrazine, di-methyl hydrazine and a hydrogen plasma through an additional reagent inlet into the second deposition zone such that the additional reagent and the Group IIIA reagent mix prior to deposition.

Abstract: An improved multiple quantum well solar cell can be achieved by ensuring the bandgap of each quantum well thin layer is not uniform compared with other such layers. Gradation of the bandgap by varying the content of at least two group II to VI elements, and/or varying the thickness of consecutive quantum well layers, within consecutively formed quantum wells provides for an increase in absorption across a greater range of the available solar spectrum.

Abstract: An apparatus for depositing a group III metal nitride film on a substrate, the apparatus comprising a plasma generator to generate a nitrogen plasma from a nitrogen source, a reaction chamber in which to react a reagent comprising a group III metal with a reactive nitrogen species derived from the nitrogen plasma so as to deposit a group III metal nitride on the substrate, a plasma inlet to facilitate the passage of nitrogen plasma from the plasma generator into the reaction chamber and a baffle having one or more flow channels for passage of the nitrogen plasma. The baffle is located between the plasma inlet and the substrate and prevents a direct line of passage for nitrogen plasma between the plasma inlet and the substrate.

Abstract: An apparatus for depositing a group III metal nitride film on a substrate, the apparatus comprising a plasma generator to generate a nitrogen plasma from a nitrogen source, a reaction chamber in which to react a reagent comprising a group III metal with a reactive nitrogen species derived from the nitrogen plasma so as to deposit a group III metal nitride on the substrate, a plasma inlet to facilitate the passage of nitrogen plasma from the plasma generator into the reaction chamber and a baffle having one or more flow channels for passage of the nitrogen plasma. The baffle is located between the plasma inlet and the substrate and prevents a direct line of passage for nitrogen plasma between the plasma inlet and the substrate.